FILARIASIS
Diagnosis, Diagnostics, Immunodiagnosis &
Immunodiagnostics:
ABSTRACTS
3240.
B Balaji Ganesh, AM Kader, GS Agarwal,
MVR Reddy & BC Harinath. A simple and inexpensive dot blot assay using a
66kDa B. malayi microfilarial antigen
protein for diagnosis of filarial infection in an endemic area. Trans. Roy. Soc. Trop. Med. Hyg. 2001; 95:
1-2. No Abstract
3241.
Bradley M. Horton J. Assessing the risk of
benzimidazole therapy during pregnancy. Transactions of the Royal Society of
Tropical Medicine & Hygiene.
95(1):72-3, 2001 Jan-Feb.
3242. Chhotray G P, Ranjit M R, Mohapatra M: Occurrence of asymptomatic microscopic haematuria in filarial endemic area of Orissa, India. J Commun Dis 2000, 32(2), 85-93.(16 May 2001).
Abstract
To determine the frequency of occurrence of asymptomatic microscopic haematuria in filarial endemic area of Orissa, where the mf rate and disease rate were observed to be 14.8% and 37.2% respectively, clinical examination, night blood smear examination, morning midstream urine examination were conducted on 697 persons randomly selected from all age groups in 8 villages of Puri tehsil. Out of them, 15.6% were found to have asymotomatic haematuria (Grade I-14.7%, Grade II-0.6%, Grade-III 0.3%). The prevalence of asymptomatic microscopic haematuria was observed to have positive statistical correlation with mf status (P<0.001), filarial antigenaemia (Ag) (P<0.001), antibody (Ab) (P<0.001) and circulating immunocomplex antigen (CIC-Ag) (P<0.001). The prevalence was also found to be increased with the prograssion of the disease process i.e. from endemic normal to chronic manifestation. None of the cases having Grade-II and III haematuria cases revealed any gross renal pathological lesions, when subjected to special investigation like X-ray, IVP, cytoscopy and urethroscopy.
3242.
No Abstract.
3243.
Das PK. Ramaiah KD. Vanamail P.
Pani SP. Yuvaraj J. Balarajan K. Bundy DA.
Placebo-controlled community trial of four cycles of single-dose
diethylcarbamazine or ivermectin against Wuchereria bancrofti infection and
transmission in India. Transactions of
the Royal Society of Tropical Medicine & Hygiene. 95(3):336-41, 2001 May-Jun.
Abstract
A double-blind placebo-controlled trial was
carried out in 1994-98 to compare the effects of 4 cycles of single-dose
diethylcarbamazine (DEC) or ivermectin on prevalence and geometric mean
intensity (GMI) of microfilaraemia in the human population, infection rates in
the vector population, and transmission intensity of Culex-transmitted
Wuchereria bancrofti in rural areas in Tamil Nadu state, south India. Fifteen
villages (population approximately 26,800) were included in the study: 5
villages each were randomly assigned to community-wide treatment with DEC or
ivermectin or placebo. People over 14 kg bodyweight received DEC 6 mg/kg,
ivermectin 400 micrograms/kg or a placebo, all identically packaged. After 2
cycles of treatment at a 6-month interval, the code was broken and the study
continued as an open trial, with third and fourth cycles of treatment at a
12-month interval; 54-77% of eligible people (20,872) received treatment during
the 4 cycles. Microfilaraemia prevalence and GMI fell by 48% and 65% with DEC
and 60% and 80% with ivermectin respectively after 4 cycles of treatment. There
was no change in the incidence of acute adenolymphangitis. Infection in resting
mosquitoes fell significantly in all arms: 82%, 78% and 42% in the ivermectin,
DEC and placebo arm, respectively. Landing mosquitoes also showed the same trend.
The decline in infectivity was significant for resting (P < 0.05) and
landing mosquitoes (P < 0.05) with ivermectin and DEC (P < 0.05), and for
neither in the placebo group (P > 0.05). Transmission intensity was reduced
by 68% with ivermectin and 63% with DEC. Transmission was apparently
interrupted in 1 village with ivermectin, but infected resting mosquitoes were
consistently found in this village. Single-dose community-level treatment with
DEC or ivermectin is effective in reducing W. bancrofti infection in humans and
mosquitoes, and may result in total interruption of transmission after several
years of control. There is an immediate need to define the role of vector,
parasite and community factors that influence the elimination of lymphatic
filariasis, particularly the duration of treatment vis-à-vis
efficacy of drugs, treatment compliance and efficiency of vectors.
3244.
Esterre P. Plichart C.
Sechan Y. Nguyen NL. The impact
of 34 years of massive DEC chemotherapy on Wuchereria bancrofti infection and
transmission: the Maupiti cohort.
Tropical Medicine & International Health. 6(3):190-5, 2001 Mar.
Abstract
Semi-annual mass DEC chemotherapy combined
with vector control at the beginning of the programme, has been administered on
the remote island of Maupiti (French Polynesia) since 1955 (except two periods
in 1960-67 and 1970-74). The results of two surveys in 1985 and 1989, reporting
0% microfilaraemia, led to the hope that the eradication of lymphatic
filariasis had been achieved. We combined parasitological criteria
(microfilaraemia by membrane filtration), immunological (antigenaemia and serum
levels of specific IgG antibodies) and molecular (PCR-based evaluation of
infection in mosquitoes) techniques and found only good control of the parasite:
We found residual microfilaraemia in 0.4% of the sample (mean level in
carriers: 101.2 mf/ml), antigenaemia in 4.6% (mean level in positive persons:
714.4 units/ml) and specific IgG in 21.6% (including in one very young child).
In addition, an infection rate of 1.4% was calculated in the Aedes
polynesiensis vector population. These data, obtained in 1997 just before a
hurricane, were partially confirmed in 1999 (0.1% of infection rate in the
vector). Together with the possibility of some resistance to DEC, various
epidemiological factors critical for the eradication of lymphatic filariasis
are discussed.
3245.
Jaoko WG. Simonsen PE. Meyrowitsch DW. Pedersen
EM. Rwegoshora RT. Michael E. Wuchereria bancrofti in a
community with seasonal transmission: stability of microfilaraemia,
antigenaemia and filarial-specific antibody concentrations. Annals of Tropical Medicine &
Parasitology. 95(3):253-61, 2001 Apr.
Abstract
The effect of seasonal transmission on
microfilaraemia, antigenaemia and filarial-specific antibody levels in
individuals infected with Wuchereria bancrofti was investigated in a follow-up
study in an endemic community in north-eastern Tanzania. The subjects were 37
adult male residents who were found to be positive for circulating filarial antigen
(CFA) at the beginning of the study (26 of whom were also found microfilaraemic
with W. bancrofti at this time). Blood samples were collected from each subject
in July 1998, January 1999 and July 1999, during the seasons when transmission
intensity was high, low and high, respectively. The mean intensities of
microfilaraemia and the mean concentrations of CFA were each slightly higher
during the low-transmission season than during the two high-transmission
seasons but the differences were not statistically significant (P > 0.05).
