ISOLATION OF A SOUTH-AFRICAN VECTOR-SPECIFIC STRAIN OF BABESIA-CANIS

A South African strain of Babesia canis parasites was isolated and sho wn to be vector-specific to only one of the two vectors in the region, Haemaphysalis leachi. This tick was found to transmit the parasite in its adult instar. When infected as larvae, the ticks would not transm it in the proceeding nymphal instar. The vector-specific strain was na med the 'Thomas strain' after one of the dogs involved in isolating it . A survey revealed a prevalence of > 50% of this strain in four widel y separated areas of the country. Rhipicephalus sanguineus, which tran smits B. canis vogeli elsewhere, has not been shown to be a vector of the South African strain of B. canis.