MALARIA

Diagnosis, Diagnostics, Immunodiagnosis & Immunodiagnostics:

 

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 January 2003 

6140.  Ache A, Escorihuela M, Vivas E, Paez E, Miranda L, Matos A, Perez W, Diaz O, Izarra E.  In vivo drug resistance of falciparum malaria in mining areas of Venezuela. Trop Med Int Health. 2002 Sep;7(9):737-43.

 

The Lot Quality Assurance Double-Sampling Plan (LQADSP) technique was used in three areas, Maripa, Kilometro 88 and Ikabaru, to assess the efficacy of antimalarials used routinely by the Venezuelan Malaria Programme. The use of chloroquine (25 mg/kg), chloroquine (40 mg/kg) and the combination of sulfadoxine (500 mg) and pyrimethamine (25 mg) registered treatment failures above the threshold level of 25% in Maripa and Kilomertro 88. In Ikabaru the use of chloroquine (40 mg/kg) did not surpass that quality level and could possibly be less than 10%. Quinine (30 mg/kg) was totally effective in curing patients in all three areas. The use of this technique seems adequate for rapid field evaluations and in this case for providing appropriate information to assist this health programme. However, whilst being an ideal technique for surveying areas in which considerable variation may exist among lots and particularly for Plasmodium falciparum infections in these areas, repeated surveys should be carried out in the same areas over time to monitor changes in the susceptibility of this parasite to first-, second- and third-line drugs. In that way, national drug policies can be modified adequately.

 

6141.  Bedu-Addo G, Bates I. Causes of massive tropical splenomegaly in Ghana. Lancet. 2002 Aug 10;360(9331):449-54.

 

BACKGROUND: The causes and diagnosis of massive tropical splenomegaly are not well studied, especially with modern investigative methods. We aimed to identify features that would help local clinicians differentiate between the underlying conditions. METHODS: We collected prospective clinical and laboratory data on 221 Ghanaian patients with spleen size of at least 10 cm. We identified conditions associated with massive splenomegaly with molecular and immunological investigations as well as routine tests. Patients were assigned to diagnostic categories on the basis of these test results and predetermined criteria. FINDINGS: Hyper-reactive malarial splenomegaly (HMS; 91 patients [41%]) and B-lymphoproliferative disorders (48 [22%]) were the most common disorders associated with massive splenomegaly. Of the remaining patients, 32 (14%) had haematological disorders, and in 50 (23%) we could not identify the cause of splenomegaly. Male sex predominated in all diagnostic groups except HMS and tropical splenic lymphoma. Age less than 40 years and absolute lymphocyte count (less than 10 x 10(9)/L) were the only useful and widely available discriminators for distinguishing patients with HMS from those with lymphoproliferative disorders. INTERPRETATION: B-lymphoproliferative disorders are a previously unrecognised cause of massive tropical splenomegaly. This finding has major implications for management of massive splenomegaly. Diagnosis of the less common causes of this disorder is usually straightforward, but differentiating between B-lympho proliferative disorders and HMS can be difficult. HMS is associated with younger age, a higher proportion of women, and lower absolute lymphocyte counts than lympho proliferative disorders.

6142.  Chotivanich K, Udomsangpetch R, Pattanapanyasat K, Chierakul W, Simpson J, Looareesuwan S, White N. Hemoglobin E: a balanced polymorphism protective against high parasitemias and thus severe P falciparum malaria. Blood. 2002 Aug 15;100(4):1172-6.

 

Hemoglobin E is very common in parts of Southeast Asia. The possible malaria protective effects of this and other inherited hemoglobin abnormalities prevalent in Thailand were assessed in a mixed erythrocyte invasion assay. In vitro, starting at 1% parasitemia, Plasmodium falciparum preferentially invaded normal (HbAA) compared to abnormal hemoglobin (HbH, AE, EE, HCS, beta-thalassemia E) red cells (HRBCs). The median (range) ratio of parasitization of HRBCs (n = 109) compared to the controls of different major blood groups was 0.40 (0.08, 0.98), less than half that of the normal red cells (NRBCs) compared to their controls 0.88 (0.53, 1.4; P =.001). The median (range) parasitemia in the HRBCs was 2% (0.1%-9%) compared to 5.2% (1.2%-16.3%) in the NRBCs (P =.001). The proportion of the RBC population that is susceptible to malaria parasite invasion can be described by a selectivity index (SI; observed number of multiply invaded RBCs/number predicted). The heterozygote AE cells differed markedly from all the other cells tested with invasion restricted to approximately 25% of the RBCs; the median (range) SI was 3.8 (1-15) compared with 0.75 (0.1-0.9) for EE RBCs (P <.01). Despite their microcytosis, AE cells are functionally relatively normal in contrast to the RBCs from the other hemoglobinopathies studied. These findings suggest that HbAE erythrocytes have an unidentified membrane abnormality that renders the majority of the RBC population relatively resistant to invasion by P falciparum. This would not protect from uncomplicated malaria infections but would prevent the development of heavy parasite burdens and is consistent with the "Haldane" hypothesis of heterozygote protection against severe malaria for hemoglobin E.

 

6143.  de Souza JB, Todd J, Krishegowda G, Gowda DC, Kwiatkowski D, Riley EM. Prevalence and boosting of antibodies to Plasmodium falciparum glycosylphosphatidylinositols and evaluation of their association with protection from mild and severe clinical malaria. Infect Immun  2002 Sep;70(9):5045-51

 

Glycosylphosphatidylinositols (GPIs), the anchor molecules of some membrane proteins of Plasmodium species, have been implicated in the induction of immunopathology during malaria infections. Hence, neutralization of GPIs by antibodies may reduce the severity of clinical attacks of malaria. To test this hypothesis, we have assessed the levels of anti-GPI antibodies in plasma from children and adults living in areas of seasonal malaria transmission in The Gambia. In a prospective study of susceptibility to clinical or asymptomatic infection, the levels of anti-GPI antibodies were measured before and after the transmission season. Samples were also obtained from children recruited into a hospital-based study of severe malaria. We find that in malaria-exposed individuals both the prevalence and the concentration of anti-GPI antibodies increase with age and that antibody levels are significantly higher at the end of the malaria transmission season than at the start of the season. Antibody levels are also higher in children with asymptomatic infections (i.e., those with a degree of clinical immunity) than in children who developed clinical malaria and high parasitemia, although this difference is not statistically significant. Importantly, antibodies appear to be rapidly boosted by clinical malaria infection, but children under the age of two years are seronegative for anti-GPI antibodies, even during an acute infection. While GPIs may be involved in the pathogenesis of human malaria, the data from this study do not provide any strong evidence to support the notion that anti-GPI antibodies confer resistance to mild or severe malarial disease. Further case-control studies, ideally of a prospective nature, are required to elucidate the role of antiglycolipid antibodies in protection from severe malaria.

6144.  Fryauff DJ, Leksana B, Masbar S, Wiady I, Sismadi P, Susanti AI, Nagesha HS, Syafruddin, Atmosoedjono S, Bangs MJ, Baird JK. The drug sensitivity and transmission dynamics of human malaria on Nias Island, North Sumatra, Indonesia. Ann Trop Med Parasitol. 2002 Jul;96(5):447-62.

 

Nias Island, off the north-western coast of Sumatra, Indonesia, was one of the first locations in which chloroquine-resistant Plasmodium vivax malaria was reported. This resistance is of particular concern because its ancient megalithic culture and the outstanding surfing conditions make the island a popular tourist destination. International travel to and from the island could rapidly spread chloroquine-resistant strains of P. vivax across the planet. The threat posed by such strains, locally and internationally, has led to the routine and periodic re-assessment of the efficacy of antimalarial drugs and transmission potential on the island. Active case detection identified malaria in 124 (17%) of 710 local residents whereas passive case detection, at the central health clinic, confirmed malaria in 77 (44%) of 173 cases of presumed 'clinical malaria'. Informed consenting volunteers who had malarial parasitaemias were treated, according to the Indonesian Ministry of Health's recommendations, with sulfadoxine-pyrimethamine (SP) on day 0 (for P. falciparum) or with chloroquine (CQ) on days 0, 1 and 2 (for P. vivax). Each volunteer was then monitored for clinical and parasite response until day 28. Recurrent parasitaemia by day 28 treatment was seen in 29 (83%) of the 35 P. falciparum cases given SP (14, 11 and four cases showing RI, RII and RIII resistance, respectively). Recurrent parasitaemia was also observed, between day 11 and day 21, in six (21%) of the 28 P. vivax cases given CQ. Although the results of quantitative analysis confirmed only low prevalences of CQ-resistant P. vivax malaria, the prevalence of SP resistance among the P. falciparum cases was among the highest seen in Indonesia. When the parasites present in the volunteers with P. falciparum infections were genotyped, mutations associated with pyrimethamine resistance were found at high frequency in the dhfr gene but there was no evidence of selection for sulfadoxine resistance in the dhps gene. Night-biting mosquitoes were surveyed by human landing collections and teste d for sporozoite infection. Among the five species of human-biting anophelines collected, Anopheles sundaicus was dominant (68%) and the only species found to be infective--two (1.2%) of 167 females being found carrying P. vivax sporozoites. The risk of malarial infection for humans on Nias was considered high because of the abundance of asymptomatic carriers, the reduced effectiveness of the available antimalarial drugs, and the biting and infection 'rates' of the local An. sundaicus.

 

6145.  Kamble MB, Raut PP, Hussain ZF. Cerebral malaria in rural India. Indian J Pediatr. 2002 Aug;69(8):659-61.

 

OBJECTIVE: A cross-sectional hospital based study was carried out to investigate clinical features and outcome of cerebral malaria in a rural area. METHODS: All children fulfilling inclusion criteria, were enrolled and were entered on specially designed proforma. Their peripheral smear (PS) were studied based on which the diagnosis was classified as definite cerebral malaria (DCM) and probable cerebral malaria (PCM). RESULT: There were 2991 admissions in pediatric ward, of which 1394 (46.6%) were for fever. Of 781 (56.6%) cases with fever no cause was identified. Of the 56 cases positive for malarial parasite on PS 4.3% were Plasmodium vivax (PV) and 2.8% Plasmodium falciparum (PF). Fifteen patients fulfilled the criteria for study of which 7 were DCM and 8 belonged to PCM group. Twelve (80%) were in school-going age group and M : F ratio was 2 : 1. All patients presented with fever, and CNS involvement, 66.6% had convulsion, 7 developed coma, anaemia was seen in 60%, but only 20% required blood transfusion. Splenomegaly and hepatomegaly was seen in 53.3% and 47% cases respectively.Two patients died, one each in DCM and PCM. Cerebral malaria is a serious complication of severe falciparum malaria and is seen in approximately 32% of PF positive cases. CONCLUSION: PCM is an entity which should be kept in mind when treating fever without definite focus in rural areas, because timely and specific therapy is lifesaving.

6146.  Knappik M, Peyerl-Hoffmann G, Jelinek T. Plasmodium falciparum: use of a NANP19 antibody-test for the detection of infection in non-immune travellers. Trop Med Int Health. 2002 Aug;7(8):652-6.

 

Circumsporozoite (CS) antibodies are a reliable serological marker for the infection of Plasmodium falciparum. The purpose of this investigation was to construct and evaluate an enzyme-linked immunosorbent assay test for the

detection of CS antibodies. While the sensitivity of the newly developed test reached 78%, the specificity was 99%. In addition, the optimized kit was used to test for infection with P. falciparum in 1903 travellers that were recruited from a prospective study for malaria chemoprophylaxis. Sixty-six of the 1903 patients (3.5%) showed elevated CS antigen antibody titres. However, seroconversion could only be demonstrated in 18 (0.95%) patients. Among those seroconverting, there was a significantly higher percentage of male travellers (1.28%) than female travellers (0.56%). Positive reactions were more frequent among returnees from West and East Africa (1.49 and 1.14%, respectively) than among those from other endemic areas, e.g. South America (n=0). Despite its limited sensitivity, this newly developed kit for CS antibody testing may be a valuable tool for the estimation of the risk for travellers in malarious regions to acquire an infection with P. falciparum. It may also be useful for the determination of the efficacy of malaria chemoprophylaxis for inhibiting outbreak of disease.

6147.  Mann M. Mass tool for diagnosis. Nature. 2002 Aug 15;418(6899):731-2.  No abstract.

6148.  Newton PN, Michelson G, Ruangveerayuth R, White NJ. Retinal haemorrhage in P falciparum malaria. Lancet. 2002 Aug 17;360(9332):515. No abstract.

6149.  Pinto MJW, Rodrigues SR, Desouza R, Verenkar MP. Usefulness of quantitative buffy coat blood parasite detection system in diagnosis of malaria. Indian J med Mecrobiol. 2001; 19(4): 219-21. No abstract.

6150.  Pombo DJ, Lawrence G, Hirunpetcharat C, Rzepczyk C, Bryden M, Cloonan N, Anderson K, Mahakunkijcharoen Y, Martin LB, Wilson D, Elliott S, Elliott S, Eisen DP, Weinberg JB, Saul A, Good MF. Immunity to malaria after administration of ultra-low doses of red cells infected with Plasmodium falciparum. Lancet. 2002 Aug 24;360(9333):610-7.

 

BACKGROUND: The ability of T cells, acting independently of antibodies, to control malaria parasite growth in people has not been defined. If such was shown to be effective, an additional vaccine strategy could be pursued. Our aim was to ascertain whether or not development of cell-mediated immunity to Plasmodium falciparum blood-stage infection could be induced in human beings by exposure to malaria parasites in very low density. METHODS: We enrolled five volunteers from the staff at our research institute who had never had malaria. We used a cryopreserved inoculum of red cells infected with P falciparum strain 3D7 to give them repeated subclinical infections of malaria that we then cured early with drugs, to induce cell-mediated immune responses. We tested for development of immunity by measurement of parasite concentrations in the blood of volunteers by PCR of the multicopy gene STEVOR and by following up the volunteers clinically, and by measuring antibody and cellular immune responses to the parasite. FINDINGS: After challenge and a extended period without drug cure, volunteers were protected against malaria as indicated by absence of parasites or parasite DNA in the blood, and absence of clinical symptoms. Immunity was characterised by absence of detectable antibodies that bind the parasite or infected red cells, but by the presence of a proliferative T-cell response, involving CD4+ and CD8+ T cells, a cytokine response, consisting of interferon gamma but not interleukin 4 or interleukin 10, induction of high concentrations of nitric oxide synthase activity in peripheral blood mononuclear cells, and a drop in the number of peripheral natural killer T cells. INTERPRETATION: People can be protected against the erythrocytic stage of malaria by a strong cell-mediated immune response, in the absence of detectable parasite-specific antibodies, suggesting an additional strategy for development of a malaria vaccine

 

Pathogenesis:

6151.  Ahlborg N, Haddad D, Siddique AB, Roussilhon C, Rogier C, Trape JF, Troye-Blomberg M, Berzins K. Antibody responses to the repetitive Plasmodium falciparum antigen Pf332 in humans naturally primed to the parasite. Clin Exp Immunol. 2002 Aug;129(2):318-25.

 

Antibodies to the degenerate repeats of EB200, a part of the Plasmodium falciparum antigen Pf332, are protective in monkeys. To analyse the prevalence, magnitude and specificity of antibodies to EB200 in malaria-exposed humans, the IgG antibody reactivity with recombinant EB200 protein as well as with crude  malaria antigen was determined in Senegalese donors (n = 100; 4-87 years). Antibody reactivity with EB200 was low or absent in children below 15 years but was prevalent and significantly higher in older donors. In comparison, all individuals displayed reactivity with a crude malaria antigen preparation, which also increased with age. The reactivity with the crude malaria antigen was correlated to the reactivity with EB200, suggesting that the low levels of IgG to EB200 found in some adult donors reflected a limited degree of recent exposure to parasites rather than a selective non-responsiveness to Pf332. Comparison of serological and clinical data showed that high levels of antibodies to crude malaria antigen and to EB200 were predictive of fewer future clinical attacks of malaria. A reactivity pattern very similar to that found in Senegalese donors was observed in Liberian adults where 80% of the sera showed reactivity with EB200 and all peptides were recognized by between 60 and 100% of the donors. This strong reactivity with EB200-derived overlapping peptides suggests that the epitopes in EB200, to a large extent, are linear. In the light of previous data on the parasite neutralizing capacity of antibodies to Pf332, the present results emphasize the potential interest of Pf332-derived sequences for inclusion in a subunit vaccine against P. falciparum malaria.

6152.  Artavanis-Tsakonas K, Riley EM. Innate immune response to malaria: rapid induction of IFN-gamma from human NK cells by live Plasmodium falciparum-infected erythrocytes. J Immunol. 2002 Sep 15;169(6):2956-63.

 

To determine the potential contribution of innate immune responses to the early proinflammatory cytokine response to Plasmodium falciparum malaria, we have examined the kinetics and cellular sources of IFN-gamma production in response to human PBMC activation by intact, infected RBC (iRBC) or freeze-thaw lysates of P. falciparum schizonts. Infected erythrocytes induce a more rapid and intense IFN-gamma response from malaria-naive PBMC than do P. falciparum schizont lysates correlating with rapid iRBC activation of the CD3(-)CD56(+) NK cell population to produce IFN-gamma. IFN-gamma(+) NK cells are detectable within 6 h of coculture with iRBC, their numbers peaking at 24 h in most donors. There is marked heterogeneity between donors in magnitude of the NK-IFN-gamma response that does not correlate with mitogen- or cytokine-induced NK activation or prior malaria exposure. The NK cell-mediated IFN-gamma response is highly IL-12 dependent and appears to be partially IL-18 dependent. Exogenous rIL-12 or rIL-18 did not augment NK cell IFN-gamma responses, indicating that production of IL-12 and IL-18 is not the limiting factor explaining differences in NK cell reactivity between donors or between live and dead parasites. These data indicate that NK cells may represent an important early source of IFN-gamma, a cytokine that has been implicated in induction of various antiparasitic effector mechanisms. The heterogeneity of this early IFN-gamma response between donors suggests a variation in their ability to mount a rapid proinflammatory cytokine response to malaria infection that may, in turn, influence their innate susceptibility to malaria infection, malaria-related morbidity, or death from malaria.

