a1 Veterinary Research Laboratories, P.O. Kabete, Kenya
Nairobi sheep disease was seen principally upon movement of susceptible animals into the enzootic areas. This occurred most frequently for marketing purposes near the main centres of population. Other outbreaks followed local breakdowns in tick control measures. The disease did not occur in epizootic form during the period under consideration.
Nairobi sheep disease was isolated from pools of Rhipicephalus appendiculatus but not from many pools of other tick species. No virus was isolated from the blood or tissues of a range of wild ruminants and rodents.
(Received January 10 1978)