Abstract:
Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected
pasture on a game farm in Mpumalanga Province, South Africa, where roan are known
to die from theileriosis. Various clinical parameters were recorded during this period.
The predominant ticks parasitising these animals at the time (January to February), were
Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5 weeks
the animals developed signs of clinical theileriosis and were treated with buparvaquone to
prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales)
near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp.
(sable) by this tick species. After recovery from theileriosis, these animals were confirmed
carriers of Theileria sp. (sable) by PCR (polymerase chain reaction) and DNA probe analysis.
Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively,
were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult
ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA
probe applied to a representative batch of dissected glands. R. appendiculatus adults collected
from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary
glands of both tick species showed infected acini on staining and were also positive for
Theileria sp. (sable) only, on multiprotozoal PCR-screening analysis. There was no statistical
significant difference between the infection rate and the intensity of infection between the
two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for
Theileria sp. (sable).