 

6153.  Clark AG. Population genetics: malaria variorum. Nature. 2002 Jul 18;418(6895):283-5. No abstract.

6154.  Coban C, Ishii KJ, Sullivan DJ, Kumar N. Purified malaria pigment (hemozoin) enhances dendritic cell maturation and modulates the isotype of antibodies induced by a DNA vaccine. Infect Immun. 2002 Jul;70(7):3939-43.

 

Hemozoin (malaria pigment) has been implicated in the modulation of immune responses during malaria infection. This study was designed to evaluate the effect of purified hemozoin on the in vitro activation of myeloid dendritic cells. Our study also revealed that in addition to enhancing the maturation of dendritic cells, hemozoin also greatly promotes immunoglobulin G2a antibody responses when coadministered with a DNA vaccine plasmid encoding Pfs25, a Plasmodium falciparum transmission-blocking antigen.

6155.  Cole-Tobian JL, Cortes A, Baisor M, Kastens W, Xainli J, Bockarie M, Adams JH, King CL.  Age-acquired immunity to a Plasmodium vivax invasion ligand, the duffy binding protein. J Infect Dis. 2002 Aug 15;186(4):531-9.

 

The interaction between the Plasmodium vivax merozoite Duffy binding protein region II (DBPII) and the human erythrocyte Duffy antigen leads to infection. Highly polymorphic regions of this protein may have arisen as a mechanism to avoid host immunity. To examine whether immunity to P. vivax is directed against these polymorphic regions of DBPII, age-associated changes in the frequency of specific DBPII alleles among 358 P. vivax-positive Papua New Guineans were examined. Although the overall number and diversity of DBPII haplotypes simultaneously infecting an individual decreased with increasing age, only certain alleles at particular loci declined in frequency, indicating preferential immune selection against these alleles. One such polymorphic locus formed part of a B cell epitope, and antibodies from exposed individuals differentially recognized alleles at this locus. Therefore, acquisition of strain-specific age-acquired immunity is partially directed against polymorphic motifs within P. vivax DBPII, suggesting that these polymorphisms are maintained and likely arose under immune pressure in the host.

6156.  Cot M, Brutus L, Pinell V, Ramaroson H, Raveloson A, Rabeson D, Rakotonjanabelo AL. Malaria prevention during pregnancy in unstable transmission areas: the highlands of Madagascar. Trop Med Int Health. 2002 Jul;7(7):565-72.

Malaria transmission in Madagascar is highly variable from one region to the next, and the consequences of the disease on pregnant women and their foetuses are not fully documented. In midwestern Madagascar, the high-transmission lowlands in the west of the country meet the central plateaux, where malaria is unstable because of the high altitude and annual indoor spraying of DDT since 1993. We studied five of the region's main maternity clinics. We began by interviewing sample groups of women of childbearing age living within the vicinity of each clinic. This enabled us to determine the extent to which they had accessed and made use of available maternal health services during pregnancy and delivery, and, hence, to estimate the feasibility of boosting the prophylaxis. We then spent a whole year (from June 1996 to May 1997) observing deliveries at the five clinics in order to gauge the prevalence of placental infection and its consequences on birthweight in various transmission situations. Although only between 2 and 15% of the women said that they had taken prophylaxis during their previous pregnancy, the vast majority had benefited from preventive care: 97% had attended an antenatal visit on at least one occasion and 84% had had the assistance of medical or paramedical staff during delivery, even when their homes were situated relatively far away from the clinic (76%). In total, we observed 1637 deliveries with a mean placental malaria prevalence rate of 8.1%. Individual prevalence rates, however, were found to differ significantly between the maternity clinics situated in the east (minimum 2.1%) and west (maximum 26.2%) of the region. There were also marked variations in line with the seasonal fluctuations in entomological transmission. On the whole, a greater percentage of low birthweights (LBWs) was recorded at the lowland clinics than at the highland ones (17.1% vs. 9.7%), possibly because of the higher malaria infection rate in low altitude areas. On the other hand, the relative risk of LBW linked to placental infection was far greater in the highlands [4.9 (3.3-7.3)] than in the lowlands [1.9 (1.2-3.0)]. Although the rate of placental malaria among women inhabiting the country's central plateaux may be low, it means that transmission--and, hence, the risk of LBW because of placental infection--still persists in spite of the indoor DDT spraying programme. For maximum efficacy, we recommend a combination of vector control (extended to lower altitude areas outside the current OPID zone) and preventive care--i.e. individual chemoprophylaxis--for all highland women during pregnancy.

6157.  Delorenzi M, Sexton A, Shams-Eldin H, Schwarz RT, Speed T, Schofield L. Genes for glycosylphosphatidylinositol toxin biosynthesis in Plasmodium falciparum. Infect Immun. 2002 Aug;70(8):4510-22.

 

About 2.5 million people die of Plasmodium falciparum malaria every year. Fatalities are associated with systemic and organ-specific inflammation initiated by a parasite toxin. Recent studies show that glycosylphosphatidylinositol (GPI) functions as the dominant parasite toxin in the context of infection. GPIs also serve as membrane anchors for several of the most important surface antigens of parasite invasive stages. GPI anchoring is a complex posttranslational modification produced through the coordinated action of a multicomponent biosynthetic pathway. Here we present eight new genes of P. falciparum selected for encoding homologs of proteins essential for GPI synthesis: PIG-A, PIG-B, PIG-M, PIG-O, GPI1, GPI8, GAA-1, and DPM1. We describe the experimentally verified mRNA and predicted amino acid sequences and in situ localization of the gene products to the parasite endoplasmic reticulum. Moreover, we show preliminary evidence for the PIG-L and PIG-C genes. The biosynthetic pathway of the malaria parasite GPI offers potential targets for drug development and may be useful for studying parasite cell biology and the molecular basis for the pathophysiology of parasitic diseases.

6158.  Fang J, McCutchan TF. Thermoregulation in a parasite's life cycle. Nature. 2002 Aug 15;418(6899):742.

 

The life cycle of the malaria parasite Plasmodium falciparum goes through three developmental stages (schizogony, gametogony and sporogony), each of which presents different environmental constraints that must be met by an adaptive response in the parasite. Here we show that thermoregulation, in which the transcription of select RNAs is upregulated at cooler temperatures, is crucial to the developmental transition that occurs during the transmission of P. falciparum from human to mosquito. Our findings offer new insight into how the malaria parasite senses and reacts to its environment.

6159.  Juliger S, Kremsner PG, Alpers MP, Reeder JC, Kun JF. Restricted polymorphisms of the mannose-binding lectin gene in a population of Papua New Guinea. Mutat Res. 2002 Aug 29;505(1-2):87-91.

 

The human mannose-binding lectin (MBL) is an important protein of the innate immune system. MBL is able to eliminate potential pathogens by activating the complement cascade or by opsonisation. We investigated the gene and promoter region of MBL in a population from Papua New Guinea infected with Plasmodium falciparum parasites and measured the appropriate serum concentrations of these individuals. Their serum levels of MBL, detected by ELISA, showed a wide range with concentrations between 632 and 7325 microg/l MBL. A known polymorphism in exon 1 at codon 54 causing an amino acid exchange from Gly to Asp occurred with a low frequency of 3%. Additional to the previously reported polymorphisms in the gene and promoter region of MBL, two novel polymorphic sites were found in the promoter region. One site was in the untranslated region of the MBL gene at position +1 (G-->A, termed R/S), and the second was located upstream of the gene at position -4 (G-->A, termed T/U).

6160.  Malaguarnera L, Musumeci S. The immune response to Plasmodium falciparum malaria. Lancet Infect Dis. 2002 Aug;2(8):472-8. Review.

 

Malaria is still a major cause of severe disease which is responsible for millions of deaths, mostly in children under 5 years old, in tropical countries, especially sub-Saharan Africa. Complications of severe anaemia and cerebral malaria are thought to be the major cause of morbidity and mortality but recent evidence suggests that the host's immunological response could also contribute to the pathophysiology of the disease in human beings. Intensive studies of the immune response to malaria parasites in human beings have provided a wealth of information about the cells and cytokines implicated in the pathophysiology of survival and fatal outcome in severe infections. This review focuses on the pivotal role of macrophages and other important cellular effectors, molecules, and cytokines involved in the activation of the immune response at the different stages of human falciparum malaria. Our understanding of the putative mechanisms by which cytokines may mediate beneficial and harmful effects, through activation of phagocytic cells, could help to develop new treatment strategies, regardless of the emergence of parasite multidrug resistance.

6161.  Mu J, Duan J, Makova KD, Joy DA, Huynh CQ, Branch OH, Li WH, Su XZ. Chromosome-wide SNPs reveal an ancient origin for Plasmodium falciparum. Nature. 2002 Jul 18;418(6895):323-6.

 

The Malaria's Eve hypothesis, proposing a severe recent population bottleneck (about 3,000-5,000 years ago) of the human malaria parasite Plasmodium falciparum, has prompted a debate about the origin and evolution of the parasite. The hypothesis implies that the parasite population is relatively homogeneous, favouring malaria control measures. Other studies, however, suggested an ancient origin and large effective population size. To test the hypothesis, we analysed single nucleotide polymorphisms (SNPs) from 204 genes on chromosome 3 of P. falciparum. We have identified 403 polymorphic sites, including 238 SNPs and 165 microsatellites, from five parasite clones, establishing chromosome-wide haplotypes and a dense map with one polymorphic marker per approximately 2.3 kilobases. On the basis of synonymous SNPs and non-coding SNPs, we estimate the time to the most recent common ancestor to be approximately 100,000-180,000 years, significantly older than the proposed bottleneck. Our estimated divergence time coincides approximately with the start of human population expansion, and is consistent with a genetically complex organism able to evade host immunity and other antimalarial efforts.

6162.  Nacher M. Worms and malaria: noisy nuisances and silent benefits. Parasite Immunol. 2002 Jul;24(7):391-3. Review.

 

The burden of malaria mortality has been a major evolutionary influence on human immunity. The selection of the most successful immune responses against malaria has been in populations concomitantly infected by intestinal helminths. Animal models have shown that coinfections with helminths and protozoa in the same host elicit a range of antagonist and synergistic interactions. Recent findings suggest similar interactions take place between helminths, Plasmodium falciparum and humans. However, as the threat of HIV and tuberculosis becomes a major selective force, what used to be a successful ecological system may now prove detrimental. Nevertheless, the understanding of the ecological forces at play may expose new intervention targets for malaria control, and give a new perspective on our shortcomings against the deadliest of human parasites.

6163.  Nwuba RI, Sodeinde O, Anumudu CI, Omosun YO, Odaibo AB, Holder AA, Nwagwu M. The human immune response to Plasmodium falciparum includes both antibodies that inhibit merozoite surface protein 1 secondary processing and blocking antibodies. Infect Immun. 2002 Sep;70(9):5328-31.

 

Malaria merozoite surface protein 1 (MSP1) is cleaved in an essential step during erythrocyte invasion. The responses of children to natural malaria infection included antibodies that inhibit this cleavage and others that block the binding of these inhibitory antibodies. There was no correlation between the titer of the antibody to the 19-kDa fragment of MSP1 and its inhibitory activity. These findings have implications for the design of MSP1-based vaccines.

6164.  Sharma BD; Gupta B Department of Medicine Safdarjung Hospital, New Delhi - 110029 Peripheral gangrene in a Complicated falciparum malaria Journal, Indian Academy of Clinical Medicine. 2002 Jul-Sep; 3(3): 297-9

 

ABSTRACT: Peripheral gangrene occuring as a rare manifestation of complicated falciparum malaria in a 65 year old lady has been reported. clinical features and pathogenesis are discussed.

 

6165.  Wootton JC, Feng X, Ferdig MT, Cooper RA, Mu J, Baruch DI, Magill AJ, Su XZ. Genetic diversity and chloroquine selective sweeps in Plasmodium falciparum. Nature. 2002 Jul 18;418(6895):320-3.

 

Widespread use of antimalarial agents can profoundly influence the evolution of the human malaria parasite Plasmodium falciparum. Recent selective sweeps for drug-resistant genotypes may have restricted the genetic diversity of this parasite, resembling effects attributed in current debates to a historic population bottleneck. Chloroquine-resistant (CQR) parasites were initially reported about 45 years ago from two foci in southeast Asia and South America, but the number of CQR founder mutations and the impact of chlorquine on parasite genomes worldwide have been difficult to evaluate. Using 342 highly polymorphic microsatellite markers from a genetic map, here we show that the level of genetic diversity varies substantially among different regions of the parasite genome, revealing extensive linkage disequilibrium surrounding the key CQR gene pfcrt and at least four CQR founder events. This disequilibrium and its decay rate in the pfcrt-flanking region are consistent with strong directional selective sweeps occurring over only approximately 20-80 sexual generations, especially a single resistant pfcrt haplotype spreading to very high frequencies throughout most of Asia and Africa. The presence of linkage disequilibrium provides a basis for mapping genes under drug selection in P. falciparum.

6166.  Xainli J, Baisor M, Kastens W, Bockarie M, Adams JH, King CL. Age-dependent cellular immune responses to Plasmodium vivax Duffy binding protein in humans. J Immunol. 2002 Sep 15;169(6):3200-7.

 

The Plasmodium vivax merozoite Duffy binding protein (DBP) contains a cysteine-rich region II (DBPII) that binds to the Duffy Ag receptor for chemokines on erythrocytes, which is essential for parasite invasion. Cellular immune responses to DBPII have not been reported in P. vivax endemic populations, although they may contribute to partial acquired immunity. To examine host cellular immunity to DBPII and identify major T cell epitopes, PBMCs from 107 individuals (2-68 years old) were examined for cytokine production by ELISPOT and/or ELISA to rDBP and overlapping peptides (displaced by 2 aa spanning a 170-aa region of DBPII corresponding to the critical binding motif to the Duffy Ag receptor for chemokines). In P. vivax-exposed subjects, 60 and 71% generated significant rDBP-induced IFN-gamma and IL-10 production, respectively, 11% stimulated IL-2, and IL-5 and IL-13 were not detected. Children <5 years of age had reduced levels and frequency of rDBP-induced IL-10 and IFN-gamma production compared with partially immune older children and adults (p < 0.01). Five major T cell epitopes were identified. Three of these T cell epitopes contained polymorphic residues present in the population. Peptides synthesized corresponding to these variants induced IFN-gamma and IL-10 production to one variant and little response to the other variant in the same individual. These results demonstrate age-dependent and variant-specific cellular immune responses to DBPII and implicate this molecule in partial acquired immunity to P. vivax in endemic populations.

Vaccines:

6167.  BenMohamed L, Wechsler SL, Nesburn AB. Lipopeptide vaccines--yesterday, today, and tomorrow. Lancet Infect Dis  2002 Jul;2(7):425-31.

 

Peptide-based vaccines offer several potential advantages over the conventional whole proteins (or whole gene, in the case of genetic immunisation) in terms of purity and a high specificity in eliciting immune responses. However, concerns about toxic adjuvants, which are critical for immunogenicity of synthetic peptides, still remain. Lipopeptides, a form of peptide vaccine, discovered more then a decade ago, are currently under intensive investigation because they can generate comprehensive immune responses, without the use of adjuvants. In this review, we address the past of lipopeptide vaccines, highlight the progress made toward their optimisation, and stress future challenges and issues related to their synthesis, formulation, and delivery. In particular, the recent development of mucosal application of lipopeptide vaccines may present an ideal strategy against many pathogens that infect mucosal surfaces.

 

6168.  Plebanski M, Proudfoot O, Pouniotis D, Coppel RL, Apostolopoulos V, Flannery G. Immunogenetics and the design of Plasmodium falciparum vaccines for use in malaria-endemic populations. J Clin Invest  2002 Aug;110(3):295-301 No abstract.

Therapy:

6169.  Gilbert IH. Inhibitors of dihydrofolate reductase in Leishmania and trypanosomes. Biochim Biophys Acta. 2002 Jul 18;1587(2-3):249-57. Review.

 

The protozoan diseases leishmaniasis, Chagas' disease and African trypanosomiasis are major health problems in many countries, particularly developing countries, and there are few drugs available to treat these diseases. Dihydrofolate reductase (DHFR) inhibitors have been used successfully in the treatment of a number of other diseases such as cancer, malaria and bacterial infections; however they have not been used for the treatment of these diseases. This article summarises studies on leishmanial and trypanosomal DHFR inhibitor development and evaluation. Possible mechanisms of resistance to DHFR inhibitors are also discussed.

6170.  Sharp B, van Wyk P, Sikasote JB, Banda P, Kleinschmidt I. Malaria control by residual insecticide spraying in Chingola and Chililabombwe, Copperbelt Province, Zambia. Trop Med Int Health. 2002 Sep;7(9):732-6.

 

Malaria is endemic in the whole of Zambia and is the leading cause of morbidity and mortality. Prior to 1980, effective malaria control was achieved in the northern mining towns of Chingola and Chililabombwe by means of annual residual spraying programmes. In the 1970s, incidence rates were as low as 20/1000 p.a., but by 2000 had increased to 68/1000 p.a. in Chingola and to 158/1000 p.a.in Chililabombwe. Konkola Copper Mines (KCM) initiated a malaria control programme in which all dwellings in the two towns and within a 10-km radius were sprayed with either dichlorodiphenyltrichloroethane or a synthetic pyrethroid (Icon by ZENECA or Deltamethrin by Aventis). Houses were sprayed in November and December 2000, at the start of the peak transmission period. There was a statistically significant reduction in malaria incidence recorded at KCM health facilities in the two towns, representing a protective incidence rate ratio of 0.65 (95% CI 0.44, 0.97) when comparing the post-spraying period with the corresponding period of the previous 2 years. This reduction followed a single round of house spraying during a year with higher rainfall than the preceding two and in an area where chloroquine was first-line treatment. This house-spraying programme is an example of private/public sector collaboration in malaria control.

6171.  Siringi S. Failure to tackle malaria in east Africa. Lancet. 2002 Jul 27;360(9329):317. No abstract.

 

April 2003

 

6782.     Biswas G; Mohanty SC; Hui PK; Samal KK. Difficulties while treating a case of malaria Antiseptic. 2002 Oct; 99(10): 33-5.

