Experimental Wuchereria bancrofti infection of Culex quinquefasciatus and Aedes aegypti.

Laboratory-derived females of Culex quinquefasciatus and Aedes aegypti were experimentally infected with Wuchereria bancrofti by allowing the insects to feed on infected volunteers of known microfilariae density between 24.00 and 2.00 hours. Of the 240 mosquitoes used for the experiments only 67 (55.8%) of C. quinquefasciatus and 83 (69.2%) of the Ae.aegypti actually fed on the volunteers' blood. After 16 days post-infection period, 50 (74.62%) of the engorged C. quinquefasciatus harboured infective L3 larval stages of W. bancrofti, while 16 (23.9%) and 1 (1.49%) harboured L2 and L1 pre-infective larval stages, respectively. On the other hand, no development to the L3 infective stage was observed in the engorged Ae.aegypti though 34 (40.96%) harboured L1 pre-infective stages of the parasite. Our results suggest that C.quinquefasciatus could be actively involved in the transmission of urban bancroftian filariasis in Nigeria.