A survey of bancroftian filariasis for microfilariae & circulating antigenaemia in two villages of Madhya Pradesh.

BACKGROUND & OBJECTIVE The estimation of filariasis prevalence in Panna district of Madhya Pradesh was so far relied upon clinical and night blood smear examination. However, night blood smear examination fails to detect the infection in individuals having low parasitaemia and cryptic filarial infection. The present study was undertaken to re-evaluate the prevalence of filariasis in two villages of Panna district by Og4C3 ELISA. METHODS The study was carried out during 2002-2003 in two villages (namely Pista and Taroni) of Panna district, Madhya Pradesh. Clinical examination was performed according to WHO criteria to classify filarial disease. Night blood smears collected during 20:00 to 00:00 h were examined to detect microfilariae (Mf). For estimation of circulating filarial antigen (CFA) by Og4C3 ELISA, 2 ml blood was collected from each individual by venepuncture. RESULTS With Og4C3 ELISA, 38 per cent serum samples of village Pista (n=332) and 47.7 per cent from village Taroni (n=88) were found positive for CFA. The overall disease rate was (243/ 420) 57.9 per cent by CFA while it was (182/420) 43.3 per cent by night blood smear examination. A total of 14.5 per cent individuals were having cryptic filarial infection detected by CFA. INTERPRETATION & CONCLUSION The study emphasizes the use of CFA estimation being a sensitive and specific diagnostic tool for the evaluation of the true prevalence of the disease. The high CFA prevalence in the study area necessitates early intervention measures to check its transmission.