Diagnosis and treatment of malaria are continuing problems at present, definite diagnosis depends on demonstration of malaria parasite. But the most important is clinical suspicion and early administration of antimalarial drugs to save this life, as drug toxicity does not outweigh the precious human life. With resurgence of malaria, we are coming across many drug resistant strains. Hence, management depends on the knowledge of the resistance to the particular strain. Proper management also depends on patient compliance, cost value of the drugs and proper health facilities to the common man.

 6783.    Das P K, Dominic Amalraj D.Vector Control and practicability in India . JIMSA 2000,13(1),85-92. (ISA 013333,Vol 38 No13 1 July 2023)

 6784.     Deininger MH, Fimmen B, Kremsner PG, Meyermann R, Schluesener HJ.Accumulation of endostatin/collagenXVIII in brains of patients who died with cerebral malaria. J Neuroimmunol  2002 Oct;131(1-2):216-21. Endostatin is a 20 kDa C-terminal fragment of collagenXVIII that, when added exogenously, inhibits angiogenesis by inducing apoptosis of endothelial cells. In cerebral malaria (CM), blood-brain barrier dysfunction is a hallmark alteration in the formation of edema, inflammation, hemorrhage and Durck's granulomas that are thought to represent the histopathological basis of neurological impairments observed in CM patients.We now analyzed endostatin/collagenXVIII expression in brains of seven patients who died with CM and in seven control patients by immunohistochemistry double-labeling experiments. Endostatin/collagenXVIII immunoreactive macrophages/microglial cells accumulated predominantly in Durck's granulomas. Some immunoreactivity was observed in macrophages located in cerebral capillaries with deposition of malarial pigment and sequestration, but almost no immunoreactivity was detected in ring hemorrhages.Focal accumulation of endostatin/collagenXVIII in granulomas but not in ring hemorrhages of CM brains suggests a novel process that is involved in the destruction of endothelial cells at the time of Durck's granuloma formation.

 6785.   Ghosh S K ,Titus E,Valecha N,Murugendrappa M V , Sharma V P. Evaluation of  a rapid immunochromatographic test (CT) for the detection of plasmodium falciparum malaria in Karnataka, India J parasitic Dis 2000 ,24(1),39-42. (ISA 018519, Vol 38 No18 ,16 Sept 2002)

 6786.    Gyan B, Goka B, Cvetkovic JT, Perlmann H, Lefvert AK, Akanmori B, Troye-Blomberg M. Polymorphisms in interleukin-1beta and interleukin-1 receptor antagonist genes and malaria in Ghanaian children. Scand J Immunol  2002 Dec;56(6):619-22

We have investigated the possible associations between polymorphisms in two interleukin-1 (IL-1) genes and severity of Plasmodium falciparum malaria in Ghanaian children with cerebral malaria, severe anaemia or uncomplicated malaria and controls. There was no significant difference in genotype and allele frequencies in IL-1beta exon 5 or interleukin-1 receptor antagonist (IL-1ra) polymorphisms between the studied groups, suggesting that the two polymorphisms may not be involved in the pathogenesis of severe malaria. When parasitaemias in uncomplicated malaria patients were evaluated, a significantly higher level of parasitaemia was observed among carriers of IL-1beta A2 allele as compared with noncarriers of this allele (P = 0.01). The mean parasitaemia in an age-matched asymptomatic group did not reveal such associations. These data suggest that IL-1beta exon 5 allele 2 may play a possible role in the clinical outcome of uncomplicated malaria.

 6787.     Jelinek T, Aida AO, Peyerl-Hoffmann G, Jordan S, Mayor A, Heuschkel C, el Valy AO, von Sonnenburg F, Christophel EM.Diagnostic value of molecular markers in chloroquine-resistant falciparum malaria in Southern Mauritania. Am J Trop Med Hyg  2002 Nov;67(5):449-53

Despite its diminishing efficacy because of increased resistance, chloroquine remains the primary antimalarial agent in many endemic areas. Evidence is mounting that point mutations on the Pfcrt and possibly the Pfmdr1 genes are conferring plasmodial resistance to chloroquine. In 1998, atypically strong rainfalls led to an increased activity of falciparum malaria in Mauritania that affected non-endemic regions bordering the Saharan desert. An in vivo study on chloroqine resistance was combined with studies for molecular markers of drug resistance. Detection of Pfmdr1-76-tyrosine showed an increased odds ratio (2.91) for resistance (P = 0.0195). However, by use of this codon alone, sensitivity for detection of resistance was 60.6%, and specificity was 65.3%. In comparison, detection of the K76T mutation at Pfcrt showed a very high sensitivity (100%) while specificity remained relatively low (65.4%). For the combination of mutations on both genes, the odds ratio for detection of resistance increased to 5.31 (P = 0.0005). Here, sensitivity was again decreased to 60.6% while specificity increased to 76.9%. The results of this study suggest that detection of Pfcrt T76 can be applied for predicting chloroquine resistance in epidemiologic settings with sufficiently high sensitivity to make it an attractive alternative to time- and labor-consuming in vivo trials. Additional testing for Pfmdr Y76 provides increased specificity to this approach.

 6788.    Mohapatra MK; Mitra I; Das SP; Kar LK. Haematological and coagulation profile in malaria Indian Practitioner. 2002 Feb; 55(2): 75-8

ABSTRACT: The haematological and coagulation profile was studied in 60 patients of falciparum malaria and 40 patients of vivax malaria The diagnosis of malaria was made by detection of parasite in the peripheral smear. The mean haemoglobin in complicated and uncomplicated falciparum malaria was 6.2 plus minus 2.02 gm percent and 8.4 plus minus 1.99 gm percent which was lower than vivax malaria (10.26 plus minus 2.16 gm percent) and control (p0.05). Leukocytosis was found in 12 (20 percent) cases of complicated falciparum malaria. Peripheral pancytopenia was found in 2(3.3 percent) cases. The bleeding time was increased in complicated falciparum malaria. Raised FDP was found in 5 (8.3 percent) cases. Inspite of thrombocytopenia and raised FDP, bleeding manifestations are uncommon.

 6789.  Parhate SM; Thawani VR; Altekar CS. Prescription trends and diagnostic approach in patients of fever of sudden onset Antiseptic. 2002 Jan; 99(1): 26-8

ABSTRACT: Adult patients suffering from fever of sudden onset were prescribed antimicrobials (100 percent), antimalarials (89.1 percent) and antipyretics (87.4 percent). Total eight categories of diseases were diagnosed, in addition to which there were patients of pyrexia of unknown origin as well as undiagnosed cases. Respiratory infections were common as a system (37.4 percent). As a single most common disease malaria was prevalent most (17.3 percent). Maximum disease prevalence was seen in patients having temperature between 100-101 degree F. Patients of pyrexia of unknown origin and undiagnosed cases were referred to specialists of other faculties as per the need. Follow up revealed varied infections (88.1 percent), cysts (5.1 percent), organic mass (5.1 percent) and acute lymphatic leukemia (1.7 percent). No diagnosis could be made in 13.2 percent of these referred patients

            Pathogenesis :

 6790.   Abdel-Latif MS, Khattab A, Lindenthal C, Kremsner PG, Klinkert MQ. Recognition of variant Rifin antigens by human antibodies induced during natural Plasmodium falciparum infections.Infect Immun. 2002 Dec;70(12):7013-21.

Antibodies from individuals living in areas where malaria is endemic are known to react with parasite-derived erythrocyte surface proteins. The major immunogenic and clonally variant surface antigen described to date is Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP-1), which is encoded by members of the multicopy var gene family. We report here that rifin proteins (RIF proteins), belonging to the largest known family of variable infected erythrocyte surface-expressed proteins, are also naturally immunogenic. Recombinant RIF proteins were used to analyze the antibody responses of individuals living in an area of intense malaria transmission. Elevated anti-rifin antibody levels were detected in the majority of the adult population tested, whereas the prevalence of such antibodies was much lower in malaria-exposed children. Despite the high degree of diversity between rif sequences and the high gene copy number, it appears that P. falciparum infections can induce antibodies that cross-react with several variant rifin molecules in many parasite isolates in a given community, and the immune response is most likely to be stable over time in a hyperendemic area. The protein was localized by fluorescence microscopy on the membrane of ring and young trophozoite-infected erythrocytes with antibodies from human immune sera with specificities for recombinant RIF protein.

 6791.   Beeson JG, Amin N, Kanjala M, Rogerson SJ. Selective accumulation of mature asexual stages of Plasmodium falciparum-infected erythrocytes in the placenta. Infect Immun. 2002 Oct;70(10):5412-5. No abstract.

 6792.   Carlton JM, Angiuoli SV, Suh BB, Kooij TW, Pertea M, Silva JC, Ermolaeva MD, Allen JE, Selengut JD, Koo HL, Peterson JD, Pop M, Kosack DS, Shumway MF,Bidwell SL, Shallom SJ, van Aken SE, Riedmuller SB, Feldblyum TV, Cho JK, Quackenbush J, Sedegah M, Shoaibi A, Cummings LM, Florens L, Yates JR, Raine JD, Sinden RE, Harris MA, Cunningham DA, Preiser PR, Bergman LW, Vaidya AB, van Lin LH, Janse CJ, Waters AP, Smith HO, White OR, Salzberg SL, Venter JC, Fraser CM, Hoffman SL, Gardner MJ, Carucci DJ. Genome sequence and comparative analysis of the model rodent malaria parasite Plasmodium yoelii yoelii. Nature. 2002 Oct 3;419(6906):512-9.

Species of malaria parasite that infect rodents have long been used as models for malaria disease research. Here we report the whole-genome shotgun sequence of one species, Plasmodium yoelii yoelii, and comparative studies with the genome of the human malaria parasite Plasmodium falciparum clone 3D7. A synteny map of 2,212 P. y. yoelii contiguous DNA sequences (contigs) aligned to 14 P. falciparum chromosomes reveals marked conservation of gene synteny within the body of each chromosome. Of about 5,300 P. falciparum genes, more than 3,300 P. y. yoelii orthologues of predominantly metabolic function were identified. Over 800 copies of a variant antigen gene located in subtelomeric regions were found. This is the first genome sequence of a model eukaryotic parasite, and it provides insight into the use of such systems in the modelling of Plasmodium biology and disease.

 6793.    Coluzzi M, Sabatini A, della Torre A, Di Deco MA, Petrarca V. A polytene chromosome analysis of the Anopheles gambiae species complex.Science. 2002 Nov 15;298(5597):1415-8.

Field-collected specimens of all known taxa in the Anopheles gambiae complex were analyzed on the basis of chromosome inversions with reference to a standard polytene chromosome map. The phylogenetic relationships among the seven described species in the complex could be inferred from the distribution of fixed inversions. Nonrandom patterns of inversion distribution were observed and, particularly on chromosome arm 2R, provided evidence for genetically distinct populations in A. gambiae, A. arabiensis, and A. melas. In A. gambiae from Mali, stable genetic differentiation was observed even in populations living in the same region, suggesting a process of incipient speciation which is being confirmed by studies with molecular markers. The possible role of chromosome differentiation in speciation of the A. gambiae complex and in the emergence of distinct chromosomal forms within the nominal species is discussed in relation to human malaria.

 6794.   Gardner MJ, Hall N, Fung E, White O, Berriman M, Hyman RW, Carlton JM, Pain A, Nelson KE, Bowman S, Paulsen IT, James K, Eisen JA, Rutherford K, Salzberg SL, Craig A, Kyes S, Chan MS, Nene V, Shallom SJ, Suh B, Peterson J, Angiuoli S, Pertea M, Allen J, Selengut J, Haft D, Mather MW, Vaidya AB, Martin DM, Fairlamb AH, Fraunholz MJ, Roos DS, Ralph SA, McFadden GI, Cummings LM, Subramanian GM, Mungall C, Venter JC, Carucci DJ, Hoffman SL, Newbold C, Davis RW, Fraser CM, Barrell B.Genome sequence of the human malaria parasite Plasmodium falciparum. Nature. 2002 Oct 3;419(6906):498-511.

The parasite Plasmodium falciparum is responsible for hundreds of millions of cases of malaria, and kills more than one million African children annually. Here we report an analysis of the genome sequence of P. falciparum clone 3D7. The 23-megabase nuclear genome consists of 14 chromosomes, encodes about 5,300 genes, and is the most (A + T)-rich genome sequenced to date. Genes involved in antigenic variation are concentrated in the subtelomeric regions of the chromosomes. Compared to the genomes of free-living eukaryotic microbes, the genome of this intracellular parasite encodes fewer enzymes and transporters, but a large proportion of genes are devoted to immune evasion and host-parasite interactions. Many nuclear-encoded proteins are targeted to the apicoplast, an organelle involved in fatty-acid and isoprenoid metabolism. The genome sequence provides the foundation for future studies of this organism, and is being exploited in the search for new drugs and vaccines to fight malaria.

  6795.   Gera T, Sachdev HP. Effect of iron supplementation on incidence of infectious illness in children: systematic review.BMJ. 2002 Nov 16;325(7373):1142.

OBJECTIVE: To evaluate the effect of iron supplementation on the incidence of infections in children. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: 28 randomised controlled trials (six unpublished and 22 published) on 7892 children. INTERVENTIONS: Oral or parenteral iron supplementation or fortified formula milk or cereals. OUTCOMES: Incidence of all  recorded infectious illnesses, and individual illnesses, including respiratory tract infection, diarrhoea, malaria, other infections, and prevalence of positive smear results for malaria. RESULTS: The pooled estimate (random effects model) of the incidence rate ratio (iron v placebo) was 1.02 (95% confidence interval 0.96 to 1.08, P=0.54; P<0.0001 for heterogeneity). The incidence rate difference (iron minus placebo) for all recorded illnesses was 0.06 episodes/child year (-0.06 to 0.18, P=0.34; P<0.0001 for heterogeneity). However, there was an increase in the risk of developing diarrhoea (incidence rate ratio 1.11, 1.01 to 1.23, P=0.04), but this would not have an overall important on public health (incidence rate difference 0.05 episodes/child year, -0.03 to 0.13; P=0.21). The occurrence of other illnesses and positive results on malaria smears (adjusted for positive smears at baseline) were not significantly affected by iron administration. On meta-regression, the statistical heterogeneity could not be explained by the variables studied. CONCLUSION: Iron supplementation has no apparent harmful effect on the overall incidence of infectious illnesses in children, though it slightly increases the risk of developing diarrhoea.

  6796.  Holt RA, Subramanian GM, Halpern A, Sutton GG, Charlab R, Nusskern DR, Wincker P, Clark AG, Ribeiro JM, Wides R, Salzberg SL, Loftus B, Yandell M,Majoros WH, Rusch DB, Lai Z, Kraft CL, Abril JF, Anthouard V, Arensburger P,Atkinson PW, Baden H, de Berardinis V, Baldwin D, Benes V, Biedler J, Blass C,Bolanos R, Boscus D, Barnstead M, Cai S, Center A, Chatuverdi K, Christophides GK, Chrystal MA, Clamp M, Cravchik A, Curwen V, Dana A, Delcher A, Dew I, Evans CA, Flanigan M, Grundschober-Freimoser A, Friedli L, Gu Z, Guan P, Guigo R, Hillenmeyer ME, Hladun SL, Hogan JR, Hong YS, Hoover J, Jaillon O, Ke Z, Kodira C, Kokoza E, Koutsos A, Letunic I, Levitsky A, Liang Y, Lin JJ, Lobo NF, Lopez JR, Malek JA, McIntosh TC, Meister S, Miller J, Mobarry C, Mongin E, Murphy SD, O'Brochta DA, Pfannkoch C, Qi R, Regier MA, Remington K, Shao H, Sharakhova MV, Sitter CD, Shetty J, Smith TJ, Strong R, Sun J, Thomasova D, Ton LQ, Topalis P, Tu Z, Unger MF, Walenz B, Wang A, Wang J, Wang M, Wang X, Woodford KJ, Wortman JR, Wu M, Yao A, Zdobnov EM, Zhang H, Zhao Q, Zhao S, Zhu SC, Zhimulev I, Coluzzi M, della Torre A, Roth CW, Louis C, Kalush F, Mural RJ, Myers EW, Adams MD, Smith HO, Broder S, Gardner MJ, Fraser CM, Birney E, Bork P, Brey PT, Venter JC, Weissenbach J, Kafatos FC, Collins FH, Hoffman SL.  The genome sequence of the malaria mosquito Anopheles gambiae. Science. 2002 Oct 4;298(5591):129-49.

Anopheles gambiae is the principal vector of malaria, a disease that afflicts more than 500 million people and causes more than 1 million deaths each year. Tenfold shotgun sequence coverage was obtained from the PEST strain of A. gambiae and assembled into scaffolds that span 278 million base pairs. A total of 91% of the genome was organized in 303 scaffolds; the largest scaffold was 23.1 million base pairs. There was substantial genetic variation within this strain, and the apparent existence of two haplotypes of approximately equal frequency ("dual haplotypes") in a substantial fraction of the genome likely reflects the outbred nature of the PEST strain. The sequence produced a conservative inference of more than 400,000 single-nucleotide polymorphisms that showed a markedly bimodal density distribution. Analysis of the genome sequence revealed strong evidence for about 14,000 protein-encoding transcripts. Prominent expansions in specific families of proteins likely involved in cell adhesion and immunity were noted. An expressed sequence tag analysis of genes regulated by blood feeding provided insights into the physiological adaptations of a hematophagous insect.

  6797.   Kennedy MC, Wang J, Zhang Y, Miles AP, Chitsaz F, Saul A, Long CA, Miller LH, Stowers AW.In vitro studies with recombinant Plasmodium falciparum apical membrane antigen 1 (AMA1): production and activity of an AMA1 vaccine and generation of a multiallelic response. Infect Immun. 2002 Dec;70(12):6948-60.

Apical membrane antigen 1 (AMA1) is regarded as a leading malaria blood-stage vaccine candidate. While the overall structure of AMA1 is conserved in Plasmodium spp., numerous AMA1 allelic variants of P. falciparum have been described. The effect of AMA1 allelic diversity on the ability of a recombinant AMA1 vaccine to protect against human infection by different P. falciparum strains is unknown. We characterize two allelic forms of AMA1 that were both produced in Pichia pastoris at a sufficient economy of scale to be usable for clinical vaccine studies. Both proteins were used to immunize rabbits, singly and in combination, in order to evaluate their immunogenicity and the ability of elicited antibodies to block the growth of different P. falciparum clones. Both antigens, when used alone, elicited high homologous anti-AMA1 titers, with reduced strain cross-reactivity. Similarly, sera from rabbits immunized with a single antigen were capable of blocking the growth of homologous parasite strains at levels theoretically sufficient to clear parasite infections. However, heterologous inhibition was significantly reduced, providing experimental evidence that AMA1 allelic diversity is a result of immune pressure. Encouragingly, rabbits immunized with a combination of both antigens exhibited titers and levels of parasite inhibition as good as those of the single-antigen-immunized rabbits for each of the homologous parasite lines, and consequently exhibited a broadening of allelic diversity coverage.

