Parasites of domestic and wild animals in South Africa. XLIX. Ticks (Acari: Ixodidae) infesting white and black rhinoceroses in southern Africa.

The objectives of the study were to determine the species composition of ticks infesting white and black rhinoceroses in southern Africa as well as the conservation status of those tick species that prefer rhinos as hosts. Ticks were collected opportunistically from rhinos that had been immobilised for management purposes, and 447 white rhinoceroses (Ceratotherium simum) and 164 black rhinoceroses (Diceros bicornis) were sampled in South Africa, 61 black rhinos in Namibia, 18 white and 12 black rhinos in Zimbabwe, and 24 black rhinos in Zambia. Nineteen tick species were recovered, of which two species, Amblyomma rhinocerotis and Dermacentor rhinocerinus, prefer rhinos as hosts. A. rhinocerotis was collected only in the northeastern KwaZulu-Natal reserves of South Africa and is endangered, while D. rhinocerinus is present in these reserves as well as in the Kruger National Park and surrounding conservancies. Eight of the tick species collected from the rhinos are ornate, and seven species are regularly collected from cattle. The species present on rhinos in the eastern, moister reserves of South Africa were amongst others Amblyomma hebraeum, A. rhinocerotis, D. rhinocerinus, Rhipicephalus maculatus, Rhipicephalus simus and Rhipicephalus zumpti, while those on rhinos in the Karoo and the drier western regions, including Namibia, were the drought-tolerant species, Hyalomma glabrum, Hyalomma rufipes, Hyalomma truncatum and Rhipicephalus gertrudae. The species composition of ticks on rhinoceroses in Zambia differed markedly from those of the other southern African countries in that Amblyomma sparsum, Amblyomma tholloni and Amblyomma variegatum accounted for the majority of infestations.

Distribution of endemic and introduced tick species in Free State Province, South Africa.

The distributions of endemic tick vector species as well as the presence of species not endemic to Free State Province, South Africa, were determined during surveys or opportunistic collections from livestock, wildlife and vegetation. Amongst endemic ticks, the presence of Rhipicephalus appendiculatus was confirmed in the north of the province, whilst Rhipicephalus decoloratus was collected at 31 localities mostly in the centre and east, and Ixodes rubicundus at 11 localities in the south, south-west and centre of the province. Amongst the non-endemic species adult Amblyomma hebraeum were collected from white rhinoceroses (Ceratotherium simum) on four privately owned farms, whilst the adults of Rhipicephalus microplus were collected from cattle and a larva from vegetation at four localities in the east of the province. The collection of Rhipicephalus evertsi mimeticus from a sheep in the west of the province is the second record of its presence in the Free State, whereas the presence of Haemaphysalis silacea on helmeted guineafowl (Numida meleagris) and vegetation in the centre of the province represents a first record for this species in the Free State. The first collection of the argasid tick, Ornithodoros savignyi, in the Free State was made from a domestic cow and from soil in the west of the province. The localities at which the ticks were collected have been plotted and the ticks' role in the transmission or cause of disease in domestic livestock and wildlife is discussed.

Detection of bovine papillomavirus DNA in sarcoid-affected and healthy free-roaming zebra (Equus zebra) populations in South Africa.

The endangered Cape mountain zebra (Equus zebra zebra) is protected in small numbers in a few isolated populations in South African game parks. Since 1995, sarcoid lesions appeared in zebras in two of the parks. This study was undertaken to investigate if bovine papillomavirus (BPV) is associated with sarcoids in these zebras. A conventional PCR, targeting the E5 ORF of BPV, and subsequent RFLP analysis were initially used to demonstrate the presence of BPV-1 and -2 DNAs in zebra sarcoid tumours. A rapid, sensitive and reliable real-time PCR to detect and distinguish between BPV-1 and -2 infections in zebras was developed. With this assay it was demonstrated that BPV-1 and -2 DNA (either single or mixed infections) are present in sarcoid tumour, healthy skin and blood of sarcoid-affected and healthy zebras from sarcoid-affected parks as well as in the blood of zebras from parks where no sarcoid has been observed before.