Similarly, the mean levels of filarial-specific IgG1, IgG2, IgG3, IgG4 or IgE
did not differ to a statistically significant degree between the three
examination times. Microfilaraemias and the levels of CFA and filarial-specific
antibodies all therefore appeared to be remarkably stable and largely
unaffected by the seasonal variation in transmission. That no variation in the
mean IgG4/IgE ratio was observed over the study period may indicate that the
level of resistance to W. bancrofti infection in the study subjects was also
unaffected by the transmission season.
3246.
King CL Transmission intensity and human immune
responses to lymphatic filariasis. [Review] [67 refs] Parasite Immunology. 23(7):363-71, 2001 Jul.
Abstract
Our understanding of how the host immune
response influences the risk of developing disease has changed dramatically
over the past decade. Previously, the spectrum of disease associated with
lymphatic filariasis was largely attributed to the nature of the host immune
response. Now, we appreciate that the duration and intensity of infection and
possibly the direct influence of parasite-derived molecules also determine the
risk of disease. Individuals chronically infected with lymphatic filariasis
generally have an impaired lymphocyte proliferation response to filarial
antigens and favour Th2-type cytokine responses. This ability to down-modulate
the host immune response may help protect the host from disease. Defects in
antigen-presenting cell (APC) function appear to participate in this acquired
immune hyporesponsiveness, although the mechanisms as to how this occurs are
poorly understood. Here, we present evidence that repeated exposure to
infective stage larvae and their secreted products may stimulate basophils and
mast cells to related products that may impair APC function. [References: 67]
3247.
Nutman TB. Kumaraswami V. Regulation of the immune
response in lymphatic filariasis: perspectives on acute and chronic infection
with Wuchereria bancrofti in South India. [Review] [91 refs] Parasite
Immunology. 23(7):389-99, 2001 Jul.
Abstract
Delineating the immune responses in
lymphatic filariasis has been complicated not only by the rapidly expanding
knowledge of new immunological mediators and effortors, but also by new
methodologies (in particular, circulating filarial antigen detection) for
defining and categorizing filarial-infected individuals. By using assays for
circulating antigen in the sera collected as part of the many immunological
studies performed on individuals in a Wuchereria bancrofti-endemic region of
South India, we have attempted to explore the influence of patency on the
antigen-driven proliferative and cytokine responses seen in peripheral blood
mononuclear cells of individuals with varying clinical manifestations of
lymphatic filarial infection. Moreover, we have provided perspectives on the
differences between acute and chronic infection with W. bancrofti and suggested
mechanisms that may underly the modulation of the immune response as patency
occurs. [References: 91]
3248. R. Alli, S. Kulkarni, M.V.R. Reddy and B.C. Harinath. Evaluation of SEVAFILACHEK immunoassay and rapid ICT-Filariasis test for detection of bancroftian filariasis. Ind. J. of Clin. Bio., 2001, 16(2), 43-46.
Abstract
A comparative analysis was
made on the utility of SEVAFILACHEK-stick based immunoassays and commercially
available ICT-filariasis test to detect active infection in different groups of
bancroftian filariasis. The SEVAFILACHEK immunoassays were found to be useful
to detect filarial infection in microfilaraemia and in a significant number of
clinical filarial cases with acute, chronic and occult clinical manifestations.
In the clinical cases, microfilariae are not usually detected in peripheral
circulation. Employing SEVAFILACHEK assays 6 and 5 of the7 samples of patients
with chronic filarial disease, and 6 and 5 of 6 microfilaraemic cases gave
positivity for filarial IgG antibodies and antigen respectively. Four of the 6
occult filarial samples were positive for antibodies and antigen. Filarial
antigen was detected by ICT-Filariasis test in blood samples of all the 6
microfilariaemic cases, 1 chronic filarial and 2 occult filarial samples. The
main advantage of ICT assay is its rapid format and convenience for field use.
3249.
Rahmah N. Lim BH.
Khairul Anuar A. Shenoy RK. Kumaraswami V. Lokman Hakim S.
Chotechuang P. Kanjanopas
K. Ramachandran CP. A recombinant
antigen-based IgG4 ELISA for the specific and sensitive detection of Brugia
malayi infection. Transactions of the Royal Society of Tropical Medicine &
Hygiene. 95(3):280-4, 2001 May-Jun.
Abstract
An IgG4 ELISA based on a novel recombinant
antigen was evaluated for detection of Brugia malayi infection, using 2487 sera
from various institutions: 2031 samples from Universiti Sains Malaysia, 276
blinded sera from 2 other institutions in Malaysia, 140 blinded sera from India
and 40 blinded sera from Thailand. These sera were from various groups of individuals,
i.e., microfilaraemics, chronic patients, endemic normals, non-endemic normals
and individuals with other parasitic and bacterial infections. Based on a
cut-off optical density reading of 0.300, the IgG4 ELISA demonstrated
specificity rates of 95.6-100%, sensitivity rates of 96-100%, positive
predictive values of 75-100% and negative predictive values of 98.9-100%. These
evaluation studies demonstrated the high specificity and sensitivity of this
test for the detection of active B. malayi infection. Thus, the IgG4 ELISA
would be very useful as a tool in diagnosis and in elimination programmes for
brugian filariasis.
3250.
Satapathy AK. Sahoo PK.
Babu Geddam JJ. Mohanty MC. Ravindran B. Human Bancroftian filariasis:
loss of patent microfilaraemia is not associated with production of antibodies
to microfilarial sheath. Parasite Immunology.
23(3):163-7, 2001 Mar.
Abstract
Antisheath antibodies have been incriminated
in elimination of circulating microfilariae in human filariasis since a very
significant inverse association has been consistently demonstrated between the
two parameters. An attempt was made in the present study to seek empirical
proof for the above proposal. Two cohorts of 43 and 73 microfilariae (mf)
carriers were examined after 13 and 10 years, respectively, for mf as well as
antisheath antibodies. The first cohort was also examined for the presence of
circulating filarial antigen (CFA). Of the 43 mf carriers examined after 13
years, 62.8% were free of circulating mf although only 3.7% of them had
demonstrable antisheath antibodies. Approximately 93% of this cohort (with or
without current microfilaraemia) tested positive for CFA after 13 years
indicating continued presence of adult filarial worms in the host after loss of
mf in circulation. When the second cohort of 73 mf carriers were examined after
10 years, 30 were found to be amicrofilaraemic and only 6.66% of them had
demonstrable antisheath antibodies. We conclude that, in human Bancroftian
filariasis, elimination of circulating microfilariae may not be mediated by
antibodies to microfilarial sheath.
3251.
Semnani RT. Sabzevari H. Iyer R. Nutman TB.
Filarial antigens impair the function of human dendritic cells during
differentiation. Infection & Immunity.
69(9):5813-22, 2001 Sep.