 6798.    Lasonder E, Ishihama Y, Andersen JS, Vermunt AM, Pain A, Sauerwein RW, Eling WM, Hall N, Waters AP, Stunnenberg HG, Mann M. Analysis of the Plasmodium falciparum proteome by high-accuracy mass spectrometry. Nature. 2002 Oct 3;419(6906):537-42.

The annotated genomes of organisms define a 'blueprint' of their possible gene products. Post-genome analyses attempt to confirm and modify the annotation and impose a sense of the spatial, temporal and developmental usage of genetic information by the organism. Here we describe a large-scale, high-accuracy (average deviation less than 0.02 Da at 1,000 Da) mass spectrometric proteome analysis of selected stages of the human malaria parasite Plasmodium falciparum. The analysis revealed 1,289 proteins of which 714 proteins were identified in asexual blood stages, 931 in gametocytes and 645 in gametes. The last two groups provide insights into the biology of the sexual stages of the parasite, and include conserved, stage-specific, secreted and membrane-associated proteins. A subset of these proteins contain domains that indicate a role in cell-cell interactions, and therefore can be evaluated as potential components of a malaria vaccine formulation. We also report a set of peptides with significant matches in the parasite genome but not in the protein set predicted by computational methods.

 6799.    McKenzie FE, Jeffery GM, Collins WE. Plasmodium malariae infection boosts Plasmodium falciparum gametocyte production. Am J Trop Med Hyg. 2002 Oct;67(4):411-4.

We analyzed records of malaria therapy patients sequentially or simultaneously inoculated with Plasmodium falciparum and Plasmodium malariae. Gametocyte production was enhanced in P. falciparum by prior or concurrent P. malariae infection but diminished or unaffected in P. malariae by P. falciparum. Conversely, asexual-form production was diminished in P. malariae but unaffected in P. falciparum.

 6800.    Moore SA, Surgey EG, Cadwgan AM. Malaria vaccines: where are we and where are we going? Lancet Infect Dis. 2002 Dec;2(12):737-43. Review.

Malaria is still killing over one million people each year and its incidence is increasing. The need for an effective vaccine is greater than ever. A major difficulty with vaccine research is that the malaria parasite presents thousands of antigens to the human immune system that vary throughout its life cycle. Identifying those that may prove to be vaccine targets is complicated and time consuming. Most vaccines are targeted at individual stages of the malaria life cycle, although it is likely that only the development of a multistage vaccine will offer complete protection to both visitors to, and residents of, a malaria-endemic area. With the development of a successful vaccine other issues such as cost, distribution, education, and compliance will have to be addressed. This review describes some of the current vaccine candidates for immunising against malaria.

  6801.   Pennisi E. Malaria research. Parasite genome sequenced, scrutinized. Science. 2002 Oct 4;298(5591):33-4.

This week, an almost complete DNA sequence of Plasmodium falciparum--one of the parasites that causes malaria--appears in Nature, and on page 129 of this issue of Science, other researchers report the DNA sequence of Anopheles gambiae, one of the mosquitoes that transmits P. falciparum to humans. Together with the human genome sequence, researchers now have in hand the genetic blueprints for the parasite, its vector, and its victim.

 6802.   Scott TW, Takken W, Knols BG, Boete C. The ecology of genetically modified mosquitoes. Science. 2002 Oct 4;298(5591):117-9.

                Ecological and population biology issues constitute serious challenges to the application of genetically modified mosquitos (GMM) for disease control.

 6803.    Severini C, Menegon M, Gradoni L, Majori G. Use of the Plasmodium vivax merozoite surface protein 1 gene sequence analysis in the investigation of an introduced malaria case in Italy. Acta Trop. 2002 Nov;84(2):151-7.

              Malaria due to Plasmodium vivax is globally widespread and is associated with substantial morbidity. The parasite was previously prevalent in temperate areas from which it has been eradicated, however there is a risk of re-introduction because of increased international travel and migration. Following the occurrence of an autochthonous case of P. vivax malaria in Italy after decades of malaria eradication, we applied a molecular approach to compare parasites involved in the introduced case and to determine whether a highly polymorphic gene marker could be useful to tag a P. vivax isolate geographically. To this end, the sequence encompassing the interspecies conserved blocks 5 and 6 of the gene encoding for merozoite surface protein 1 (msp-1) was determined in 16 P. vivax isolates from different regions, and analysed along with 24 pvmsp-1 sequences downloaded from published data. Results have shown that: (i). parasites from the introduced case and the putative source of infection identified following epidemiological investigation, although very similar, differed in three nucleotide substitutions, of which one non synonymous; ii). some geographical isolates looked tightly clustered (e.g. Korean and Punjab isolates), but others were less so.

 6804.    Sharma BD; Gupta B.Peripheral gangrene in a Complicated falciparum malaria Journal, Indian Academy of Clinical Medicine. 2002 Jul-Sep; 3(3): 297-9

               Peripheral gangrene occuring as a rare manifestation of complicated falciparum malaria in a 65 year old lady has been reported. clinical features and pathogenesis are discussed.

 6805.    Sokrab TE, Eltahir A, Idris MN, Hamid M. Guillain-Barre syndrome following acute falciparum malaria. Neurology. 2002 Oct 22;59(8):1281-3.

             Plasmodium falciparum malaria is often complicated by involvement of the gastrointestinal, cardiovascular, and nervous systems. The development of Guillain-Barre syndrome in 10 patients who had had acute P. falciparum malaria during its seasonal exacerbation is reported.

 6806.    Taylor HM, Grainger M, Holder AA. Variation in the expression of a Plasmodium falciparum protein family implicated in erythrocyte invasion. Infect Immun. 2002 Oct;70(10):5779-89.

             The PfRH protein family of Plasmodium falciparum is implicated in erythrocyte invasion. Here we report variations in the sequence, transcription, and protein expression of four different members of this family in three parasite lines, 3D7, T996, and FCB1. There are sequence polymorphisms in PfRH1, PfRH2a, PfRH2b, and PfRH3, ranging from variations across repeat regions to a 585-bp deletion in the 3' end of PfRH2b in T996. Not all the genes are transcribed: although all members of the family are transcribed in 3D7 and T996, PfRH2a and PfRH2b are not transcribed in FCB1. The PfRH1, PfRH2a, and PfRH2b proteins are expressed in late schizonts and merozoites and are located in apical organelles and on the apical surface. However, the PfRH1 protein does not appear to be correctly targeted to the apex in 3D7 and T996. In contrast, the PfRH1 protein is present at the apical end of FCB1 merozoites, but the PfRH2a and PfRH2b proteins are undetectable. The apparent redundancy in the PfRH family of proteins at the level of gene number and sequence and the variations in transcription and protein expression may allow the parasite to use alternative invasion pathways.

  6807.   Torre D, Speranza F, Martegani R. Role of proinflammatory and anti-inflammatory cytokines in the immune response to Plasmodium falciparum malaria. Lancet Infect Dis. 2002 Dec;2(12):719-20.No abstract.

 6808.   Varadharajan S, Dhanasekaran S, Bonday ZQ, Rangarajan PN, Padmanaban G. Involvement of delta-aminolaevulinate synthase encoded by the parasite gene in de novo haem synthesis by Plasmodium falciparum. Biochem J. 2002 Oct 15;367(Pt 2):321-7.

               The malaria parasite can synthesize haem de novo. In the present study, the expression of the parasite gene for delta-aminolaevulinate synthase (Pf ALAS ) has been studied by reverse transcriptase PCR analysis of the mRNA, protein expression using antibodies to the recombinant protein expressed in Escherichia coli and assay of ALAS enzyme activity in Plasmodium falciparum in culture. The gene is expressed through all stages of intra-erythrocytic parasite growth, with a small increase during the trophozoite stage. Antibodies to the erythrocyte ALAS do not cross-react with the parasite enzyme and vice versa. The recombinant enzyme activity is inhibited by ethanolamine and the latter inhibits haem synthesis in P. falciparum and growth in culture. The parasite ALAS is localized in the mitochondrion and its import into mitochondria in a cell-free import assay has been demonstrated. The import is blocked by haemin. On the basis of these results, the following conclusions are arrived at: PfALAS has distinct immunological identity and inhibitor specificity and is therefore a drug target. The malaria parasite synthesizes haem through the mitochondrion/cytosol partnership, and this assumes significance in light of the presence of apicoplasts in the parasite that may be capable of independent haem synthesis. The Pf ALAS gene is functional and vital for parasite haem synthesis and parasite survival.

  6809.   Wooltorton E. Mefloquine: contraindicated in patients with mood, psychotic or seizure disorders. CMAJ. 2002 Nov 12;167(10):1147.No abstract.

             

            Therapy

  6810.   Sampath S; Somani BL; Sharma YV; Arora MM; Ambade VN .India Serum Ornithine carbamoyl transferase as a surrogate marker in malaria Medical Journal Armed Forces India. 2002 Oct; 58(4): 315-8.

ABSTRACT: Ornithine carbamoyl transferase (OCT) activity and other liver function tests were studied in a total of 50 patients of clinical malaria and 15 controls. They were grouped as group I (positive for malarial parasite. on peripheral blood smear, n=18), group II (negative for malarial parasite on peripheral blood smear (PBS) responded to antimalarials, n=17) and group III (peripheral blood smear negative and did not respond to antimalarial therapy, n=15), The mean OCT levels were significantly raised in group I (6.79 plus minus 1.84 IU/L, p value = 0.006) and group II (5.0 plus minus 1.13 IU/L, p value = 0.014) as compared to controls (2.5 plus minus 1.13 IU/L) and returned to normal aft treatment. In contrast group III had normal levels except in a case of kala azar and septicemia where OCT level were high and increased further on treatment. Taking PBS positivity as a gold standard of diagnostic criteria, OCT had a sensitivity of 83 percent and specificity of 86 percent with a high positive predictive value of 88 percent as compared to ALT which had a lower sensitivity of 55 percent and specificity of 80 percent. the clinical response rate in PBS negative cases of fever having high OCT level was 83 percent as compared to 35 percent in case with normal OCT level, making OCT a good surrogate marker of malaria. OCT levels could also be of prognostic significance as 2 cases of cerebral malaria had high OCT levels of 11.1 U/L and 10.7 IU/L, respectively

6811. Warhurst DC, Craig JC, Adagu IS. Lysosomes and drug resistance in malaria. Lancet. 2002 Nov 16;360(9345):1527-9. No abstract.

    July 2003

7336.  Baheti R; Raddha P; Gehlot RS. Liver involvement in falciparum malaria a histopathological analysis Journal, Indian Academy of Clinical Medicine. 2003 Jan-Mar; 4(1): 34-8.

ABSTRACT: The present study has been undertaken to evaluate the histopathological alteration in the liver due to P. falciparum. Does it help in diagnosis of PUO due to falciparum malaria when other methods of diagnosing falciparum malaria are inconclusive? 60 patients of slide positive falciparum malaria, age more than 18 years, were subjected to liver biopsy. The patients of known liver disease were excluded and histopathology slides were examined under light microscopy at Deptt. of Pathology, Dr. S.N. Medical College Jodhpur. The specific histopathological changes in liver due to P. Falciparum observed by us were RE cell proliferation - 90 percent haemazoin pigmentation - 90 percent, congestion 80 percent, portal infiltration-75 percent, sinusoidal infiltration and dilatations-71.6 percent, cholestasis -40percent, while minor changes in the form of nuclear vacuolation-23.3 percent liver cell necrosis - 18.3 percent, and vacuolated cytoplasm in 10 percent, of cases. Thus, liver biopsy may be helpful in diagnosis when other methods of diagnosing P. falciparum are inconclusive.

7337.      Banerjee A, Nayak B. Epidemilogical and entomological correlation of  malaria transmission in an air force station. Med J Armed Forces India 2001, 57 (3), 191-3. (23902)Vol 38, No. 23, 1 dec 2002. No abstract available

7338.      Barone R, Simpore J, Malaguarnera L, Pignatelli S, Musumeci S.  Plasma chitotriosidase activity in acute Plasmodium falciparum malaria. J Trop Pediatr. 2003 Feb;49(1):63 No abstract available

7339.      Birkholtz L, Joubert F, Neitz AW, Louw AI. Comparative properties of a three-dimensional model of Plasmodium falciparum ornithine decarboxylase. Proteins. 2003 Feb 15;50(3):464-73.

The ornithine decarboxylase (ODC) component of the bifunctional S-adenosylmethionine decarboxylase/ornithine decarboxylase enzyme (PfAdoMetDC-ODC) of Plasmodium falciparum was modeled on the crystal structure of the Trypanosoma brucei enzyme. The homology model predicts a doughnut-shaped active homodimer that associates in a head-to-tail manner. The monomers contain two distinct domains, an N-terminal alpha/beta-barrel and a C-terminal modified Greek-key domain. These domains are structurally conserved between eukaryotic ODC enzymes and are preserved in distant analogs such as alanine racemase and triosephosphate isomerase-like proteins. Superimposition of the PfODC model on the crystal structure of the human enzyme indicates a significant degree of deviation in the carbon alpha-backbone of the solvent accessible loops. The surface locality of the ab initio modeled 38 amino acid parasite-specific insert suggests a role in the stabilization of the large bifunctional protein complex. The active site pockets of PfODC at the interface between the monomers appear to be conserved regarding the binding sites of the cofactor and substrate, but each contains five additional malaria-specific residues. The predicted PfODC homology model is consistent with mutagenesis results and biochemical studies concerning the active site residues and areas involved in stabilizing the dimeric form of the protein. Two competitive inhibitors of PfODC could be shown to interact with several parasite-specific residues in comparison with their interaction with the human ODC. The PfODC homology model contributes toward a structure-based approach for the design of novel malaria-specific inhibitors. Copyright 2003 Wiley-Liss, Inc.

7340.      Cattamanchi A, Kyabayinze D, Hubbard A, Rosenthal PJ, Dorsey G.  Distinguishing recrudescence from reinfection in a longitudinal antimalarial drug efficacy study: comparison of results based on genotyping of msp-1, msp-2, and glurp. Am J Trop Med Hyg. 2003 Feb;68(2):133-9.

Genotyping frequently is used to distinguish recrudescent from new infections inantimalarial drug efficacy trials, but methodology and interpretation of results have not been standardized. We compared the utility of polymorphisms within 3 Plasmodium falciparum genes during a longitudinal trial in Kampala, Uganda. Merozoite surface protein-1 (msp-1) and merozoite surface protein-2 (msp-2) revealed greater diversity than glutamate-rich protein. Genotypes based on  msp-1, msp-2, and all 3 genes combined were compared for 394 initial and subsequent isolates. Classification of most episodes as due to recrudescence or reinfection was straightforward. In 24% (msp-1), 16% (msp-2), and 62% (3 genes combined) of samples, subsequent episodes contained identical and new alleles,  however. Our analysis suggested that such episodes should be classified as reinfections and not recrudescence. Comparing the 3 studied genes, msp-2 results were most accurate, and analysis of this single gene effectively distinguished recrudescence from reinfection in our study population.

7341.      Chattopadhyay R, Sharma A, Srivastava VK, Pati SS, Sharma SK, Das BS, Chitnis CE.  Plasmodium falciparum infection elicits both variant-specific and cross-reactive antibodies against variant surface antigens. Infect Immun. 2003 Feb;71(2):597-604.

Naturally acquired antibodies to Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1), the variant surface antigens expressed on the surface of infected erythrocytes, are thought to play a role in protection against P. falciparum malaria. Here, we have studied the development of antibodies to PfEMP-1 in adult malaria patients living in Rourkela, India, an area with a low malaria transmission rate, and prevalence of antibodies to PfEMP-1 in residents of San Dulakudar, India, a village in which P. falciparum malaria is hyperendemic. Convalescent-phase sera from adult malaria patients from Rourkela agglutinate homologous P. falciparum isolates as well as some heterologous isolates, suggesting that they develop partially cross-reactive antibodies to PfEMP-1 following infection. Adult sera from San Dulakudar agglutinate diverse P. falciparum isolates, suggesting that they have antibodies with wide recognition of diverse PfEMP-1. Mixed-agglutination assays using pairs of P. falciparum isolates confirm the presence of both variant-specific and partially cross-reactive antibodies in convalescent-phase sera from Rourkela and adult sera from San Dulakudar. Analysis of PfEMP-1 sequences suggests a molecular basis for the observed cross-reactivity.

 

7342.      Dev V, Ansari M  A, Hira C R, Barman K. An outbreak of Plasmodium falciparum malaria due to Anopheles minimus in central Assam, India. Indian J Malar 2001, 38(1-2), 32-8.(21851) Vol 38, No. 21, 1 Nov 2002.

7343.      Dua V K, Gupta N C, Kar P K, Edwards G, Singh N, Sharma V P. Pharmacokinetics of chloroquine in Indian tribal and non-tribal healthy volunteers and patients with Plasmodium falciparum malaria. Curr Sci 2002, 83(9), 1128-31. (24871) Vol 38, No. 20, 16 oct 2002.

7344.      Grau GE, Mackenzie CD, Carr RA, Redard M, Pizzolato G, Allasia C, Cataldo C, Taylor TE, Molyneux ME.  Platelet accumulation in brain microvessels in fatal pediatric cerebral malaria. J Infect Dis. 2003 Feb 1;187(3):461-6.

The pathogenesis of fatal cerebral malaria (CM) is not well understood, in part because data from patients in whom a clinical diagnosis was established prior to death are rare. In a murine CM model, platelets accumulate in brain microvasculature, and antiplatelet therapy can improve outcome. We determined whether platelets are also found in cerebral vessels in human CM, and we performed immunohistopathology for platelet-specific glycoprotein, GPIIb-IIIa, on tissue from multiple brain sites in Malawian children whose fatal illness was severe malarial anemia, CM, or nonmalarial encephalopathy. Platelets were observed in 3 locations within microvessels: between malaria pigment and leukocytes, associated with malaria pigment, or alone. The mean surface area of platelet staining and the proportion of vessels showing platelet accumulation were significantly higher in patients with CM than in those without it. Platelet accumulation occurs in the microvasculature of patients with CM and may play a role in the pathogenesis of the disease.

