Seroprevalences of antibodies against thoracic proteins of three species of mosquito, among the residents of an area where filariasis is endemic: relationship with the mosquito densities.

Attempts were made to correlate the numbers of indoor-resting Culex quinquefasciatus, Armigeres theobold and Anopheles vagus in Raipur, Chattisgarh state, India, with the seroprevalences, among the city's microfilaraemic and 'endemic normal' residents, of antibodies reacting with thoracic proteins from the adult females of each of these species. Overall, 6478 female mosquitoes were collected in about 176 man-hours spread over a 12-month period. Antibodies to Cx. quniquefasciatus, the commonest species and the only one to be prevalent in all seasons of the year, were detected in 90% of the microfilaraemic subjects and 27% of the endemic normal. Although Armigeres theobold only constituted 5% of the mosquitoes collected, 96% of the microfilaraemic subjects and 69% of the endemic normal subjects had antibodies against thoracic proteins of this species (almost 50% of all the sera having high titres of such antibodies). Antibodies to An. vagus were detected, although almost always at very low titres, in 84% of the microfilaraemic subjects and 42% of the endemic normal. Thus, the seroprevalence of antibodies to thoracic antigens from a mosquito species bore no relationship with the indoor-resting densities of that species.