Abstract
The antigen-specific T-cell unresponsiveness
seen in lymphatic filariasis is mediated, in part, by diminished
antigen-presenting cell function and is most specific for microfilariae (MF),
the parasite stage found in large numbers in the peripheral circulation. We
investigated the effect of MF antigen (MFAg) on dendritic cells (DC) in both
their differentiation process from monocyte precursors and also after they have
developed into DC. When MFAg was added to cultures of monocytes during their differentiation
process to immature DC, the production of interleukin 12 (IL-12) p40, p70
protein, and IL-10 was significantly (P < 0.03) inhibited in response to
Staphylococcus aureus Cowan (SAC) and SAC-gamma interferon (IFN-gamma) (60% to
80% inhibition). IL-10 was also inhibited (P = 0.04) in response to CD40
ligand-IFN-gamma. Moreover, MFAg inhibited the mRNA expression of IL-12 p40 and
IL-10 as assessed by RNA protection assays. This effect was antigen specific,
as another parasite antigen (soluble Toxoplasma gondii antigen) did not inhibit
the production of these cytokines. This effect was also not a result of
diminished cell viability nor of an alteration in surface expression of most
costimulatory surface molecules, including major histocompatibility complex
class I and class II. In contrast to exposure throughout the differentiation
process, MFAg added to immature DC had no effect on DC cytokine expression.
Although MF-differentiated DC were capable of inducing an allogeneic mixed
lymphocyte reaction, they did so to a significantly lesser degree than DC
without antigen exposure. These data collectively suggest that once DC are
differentiated from their precursor cells, they become resistant to changes by
MFAg.
3252. Wilson ME. Worms that cause lumps in the mouth. Lancet. 357(9271):1888, 2001 Jun 9. No Abstract.
Apr 02
4036.
Ahorlu CK, Dunyo SK, Asamoah G, Simonsen PE.
Consequences of hydrocele and the benefits of hydrocelectomy: a qualitative
study in lymphatic filariasis endemic communities on the coast of Ghana. Acta
Trop 2001 Dec 21;80(3):215-21
A study using focus group discussions and in-depth interviews was conducted to determine the consequences of hydrocele and the benefits of hydrocelectomy on physical activity and social life in three lymphatic filariasis endemic villages where males had recently been offered surgical operations to repair their hydroceles. Respondents were of the view that hydrocele, especially large ones, severely reduced the patients' work capacity and impaired sexual function, and that overall it had a considerable negative effect on the quality of living for the patients, their families and the community. The main reasons for refusing hydrocelectomy in the past were the high cost of surgery, and to some extent fear of death, impotence and/or sterility that might result from the operation. The recently offered hydrocele operations, which included 40 males, were financially supported and preceded by appropriate counselling, and from the patients' point of view were highly successful. Patients spent between 4 and 12 days in the hospital and there were no post-operative complications. Patients observed that, between 3 and 6 months after surgery, there were remarkable improvements in their work capacity and sexual function, and restoration of self-esteem, thus enabling them to participate more actively in community activities. The need for hydrocelectomy to be incorporated as an important morbidity control measure in lymphatic filariasis control programmes is discussed.
4037.
Bradley JE, Nirmalan N, Klager SL, Faulkner H,
Kennedy MW. River blindness: a role for parasite retinoid-binding proteins in
the generation of pathology? Trends Parasitol
2001 Oct;17(10):471-5
A new family of fatty acid- and retinoid-binding proteins has recently been identified in nematodes. These are apparently nematode specific and have very different structures and binding characteristics to their mammalian counterparts. Retinoids have important roles in vision, tissue differentiation and repair, and can profoundly affect collagen synthesis. Binding proteins released by a parasite might therefore play a part in the generation of the skin and eye pathology seen in river blindness. They might also be involved in the formation of the subcutaneous nodules induced by this parasite.
4038.
Murray J, Gregory WF, Gomez-Escobar N, Atmadja
AK, Maizels RM. Expression and immune recognition of Brugia malayi VAL-1, a
homologue of vespid venom allergens and Ancylostoma secreted proteins. Mol
Biochem Parasitol 2001 Nov;118(1):89-96
Several important nematode parasites have been found to express members of a gene family variously termed as venom allergen antigen homologue (vah) or Ancylostoma secreted protein (asp). In some cases these products are secreted by infective larval stages and have been suggested to be effective vaccine immunogens. We isolated the corresponding gene from the human filarial nematode, Brugia malayi, by first searching the expressed sequence tag (EST) dataset generated by the Filarial Genome Project and then using gene-specific nondegenerate primers matching the selected gene for PCR, from B. malayi Cdna libraries. We report here the full-length gene sequence, which we have designated as Bm-val-1, for vah/asp-like. The corresponding protein (Bm-VAL-1) contains 232 amino acids in a single homology unit, unlike products from some other species in which there is a tandem repeat. A putative signal sequence is present at the 5' end and there are two potential N-glycosylation sites. Murine antibodies to recombinant Bm-VAL-1 react with a 28 kDa protein in L3 extracts and recombinant Bm-VAL-1 is recognised by murine T cells primed with soluble L3 proteins. Of 82 ESTs corresponding to Bm-val-1, 72 are recorded from the infective larval (L3) stage. However, PCR on the first-strand cDNA from later mammalian stages revealed some expression at most subsequent time points. Over 95% (20/21) of microfilaraemic human filariasis patients are seropositive for antibodies to Bm-VAL-1, with particularly high levels of IgG3 and IgG4 isotypes. The IgG4 subclass may indicate stimulation by adult and/or microfilarial-derived immunogens. The association of Bm-VAL-1 with the infective stage and its recognition by humans exposed to filariasis suggests that further evaluation of this antigen as a vaccine candidate should be performed.
4039.
Njenga SM, Wamae CN. Evaluation of ICT filariasis
card test using whole capillary blood: comparison with Knott's concentration
and counting chamber methods. J Parasitol
2001 Oct;87(5):1140-3
An immunochromatographic card test (ICT) that uses fingerprick whole blood instead of serum for diagnosis of bancroftian filariasis has recently been developed. The card test was validated in the field in Kenya by comparing its sensitivity to the combined sensitivity of Knott's concentration and counting chamber methods. A total of 102 (14.6%) and 117 (16.7%) persons was found to be microfilaremic by Knott's concentration and counting chamber methods, respectively. The geometric mean intensities (GMI) were 74.6 microfilariae (mf)/ml and 256.5 mf/ml by Knott's concentration and counting chamber methods, respectively. All infected individuals detected by both Knott's concentration and counting chamber methods were also antigen positive by the ICT filariasis card test (100% sensitivity). Further, of 97 parasitologically amicrofilaremic persons, 24 (24.7%) were antigen positive by the ICT. The overall prevalence of antigenemia was 37.3%. Of 100 nonendemic area control persons, none was found to be filarial antigen positive (100% specificity). The results show that the new version of the ICT filariasis card test is a simple, sensitive, specific, and rapid test that is convenient in field settings.
4040.
Sethi S, Misra K, Singh UR, Kumar D. Lymphatic
filariasis of the ovary and mesosalpinx. J Obstet Gynaecol Res 2001 Oct;27(5):285-92
We report 2 cases of filariasis, one in the ovary and the other in the mesosalpinx. In the first case, the patient underwent panhystrectomy and in the second case, right ovarian cystectomy with right salpingectomy were performed under general anaesthesia. Histopathology showed adult filarial worms in the dilated lymphatics of the right ovary, in the first case and in the mesosalpinx, in the second case. Both patients presented with complaints related to gynecological problems and not filariasis. Reports of filariasis in the literature and possible treatments and prevention strategies are also discussed.
4041.
