In vitro transmission of Wuchereria bancrofti L3-stage larvae by experimentally infected culex pipiens L [Diptera: culicidae]

ABSTRACT

Females of Culex pipiens L. experimentally infected with Wuchereria bancrofti were tested for in vitro transmission of infective stage L[3] larvae using a capillary tube technique. Of the females harbouring L[3] larvae, 60.7% [34/56] transmitted a geometric mean of 2.84 L[3] larvae [range 1- 35]. Transmitting Cx. pipiens contained significantly more L[3] larvae than non-transmitters. Both the probability of transmission and the number of L[3] larvae transmitted were related to the total number of L[3] larvae/mosquito. Almost all females with L[3] loads >/= 10 transmitted larvae in vitro. The possibility is discussed that the detection of L[3] larvae in field collected mosquitoes by dissection may overestimate the proportion capable of parasite transmission and the proportion of L[3] larvae deposited on host skin by Ca. 40%