Studies in Tick-borne Fever of Sheep: II. Experiments on Transmission and Distribution of the Disease

摘要: (1) Female Ixodes ricinus ticks which feed on a sheep infected with tick-borne fever are not capable of transmitting the infective agent to their progeny. Only nymphs and females, therefore, can be sheep. In case an female, infection may have been acquired, ( ) in immediately preceding stage, or b larval remaining tissues tick during nymphal engorgement subsequent moult. This appears occur irrespective whether host nymph feeds is susceptible insusceptible. animal. (2) Ticks acquired as soon after moulting next stage they able attach hosts. Unfed were found period about 14 months. (3) Infection transmitted course 2nd day attachment nymphs. (4) The disease by inoculation emulsions ticks, if these allowed commence engorgement. use saline for such inadvisable.