Sommer A, Nimtz M, Conradt HS, Brattig N,
Boettcher K, Fischer P, Walter RD, Liebau E. Structural analysis and antibody
response to the extracellular glutathione S-transferases from Onchocerca
volvulus. Infect Immun 2001
Dec;69(12):7718-28
Onchocerca volvulus is a human pathogenic filarial parasite which, like other parasitic nematodes, is capable of surviving in an immunologically competent host by employing a variety of immune evasion strategies and defense mechanisms including the detoxification and repair mechanisms of the glutathione S-transferases (GSTs). In this study we analyzed the glycosylation pattern and the immunological properties of extracellular O. volvulus GST1a and -1b (OvGST1a and -1b). The enzymes differ in only 10 amino acids, and both are glycoproteins that have cleavable signal peptides and unusual N-terminal extensions. These characteristics have not been described for other GSTs so far. Mass spectrometry analyses indicate that both enzymes carry high-mannose type oligosaccharides on at least four glycosylation sites. Glycosylation sites 1 to 3 of OvGST1a (OvGST1b sites 2 to 4) are occupied by truncated N-glycans (Man(2)GlcNAc2 to Man(5)GlcNAc(2)), and N glycosylation site 4 of OvGST1a (OvGST1b site 5) carries Man(5)GlcNAc2 to Man(9)GlcNAc(2). To analyze the capacity of these secretory GSTs to stimulate host immune responses, we studied the antibody responses of onchocerciasis patients against the native affinity-purified OvGST1a and -1b. By enzyme-linked immunosorbent assay we showed that OvGST1a and -1b are immunodominant antigens, with less than 7% nonresponder patients. A direct comparison of the antibody responses to the glycosylated and deglycosylated forms demonstrates the high immunogenicity of the N-glycans. Analyses of the antibody responses to the unusual N-terminal extension show an enhanced recognition of this portion by patients as opposed to recognition of the recombinant protein without extension.
4042.
Steel C, Ottesen EA, Weller PF, Nutman TB. Worm
burden and host responsiveness in Wuchereria bancrofti infection: use of antigen
detection to refine earlier assessments from the South Pacific. Am J Trop Med
Hyg 2001 Nov;65(5):498-503
A population from the Wuchereria bancrofti-endemic island of Mauke was reevaluated retrospectively by use of the Og4C3 circulating antigen (CAg) enzyme-linked immunosorbent assay to assess active infection in relation to host responses by age and gender. Use of microfilaremia (Mf) alone misclassified approximately 50% of infected people, although CAg and Mf levels were positively correlated. Levels of CAg peaked between those aged 31-60 years; men aged > 60 years had a significantly higher CAg prevalence (> 90%) than women. Filaria-specific immunoglobulin (Ig) G4 reached maximum levels in both genders at age 51-60 years. By analysis of variance, both age and gender significantly influenced CAg and IgG4, with men having higher levels of both in the total population. Individuals positive for CAg had significantly lower lymphocyte proliferation responses to parasite antigen than did CAg-negative people, regardless of clinical status. This study reemphasizes the importance of Cag measurements for accurately assessing filarial prevalence and clinical status and demonstrates the relationship between active infection and immune responsiveness.
4043.
Tisch DJ, Hazlett FE, Kastens W, Alpers MP,
Bockarie MJ, Kazura JW. Division of Geographic Medicine, Case Western Reserve
University and University Hospitals of Cleveland, Cleveland, Ohio, USA.
Ecologic and biologic determinants of filarial antigenemia in bancroftian
filariasis in Papua New Guinea. J Infect Dis
2001 Oct 1;184(7):898-904
The relationship between filarial antigenemia and lymphatic pathology was investigated in residents of 11 villages in an area of Papua New Guinea where Wuchereria bancrofti is endemic. Antigenemia was determined in 1322 persons by means of the Og4C3 antibody capture assay. Prevalence of antigenemia by village ranged from 61.7% to 98.2% and did not vary by sex. Antigen level increased with transmission potential among the 4 villages with measured transmission potential (r(2)=.945; P=.028). Antigenemia was associated positively with age in villages with the lowest annual transmission potentials (45 and 404 infective larvae/year; P<.001), but was distributed evenly across age groups in villages with increased transmission (1485 and 2518 infective larvae/year). These data suggest that children and adults have similar worm burdens in areas of high transmission, whereas worm burdens in areas of lower transmission increase with age. These results may be useful in the design and evaluation of programs aimed at eliminating lymphatic filariasis.
4044.
Tisch DJ, Hazlett FE, Kastens W, Alpers MP,
Bockarie MJ, Kazura JW. Ecologic and biologic determinants of filarial
antigenemia in bancroftian filariasis in Papua New Guinea. J Infect Dis 2001 Oct 1;184(7):898-904
The
relationship between filarial antigenemia and lymphatic pathology was
investigated in residents of 11 villages in an area of Papua New Guinea where
Wuchereria bancrofti is endemic. Antigenemia was determined in 1322 persons by
means of the Og4C3 antibody capture assay. Prevalence of antigenemia by village
ranged from 61.7% to 98.2% and did not vary by sex. Antigen level increased
with transmission potential among the 4 villages with measured transmission
potential (r(2)=.945; P=.028). Antigenemia was associated positively with age
in villages with the lowest annual transmission potentials (45 and 404
infective larvae/year; P<.001), but was distributed evenly across age groups
in villages with increased transmission (1485 and 2518 infective larvae/year).
These data suggest that children and adults have similar worm burdens in areas
of high transmission, whereas worm burdens in areas of lower transmission
increase with age. These results may be useful in the design and evaluation of
programs aimed at eliminating lymphatic filariasis.
4045.
Urbani C, Palmer K. Drug-based helminth control
in Western Pacific countries: a general perspective. Trop Med Int Health 2001 Nov;6(11):935-44
Helminthiases still have a relevant detrimental role in the health of large groups of human population. Where poor hygiene and lack of access to education, health services and essential care characterize living conditions, parasitic infections dramatically affect essential aspects of individual life, such as nutrition, cognitive performance, susceptibility to infections and micronutrient deficiency. Severe illness is associated with schistosomiasis, lymphatic filariasis and food-borne trematode infections. Drugs are the cornerstone of control strategies for such infections, the World Health Organization (WHO) list of essential drugs contains several highly efficacious anthelmintics which are all safe, single-dose and cheap. If given regularly to infected communities, these drugs effectively control the morbidity related to the major endemic helminth infections. New strategies for mass drug administration to human populations have been tested, and several endemic Western Pacific countries have achieved excellent results in reducing morbidity in spite of continuous transmission. In this region, experience over the last decades proves the feasibility of helminth control, but also shows the need for long-term commitment and continuous support.
4046.
Usha Rani, Manjula, Bharti: Rare case of
condyloma acuminatum with filarial lesion in pregnancy. Indian med J 2001, 95
(5), 137.(017459) Sept 1, 2023 No Abstract.
4047.
