Page 54 - VHSA - Onderstepoort 100 Years - Part 3

OND
ERSTEPOORT 100
In the relatively short time P.A. Basson was at Onderstepoort his research output was phenomenal and included a wide range of topics, but he will, however, perhaps best be remembered for unraveling, virtually single-handed, the cause, epidemiology, pathogenesis, experimental transmission, symptomatology, macro- and micropathology, and control of a disease colloquially named uitpeuloog (‘bulging eye disease’) or specific oculo-vascular myiasis of livestock. This disease occurs chiefly in sheep although cattle, goats and equines can also be affected and is a classic manifestation of a parasitic infection in an aberrant host. It is caused by infestation of livestock by certain species of larvae of oestrid flies of the genus Gedoelstia which occur naturally in certain game species, chiefly blue wildebeest and hartebeest, in the Kalahari regions of southern Africa. Another problem disease of unknown aetiology in sheep, particularly Karakuls in Namibia, which was solved by Basson and co-workers is grootlamsiekte (literally ‘large lamb disease’), a condition of prolonged gestation which is caused by ingestion of the shrub, Salsola tuberculata. By correct pasture management the incidence of the disease can be reduced.
Basson took an intense interest in the diseases of game and many of the studies in which he was concerned, generally as a member of a team, involved macro- and microscopical pathological surveys in which numerous wild animal species, e.g. baboons, African elephants, African buffaloes and
blue wildebeest, were examined. A variety of disease conditions were recorded, some for the first time. One serendipitous finding, as far as the latter is concerned, was the observation of Besnoitia
sp. cysts in the endocardium and intima of blood vessels of particularly blue wildebeest in the Kruger National Park. It was subsequently experimentally found that this parasite is considerably
less pathogenic to cattle and rabbits than is Besnoitia besnoiti, the cause of the cattle disease known
as besnoitiosis or elephant skin disease which is of considerable importance in some parts of South Africa. This finding eventually lead to the use of the blue wildebeest strain of B. besnoiti in a live vaccine against besnoitiosis in cattle. This is the first time that a living organism, originating from a wild animal and grown in tissue culture, has been used in domestic animals as a
vaccine (see Part 3: Protozoology).
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PART 3
History of Individual Disciplines
1908-2008
Years