Circulating filarial antigen in serum and hydrocele fluid from individuals living in an endemic area for bancroftian filariasis.

This study examined circulating filarial antigen by monoclonal antibody Og4C3-enzyme-linked immunosorbent assay (ELISA) from 114 men with hydrocele, living in an endemic area. Nocturnal blood and hydrocele fluid were collected and examined for microfilaria. ELISA was performed on serum and hydrocele fluid for detection of antigen. Amongst 114 cases, 5(4.4%) showed microfilaria in blood but none in fluid. ELISA was positive in 13(11.40%) serum and 5 (4.4%) fluid samples. All five fluid antigen positive cases were positive for antibodies and showed microfilaria in blood. These findings emphasize the use of circulating filarial antigen detection and alternative usage of hydrocele fluid for diagnosis of filariasis.