Vazquez-Talavera J, Solis CF, Medina-Escutia E,
Lopez ZM, Proano J, Correa D, Laclette JP. Human T and B cell epitope mapping
of Taenia solium paramyosin. Parasite Immunol
2001 Nov;23(11):575-9
Taenia solium paramyosin is an immunodominant antigen in human and
porcine cysticercosis that has shown promise as a vaccine candidate against
schistosomiasis and some filariasis. There are few studies to identify the
immunologically relevant regions of paramyosin. In this work, we characterize
the humoral and cellular response of neurocysticercotic patients against T.
solium paramyosin. Western blots using different recombinant fragments of T.
solium paramyosin, showed that the sera from neurocysticercotic patients were
strongly reactive against the carboxyl end region, with poor recognition of the
central and amino regions. In contrast, the cellular immune response of
patients did not show preferential recognition of any region of paramyosin.
July 02
4591.
Akue JP, Devaney E. Transmission intensity affects both
antigen-specific and nonspecific T-cell proliferative responses in Loa loa
infection. Infect Immun. 2002
Mar;70(3):1475-80.
T-cell proliferative responses were studied in two villages in Gabon with different levels of Loa loa transmission. The first village (Okoumbi) had an annual transmission potential (ATP) of approximately 9,000 infective larvae (L3)/person/year (high transmission village), while the second village (Ndjokaye) had an ATP of approximately 1,000 L3/person/year (low transmission village). Proliferation and cytokine assays were performed on peripheral blood mononuclear cells (PBMC) from individuals aged 18 years and over using either mitogens (concanavalin A or phytohemagglutinin), antigens (purified protein derivative [PPD], irrelevant antigen), or soluble extracts of L3, microfilariae, or adult L. loa. PBMC from individuals in the low transmission village responded better to stimulation with adult antigen and to PPD than did PBMC from individuals in the high transmission village (P = 0.0031 and P = 0.0012, respectively). These data suggest that high levels of transmission of L. loa depress both specific and nonspecific T-cell proliferative responses in infected humans.
4592.
Anjaria
PH; Mhatre PN. Unilateral lower limb oedema in pregnancy Bombay Hospital
Journal 2002 Jan; 44(1): 113-5
ABSTRACT: Unilateral lower limb oedema in pregnancy is a non-physiological phenomenon. It is attributed to lymphatic or venous obstruction in the lower limb, apart from local inflammatory or traumatic causes. Lymphoedema may occur following radical surgery or due to malignant infiltration or may be attributed to an infective process namely, tuberculosis, fungal infection or filariasis of the lower limb. Venous causes of unilateral oedema of the lower limb are superficial vein thrombophlebitis or thrombosis, deep vein thrombosis or chronic venous insufficiency.
4593.
McCarthy JS, Wieseman M, Tropea J, Kaslow D, Abraham D,
Lustigman S, Tuan R, Guderian RH, Nutman TB.
Onchocerca volvulus glycolytic enzyme fructose-1,6-bisphosphate aldolase
as a target for a protective immune response in humans. Infect Immun. 2002
Feb;70(2):851-8.
To identify potential vaccine candidates for the prevention of infection with the filarial nematode Onchocerca volvulus, we screened an O. volvulus L3 stage cDNA library with sera from putatively immune (PI) subjects, and a prominent immunogenic clone of 1,184 nucleotides was identified. It contained an open reading frame of 363 amino acids encoding the glycolytic enzyme fructose 1,6 bisphosphate aldolase (Ov-fba-1). Immunolocalization experiments demonstrated that the protein was most abundantly expressed in metabolically active tissues, including body wall muscle and the reproductive tract of adult female worms. Immunoelectron microscopy of L3 demonstrated binding in the region where the cuticle separates during molting, in the channels connecting the esophagus to the cuticle, and in the basal lamina surrounding the esophagus and the body cavity. Among subjects from areas where this organism is endemic specific humoral and cellular immune responses to recombinant protein were observed in both PI and infected subjects, whereas responses were not observed among subjects who had not been exposed to O. volvulus. Despite the absence of differential responsiveness in parasite-exposed human populations, when the recombinant was tested for protective efficacy in a mouse chamber model, a reduction in survival of larvae by ca. 50% was seen. This observation provides support for the further study of this parasite enzyme as a vaccine candidate in larger animal models.
4594.
Ng WK, Siu TH, Fung B, Kong JH. Dirofilariasis of breast: report
of two cases diagnosed by fine-needle aspiration biopsy. Diagn Cytopathol. 2002
Jan;26(1):22 5.
We report on 2 cases of dirofilariasis of the breast occurring in adult Chinese females residing in Hong Kong. The diagnosis was made by fine-needle aspiration biopsies. The direct smears contained numerous acute inflammatory cells, including eosinophils. A partially necrotic adult nematode of about 400-450 microm in diameter was identified in the cell-block sections of each case. The worm was characterized by a thick cuticle with longitudinal cuticular ridges and fine transverse surface striations, abundant somatic muscle, an intestine, and a reproductive tube or uterus. The morphologic features of this round worm were most compatible with those of Dirofilaria repens. While the clinical and radiologic findings of dirofilariasis of the breast are nonspecific and mimic those of breast neoplasms or inflammatory conditions, a definitive diagnosis is possible with fine-needle aspiration biopsy. A correct diagnosis of dirofilariasis may help to spare patients from unnecessary medical and surgical interventions. Copyright 2002 Wiley-Liss, Inc.
4595.
Pennisi E. Infectious disease. New culprit emerges in river
blindness. Science. 2002 Mar 8;295(5561):1809-11. No Abstract.
4596.
Rawal A, Hayer J, Dey P. Microfilariae in esophageal stricture.
Acta Cytol. 2002 Jan-Feb;46(1):70-1. No Abstract.
4597.
Sah SP, Rani S, Mahto R. Microfilariae in lymph node aspirates.
Acta Cytol. 2002 Jan-Feb;46(1):73-5. No Abstract.
4598.
Saint Andre A, Blackwell NM, Hall LR, Hoerauf A, Brattig NW,
Volkmann L, Taylor MJ, Ford L, Hise AG, Lass JH, Diaconu E, Pearlman E. The
role of endosymbiotic Wolbachia bacteria in the pathogenesis of river
blindness. Science. 2002 Mar 8;295(5561):1892-5.
Parasitic filarial nematodes infect more than 200 million individuals worldwide, causing debilitating inflammatory diseases such as river blindness and lymphatic filariasis. Using a murine model for river blindness in which soluble extracts of filarial nematodes were injected into the corneal stroma, we demonstrated that the predominant inflammatory response in the cornea was due to species of endosymbiotic Wolbachia bacteria. In addition, the inflammatory response induced by these bacteria was dependent on expression of functional Toll-like receptor 4 (TLR4) on host cells.
4599.
Sunish IP, Rajendran R, Mani TR, Munirathinam A, Tewari SC,
Hiriyan J, Gajanana A, Satyanarayana K. Resurgence in filarial transmission
after withdrawal of mass drug administration and the relationship between
antigenaemia and microfilaraemia--a longitudinal study. Trop Med Int Health.
