Arbovirus isolations from ixodid ticks infesting livestock, Kano Plain, Kenya.

In a study conducted on the Kano Plain, Kenya, virus isolation attempts were made on ixodid ticks collected, over a 14-month period, from livestock held in family enclosures (bomas) before releasing the animals for daily foraging. 8735 Amblyomma variegatum (Fabricius) were tested, 98.6% of which were taken from cattle, yielding 36 strains of Dugbe (DUG), four strains of Nairobi sheep disease (NSD), three strains of Bhanja (BHA), one strain of Thogoto (THO) and five strains of virus which could not be characterized. 6549 Rhipicephalus spp. ticks were collected (60.3% from cattle). NSD, DUG and BHA viruses were each isolated twice from ticks taken from cattle. One BHA virus strain was recovered from ticks from a sheep. One strain recovered from ticks on cattle could not be characterized.

Arbovirus isolations from, and serological studies on, wild and domestic vertebrates from Kano Plain, Kenya.

Arbovirus infection and presence of haemagglutination-inhibiting antibodies in small mammals, birds and livestock were examined over a period of five years on the Kano Plain in western Kenya. Eleven isolations were made from mammals and birds. The viruses were identified as Arumowot and Germiston while three different agents could not be shown to be related to 188 African arboviruses. Prevalence of antibodies against arboviruses suspected of occurring in the area was generally low.

Arbovirus isolations from mosquitoes: Kano Plain, Kenya.

Arbovirus isolation attempts on 324,486 mosquitoes captured over a four-year period on the Kano Plain, Kenya, yielded 15 isolates including Pongola (six strains), Ilesha (three strains), Germiston (two strains), Sindbis (one strain), Barur (one strain) and two viruses which could not be characterized. Mansonia uniformis, Anopheles gambiae and Culex antennatus constituted 70% of the total collection and accounted for all of the isolates except one, which came from Anopheles funestus.

Investigation of the ecology of Soldado virus on Puffin Island, North Wales.

The prevalence of Soldado (SOL) virus and SOL virus antibodies was investigated on immature sea birds and the argasid tick Ornithodoros (Alectorobius) maritimus collected on Puffin Island, North Wales. No SOL virus was recovered from 133 bird sera, but 2 of the birds exhibited neutralizing antibodies against SOL virus. Nine of 27 tick pools (226 individuals) and 34 of 173 ticks tested individually proved to be infected with SOL virus.

The isolation of a Bwamba virus variant from man in Western Kenya.

A bwamba group virus was isolated from the blood of a febrile child on the Kano Plain, Kenya. The isolate (NY-45), closely resembling Bwamba, established infection in both Anopheles gambiae and Mansonia uniformis. Neither the Bwamba nor the Pongola prototype strains grew in both species. In gel-diffusion tests NY-45 virus passaged through mosquitoes exhibited a line of identity with Pongola antiserum. In contrast no cross-reaction was observed with NY-45 virus which had not previously been passaged through mosquitoes.