7345.      Jaganathan C, Khan S A, Ramesh Chandra, Singh H, Srivasrava V, Raju P L N. characterization of malaria vector habitats using  remote sensing and GIS. J Indian Soc Remote Sensing 2001, 29(1-2), 31-6.. (23956)Vol 38, No. 23, 1 dec 2002.

7346.      Kamal S, Das S C. Epidemiological observation on malaria in some parts of Darrang district, Assam. Indian J Malar 2001, 38(1-2), 25-31.(21903)  Vol 38, No. 21, 1 Nov 2002.

7347.      Kamble M B, Raut P P, Hussain Z F. Cerebral malaria in rural India. Indian J Pedeat 2002, 69(8), 659-61. (23962) Vol 38, No. 23, 1 dec 2002.

7348.      Kinyanjui SM, Bull P, Newbold CI, Marsh K.  Kinetics of antibody responses to Plasmodium falciparum-infected erythrocyte variant surface antigens. J Infect Dis. 2003 Feb 15;187(4):667-74.

The kinetics of antibody responses to the Plasmodium falciparum malaria parasite-induced erythrocyte surface antigens (PIESAs) in 26 Kenyan children were examined by use of flow cytometry and agglutination assays. Although 19 of the 26 children mounted a primary antibody response to PIESAs within 2 weeks of experiencing an acute episode and maintained high antibody levels for at least 12 weeks, the remaining 7 children had responses that were weak and brief. Resistance to reparasitization was decreased in the children with short-lived responses. Isotype profiles of responses in 11 of the children studied suggest that they may have failed to switch to IgG after the initial IgM response. These data suggest that children vary widely in their ability to respond to PIESAs and that, in some individuals or with certain PIESA variants, short-lived antibodyresponses are induced that may be associated with poor antibody class switching.

7349.      Manish R, Tripathy R, Das BK.  Plasma glucose and tumour necrosis factor-alpha in adult patients with severe falciparum malaria. Trop Med Int Health. 2003 Feb;8(2):125-8.

Plasma glucose was assessed in 81 patients with severe falciparum malaria at the time of presentation along with tumour necrosis factor-alpha (TNF-alpha). The lowest plasma glucose value was 3.38 mmol/l and none of the patients had hypoglycaemia at admission. Plasma glucose values were not significantly lower in those with multiple organ dysfunction (MOD) than in patients with single organ dysfunction (cerebral malaria only) and in those who died compared with patients who survived. Conversely, TNF-alpha showed a good correlation with depth of coma and was significantly higher in patients who had MOD and those who died. There was no correlation between plasma glucose and TNF-alpha values.

7350.      Mehta S R, Kashyap A S, Thergaonkar R, Dhaliwal H. Management of cerebral malaria in the year 2001. Med J Armed Forces India 2001, 57(4), 317-9. (23993)Vol 38, No. 23, 1 dec 2002.

7351.      Patsoula E, Spanakos G, Sofianatou D, Parara M, Vakalis NC.  A single-step, PCR-based method for the detection and differentiation of Plasmodium vivax and P. falciparum. Ann Trop Med Parasitol. 2003 Jan;97(1):15-21.

The ability to detect and differentiate between Plasmodium falciparum and P. vivax is of great importance for the routine laboratory diagnosis of malaria, donor-blood screening and epidemiological studies. Most PCR-based methods for the discrimination of these two species require nested protocols or an additional hybridization reaction, leading to high labour costs and long turn-around times. A simple, time-effective and yet sensitive and specific technique, based on a multiplex PCR, has now been developed for the simultaneous detection and differentiation of P. falciparum and P. vivax in blood samples. Compared with the 'gold standard' of microscopy, this method had a sensitivity and specificity of 100%, with a detection limit of just one P. falciparum orthree P. vivax parasites/microl blood.

7352.      Perandin F, Manca N, Piccolo G, Calderaro A, Galati L, Ricci L, Medici MC, Arcangeletti C, Dettori G, Chezzi C.  Identification of Plasmodium falciparum, P. vivax, P. ovale and P. malariae and detection of mixed infection in patients with imported malaria in Italy. New Microbiol. 2003 Jan;26(1):91-100. 

The species-specific nested-PCR previously described by Snounou and others for detecting the four parasite species that cause human malaria is evaluated in the current study testing 230 blood samples. The results are compared with those obtained by microscopy and, for 101 samples out of 230, with those previously obtained by a genus-specific PCR based method (pg-PCR) followed by species-specific Southern-blot hybridization. All blood specimens were obtained from patients (127 foreigners and 103 Italians) with a suspect clinicaldiagnosis of imported malaria in Italy: 76 were positive by microscopy and 83 were positive by nested-PCR. The last method also revealed 10 double infections (8 foreigners and 2 Italians) which were not identified by microscopy or bypg-PCR with species-specific Southern-blot hybridization. Fifty-four out of 83 positive samples tested by nested-PCR were submitted to genomic sequence analysis, which confirmed the presence of DNA region portion encoding the 18S rRNA corresponding to the Plasmodium species identified by nested-PCR. These results demonstrate that the nested-PCR assay surpasses microscopy and pg-PCRwith species-specific Southern-blot hybridization, both in sensitivity and in diagnostic accuracy. Moreover, it is quicker because it requires no further blotting or hybridization of PCR amplification products. This method also offers a clear advantage in the detection of mixed infections, which is important not only for successful medical treatment but also for the study of malaria epidemiology. Finally, our study also highlights the value of genomic sequence analysis for validating PCR results.

7353.      Raut D K, Pandey G K. Childhood malaria and use of bednets in Kolkata. Indian J Malar 2001, 38(1-2), 39-42. (22011) Vol 38, No. 21, 1 Nov 2023 .

7354.      Rogerson SJ, Pollina E, Getachew A, Tadesse E, Lema VM, Molyneux ME.   Placental monocyte infiltrates in response to Plasmodium falciparum malaria infection and their association with adverse pregnancy outcomes. Am J Trop Med Hyg. 2003 Jan;68(1):115-9.

Maternal anemia and low birth weight (LBW) may complicate malaria in pregnancy, and placental monocyte infiltrates have been associated with LBW, and anecdotally with anemia. We examined placental pathology from 357 Malawian women. Intervillous monocyte infiltrates were frequent in placental malaria and were not seen in uninfected placentas. Histology was grouped according to a 5-point scale. Dense monocyte infiltrates and presence of intramonocytic malaria pigment were associated with anemia and LBW. Of factors associated with LBW and/or anemia in univariate analysis, gravidity (P = 0.002), number of antenatal clinic (ANC) visits (P < 0.001), malaria pigment in fibrin (P = 0.03), and monocyte malaria pigment (P = 0.0001) remained associated with lower birth weight by multivariate analysis. Associated with maternal anemia were HIV infection (P < 0.0001), intervillous monocyte numbers (P < 0.0001), number of ANC visits (P = 0.002), and recent febrile symptoms (P = 0.0001). Pigment-containing placental monocytes are associated with anemia and LBW due tomalaria, and may have a causative role in their development.

7355.      Singh N, Valecha N, Nagpal AC, Mishra SS, Varma HS, Subbarao SK.  The hospital- and field-based performances of the OptiMAL test, for malaria diagnosis and treatment monitoring in central India. Ann Trop Med Parasitol. 2003 Jan;97(1):5-13

The performance of the OptiMAL test, to detect and differentiate Plasmodium falciparum and P. vivax, was evaluated in central India. The subjects were either symptomatic patients, who presented at a referral hospital in urban Jabalpur, or the inhabitants of remote, tribal, forested villages where malaria is a major public-health problem. In each setting, the results of conventional microscopy were used as the 'gold standard'. Under hospital conditions, the test had excellent sensitivity (100%), good specificity (97%), a high positive predictive value (98%) and a high negative predictive value (100%). The corresponding values in the field-based study in the tribal villages (100%, 67%, 84% and 100%, respectively) were almost as good. The results of OptiMAL testing reveal the decline in parasitaemias (of P. falciparum or P. vivax) after drug administration. For monitoring the effectiveness of treatment, the test could therefore be a useful alternative to microscopy, particularly (1) in places where the facilities for microscopy are poor or non-existent and (2) among hospitalized patients with severe, complicated malaria (in whom parasitaemia and drug response need to be followed very carefully). Follow-up (within 28 days of diagnosis) of the 58 malaria cases detected in the field revealed that the OptiMAL test can be used to detect re-infection with a different Plasmodium sp. (sensitivity = 100%; specificity = 100%; J-index = 1) or recrudescence/re-infection with the same Plasmodium sp. (sensitivity = 83%; specificity = 100%; J-index = 0.83) accurately. The ability to use the test to distinguish P. falciparum from P. vivax, and to identify mixed infections of these two species, is of great significance in areas where the preferred and effective therapy for P. falciparum malaria differs from that for P. vivax.

 

7356.      Utarini A, Winkvist A, Ulfa FM.  Rapid assessment procedures of malaria in low endemic countries: community perceptions in Jepara district, Indonesia. Soc Sci Med. 2003 Feb;56(4):701-12.

Most studies on community perceptions toward malaria have been undertaken in high-endemic countries, and studies from low-endemic countries have only recently been published. Similar information is also needed for hypoendemic countries such as Indonesia, to cope with the persistence of foci-endemic malaria in these regions. An applied qualitative method, Rapid Assessment Procedures, was employed during a 3-month intensive data collection period in Jepara district, Central Java province. Data were retrieved from 38 free-listings, 28 in-depth interviews, seven focus group discussions and unstructured observation. Qualitative thematic content analysis was applied. In this community, malaria (known as katisen or panas tis) was considered a common but minor illness. Insufficient understanding of malaria signs and symptoms in the subvillages likely leads to delay in illness recognition and treatment; not surprisingly self-treatment is common and the dosage most likely below the recommended dose. The health center was used but when it did not work, most people would shift back to traditional services due to cost considerations. Low understanding and acceptance of the causal link between the mosquito and malaria, likely leading to poor comprehension of preventive activities, as well as confusion of malaria with dengue fever, were identified. In conclusion, this study highlights a consistent gap between the common understanding and the biomedical description of malaria. If case management continues to be the main strategy in malaria control program, the emic perspective of the people must be well-integrated into the program. Likewise, interventions to improve home-treatment should also be developed.

 

Pathogenesis:

 

7357.      Boutlis CS, Fagan PK, Gowda DC, Lagog M, Mgone CS, Bockarie MJ, Anstey NM.  Immunoglobulin G (IgG) responses to Plasmodium falciparum glycosylphosphatidylinositols are short-lived and predominantly of the IgG3 subclass.J Infect Dis  2003 Mar 1;187(5):862-5

The induction of neutralizing immunity to Plasmodium falciparum toxins by vaccination has been proposed as a preventive strategy to limit the severity of malaria. For this approach to be successful, generation of a sustained immune response would be necessary. This study shows that immunoglobulin G (IgG)-subclass responses elicited by the proposed P. falciparum toxin glycosylphosphatidylinositol (GPI) in Papua New Guinean subjects 5-60 years old predominantly involve IgG(3), with a lesser contribution from IgG(1) and an absence of IgG(2) and IgG(4). IgG(3) levels declined sharply within 6 weeks of pharmacological clearance of parasitemia in all subjects, whereas a significant  decrease in IgG(1) levels was seen only in subjects < or =19 years old. Because the natural antibody response to P. falciparum GPIs is skewed toward the short-lived IgG(3) subclass, a vaccination strategy with GPI analogues would likely require augmentation by costimulatory molecules, to induce a more persistent anti-GPI response.

7358.      Cot M, Le Hesran JY, Staalsoe T, Fievet N, Hviid L, Deloron P.  Maternally  transmitted antibodies to pregnancy-associated variant antigens on the surface of erythrocytes infected with Plasmodium falciparum: relation to child susceptibility to malaria. Am J Epidemiol. 2003 Feb 1;157(3):203-9.

The consequences of pregnancy-associated malaria on a child's health have been poorly investigated. Malarial infection of the placenta seems to result in a higher susceptibility of children to the parasite during their first year of life. In 1993-1995, the authors investigated the role of antibodies in variable surface antigens (VSA) specific to chondroitin sulfate A (CSA)-binding parasites to assess the parasitologic status of the child. Flow cytometry was used to measure levels of antibodies to VSA from CSA-selected and -unselected parasite lines in the cord blood of 79 newborns in Ebolowa, Cameroon. These newborns were subsequently followed up for 2 years to determine the date of first occurrence of blood parasites and mean parasite density during follow-up. Maternally transmitted antibodies to VSA expressed by CSA-binding parasites, but not antibodies to any other specificity, were negatively related to time of first appearance of Plasmodium falciparum in a child's blood and were positively related to mean parasite density during the first 2 years of life. If maternal infection is thought to be the main mechanism influencing susceptibility of the newborn to malaria, antibodies to VSA may better denote maternal malaria infection during almost the entire pregnancy as opposed to placental blood smear reflecting infection during the last few months of pregnancy.

7359.      Crispe IN.   Hepatic T cells and liver tolerance. Nat Rev Immunol. 2003 Jan;3(1):51-62.

The T-cell biology of the liver is unlike that of any other organ. The local lymphocyte population is enriched in natural killer (NK) and NKT cells, which might have crucial roles in the recruitment of circulating T cells. A large macrophage population and the efficient trafficking of dendritic cells from sinusoidal blood to lymph promote antigen trapping and T-cell priming, but the local presentation of antigen causes T-cell inactivation, tolerance and apoptosis. These local mechanisms might result from the need to maintain immunological silence to harmless antigenic material in food. The overall bias of intrahepatic T-cell responses towards tolerance might account for the survival of liver allografts and for the persistence of some liver pathogens.

7360.      Gunther A, Grobusch MP, Slevogt H, Abel W, Burchard GD.  Myocardial damage in falciparum malaria detectable by cardiac troponin T is rare. Trop Med Int Health. 2003 Jan;8(1):30-2.

OBJECTIVES: To estimate the prevalence of myocardial damage in falciparum malaria by serum concentration of cardiac troponin T. METHODS: Retrospective study of stored sera and patient files; assessment of acute myocardial damage by serum concentration or activity of cardiac troponin T, creatine kinase, creatine kinase MB and myoglobin and by routine electrocardiography. RESULTS: A total of 161 patients with falciparum malaria were included in the study; troponin T was elevated in one case (0.6%), no CK-MB elevations were found, myoglobin was elevated in 10 of 161 patients (6.2%), all of whom were elderly and had concomitant elevated serum concentration levels of cystatin C; ECG abnormalities were seen in 23 patients. CONCLUSION: Assessed by troponin T, myocardial damage in falciparum malaria is rare.

7361.      Heales S.  Increased nitric oxide production and protection from malaria. Lancet. 2003 Feb 15;361(9357):609-10. No abstract available.

7362.      Juliger S, Bongartz M, Luty AJ, Kremsner PG, Kun JF.   Functional analysis of a promoter variant of the gene encoding the interferon-gamma receptor chain I. Immunogenetics. 2003 Jan;54(10):675-80.

We analyzed a single nucleotide polymorphism (SNP) at position -56 (T-->C) in the promoter region of the gene encoding the human interferon-gamma receptor ligand-binding chain I (IFN-gammaR1). The mutation was present at similar frequencies in Gabonese children with either mild or severe malaria. Functional investigations of the promoter in a transfected human B-cell line showed lower levels of luciferase reporter gene expression in the presence of the mutation, indicating the importance of this position for promoter activity, and suggesting that this SNP might negatively influence the expression level of IFN-gammaR1 at the cell surface. Further examinations of the DNA sequence at this polymorphic site showed a perfectly matched binding site for the transcription factor activator protein 4 (AP-4) on both strands. Binding sites for other important transcription factors involved in gene expression and regulation of the immune response against infections, including Ikaros 2 (Ik-2), nuclear factor kappaB (NFkappaB),  and CETS1p54, are also situated in this region.

7363.      Khattab A, Kremsner PG, Klinkert MQ. Common surface-antigen var genes of limited diversity expressed by Plasmodium falciparum placental isolates separated by time and space. J Infect Dis. 2003 Feb 1;187(3):477-83.

Plasmodium falciparum placental parasites from Cameroon have been shown to express surface variant var genes encoding Duffy binding-like (DBL)-gamma domains that bind chondroitin sulfate A. All 5 domains exhibited sequences with 39%-55% amino acid (aa) identities and appear sufficiently conserved to function in receptor binding. Transcripts of 2 samples showed complete conservation over 4 kb, demonstrating for the first time distinct conserved placental var genes. Four placental isolates from Gabon collected 4 years later expressed DBL-gamma sequences with 85%-99% aa identities to those from Cameroon, confirming the conserved nature of placental variants separated by time and location. Five peripheral parasites from children also displayed DBL-gamma sequences with 75%-97% homologies. From this, it can be concluded that P. falciparum parasites expressing unique var DBL-gamma genes can cause placental malaria, referred to as varPAM genes. This demonstration of structurally/functionally constrained DBL-gamma chondroitin sulfate A-binding domains is relevant to understanding pregnancy-associated malaria pathogenesis and to vaccine development.

7364.      Li JL, Cox LS.  Characterisation of a sexual stage-specific gene encoding ORC1 homologue in the human malaria parasite Plasmodium falciparum. Parasitol Int. 2003 Mar;52(1):41-52.

The origin recognition complex (ORC) is a multisubunit protein composed of six polypeptides that binds to replication origins and is essential for the initiation of chromosomal DNA replication. Using the Vectorette technique, we have isolated a novel gene encoding an ORC1-like protein from the human malaria parasite Plasmodium falciparum. The gene has no introns and encodes a protein (PfORC1) of 1189 amino acid residues with a predicted molecular mass of 139 kDa. PfORC1 contains all conserved sequences in the ORC1/Cdc6/Cdc18 family and displays the highest homology to the Schizosaccharomyces pombe ORC1. However, PfORC1 possesses an extensive N-terminal segment with several interesting features including multiple potential phosphorylation sites, a large proportion of charged amino acids, four copies of a heptamer repeat, two nuclear localisation signals, and a leucine zipper motif. Southern blot analyses show that the Pforc1 gene is present as a single copy per haploid genome and is located on chromosome 12. A 5600 nucleotide transcript of this gene is expressed predominantly in the sexual erythrocytic stage, indicating that PfORC1 may be involved in gametogenesis during which DNA is quickly replicated. Copyright 2002 Elsevier Science Ireland Ltd.

