A comparison between ELISA and dissection for detection of Plasmodium infections in Anopheles mosquitoes. Consequences of the estimation of malaria transmission in Ndiop, Senegal in 1995

An entomological study was carried out in Ndiop village, Senegal, an area of sudan-type savana, from January to December 1995, to compare the malaria inoculation rate measured by the dissection of salivary glands of anophelines and the enzyme-linked immunosorbent assay (ELISA). Mosquitoes were sampled by night-bite collections, Species from the Anopheles gambiae complex were identified using the polymerase chain reaction. 1292 females Culicidae were collected. 597 anophelines mosquitoes known to be malaria vectors were captured during 148 man-nights of capture. Of the 572 anophelines investigated, 14 were positive using dissection while 21 were found to be positive with ELISA. The sporozoite rates were 2.5 %, 2.2 % and 3.8 % for An. arabiensis, An. gambiae and An. funestus, respectively. The circumsporozoite rates were 3.5 %, 2.2% and 7.7 % far these three species, respectively. ELISA detected 1.5 times more positive mosquitoes than dissection. These results ore discussed with reference to the duration of the sporogonic cycle, the delay before CSP antigens are apparent, and the dolly survival rate of Anopheles mosquitoes.