2002 Jan;7(1):59-69.
Seven village units endemic for filariasis were assigned randomly into three arms with different intervention strategies in the years 1995 and 1996. Villages in Group A received two annual mass drug administrations (MDAs) of diethylcarbamazine (DEC) plus ivermectin (IVR). Group B received the same MDAs in combination with vector control; in Group C only placebo was administered. Post-treatment evaluation in 1997 revealed marked reductions in microfilaraemia prevalences (MFP) and geometric mean intensities (GMI). Subsequently, vector control in Group B was continued by the community. Groups A and B received no MDAs between 1997 and 1999 and were re-evaluated in 1999. During this evaluation, antigenaemia prevalence (AGP) was estimated along with MFP, using immunochromatographic test (ICT) kits. The gains of the MDAs were sustained in Group B, while resurgences occurred in Group A, where annual transmission potential (ATP) rose from 21 to 631.6 and MFP doubled. Group C continued to have high ATPs (1057-1617), while Group B had very low ATPs (0-63). After Mulla's corrections, the reductions in MFP were 62.7 and 83.5% and for GMI 72.1 and 91.4% in Group A and B, respectively, compared with Group C. Vector control preserved the gains of MDAs and accounted for 55.8% and 67.1% reductions in MFP and GMI in Group B compared with Group A. The reductions in AGP were 29.4% in Group A and 39.2% in Group B against Group C. The differences between MFP and AGP were nearly uniform across all villages and there was a significant correlation (r=0.98) between the two variables. A similar significant relationship was observed between MFP and AGP values across age groups (r=0.95). Prediction of AGP values from MFP values was proposed with regression equations. We conclude that vector control would be useful as an adjuvant to chemotherapy to prevent resurgences.
4600.
Syed S, Xiao SY, Schnadig VJ. Pathologic quiz case: adolescent
girl presenting with solitary pulmonary nodule. Arch Pathol Lab Med. 2002
Feb;126(2):227-8. No Abstract.
4601.
Van D, Maddox DE, Dutta EJ. Masqueraders of angioedema and
urticaria. Ann Allergy Asthma Immunol. 2002 Jan;88(1):10-14; quiz 15, 41.
OBJECTIVES: Reading this article will remind the reader that some patients presenting with complaints of urticaria and angioedema may not have urticaria or angioedema at all, but may have other causes, often unusual, sometimes treatable. It will also increase the reader's ability to recognize masqueraders of angioedema, urticaria, and facial swelling thought to be angioedema. DATA SOURCES: Data for this article come mainly from the authors' personal experiences and selected references to illustrate points made in the article. STUDY SELECTION: The criteria used are patients and articles from the authors' experiences that illustrate the point of this article that patients presenting with urticaria and angioedema may have other diseases and some of these are treatable. RESULTS: The objectives will be met by patient presentations plus pertinent literature review. CONCLUSIONS: Some patients presenting as angioedema and urticaria have swelling and skin lesions attributable to other causes. Although they are uncommon, they are sometimes treatable. Not all patients referred to an allergist for angioedema have angioedema.
Oct 2002
5308.
Beuria MK,
Bal MS, Mandal NN, Das MK. Long-term follow-up of asymptomatic amicrofilaraemic
individuals living in a filarial-endemic region of Orissa, India. Infection and
disease status. Trans Royal Soc Trop Med Hyg. 2001; 95(4), 408-09. No Abstract.
5309.
Beuria MK,
Mandal NN, Bal MS, Das MK. Immediate type hypersensitivity reaction: an
immunological marker for microfilariae negative individuals with hydrocele.
Curr Sci. 2001, 80(2), 125-6. No Abstract.
5310.
Bhunia B, Kulkarni S, Reddy MVR, Harinath BC. Diagnostic
evaluation of circulating filarial antigen assay using sera samples with and
without acid – heat treatment. Biomedical Research 2002;13(1):39-42.
A total of 125 sera samples of different groups of bancroftian filariasis and
endemic normals were treated with glycine –HCl
buffer(0.1 M, pH 2.8) and heat (650C for 15 min). Both
untreated and acid –heat treated sera samples were analysed for filarial
antigen by an inhibition ELISA developed using Brugia malayi microfilarial excretory-secretory (Bm
Mf ES) antigen-penicillinase and IgG antibodies of chronic filarial patients.
The geometrical mean titre (GMT) of circulating filarial antigen increased
significantly (p<0.05) in acute (n=25) and occult (n = 25) clinical filarial
sera followed by acid-heat treatment.
In contrast the GMT of filarial antigen decreased significantly (p <0.05) in the acid-heat treated microfilaraemic sera (n =25). The change in the GMT of
filarial antigen in chronic clinical
filarial cases (n =25) and endemic normals (n=25 ) was not significant.
The filarial antigen positivity increased from 84% to 88% in acute filarial
cases, 72 % to 80 % in chronic filarial cases, 48% to 78 % in occult filarial
group where acid- heat treated sera were used. The antigen positivity decreased
from 80% to 68% in microfilaraemic group when acid-heat treated sera were used
and the positivity remained same in endemic normal group. The findings of the
present study suggest for analysis of sera samples with and without acid-heat
treatment to detect clinical filarial cases with increased sensitivity and at
the same time ensuring that maximum number of microfilaraemics are detected.
5311.
Das PK,
Ramaiah KD, Vanamail P, Pani SP, Yuvaraj J, Balarajan K, Bundy DAP.
Placebo-controlled community trial of four cycles of single-dose
Diethylcarbamazine of ivermectin against Wuchereria bancrofti infection and
transmission in India. Trans Royal Soc trop Med Hyg. 2001; 95(3), 336-41.
Double blind placebo-controlled trial was carried out in 1994-98 to
compare the effect of 4 cycles of single-dose Diethylcarbamazine (DEC) or
ivermectin prevalence and geometric
mean intensity (GMI) of microfilaraemic
in the human population, infection rates in the vector population, and
transmission intensity of culex-transmitted Wuchereria bancrofti in rural areas
in Tamil Nadu state, south India. Fifteen villages (population similar to
26800) were included in the study : 5 villages each were randomly assigned to
community-wide treatment with DEC or
ivermictin or placebo. People over 14 kg body weight received DEC 6 mg/kg,
ivermectin 400 mg/kg or placebo, all identically packaged. After 2 cycles of
treatment at a 12- month interval, the code was broken and the study continued
as an open trial, with third and fourth cycle of treatment at 12-month
interval; 54-77% of eligible people (20872) received treatment during the 4 cycles. Microfilariaemia prevalence and
GMI fell by 48% and 65% with DEC and treatment. There was no change in the
incidence of acute adenolymphangitis. Infection in resting mosquitoes fell significantly in all arms: 82%, 78%
and 42% in the ivermectin, DEC and placebo arm respectively. Landing mosquitoes
also showed the same trend.
5312.
Greenberg H.
Case 1-2002: Loa loa. N Engl J Med. 2002 May 30;346(22):1751; discussion
1751. No Abstract.
5313.
Hemal AK,
Gupta NP. Retroperitoneoscopic lymphatic management of intractable chyluria. J
Urol. 2002 Jun;167(6):2473-6.
PURPOSE: We present our
experience with retroperitoneoscopic lymphatic disconnection for the treatment
of patients with intractable chyluria and review the current literature.
