Aedes furcifer and other mosquitoes as vectors of chikungunya virus at Mica, northeastern Transvaal, South Africa.

From 1977 to 1981, studies were conducted on a farm at Mica where Aedes furcifer had been a vector during an epidemic of chikungunya virus in 1976 to determine whether the virus persisted in this mosquito, the likelihood of vertical transmission, and whether any other Aedes species could have been vectors. Aedes furcifer/cordellieri was the only prevalent tree hole Aedes which fed readily on monkeys and humans and occurred through the summer until the onset of winter. Virus was not isolated from 7,241 females and 4,052 males of this group, which were largely Ae. furcifer and which included a sample of the first post-epidemic population. Five additional Aedes species were prevalent in bamboo pots, 3 of which (Ae. aegypti, Ae. fulgens and Ae. vittatus) were shown to be competent laboratory vectors. Virus was not isolated from a sample of 13,029 such newly emerged mosquitoes representing the first post-epidemic population. It is concluded that Ae. furcifer is an epidemic-epizootic vector which does not maintain the virus at Mica and that no other mosquito species could have been important vectors.