7365.      Li T, Glushakova S, Zimmerberg J.  A new method for culturing Plasmodium falciparum shows replication at the highest erythrocyte densities. J Infect Dis. 2003 Jan 1;187(1):159-62.

Plasmodium falciparum replicates poorly in erythrocyte densities greater than a hematocrit of 20%. A new method to culture the major malaria parasite was developed by using a hollow fiber bioreactor that preserves healthy erythrocytes at hematocrit up to 100%. P. falciparum replicated equally well at all densities studied. This method proved advantageous for large-scale preparation of parasitized erythrocytes (and potentially immunogens thereof), because high yields ( approximately 10(10) in 4 days) could be prepared with less cost and labor. Concomitantly, secreted proteins were concentrated by molecular sieving during culture, perhaps contributing to the parasitemic limit of 8%-12% with the 3D7 strain. The finding that P. falciparum can replicate at packed erythrocyte densities suggests that this system may be useful for study of the pathogenesis of fatal cerebral malaria, of which one feature is densely packed blood cells inbrain microvasculature.

7366.      Maier AG, Duraisingh MT, Reeder JC, Patel SS, Kazura JW, Zimmerman PA, Cowman AF.  Plasmodium falciparum erythrocyte invasion through glycophorin C and selection for Gerbich negativity in human populations. Nat Med. 2003 Jan;9(1):87-92.

Geographic overlap between malaria and the occurrence of mutant hemoglobin and erythrocyte surface proteins has indicated that polymorphisms in human genes have been selected by severe malaria. Deletion of exon 3 in the glycophorin C gene (called GYPCDeltaex3 here) has been found in Melanesians; this alteration changes the serologic phenotype of the Gerbich (Ge) blood group system, resulting in Ge negativity. The GYPCDeltaex3 allele reaches a high frequency (46.5%) in coastal areas of Papua New Guinea where malaria is hyperendemic. The Plasmodium falciparum erythrocyte-binding antigen 140 (EBA140, also known as BAEBL) binds with high affinity to the surface of human erythrocytes. Here we show that the receptor for EBA140 is glycophorin C (GYPC) and that this interaction mediates a principal P. falciparum invasion pathway into human erythrocytes. EBA140 does not bind to GYPC in Ge-negative erythrocytes, nor can P. falciparum invade such cells using this invasion pathway. This provides compelling evidence that Ge negativity has arisen in Melanesian populations through natural selection by severe malaria.

7367.      May J, Meyer CG.  Association of Plasmodium falciparum chloroquine resistance transporter variant T76 with age-related plasma chloroquine levels. Am J Trop Med Hyg. 2003 Feb;68(2):143-6.

The mutation leading to the substitution of a threonine (T76) for a lysine at position 76 of the Plasmodium falciparum chloroquine resistance transporter (PfCRT) was genotyped in 100 Nigerian children with asymptomatic parasitemia. Isolates containing both pfcrt variants were found to harbor higher numbers of parasite clones (P < 0.002). The prevalence of the pfcrt T76 variant decreased with age (P < 0.0001) and increased with blood levels of chloroquine (CQ) (P < 0.0001). Whereas the K76 allele was more frequent in individuals without detectable plasma CQ levels (79.7%), only the pfcrt T76 variant was observed in children with CQ levels > 150 nmol/L. In individuals without detectable plasma CQ, the proportion of those with pfcrt T76 decreased from 60% in children < 2 years old to 23.5% in children > or = 6 years old (P < 0.01). The association of actual blood levels of CQ and the occurrence of pfcrt T76 underlines that the pfcrt T76 variant is in fact the mediator of CQ resistance.

7368.      Mockenhaupt FP, Mandelkow J, Till H, Ehrhardt S, Eggelte TA, Bienzle U.  Reduced prevalence of Plasmodium falciparum infection and of concomitant anaemia in pregnant women with heterozygous G6PD deficiency. Trop Med Int Health. 2003 Feb;8(2):118-24.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency confers protection against malaria in children, yet its role in malaria in pregnancy is unknown. In a cross-sectional study among 529 pregnant Ghanaian women, Plasmodium falciparum infection, anaemia and G6PD genotypes were assessed. Of these, 30.4% were heterozygous and 2.6% were homozygous for G6PD deficiency. The prevalence of P. falciparum infection decreased from 66% in G6PD-normal women to 58% in heterozygotes, and to 50% in individuals with homozygous G6PD deficiency (Chi2(trend) = 4.4, P = 0.04). Multivariate analysis revealed that in multigravid women but not in primigravidae, heterozygous G6PD deficiency was associated with a reduced risk of P. falciparum infection (Odds ratio (OR), 0.6; 95% confidence interval (95% CI), [0.4-0.9]). This protection against infection was limited to the third trimenon of pregnancy. In addition, heterozygous G6PD deficiency was associated with a reduced risk of anaemia among infected multigravidae (OR, 0.5 [0.3-1.0]). Pregnancy is a period of high vulnerability to malaria. The results of this study provide evidence for protection against malaria in pregnancy caused by heterozygous G6PD deficiency. This advantage, even if confined to multigravid women, may contribute to the selection of G6PD variants in malaria-endemic regions.

 

7369.      Ofori MF, Staalsoe T, Bam V, Lundquist M, David KP, Browne EN, Akanmori BD, Hviid L.  Expression of variant surface antigens by Plasmodium falciparum parasites in the peripheral blood of clinically immune pregnant women indicates ongoing placental infection. Infect Immun. 2003 Mar;71(3):1584-6.

Placenta-sequestered Plasmodium falciparum parasites that cause pregnancy-associated malaria (PAM) in otherwise clinically immune women express distinct variant surface antigens (VSA(PAM)) not expressed by parasites in nonpregnant individuals. We report here that parasites from the peripheral blood of clinically immune pregnant women also express VSA(PAM), making them a convenient source of VSA(PAM) expressors for PAM vaccine research.

7370.      Rogerson SJ, Brown HC, Pollina E, Abrams ET, Tadesse E, Lema VM, Molyneux ME.  Placental tumor necrosis factor alpha but not gamma interferon is associated with placental malaria and low birth weight in Malawian women. Infect Immun. 2003 Jan;71(1):267-70.

Malaria in pregnancy predisposes to maternal anemia and low birth weight (LBW). We examined the possible roles of the cytokines tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) in these adverse outcomes. We measured cytokine concentrations in placental, peripheral, and cord blood plasma in relation to malaria parasitemia and placental monocyte accumulation in 276 Malawian women. Maternal hemoglobin concentration, human immunodeficiency virus status, and infant birth weight were determined. Concentrations of TNF-alpha in placental blood were correlated with densities of Plasmodium falciparum-infected erythrocytes (P < 0.0001) and of intervillous monocyte infiltrates (P < 0.0001) on placental histology. Peripheral blood TNF-alpha concentrations were relatively low and were weakly associated with malaria. TNF-alpha concentrations were higher in placental blood, where they were strongly associated with malaria. Placental plasma TNF-alpha levels were higher in women who had LBW babies (P = 0.0027), women with febrile symptoms (P < 0.0001), and teenage mothers (P = 0.04) than in other women. The presence of TNF-alpha in cord blood was not associated with malaria infection. IFN-gamma levels were infrequently elevated, and elevated IFN-gamma levels were not associated with poor pregnancy outcomes. Placental production of TNF-alpha, but not of IFN-gamma, may be implicated in impaired fetal growth in Malawian women.

7371.      Schmider N, Peyerl-Hoffmann G, Restrepo M, Jelinek T.  Short communication: point mutations in the dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Colombia. Trop Med Int Health. 2003 Feb;8(2):129-32.

Point mutations in the dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum can lead to an increasing resistance of P. falciparum to pyrimethamine/sulphadoxine. We examined the prevalence of these mutations in 36 samples from Colombia. Analysed by polymerase chain reaction (PCR) for infection with P. falciparum, 25 (69%) tested positive. These positive isolates were tested further for point mutations in the genes of DHFR (codons 16, 51, 59, 108 and 164) and DHPS (codons 436, 437, 540, 581 and 613) by nested PCR and following mutation-specific restriction enzyme digestion. Gene mutations occurred in both the DHFR and DHPS gene of the Colombian isolates, suggesting that resistance to antifolate drugs exists or may develop soon in Colombia.

7372.      Schwarzer E, Kuhn H, Valente E, Arese P.  Malaria-parasitized erythrocytes and hemozoin nonenzymatically generate large amounts of hydroxy fatty acids that inhibit monocyte functions. Blood. 2003 Jan 15;101(2):722-8.

Plasmodium falciparum digests up to 75% of erythrocyte (red blood cell [RBC]) hemoglobin and forms hemozoin. Phagocytosed hemozoin and trophozoites inhibit important monocyte functions. Delipidized trophozoites and hemozoin were remarkably less toxic to monocytes. Parasitized RBCs and hemozoin contained large amounts of mostly esterified monohydroxy derivatives (OH-PUFAs), the stable end products of peroxidation of polyenoic fatty acids. The concentrations of OH-PUFA were 1.8 micromoles per liter RBCs in nonparasitized RBCs, 11.1 micromoles per liter RBCs in rings, 35 micromoles per liter RBCs in trophozoites; and approximately 90 micromoles per liter RBC equivalents in hemozoin. In parasitized RBCs and hemozoin a complex mixture of monohydroxy derivatives of arachidonic (HETEs) and linoleic (HODEs) acid was determined. Respectively, 13- and 9-HODE and 9- and 12-HETE were predominant in hemozoin and parasitized RBCs. The estimated concentrations of all HETE isomers were 33 and 39 micromoles per liter RBCs or RBC equivalents in trophozoites and hemozoin, respectively. No evidence of lipoxygenase activity was found, whereas the large number of positional and optical isomers, the racemic structure, and their generation by incubation of arachidonic acid with hemozoin indicated nonenzymatic origin via heme-catalysis. Sub/low micromolar concentrations of 12- and 15-HETE were toxic to monocytes, whereas HODE isomers were ineffective. Low micromolar concentrations of HETE isomers were estimated to be similarly present in monocytes after phagocytosis of trophozoites or hemozoin. Thus, specific products of heme-catalyzed lipid peroxidation appear to contribute to hemozoin toxicity to phagocytes and may thus play a role in increased cytoadherence, vascular permeability, and chemotaxis, as well as in immunodepression in malaria.

7373.      Seoh JY, Khan M, Park SH, Park HK, Shin MH, Ha EH, Lee BE, Yoo K, Han HS, Oh S, Wi JH, Hong CK, Oh CH, Kim YA, Park JW. Serum cytokine profiles in patients with Plasmodium vivax malaria: a comparison between those who presented with and without hyperpyrexia. Am J Trop Med Hyg. 2003 Jan;68(1):102-6.

Serum cytokine profiles in patients with Plasmodium vivax malaria who presented with and without hyperpyrexia were compared by a retrospective review of the medical records of the consecutive patients seen at the military hospitals near the demilitarized zone in the Republic of Korea from April 2000 through October 2001. Of 162 male patients studied, 120 (86.4%) presented with hyperpyrexia (i.e., an axillary temperature > or = 40 degrees C). The mean +/- SEM ages of the patients with and without hyperpyrexia were 21.5 +/- 0.14 and 21.9 +/- 0.39 years, respectively (P = 0.33). The mean +/- SEM concentrations of serum interleukin (IL)-6 (379.7 +/- 44.1 pg/mL versus 105.4 +/- 26.8 pg/mL; P = 0.002), IL-10 (583.4 +/- 58.2 pg/mL versus 142.4 +/- 39.7 pg/mL; P = 0.0001), and interferon-gamma (312.6 +/- 33.9 pg/mL versus 112.9 +/- 27.1 pg/mL; P = 0.0001) were significantly higher in patients with hyperpyrexia compared with those without hyperpyrexia. The mean +/- SEM concentrations of serum tumor necrosis factor-alpha were 155.5 +/- 54.5 pg/mL and 109.9 +/- 29.3 pg/mL (P = 0.27) in patients who presented with and without hyperpyrexia, respectively. Further studies are needed to examine whether serum concentrations of these cytokines also parallel their concentrations at the tissue sites of their production and action.

7374.      Siekmann JH, Allen LH, Watnik MR, Nestel P, Neumann CG, Shoenfeld Y, Peter JB, Patnik M, Ansari AA, Coppel RL, Gershwin ME.   Titers of antibody to common pathogens: relation to food-based interventions in rural Kenyan schoolchildren. Am J Clin Nutr. 2003 Jan;77(1):242-9.

BACKGROUND: Undernutrition is widely perceived to affect the development of an effective immune system. OBJECTIVE: We used a mini-analysis system to quantitate antibody titers and evaluate the sera of 200 Kenyan schoolchildren for antibodies to Helicobacter pylori [isotypes of immunoglobulins A (IgA), G (IgG), and M (IgM)], hepatitis A virus, rotavirus, tetanus toxoid (IgG), and a panel of recombinant malarial antigens (MSP1(19), MSP2, Ag512, MSP4, and MSP5). DESIGN: Children participated in a school-based feeding intervention with meat, milk, or nonanimal-source foods or in a nonintervention control group. Microvolumes (200 mL) of sera were analyzed at baseline and after 1 y. RESULTS: Nearly all children had elevated titers of antibody to H. pylori, hepatitis A virus, rotavirus, and malaria at the outset, despite a high prevalence of apparent biochemical micronutrient deficiencies and stunting, but many had titers of tetanus toxoid IgG antibodies below the protective concentration. Children with low hemoglobin had a greater proportion of elevated H. pylori IgM antibody titers at baseline, which suggests that current infection with H. pylori may be associated with anemia. Compared with the control subjects, only the group eating meat had a significant increase in H. pylori IgM antibodies during the intervention (P = 0.019). No other group comparisons with the control subjects were statistically significant. The additional finding that the sera of some children showed inadequate tetanus-protective antibodies, despite immunization, suggests that the vaccination program was suboptimal. CONCLUSIONS: A large battery of immune assays can be performed on microvolumes of sera. Furthermore, despite evidence of malnutrition, children do develop significant antibody-mediated responses to common pathogens.

 

Vaccines:

 

7375.      Boutlis CS, Fagan PK, Gowda DC, Lagog M, Mgone CS, Bockarie MJ, Anstey NM. Immunoglobulin G (IgG) responses to Plasmodium falciparum glycosylphosphatidylinositols are short-lived and predominantly of the IgG3 subclass. J Infect Dis  2003 Mar 1;187(5):862-5

The induction of neutralizing immunity to Plasmodium falciparum toxins by vaccination has been proposed as a preventive strategy to limit the severity of malaria. For this approach to be successful, generation of a sustained immune response would be necessary. This study shows that immunoglobulin G (IgG)-subclass responses elicited by the proposed P. falciparum toxin glycosylphosphatidylinositol (GPI) in Papua New Guinean subjects 5-60 years old predominantly involve IgG(3), with a lesser contribution from IgG(1) and an absence of IgG(2) and IgG(4). IgG(3) levels declined sharply within 6 weeks of pharmacological clearance of parasitemia in all subjects, whereas a significant decrease in  IgG(1) levels was seen only in subjects < or =19 years old. Because the natural antibody response to P. falciparum GPIs is skewed toward the short-lived IgG(3) subclass, a vaccination strategy with GPI analogues would likely require augmentation by costimulatory molecules, to induce a more persistent anti-GPI response.

Therapy:

 

7376.      Heales S.  Increased nitric oxide production and protection from malaria. Lancet. 2003 Feb 15;361(9357):609-10. No abstract available.

7377.      Schmider N, Peyerl-Hoffmann G, Restrepo M, Jelinek T. Short communication: point mutations in the dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Colombia. Trop Med Int Health. 2003 Feb;8(2):129-32.

Point mutations in the dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum can lead to an increasing resistance of P. falciparum to pyrimethamine/sulphadoxine. We examined the prevalence of these mutations in 36 samples from Colombia. Analysed by polymerase chain reaction (PCR) for infection with P. falciparum, 25 (69%) tested positive. These positive isolates were tested further for point mutations in the genes of DHFR (codons 16, 51, 59, 108 and 164) and DHPS (codons 436, 437, 540, 581 and 613) by nested PCR and following mutation-specific restriction enzyme digestion. Gene mutations occurred in both the DHFR and DHPS gene of the Colombian isolates, suggesting that resistance to antifolate drugs exists or may develop soon in Colombia.

7378.      Siekmann JH, Allen LH, Watnik MR, Nestel P, Neumann CG, Shoenfeld Y, Peter JB, Patnik M, Ansari AA, Coppel RL, Gershwin ME.  Titers of antibody to common pathogens: relation to food-based interventions in rural Kenyan schoolchildren. Am J Clin Nutr. 2003 Jan;77(1):242-9.

BACKGROUND: Undernutrition is widely perceived to affect the development of an effective immune system. OBJECTIVE: We used a mini-analysis system to quantitate antibody titers and evaluate the sera of 200 Kenyan schoolchildren for antibodies to Helicobacter pylori [isotypes of immunoglobulins A (IgA), G (IgG), and M (IgM)], hepatitis A virus, rotavirus, tetanus toxoid (IgG), and a panel of recombinant malarial antigens (MSP1(19), MSP2, Ag512, MSP4, and MSP5). DESIGN: Children participated in a school-based feeding intervention with meat, milk, or nonanimal-source foods or in a nonintervention control group. Microvolumes (200 mL) of sera were analyzed at baseline and after 1 y. RESULTS: Nearly all children had elevated titers of antibody to H. pylori, hepatitis A virus, rotavirus, and malaria at the outset, despite a high prevalence of apparent biochemical micronutrient deficiencies and stunting, but many had titers of tetanus toxoid IgG antibodies below the protective concentration. Children with low hemoglobin had a greater proportion of elevated H. pylori IgM antibody titers at baseline, which suggests that current infection with H. pylori may be associated with anemia. Compared with the control subjects, only the group eating meat had a significant increase in H. pylori IgM antibodies during the intervention (P = 0.019). No other group comparisons with the control subjects were statistically significant. The additional finding that the sera of some children showed inadequate tetanus-protective antibodies, despite immunization, suggests that the vaccination program was suboptimal. CONCLUSIONS: A large battery of immune assays can be performed on microvolumes of sera. Furthermore, despite evidence of malnutrition, children do develop significant antibody-mediated responses to common pathogens.