MATERIALS AND METHODS: Our study included 6 males and 3 females 22 to 55 years
old who presented with intractable chyluria of filarial origin and variable
duration (2 to 11 years), and were selected for retroperitoneoscopic management
of 11 renoureteral units. Diagnosis was based on urine examination for the
presence of chyle and fat globules, cystoscopy, excretory urogram and
retrograde ureteropyelography. The technique of retroperitoneoscopic management
of chyluria consisted of nephrolympholysis, ureterolympholysis, hilar vessel
stripping, fasciectomy and nephropexy. The first 3 procedures were done in all
cases, whereas fasciectomy was only done in 4 cases and nephropexy in 3 as
required. RESULTS: Chyluria disappeared in all ipsilateral renal units of the
patients who underwent retroperitoneoscopic management but it recurred in 2
patients at 1 and 9 months of followup from the contralateral side. Both cases
have since been successfully treated with contralateral retroperitoneoscopic
management. Complications included lymphatic leak through the drain which persisted
for 5 days in 1 case and an inadvertent clipping of a branch of the posterior
segmental artery of the kidney in 1. The latter patient did not have pain or
hypertension and the renal scan did not reveal any focal deficit at followup.
All patients were followed periodically from 6 months to 41/2 years (mean of 31
months). CONCLUSIONS: The objectives of open surgical treatment of intractable
chyluria can be achieved by the minimally invasive retroperitoneoscopic
technique. Nephrolympholysis, ureterolympholysis and stripping of hilar vessels
were essential in all cases. Fasciectomy and nephrectomy were done in a few
patients and as mentioned are not recommended routinely. This approach has all
of the benefits of laparoscopic surgery without compromising the principles of
open surgery. Retroperitoneoscopic management was safe, effective and
efficient.
5314.
Lau LI, Lee
FL, Hsu WM, Pampiglione S, Fioravanti ML, Orihel TC. Human subconjunctival
infection of Macacanema formosana: the first case of human infection reported
worldwide. Arch Ophthalmol. 2002 May;120(5):643-7. No Abstract.
5315.
Mahanta B,
Handique R, Narain K, Dutta P, Mahanta J. Natural infection with filarial and
infectivity status of indoor resting Culex quinquefasciatus in tea
agro-ecosystem of Assam, India. Asian J Microbiol Biotech Envir. 2001; 3(1-2),
33-6.
Assam is the most populous state in the north-eastern part of India and
produces more then 70% of India’s tea. Tea is labour intensive industry and
filarial is mostly localized in the tea garden in colonies. Studies conducted
in two consecutive years revealed that among the resting Cx. Quinquefasciatus,
1.6% were infected with filarial and an average of 3.42 larvae are detected per
mosquitoes. The probability of infected mosquitoes surviving 13 days (average
duration of extrinsic cycle of Wuchereria banacrofti in Cx. Quinquefasciatus)
was 0.17. Expectation of infective life was 1.04 days for indoor resting female
mosquitoes. Monthly variation in daily survival rates of indoor resting Cx.
Quinquefasciatus ranged from 81.5% to 92.3%. The estimated adult survival rate
of indoors resting mosquitoes was 87.6%. In both the year no infection was
detected during February and March in indoor resting mosquitoes and infection
rate remained low up to May. 16 ref.
5316. Mohanti BP. Wolbachia: potential targets for control of filariasis. Curr Sci. 2001; 80(5), 614-6. No Abstract.
5317. Murthy PK, Sarin S, Mukherjee PK, Sirkar AR, Katiyar JC. Filarial infection in chest diseases patients from Wuchereria bancrofti-endemic areas of Uttar Pradesh, India. Curr Sci. 2001; 81(1), 83-7. Determines the extent of co-occurrence and the influence of filariasis in chest-symptomatic patients from filaria-endemic areas of Uttar Pardesh, India. People with chest and respiratory symptoms were categorized on the basis of clinical, radiological, sputum and haematological examinations as cases of tropical pulmonary eosinophilia (TPE) with asthma type syndrome (n=36), pleural effusion (PE; n=13) and pulmonary tuberculosis (PT; n=36). Twenty-six asymptomatic (Asym) microfilaraemic cases, but without chest symptoms were included for comparison. Patients were examined for filarial infection by filarial skin test (FST), microfilariae in blood and pleural aspirates and for filarial-specific IgG4 by 92, 85, 89 and 96% and filarial-specific IgM by 94, 69, 86, and 77% of TPE, PE, PT and Asym microfilaraemic cases, respectively. Treatment of some of the chest-symptomatic microfilaraemic or amicrofilaraemic patients (5 to 6 patients in each category) with the antifilarial, Diethylcarbamazine, provided considerable improvement in the chest condition. Alteration in the filaeia-spicific antibody responses further supported that the patients displaying chest symptoms had concurrent filarial infection….2 tables, 29 ref.
5318.
O'Reilly MA, O'Reilly PM, Knee G. Breast infection due to
dirofilariasis. Eur Radiol. 2002 May;12(5):1097-9.
We describe a case of dirofilariasis of the breast in a woman presenting with a
breast lump. The mammogram and ultrasound appearances are described with
histopathological correlation. The suspicion of a parasitic infection was
raised by the presence of rod-like structures within a hypoechoic nodule on
sonography, appearances that have not been previously described. The case
illustrates an unusual diagnostic problem since it presented in a non-endemic
area.
5319.
Parhate SM, Thawani VR, Motghare VM. Efficiency and safety of
antiemetics in children in gastrointestinal and respiratory infections.
Antiseptic, Madurai. 2001; 98(9), 31-2.
Children suffering from vomiting associated with RTI, GII were treated with
antiemetics-domperidone (27.7%), cisapride (25.7%), metaclopramide 25.3%) and
promethazine (21.3%). Antiemetic effect was most in patients of
gastrointestinal infection (85%). The highly effective drug was promethazine
(88%). The antihistaminic, anticholinergic and sedative actions of promithazine
were found beneficial in fair control of effect were loose stool (cisapride,
metaclopramide), resh(domperidone, metaclopramide), dyskinesia (metaclopramide)
and sedation (promethazine).
5320.
Rahmah N, Lim
BH, Anuar AK, Shenoy RK, Kumaraswami V, Hakim SL, Chotechuang P, Kanjanopas K,
Ramachandran SCP. Recombinant antigenbased IgG4 ELISA for the sprcific
and sensitive detection of Brugia malayi infection. Trans Royal Soc trop med
Hyg. 2001; 95(3), 280-84.
IgG4 ELISA based on a novel recombinant antigen was evaluated
for detection of Brugia malayi infection using 2487 sera from various
institutions: 2031 samples from University Sains Malasia, 276 blinded sera from
2 other institutions in Malasia, 140 blinded sera from India and 40 blinded
sera from Thailand. These sera were from various group of individuals, i.e.,
microfilaraemic, chronic patients, endemic normals, non-endemic normals and
individuals with other parasitic and bacterial infections. Based on a cut-off
optical density reading of 0.300 sensitivity rates of 96-100%, positive
predictive values of 75-100% and negative predictive values of 98.9-100%. These
evaluation studies demonstrated the high specificity and sensitivity of this
test for the detection of active B. malayi infection. Thus, the IgG4
ELISA would be very useful as a tool in diagnosis and in elimination programmes
for Brugian filariasis.
5321.
