Nairobi Sheep Disease: Natural and Experimental Transmission by Ticks other than Rhipicephalus appendiculatus

Abstract

Montgomery (1917) showed that Nairobi sheep disease was commonly transmitted by Rhipicephalus appendiculatus. In 1931 we confirmed Montgomery's findings and extended them considerably in respect of transmission by this species of tick. It was shown that infection of any instar would result in transmission by the next succeeding stage, which would then in the normal course lose its infection during the next moult. A female tick infected in this manner as an adult would pass infection through the eggs to the larvae of the next generation. Further it was demonstrated that the transmitting stage could be reinfected if the reaction of the host animal commenced before the infecting meal was completed, thus ensuring the carrying on of infetion for a further stage.