Nairobi sheep disease: the survival of the virus in the tick Rhipicephalus appendiculatus

Montgomery (1917) showed that Nairobi sheep disease, a tick-borne gastro-enteritis of sheep and goats in East Africa, was caused by a filtrable virus transmitted most commonly by the brown tick, Rhipicephalus appendiculatus. The transmission of the disease by this tick was confirmed by Daubney & Hudson (1931, 1934), who demonstrated also that ticks infected in any instar usually transmitted the disease when fed in the succeeding stage on susceptible sheep; and that the virus ingested by a female fed on an infected sheep passed through the eggs to the larvae of the next generation.