Isolations of arboviruses in the Lagos area of Nigeria, and a survey of antibodies to them in man and animals

The isolation, from pools of mosquitoes in Nigeria, and the identification, of strains of Bunyamwera, of Pongola, and of Chikungunya viruses are described. The last two are new isolations for Nigeria. Most of the isolations were from Mansonia africana, the dominant mosquito species in the area investigated, but other species of mosquito are probably involved in their cycles of transmission. Aedes aegypti was readily infected with all the viruses in the laboratory. Little is known about their natural cycles. Serological studies showed that monkeys may sometimes be involved, and this was supported by laboratory observation. Human infection with all these viruses occurs in Southern Nigeria, with some regional variations.