Wright RW,
Neafie RC, McLean M, Markman AW. Zoonotic onchocerciasis of the shoulder. A
case report. J Bone Joint Surg Am. 2002 Apr;84-A(4):627-9. Review. No Abstract.
Pathogenesis:
5322.
Blanke
CH. Wolbachia DNA recognition. Lancet. 2002
Apr 13;359(9314):1345-6. No Abstract.
5323.
Brattig NW,
Lepping B, Timmann C, Buttner DW, Marfo Y, Hamelmann C, Horstmann RD. Onchocerca volvulus-exposed persons fail to
produce interferon-gamma in response to O. volvulus antigen but mount
proliferative responses with interleukin-5 and IL-13 production that decrease
with increasing microfilarial density. J Infect Dis. 2002 Apr
15;185(8):1148-54.
The cellular immune
response to Onchocerca volvulus antigen (OvAg) was studied in 551 persons
exposed to O. volvulus transmission in a hyperendemic area of Ghana, West
Africa. A whole-blood assay showed that, in response to a soluble O. volvulus
extract, cell proliferation, as well as interleukin (IL)-5 and IL-13
concentrations in the supernatants, were high in cultures of blood from
microfilaria (mf)-negative persons and significantly decreased with increasing
mf counts of the donors. Only background concentrations of interferon
(IFN)-gamma were found, and these did not correlate with mf counts. In response
to a mitogen, cells from all persons strongly reacted with proliferation and
secretion of all 3 cytokines studied. These findings show that the response of
human peripheral blood cells to OvAg does not include significant IFN-gamma
production; that mf negativity is associated with IL-5 and IL-13 production but
not, as previously suggested, with IFN-gamma production; and that IL-5 and
IL-13 production decreases with increasing mf density.
5324.
Kennedy D.
Good news on a tropical disease. Science. 2002 May 24;296(5572):1365. No Abstract.
5325.
Klintworth
GK. A worm can be monkey business. Arch Ophthalmol. 2002 May;120(5):634-5. No Abstract.
5326.
MacDonald AJ,
Turaga PS, Harmon-Brown C, Tierney TJ, Bennett KE, McCarthy MC, Simonek SC,
Enyong PA, Moukatte DW, Lustigman S.
Differential cytokine and antibody responses to adult and larval stages
of Onchocerca volvulus consistent with the development of concomitant immunity.
Infect Immun. 2002 Jun;70(6):2796-804.
The possibility of
concomitant immunity and its potential mechanisms in Onchocerca volvulus
infection were examined by analyzing cytokine and antibody responses to
infective larval (third-stage larvae [L3] and molting L3 [mL3]), adult female
worm (F-OvAg), and skin microfilaria (Smf) antigens in infected individuals in
a region of hyperendemicity in Cameroon as a function of age. Peripheral blood
mononuclear cell interleukin 5 (IL-5) responses to F-OvAg and Smf declined
significantly with age (equivalent to years of exposure to O. volvulus). In
contrast, IL-5 secretion in response to L3 and mL3 remained elevated with
increasing age. Gamma interferon responses to L3, mL3, and F-OvAg were low or
suppressed and unrelated to age, except for responses to Smf in older subjects.
IL-10 levels were uniformly elevated, regardless of age, in response to L3,
mL3, and F-OvAg but not to Smf, for which levels declined with age. A total of
49 to 60% of subjects had granulocyte-macrophage colony-stimulating factor
responses to all O. volvulus antigens unrelated to age. Analysis of levels of
stage-specific immunoglobulin G3 (IgG3) and IgE revealed a striking,
age-dependent dissociation between antibody responses to larval antigens (L3
and a recombinant L3-specific protein, O. volvulus ALT-1) which were
significantly increased or maintained with age and antibody responses to
F-OvAg, which decreased. Levels of IgG1 to L3 and F-OvAg were elevated
regardless of age, and levels of IgG4 increased significantly with age,
although not to O. volvulus ALT-1, which may have unique L3-specific epitopes.
Immunofluorescence staining of whole larvae showed that total anti-L3
immunoglobulin levels also increased with the age of the serum donor. The
separate and distinct cytokine and antibody responses to adult and infective
larval stages of O. volvulus which are age related are consistent with the
acquisition of concomitant immunity in infected individuals.
5327.
Pradeep Kumar
N, Patra KP, Hoti SL, Das PK. Genetic variability of the human filarial
parasite, Wuchereria bancrofti in South India. Acta Trop. 2002 Apr;82(1):67-76.
The genetic variability
of the lymphatic filarial parasite Wuchereria bancrofti, from three localities
(one urban and two rural areas) in southern India, endemic for filariasis was
studied using random amplified polymorphic DNA (RAPD) markers. The RAPD
profiles were generated for 21 parasite populations (7 populations from each
area), using a 10-mer random primer. The analysis of profiles indicated the
existence of considerable genetic variability among parasite populations. The
Nei's gene diversity between the individual populations in the 2 areas (one
urban and another rural) was comparatively greater (0.3372+/-0.1462 &
0.2830+/-0.1764) than that of populations in another village (0.0490+/-0.1373).
The greater genetic diversity among the former areas may be due to human
migration, endemicity for long time and drug (diethyl-carbamazine citrate)
pressure unlike the populations of latter village where the filariasis is
relatively a recent introduction and which was never under active chemotherapy.
The Nei's genetic distance was estimated and the phylogenetic tree was
constructed using 'UPGMA'. These analyses indicated the prevalence of at least
two genetically distinct clusters, among the populations studied, their maximum
genetic distance being 0.2444. The finding of two genetic 'variants' of W.
bancrofti, in the present study, may have important implications in filariasis
epidemiology and control/elimination programmes.
5328.
Wanji S,
Tendongfor N, Esum ME, Enyong P. Chrysops silacea biting densities and transmission
potential in an endemic area of human loiasis in south-west Cameroon. Trop Med
Int Health. 2002 Apr;7(4):371-7.
We studied the biting
densities of Chrysops silacea and the transmission of loiasis over 1 year in a
regenerated forest in the south-west province of Cameroon. A total of 3015
flies caught near a wood fire at ground level during rainy and dry seasons were
identified morphologically and 1975 caught during the rainy season were
dissected to determine their physiological age and infection rate. The
prevalence of microfilaraemia in the human population in the study area was
determined using the thick blood smear method. Chrysops silacea was the only
species caught. The daily and seasonal biting cycle of C. silacea showed two
peaks of activities, 9-11 a.m. and 2-4 p.m. The biting cycles of parous and
nulliparous flies showed the same trends, but the density of nulliparous flies
biting at all time of the day was 2-3 times higher. Chrysops silacea biting
density was high during the rainy season (9.06 +/- 6.88 flies/man/h) and lowest
during the dry season (0.44 +/- 0.75 flies/man/h). An infection rate of 1.72%
and a monthly morning and afternoon transmission potentials of 120769.11 and
139016.64 infective head L3/man were observed, respectively, in the rainy
season. Even though few Chrysops carried Loa loa infective larvae (0.7%), their
parasite load was high, giving a high level of transmission of L. loa in the
area. A total of 20.37% of the people examined for blood microfilariae were positive.
These results suggest that the study area is an active focus of loiasis
transmission.