Further to their account of yellow-fever virus isolation from mammals (Andral et al., I968), the authors describe the isolation of virus strains from mosquitos collected in the forest near the Manera experimental station in Ethiopia.
Mosquitos were pooled by species or by genus, and the pools were ground in a bovalbumin solution and injected intraperitoneally, intracerebrally and subcutaneously into 1-3-day-old mice. From among 367 pools totalling 52 381 mosquitos, the following isolations were made: 2 yellow-fever strains, from a pool of 46 Aedes africanus ind a lot of 155 Aedes dentatus, respectively; 2 strains of Nyando virus, from lots of 131 and 204 Eretmapodites spp.; and 1 strain of Ntaya virus from a lot of Culex Spp. This brings to 24 the number of virus strains isolated by the authors in Ethiopia between February 196I1and July 1964, 21 of these strains being of yellow fever.
The isolation from Aedes africanus confirms the findings of Neri et al. (I968) as to the importance of this species in the area. No yellow-fever virus had previously been found in Aedes dentatus, but the fact that only the one isolation could be made in I4 pools of this mosquito does not allow the authors to draw any conclusions as to its role in the spread of yellow fever. Despite the abundance of Eretmapodites in the Manera forest no strain of yellow fever could be isolated from over 13 000 specimens; however, the isolations of Nyando virus are the first from this genus and it is suggested that it would interesting to de- termine by serological investigations to what extent man and animals in the area may be involved in a transmission cycle. The isolation of Ntaya virus is linked with the finding (Sérié et al., I968) of Ntaya antibody in 7%-8% of the human sera examined in the Manera area.