 

7379.      Urban BC, Roberts DJ.  Inhibition of T cell function during malaria: implications for immunology and vaccinology. J Exp Med. 2003 Jan 20;197(2):137-41. No abstract available.

October 2003

8053.  Banumathy G, Singh V, Pavithra SR, Tatu U. Heat shock protein 90 function is essential for Plasmodium falciparum growth in human erythrocytes. J Biol Chem. 2003 May 16;278(20):18336-45. Epub 2003 Feb 12.

 

          Hsp90 is important for normal growth and development in eukaryotes. Together with Hsp70 and other accessory proteins, Hsp90 not only helps newly synthesized proteins to fold but also regulates activities of transcription factors and protein kinases. Although the gene coding for heat shock protein 90 from Plasmodium falciparum (PfHsp90) has been characterized previously, there is very little known regarding its function in the parasite. We have analyzed PfHsp90 complexes and addressed its role in parasite life cycle using Geldanamycin (GA), a drug known to interfere with Hsp90 function. Sedimentation analysis and size exclusion chromatography showed PfHsp90 to be in 11 s(20,(w)) complexes of approximately 300 kDa in size. Similar to the hetero-oligomeric complexes of Hsp90 in mammals, PfHsp70 was found to be present in PfHsp90 complexes. Homology modeling revealed a putative GA-binding pocket at the amino terminus of PfHsp90. The addition of GA inhibited parasite growth with LD(50) of 0.2 microm. GA inhibited parasite growth by arresting transition from Ring to trophozoite. Transition from trophozoite to schizonts and reinvasion of new erythrocytes were less significantly affected. While inducing the synthesis of PfHsp70 and PfHsp90, GA did not significantly alter the pattern of newly synthesized proteins. Pre-exposure to heat shock attenuated GA-mediated growth inhibition, suggesting the involvement of heat shock proteins. Specificity of GA action on PfHsp90 was evident from selective inhibition of PfHsp90 phosphorylation in GA-treated cultures. In addition to suggesting an essential role for PfHsp90 during parasite growth, our results highlight PfHsp90 as a potential drug target to control malaria.

8054.  Church DL, Lichtenfeld A, Elsayed S, Kuhn S, Gregson DB. A regional centralized microbiology service in Calgary for the rapid diagnosis of malaria. Arch Pathol Lab Med. 2003 Jun;127(6):687-93.

 

          CONTEXT: A regional centralized laboratory service for the rapid diagnosis of malaria was implemented 3 years ago in May 1999 within the Division of Microbiology, Calgary Laboratory Services. OBJECTIVE: To describe the design and performance of this unique microbiology laboratory service. DESIGN: Blood specimens must arrive at the central laboratory within 2 hours of collection. Thin blood smears are read and reported from suspected acute cases within 1 hour of receipt, 24 hours per day, 7 days a week, by trained and experienced microbiology technologists. All positive malaria smears are reviewed by a medical microbiologist and confirmed by polymerase chain reaction at a reference laboratory. SETTING: Calgary Laboratory Services provides integrated laboratory services to the Calgary Health Region, an urban area of more than 1 million people. MAIN OUTCOME MEASURES: Performance of the service has been continuously monitored by measuring preanalytic and analytic test turnaround times, test accuracy, clinical relevance, and the results of proficiency testing. RESULTS: More than 90% of blood specimens for malaria from community locations have consistently arrived within 2 hours of collection, and hospitals have reached this target within the past year. Although polymerase chain reaction was more sensitive at detecting the presence of malaria, the expert microscopists were as accurate at determining the type of Plasmodium infection. More than 95% of all positive smear results are consistently reported within 2 hours of receipt of a blood specimen. CONCLUSIONS: Implementation of a regional centralized microbiology service has improved our ability to make a rapid and accurate diagnosis of malaria in this region.

8055.  Day N. Malaria and the blood film.Trop Doct. 2003 Apr;33(2):65.  No abstract.

8056.  Gilberger TW, Thompson JK, Triglia T, Good RT, Duraisingh MT, Cowman AF. A novel erythrocyte binding antigen-175 paralogue from Plasmodium falciparum defines a new trypsin-resistant receptor on human erythrocytes. J Biol Chem. 2003 Apr 18;278(16):14480-6. Epub 2003 Jan 29.

 

          The recognition and invasion of human erythrocytes by the most lethal malaria parasite Plasmodium falciparum is dependent on multiple ligand-receptor interactions. Members of the erythrocyte binding-like (ebl) family, including the erythrocyte binding antigen-175 (EBA-175), are responsible for high affinity binding to glycoproteins on the surface of the erythrocyte. Here we describe a paralogue of EBA-175 and show that this protein (EBA-181/JESEBL) binds in a sialic acid-dependent manner to erythrocytes. EBA-181 is expressed at the same time as EBA-175 and co-localizes with this protein in the microneme organelles of asexual stage parasites. The receptor binding specificity of EBA-181 to erythrocytes differs from other members of the ebl family and is trypsin-resistant and chymotrypsin-sensitive. Furthermore, using glycophorin B-deficient erythrocytes we show that binding of EBA-181 is not dependent on this sialoglycoprotein. The level of expression of EBA-181 differs among parasite lines, and the importance of this ligand for invasion appears to be strain-dependent as the EBA-181 gene can be disrupted in W2mef parasites, without affecting the invasion phenotype, but cannot be targeted in 3D7 parasites.

 

8057.  Hora B, Chauhan VS. Malaria vaccines: targets and strategies. Proc Indian Natn Sci Acad – Pt B 2002, 68(1), 233-59. ISA 003634, Vol 39, No 3,1 Feb 2003.

8058.  Iqbal J, Muneer A, Khalid N, Ahmed MA. Performance of the OptiMAL test for malaria diagnosis among suspected malaria patients at the rural health centers. Am J Trop Med Hyg. 2003 May;68(5):624-8.

 

          The OptiMAL test detects both Plasmodium falciparum and P. vivax malaria infections. In this study, we evaluated the performance of the OptiMAL test at the Basic Health Units (BHUs) and the District Health Quarter (DHQ) Center in rural villages of Punjab, Pakistan that provide minimal health services. Two sets of blood specimens obtained from 930 suspected malaria patients attending these BHUs were tested at BHUs and the DHQ Center by microscopy and the OptiMAL test. At the BHUs, 231 (25%) of the patients were positive by microscopy and 278 (30%) patients tested positive by the OptiMAL test. At the DHQ Center, microscopic analysis of a second set of specimens from the same patients confirmed the malaria infection in 386 (42%) patients and the OptiMAL test result was positive in 300 (32%) patients. To determine the performance of OptiMAL test at the BHUs and the DHQ Center, all data were compared with microscopy results obtained at the DHQ Center. The OptiMAL test results for P. falciparum at the BHUs were comparable to those of the OptiMAL test at the DHQ Center. However, the sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of the OptiMAL test were considerably lower for P. vivax infections than for P. falciparum infections, irrespective of whether the test was performed at the BHUs or at the DHQ Center (P. falciparum: sensitivity = 78-85%, PPV = 89-97%, NPV = 96-98%; P. vivax: sensitivity = 61-76%, PPV = 88-95%, NPV = 90-93%). The OptiMAL test also detected a number of false positive and false-negative results at both the BHUs and the DHQ Center. The false-positive results ranged from 1% to 2%; however, the number of false-negative results was much higher (BHUs: P. falciparum = 22%, P. vivax =39%; DHQ Center: P. falciparum = 15%, P. vivax = 24%). In conclusion, these results, when combined with other advantages of the OptiMAL test, suggest that this test can be used by relatively inexperienced persons to diagnose malaria infection in rural areas where facilities for microscopy are not available.

8059.  Lochhead J, Movaffaghy A, Falsini B, Winstanley PA, Mberu EK, Riva CE, Molyneux ME, Taylor TE, Harding SP. The effect of quinine on the electroretinograms of children with pediatric cerebral malaria. J Infect Dis. 2003 Apr 15;187(8):1342-5. Epub 2003 Apr 02.

 

          To investigate the effects of quinine on the electroretinograms (ERGs) of children with cerebral malaria (CM), we recruited subjects during a single malaria season in Blantyre, Malawi. Seventy ERG investigations were performed, on 34 children with CM. Time recorded from completion of the most recent quinine infusion was termed "quinine elapsed time" (QET). In a subgroup of 16 children, whole-blood quinine concentrations were estimated in a sample of capillary blood, for validation. A significant positive association was found between QET and both maximal-response A-wave amplitude (MRAWA; P=.03) and cone A-wave amplitude (P=.04). Longitudinal analysis demonstrated a significant trend of increasing MRAWA with increasing QET (P=.03). Parenteral quinine administered in therapeutic doses to a pediatric population appears to cause a transient depression in photoreceptor function. No evidence of ocular quinine toxicity was found at the therapeutic doses used.

8060.  Makani J, Matuja W, Liyombo E, Snow RW, Marsh K, Warrell DA. Admission diagnosis of cerebral malaria in adults in an endemic area of Tanzania: implications and clinical description. QJM. 2003 May;96(5):355-62.

 

          BACKGROUND: Cerebral malaria is commonly diagnosed in adults in endemic areas in Africa, both in hospitals and in the community. This presents a paradox inconsistent with the epidemiological understanding that the development of immunity during childhood confers protection against severe disease in adult life. AIM: To establish the contribution of Plasmodium falciparum infection in adults admitted with neurological dysfunction in an endemic area, to assess the implications of an admission clinical diagnosis of 'cerebral malaria' on the treatment and clinical outcome, and to describe the clinical features of patients with malaria parasitaemia. DESIGN: Prospective observational study. METHODS: We studied adult patients admitted with neurological dysfunction to Muhimbili National Hospital, Dar-es-Salaam, Tanzania from October 2000 to July 2001. A full blood count was done and serum creatinine, blood glucose and P. falciparum parasite load were measured. RESULTS: Of 199 patients (median age 34.6 years), 38% were diagnosed as 'cerebral malaria' on admission, but only 7.5% had detectable parasitaemia, giving a positive predictive value of 13.3%. Only 1% fulfilled the WHO criteria for cerebral malaria. The prevalence of parasitaemia (7.5%) was less than that observed in a group of asymptomatic controls (9.3%), but distribution of parasite densities was higher in the patients. Mortality was higher in patients with no parasitaemia (22.3%) than in those with parasitaemia (13%). DISCUSSION: Cerebral malaria was grossly overdiagnosed, resulting in unnecessary treatment and insufficient investigation of other possible diagnoses, which could lead to higher mortality. Extension of this misperception to the assessment of cause of death in community surveys may lead to an overestimation of the impact of malaria in adults.

 

8061.  Moore DA, Jennings RM, Doherty TF, Lockwood DN, Chiodini PL, Wright SG, Whitty CJ.  Assessing the severity of malaria. BMJ. 2003 Apr 12;326(7393):808-9. Review.  No abstract.

8062.  Mwatha JK, Jones FM, Mohamed G, Naus CW, Riley EM, Butterworth AE, Kimani G, Kariuki CH, Ouma JH, Koech D, Dunne DW. Associations between anti-Schistosoma mansoni and anti-Plasmodium falciparum antibody responses and hepatosplenomegaly, in Kenyan schoolchildren. J Infect Dis. 2003 Apr 15;187(8):1337-41. Epub 2003 Apr 02.

 

          Schoolchildren from 2 areas of Kenya, Kangundo and Kambu, have contrasting prevalences of hepatosplenomegaly, despite having similar prevalences and intensities of Schistosoma mansoni infection. However, in individual children, S. mansoni infection intensity is positively correlated with organomegaly. In a previous study, hepatosplenomegaly was associated with Th1-type anti-schistosome cytokine responses. Although the high-morbidity Kambu area had higher malaria transmission than did low-morbidity Kangundo, hepatosplenomegaly was not associated with clinical malaria or with patent malarial parasitemia. However, chronic exposure to malaria might be involved. Here, retrospectively, we assayed plasma from this original study, for anti-Plasmodium falciparum and anti-S. mansoni antibodies, to test whether greater exposure to Plasmodium was a cofactor for hepatosplenomegaly. We found that hepatosplenic children had significantly higher levels of anti-P. falciparum antibodies, compared with nonhepatosplenic children, a finding that strongly suggests that some experience of P. falciparum influenced the development of hepatosplenomegaly in these S. mansoni-infected children.

 

8063.  Rogerson SJ, Mkundika P, Kanjala MK. Diagnosis of Plasmodium falciparum malaria at delivery: comparison of blood film preparation methods and of blood films with histology. J Clin Microbiol. 2003 Apr;41(4):1370-4.

 

          We compared peripheral and placental blood films (made by different techniques) with placental histology for diagnosis of Plasmodium falciparum malaria in pregnancy. Samples from 464 women were examined, of whom 124 (26.7%) had active P. falciparum infection and 148 (31.9%) had past infection. Placental histology was more sensitive (91%) than peripheral blood film (47%) or placental blood film (63%) examination and also detected past infection. Few women had microscopically detectable infection without a positive histology. Infection detected by histology only and past infection were both associated with significantly lower infant birth weight and with lower hemoglobin concentrations compared to the results for uninfected women. Thick blood films were prepared with blood obtained by placental incision or scraping of the incision margin (263 samples) or by washing of placental tissue (235 samples). Each gave similar sensitivities (76 to 78%), specificities (98 to 99%), positive predictive values (92 to 98%), and negative predictive values (93 to 94%); but the median levels of parasitemia were lower for incision samples (840 parasites/ micro l) than scrapings (2,295 parasites/ micro l) (P = 0.02). Placental histology is the most sensitive method for the diagnosis of malaria in pregnancy. Methods for preparation of placental films may affect the density, but not the prevalence, of P. falciparum infection detected.

8064.  Singh H, Sen R, Singh S, Siwach SB, Jagdish, Singh RM. Utility of intradermal smear in the diagnosis of malaria. Trop Doct. 2003 Apr;33(2):108-10.

          The objective of this preliminary study was to evaluate the usefulness of the intradermal smear test in the diagnosis of malaria. One hundred cases of suspected malaria (having received no prior antimalarials) were investigated. Both peripheral blood film (PBF) and intradermal smears (IDS) were simultaneously prepared and patients placed on antimalarial therapy. The slides were repeated for the next 2 days. At admission, 70 cases were positive on PBF--59 were Plasmodium falciparum (PF) and 11 were Plasmodium vivax (PV) whereas surprisingly 62 cases were positive on IDS at admission--61 were PF, one was PV. IDS identified two more cases of PF [P value (not significant)] but failed to identify any new cases of PV (P value NS). On subsequent days IDS positivity for PF was higher than for PBF (P < 0.05 for day 1 and P < 0.001 for day 2). However, the PV yield was poor for any further statistical evaluation on subsequent days. We conclude that IDS is simple, easy to perform, requires no special infrastructure compared to PBF, and is a helpful diagnostic tool in cases where malaria is strongly suspected but peripheral blood slides are repeatedly negative due to prior use of antimalarial therapy. IDS may be added to routine PBF in malaria (especially PF).

         Pathogenesis:

8065.  Ayisi JG, Branch OH, Rafi-Janajreh A, van Eijk AM, ter Kuile FO, Rosen DH, Kager PA, Lanar DE, Barbosa A, Kaslow D, Nahlen BL, Lal AA.   Does infection with Human Immunodeficiency Virus affect the antibody responses to Plasmodium falciparum antigenic determinants in asymptomatic pregnant women? J Infect. 2003 Apr;46(3):164-72.

 

          OBJECTIVES: HIV-seropositive pregnant women are more susceptible to malaria than HIV-seronegative women. We assessed whether HIV infection alters maternal and cord plasma malarial antibody responses and the mother-to-infant transfer of malaria antibodies. METHODS: We determined plasma levels of maternal and cord antibodies [Immunoglobulin (IgG)] to recombinant malarial proteins [merozoite surface protein 1 (MSP-1(19kD)), the erythrocyte binding antigen (EBA-175)], the synthetic peptides [MSP-2, MSP-3, rhoptry associated protein 1 (RAP-1), and the pre-erythrocytic stage, circumsporozoite protein (NANP)(5)] antigenic determinants of Plasmodium falciparum; and tetanus toxoid (TT) by ELISA among samples of 99 HIV-seropositive mothers, 69 of their infants, 102 HIV-seronegative mothers and 62 of their infants. RESULTS: The prevalence of maternal antibodies to the malarial antigenic determinants ranged from 18% on MSP3 to 91% on EBA-175; in cord plasma it ranged from 13% to 91%, respectively. More than 97% of maternal and cord samples had antibodies to TT. In multivariate analysis, HIV infection was only associated with reduced antibodies to (NANP)(5) in maternal (P=0.001) and cord plasma (P=0.001); and reduced mother-to-infant antibody transfer to (NANP)(5) (P=0.012). This effect of HIV was independent of maternal age, gravidity and placental malaria. No consistent HIV-associated differences were observed for other antigenic determinants. CONCLUSION: An effect of HIV infection was only observed on one malarial antigenic determinant, suggesting that the increased susceptibility to malaria among HIV-infected pregnant women may not be explained on the basis of their reduced antibody response to malaria antigens.

 

8066.  Chang WL, Li J, Sun G, Chen HL, Specian RD, Berney SM, Granger DN, van der Heyde HC. P-selectin contributes to severe experimental malaria but is not required for leukocyte adhesion to brain microvasculature. Infect Immun. 2003 Apr;71(4):1911-8.

