Incidence of filariasis in clinically diagnosed primary vaginal hydrocele

Background: Lymphatic filariasis is caused by a mosquito-borne parasite affecting roughly 100 million people round the world. There is consensus that hydrocele is the most frequent clinical manifestation of bancroftian filariasis. In endemic areas, about 40% of men are suffering from testicular hydrocele. With this background, the present study was aimed to find the incidence of filariasis in clinically diagnosed primary vaginal hydrocele.Methods: A hospital based prospective, cross-sectional study was conducted with 60 patients diagnosed clinically as primary vaginal hydrocele coming to the department of surgery, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, to assess the incidence of filariasis.Results: Anti-filarial antibody and circulating filarial antigen in serum were detected in 5 (8.3%). Out of 60 patients and anti-filarial antibody was detected in hydrocele fluid of 2 (3.3%) patients. 2 patients out of these 5 showed microfilaria in peripheral blood smear and eosinophilic infiltrates in histopathological examination of sac.Conclusions: In 5 out of 60 cases both anti-filarial antibody and circulating filarial antigen in serum are positive thus proving that incidence of filarial hydrocele is 8% in clinically diagnosed primary vaginal hydrocele which is supposed to be idiopathic. Even though these cases have presented as clinically primary vaginal hydrocele, they are found to be filarial hydrocele after analysis of serum and hydrocele fluid. So, it is advised that all cases of clinically diagnosed primary vaginal hydroceles should be investigated for filariasis and if not, may lead to recurrence in these cases.

Comparison of tests for the detection of circulating filarial antigen (Og4C3-ELISA and AD12-ICT) and ultrasound in diagnosis of lymphatic filariasis in individuals with microfilariae

Significant advances were made in the diagnosis of filariasis in the 1990s with the emergence of three new alternative tools: ultrasound and tests to detect circulating antigen using two monoclonal antibodies, Og4C3 and AD12-ICT-card. This study aimed to identify which of these methods is the most sensitive for diagnosis of infection. A total of 256 individuals, all male and carrying microfilariae (1-15,679 MF/mL), diagnosed by nocturnal venous blood samples, were tested by all three techniques. The tests for circulating filarial antigen concurred 100 percent and correctly identified 246/256 (96.69 percent) of the positive individuals, while ultrasound detected only 186/256 (73.44 percent). Of the circulating antigen tests, ICT-card was the most convenient method for identification of Wuchereria bancrofti carriers. It was easy to perform, practical and quick.

Analysis, characterization and diagnostic use of circulating filarial antigen in bancroftian filariasis.

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of circulating filarial antigen fraction-2 isolated from plasma of microfilaraemic patients with Wuchereria bancrofti infection has shown 21 bands with molecular weights ranging from 12 to 120 kDa. The gel (12 cm) was sliced at an interval of one cm and the eluates of all the gel slices viz., CFA2–1 to CFA2–12 showed the presence of filarial antigen by sandwich enzyme-linked immunosorbent assay. The low molecular weight circulating filarial antigen fractions were found to share a common epitope with Wuchereria bancrofti microfilariae excretory-secretory antigen and urinary filarial antigen. The 3 antigen fractions CFA2-1, CFA2–9 and CFA2–12 showed higher sensitivity in detecting filarial immunoglobulin Μ antibodies than immunoglobulin G antibodies. However CFA2–9 fraction was found useful in serological differentiation of microfilaraemics from those with disease manifestations when filarial immunoglobulin G antibodies were detected. The antigenic epitope of CFA2–1 appears to be a carbohydrate, whereas CFA2–9 appears to be protein in nature.

Diagnostic utility of monoclonal antibodies raised against microfilarial excretory-secretory antigens in bancroftian filariasis.

Two monoclonal antibodies Wuchereria bancrofti Ε 33 and Wuchereria bancrofli Ε 34 raised against Wuchereria bancrofti microfilarial excretory-secretory antigens were studied for their diagnostic utility. Wuchereria bancrofti Ε 34 monoclonal antibody was found to be relatively specific and sensitive in detection of circulating filarial antigen. When Wuchereria bancrofti Ε 34 monoclonal antibody was used alongwith immunoglobulin G fraction of human filarial serum immunoglobulins in double antibody sandwich enzyme linked immunosorbent assay. 68% of microfilaraemic sera (26 out of 38). 12% of clinical filarial sera (3 out of 25), 13% endemic normal sera (2 out of 15) and none of the 20 non-endemic normal sera showed the presence of filarial antigen. The filarial antigen detected by Wuchereria bancrofti Ε 34 monoclonal antibody in double antibody sandwich enzyme linked immunosorbent assay is possibly associated with the active stage (microfilaraemia) of infection.