 

          Plasmodium berghei-infected mice, a well-recognized model of experimental cerebral malaria (ECM), exhibit many of the hallmarks of a systemic inflammatory response, with organ damage in brain, lung, and kidneys. Identification of the molecules mediating pathogenesis of the inflammatory response, such as leukocyte adhesion, may lead to new therapies. Indeed, mice lacking the cell adhesion molecule P-selectin were significantly (P = 0.005) protected from death due to P. berghei malaria compared with C57BL/6 controls despite similar parasitemia (P = 0.6) being found in both groups of mice. P-selectin levels assessed by the quantitative dual radiolabeled monoclonal antibody technique increased significantly (P < 0.05) in several organs in C57BL/6 mice infected with P. berghei, supporting the concept of a systemic inflammatory response mediating malarial pathogenesis. Intravital microscopic analysis of the brain microvasculature demonstrated significant (P < 0.001) leukocyte rolling and adhesion in brain venules of P. berghei-infected mice compared with those found in uninfected controls. The maximum leukocyte adhesion occurred on day 6 of P. berghei infection, when the mice become moribund and exhibit marked vascular leakage into the brain, lung, and heart. However, P-selectin levels were significantly (P < 0.005) increased in brain, lung, and kidneys during P. berghei malaria in ECM-resistant BALB/c mice compared with those found in uninfected BALB/c controls, indicating that increased P-selectin alone is not sufficient to mediate malarial pathogenesis. Leukocyte adhesion to brain microvessels of P-selectin-deficient mice with P. berghei malaria was similar to that observed in control mice. Collectively, these results indicate that P-selectin is important for the development of malarial pathogenesis but is not required for leukocyte adhesion in brain.

 

8067.  Daubenberger CA, Diaz D, Curcic M, Mueller MS, Spielmann T, Certa U, Lipp J, Pluschke G.  Identification and characterization of a conserved, stage-specific gene product of Plasmodium falciparum recognized by parasite growth inhibitory antibodies. Infect Immun. 2003 Apr;71(4):2173-81.

 

          We have identified a novel conserved protein of Plasmodium falciparum, designated D13, that is stage-specifically expressed in asexual blood stages of the parasite. The predicted open reading frame (ORF) D13 contains 863 amino acids with a calculated molecular mass of 99.7 kDa and displays a repeat region composed of pentapeptide motives. Northern blot analysis with lysates of synchronized blood stage parasites showed that D13 is highly expressed at the mRNA level during schizogony. The first N'-terminal 138 amino acids of D13 were expressed in Escherichia coli and the purified protein was used to generate anti-D13 monoclonal antibodies (MAbs). Using total lysates of blood stage parasites and Western blot analysis, these MAbs stained one single band of approximately 100 kDa, corresponding to the predicted molecular mass of ORF D13. Western blot analysis demonstrated further that D13 is expressed during schizogony, declines rapidly in early ring stages and is undetectable in trophozoites. D13 protein is localized in individual merozoites in a distinct area, as demonstrated by indirect immunofluorescence analysis. After subcellular fractionation, D13 was confined to the pelleted fraction of the parasite lysate and its extraction by alkaline carbonate buffer treatment indicated that D13 is not a membrane-integral protein. Inclusion of certain anti-D13 MAbs into in vitro cultures of blood stage parasites resulted in considerable reduction in parasite growth. The N'-terminal domain encompassing 158 amino acids is 94 and 95%, respectively, identical at the amino acid level between Plasmodium knowlesi, Plasmodium yoelii, and P. falciparum. In summary, we describe a ovel stage-specifically expressed, highly conserved gene product of P. falciparum that is recognized by parasite growth inhibitory antibodies.

8068.  Gilberger TW, Thompson JK, Triglia T, Good RT, Duraisingh MT, Cowman AF. A novel erythrocyte binding antigen-175 paralogue from Plasmodium falciparum defines a new trypsin-resistant receptor on human erythrocytes. J Biol Chem. 2003 Apr 18;278(16):14480-6. Epub 2003 Jan 29.

          The recognition and invasion of human erythrocytes by the most lethal malaria parasite Plasmodium falciparum is dependent on multiple ligand-receptor interactions. Members of the erythrocyte binding-like (ebl) family, including the erythrocyte binding antigen-175 (EBA-175), are responsible for high affinity binding to glycoproteins on the surface of the erythrocyte. Here we describe a paralogue of EBA-175 and show that this protein (EBA-181/JESEBL) binds in a sialic acid-dependent manner to erythrocytes. EBA-181 is expressed at the same time as EBA-175 and co-localizes with this protein in the microneme organelles of asexual stage parasites. The receptor binding specificity of EBA-181 to erythrocytes differs from other members of the ebl family and is trypsin-resistant and chymotrypsin-sensitive. Furthermore, using glycophorin B-deficient erythrocytes we show that binding of EBA-181 is not dependent on this sialoglycoprotein. The level of expression of EBA-181 differs among parasite lines, and the importance of this ligand for invasion appears to be strain-dependent as the EBA-181 gene can be disrupted in W2mef parasites, without affecting the invasion phenotype, but cannot be targeted in 3D7 parasites.

8069.  Iqbal J, Muneer A, Khalid N, Ahmed MA. Performance of the OptiMAL test for malaria diagnosis among suspected malaria patients at the rural health centers. Am J Trop Med Hyg. 2003 May;68(5):624-8.

 

          The OptiMAL test detects both Plasmodium falciparum and P. vivax malaria infections. In this study, we evaluated the performance of the OptiMAL test at the Basic Health Units (BHUs) and the District Health Quarter (DHQ) Center in rural villages of Punjab, Pakistan that provide minimal health services. Two sets of blood specimens obtained from 930 suspected malaria patients attending these BHUs were tested at BHUs and the DHQ Center by microscopy and the OptiMAL test. At the BHUs, 231 (25%) of the patients were positive by microscopy and 278 (30%) patients tested positive by the OptiMAL test. At the DHQ Center, microscopic analysis of a second set of specimens from the same patients confirmed the malaria infection in 386 (42%) patients and the OptiMAL test result was positive in 300 (32%) patients. To determine the performance of OptiMAL test at the BHUs and the DHQ Center, all data were compared with microscopy results obtained at the DHQ Center. The OptiMAL test results for P. falciparum at the BHUs were comparable to those of the OptiMAL test at the DHQ Center. However, the sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of the OptiMAL test were considerably lower for P. vivax infections than for P. falciparum infections, irrespective of whether the test was performed at the BHUs or at the DHQ Center (P. falciparum: sensitivity = 78-85%, PPV = 89-97%, NPV = 96-98%; P. vivax: sensitivity = 61-76%, PPV = 88-95%, NPV = 90-93%). The OptiMAL test also detected a number of false-positive and false-negative results at both the BHUs and the DHQ Center. The false-positive results ranged from 1% to 2%; however, the number of false-negative results was much higher (BHUs: P. falciparum = 22%, P. vivax   39%; DHQ Center: P. falciparum = 15%, P. vivax = 24%). In conclusion, these results, when combined with other advantages of the OptiMAL test, suggest that this test can be used by relatively inexperienced persons to diagnose malaria infection in rural areas where facilities for microscopy are not available.

8070.  Luckhart S, Crampton AL, Zamora R, Lieber MJ, Dos Santos PC, Peterson TM, Emmith N, Lim J, Wink DA, Vodovotz Y. Mammalian transforming growth factor beta1 activated after ingestion by Anopheles stephensi modulates mosquito immunity. Infect Immun. 2003 Jun;71(6):3000-9.

 

          During the process of bloodfeeding by Anopheles stephensi, mammalian latent transforming growth factor beta1 (TGF-beta1) is ingested and activated rapidly in the mosquito midgut. Activation may involve heme and nitric oxide (NO),agents released in the midgut during blood digestion and catalysis of L-arginine oxidation by A. stephensi NO synthase (AsNOS). Active TGF-beta1 persists in the  mosquito midgut to extended times postingestion and is recognized by mosquito cells as a cytokine. In a manner analogous to the regulation of vertebrate inducible NO synthase and malaria parasite (Plasmodium) infection in mammals by TGF-beta1, TGF-beta1 regulates AsNOS expression and Plasmodium development in A. stephensi. Together, these observations indicate that, through conserved immunological cross talk, mammalian and mosquito immune systems interface with each other to influence the cycle of Plasmodium development.

8071.  Mawili-Mboumba DP, Borrmann S, Cavanagh DR, McBride JS, Matsiegui PB, Missinou MA, Kremsner PG, Ntoumi F. Antibody responses to Plasmodium falciparum merozoite surface protein-1 and efficacy of amodiaquine in Gabonese children with P. falciparum malaria. J Infect Dis. 2003 Apr 1;187(7):1137-41. Epub 2003 Mar 13.

 

          The relationship between the efficacy of amodiaquine for the treatment of uncomplicated Plasmodium falciparum malaria and preexisting antibodies against merozoite surface protein (MSP)-1, a blood-stage P. falciparum antigen, was investigated. The immunoglobulin G antibody response to different MSP-1 recombinant proteins was evaluated in plasma samples from Gabonese children with uncomplicated malaria who were treated with amodiaquine. The prevalence of anti-MSP-1 antibodies was similar among patients with either parasitological and clinical cure after treatment (n=102) or treatment failure (n=51) by day 28 (83% in both groups). However, associations between antibody responses to K1 and MAD20 allelic families and therapeutic success were found (P< .001 and P= .034, respectively). A high proportion of plasma samples recognizing several antigens was found in the cured group. This association was significant even when data were stratified by age, particularly for the K1 family antigens (P= .029). These results suggest that humoral immune responses play a supportive role in the efficacy of amodiaquine treatment.

 

8072.  Naus CW, Jones FM, Satti MZ, Joseph S, Riley EM, Kimani G, Mwatha JK, Kariuki CH, Ouma JH, Kabatereine NB, Vennervald BJ, Dunne DW. Serological responses among individuals in areas where both schistosomiasis and malaria are endemic: cross-reactivity between Schistosoma mansoni and Plasmodium falciparum. J Infect Dis. 2003 Apr 15;187(8):1272-82. Epub 2003 Apr 02.

 

          We examined specific immunoglobulin G1 (IgG1) and IgG3 responses to Plasmodium falciparum schizont and Schistosoma mansoni egg and worm antigens in individuals from Kenya, Uganda, and the Sudan who had been exposed to malaria and schistosomiasis. A strong correlation between malaria- and schistosome-specific IgG3 responses was observed. This association appears to result from the presence of cross-reactive components of the 2 parasites that bind IgG3 antibodies, rather than to be mediated by immunological cross-regulation or specific regulatory mechanisms induced by either parasite. Cross-reactivity of IgG3 antibodies was confirmed in a Brazilian cohort of individuals living in an area where schistosomiasis is endemic but no malaria occurs and in a Pakistani cohort from an area where malaria is endemic but no schistosomiasis occurs. An IgG3 interaction with antigens from both parasites was observed in individuals from both cohorts, but not in uninfected European control subjects. The immunological and biological implications of this observation require further exploration.

8073.  Polley SD, Tetteh KK, Cavanagh DR, Pearce RJ, Lloyd JM, Bojang KA, Okenu DM, Greenwood BM, McBride JS, Conway DJ. Repeat sequences in block 2 of Plasmodium falciparum merozoite surface protein 1 are targets of antibodies associated with protection from malaria. Infect Immun. 2003 Apr;71(4):1833-42. 

 

          Human antibodies to the block 2 region of Plasmodium falciparum merozoite surface protein 1 (MSP1) are associated with a reduced prospective risk of clinical malaria. Block 2 is highly polymorphic, but all known alleles can be grouped into three major types. Two of these types (the K1-like and MAD20-like types) contain type-specific sequences (found in all alleles of a particular type) that flank polymorphic tripeptide repeats. These repeats contain both type-specific and subtype-specific sequences. To evaluate the antibody recognition of these parts of block 2, a new panel of six recombinant proteins was used (fused type-specific flanking sequences and two representative repeat sequences for each of the K1-like and MAD20-like types separately). Extensive testing of these antigens and full-length block 2 antigens showed that human serum immunoglobulin G antibodies induced by infection can recognize (i) type-specific epitopes in the repeats, (ii) subtype-specific epitopes in the repeats, or (iii) type-specific epitopes in flanking sequences. A large prospective study in The Gambia showed that antibodies to the repeats are strongly associated with protection from clinical malaria. The results are important for design of a vaccine to induce protective antibodies, and they address hypotheses about repeat sequences in malaria antigens.

8074.  Rogerson SJ, Mkundika P, Kanjala MK. Diagnosis of Plasmodium falciparum malaria at delivery: comparison of blood film preparation methods and of blood films with histology. J Clin Microbiol. 2003 Apr;41(4):1370-4.

 

We compared peripheral and placental blood films (made by different techniques) with placental histology for diagnosis of Plasmodium falciparum malaria in pregnancy. Samples from 464 women were examined, of whom 124 (26.7%) had active P. falciparum infection and 148 (31.9%) had past infection. Placental histology was more sensitive (91%) than peripheral blood film (47%) or placental blood film (63%) examination and also detected past infection. Few women had microscopically detectable infection without a positive histology. Infection detected by histology only and past infection were both associated with significantly lower infant birth weight and with lower hemoglobin concentrations compared to the results for uninfected women. Thick blood films were prepared with blood obtained by placental incision or scraping of the incision margin (263 samples) or by washing of placental tissue (235 samples). Each gave similar sensitivities (76 to 78%), specificities (98 to 99%), positive predictive values (92 to 98%), and negative predictive values (93 to 94%); but the median levels of parasitemia were lower for incision samples (840 parasites/ micro l) than scrapings (2,295 parasites/ micro l) (P = 0.02). Placental histology is the most sensitive method for the diagnosis of malaria in pregnancy. Methods for preparation of placental films may affect the density, but not the prevalence, of P. falciparum infection detected.

 

8075.  Serirom S, Raharjo WH, Chotivanich K, Loareesuwan S, Kubes P, Ho M.  Anti-adhesive effect of nitric oxide on Plasmodium falciparum cytoadherence under flow. Am J Pathol. 2003 May;162(5):1651-60.

 

          Nitric oxide (NO) is widely known to inhibit platelet and leukocyte adhesion to endothelium through its regulatory effect on adhesion molecule expression. The objective of the present study was to investigate if NO affects the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBCs) to human microvascular endothelium (HDMECs) under flow conditions in vitro. The effect of endogenous NO was studied using the NO synthase inhibitor L-N(G)-nitro-arginine-methyl-ester (L-NAME). Treatment of HDMECs with 3 mmol/L of L-NAME for 4 hours significantly enhanced IRBC adhesion and the effect could be reversed by an anti-P-selectin but not an anti-VCAM-1 antibody. The effect of exogenous NO on cytoadherence was studied by using the NO donor 3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine (PPN). PPN (300 micro mol/L) treatment reduced the number of adherent IRBCs on resting HDMECs by down-regulating basal ICAM-1 expression, and on tumor necrosis factor-alpha-stimulated HDMECs by inhibition of VCAM-1 induction and down-regulation of ICAM-1 expression. The inhibitory effect of PPN on tumor necrosis factor-alpha-induced VCAM-1 expression at 24 hours was evident when the NO donor was added for as short as 2 hours. These findings suggest that NO may be protective against P. falciparum infection by inhibiting cytoadherence, and underscore the therapeutic potential of NO in the treatment of severe falciparum malaria.

 

8076.  Wrenger C, Muller S. Isocitrate dehydrogenase of Plasmodium falciparum. Eur J Biochem. 2003 Apr;270(8):1775-83.

 

          Erythrocytic stages of the malaria parasite Plasmodium falciparum rely on glycolysis for their energy supply and it is unclear whether they obtain energy via mitochondrial respiration albeit enzymes of the tricarboxylic acid (TCA) cycle appear to be expressed in these parasite stages. Isocitrate dehydrogenase (ICDH) is either an integral part of the mitochondrial TCA cycle or is involved in providing NADPH for reductive reactions in the cell. The gene encoding P. falciparum ICDH was cloned and analysis of the deduced amino-acid sequence revealed that it possesses a putative mitochondrial targeting sequence. The protein is very similar to NADP+-dependent mitochondrial counterparts of higher eukaryotes but not Escherichia coli. Expression of full-length ICDH generated recombinant protein exclusively expressed in inclusion bodies but the removal of 27 N-terminal amino acids yielded appreciable amounts of soluble ICDH consistent with the prediction that these residues confer targeting of the native protein to the parasites' mitochondrion. Recombinant ICDH forms homodimers of 90 kDa and its activity is dependent on the bivalent metal ions Mg2+ or Mn2+ with apparent Km values of 13 micro m and 22 micro m, respectively. Plasmodium ICDH requires NADP+ as cofactor and no activity with NAD+ was detectable; the for NADP+ was found to be 90 micro m and that of d-isocitrate was determined to be 40 micro m. Incubation of P. falciparum under exogenous oxidative stress resulted in an up-regulation of ICDH mRNA and protein levels indicating that the enzyme is involved in mitochondrial redox control rather than energy metabolism of the parasites.

         Therapy:

8077.  Geerligs PP, Brabin B, Mkumbwa A, Broadhead R, Cuevas LE. The effect on haemoglobin of the use of iron cooking pots in rural Malawian households in an area with high malaria prevalence: a randomized trial. Trop Med Int Health. 2003 Apr;8(4):310-5.

 

          BACKGROUND: Innovative low-cost sustainable strategies are required to reduce the high prevalence of iron-deficiency anaemia in developing countries. METHODS: We undertook a community-based randomized controlled intervention trial to assess the effects of cooking in iron or aluminium cooking pots in Malawian households in an area with high malaria prevalence. Analysis was by intention to treat and consistency of use. The primary outcomes were change in haemoglobin and iron status. FINDINGS: The study population comprised 164 participants eating from aluminium cooking pots and 158 from iron cooking pots. The mean haemoglobin change was significantly increased after 6 weeks in adults who consistently ate from an iron cooking pot (+3.6 g/l compared to -3.2 g/l, mean difference between groups 6.8 g/l, 95% CI +0.86, +12.74). In children, no significant haemoglobin change was observed in consistent pot users, although they showed a significant reduction in iron deficiency (iron 8.6 ZP/g and aluminium 10.8 ZP/g, mean difference 2.2 ZP/g, 95% CI +1.08, +3.32). INTERPRETATION: Rural Malawian adults in a high malaria transmission area who consistently consume food prepared in iron cooking pots show a significant rise in haemoglobin after 6 weeks use. Children showed a reduction in iron deficiency, but no significant improvement in haemoglobin, possibly because of their high malaria parasite prevalence. Using iron cooking pots in developing countries could provide an innovative way to prevent iron deficiency and anaemia in malarious areas where regular iron supplementation is problematic.

 

 

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