Page 44 - VHSA - Onderstepoort 100 Years - Part 3

OND
ERSTEPOORT 100
degree in Zoology from the University of the Free State, and was appointed in the Section of Helminthology at the Institute in 1956. She produced treatises on the tape worms, Echinococcus and Taenia that are still considered as core literature on these cestodes, and was awarded a PhD for this work. She was also a pioneer in the
use of irradiation for the sterilization of Taenia cysticerci in meat. Verster joined the Department of Parasitology at the Faculty in 1985 and continued to work on the tapeworms that infect humans and domestic and wild animals. She maintained a menagerie of animals for her research, including lions, leopards, African wild dogs, black-backed jackals, chacma baboons and gibbons. She had an incredible knowledge of plants and was inundated with speci- mens of garden varieties, which she al- ways found the time to identify for her friends. She also trained as a paramedical assistant and would, in the evening, work with the paramedics at the scene of accidents. Upon Reinecke’s retirement she assumed responsibility for the lectures in Helminthology. In later years she was assisted in these by R.C. (Tammi) Krecek.
I.G. (Ivan) Horak, qualified as a veterinarian in 1957 and after 3 years of practice on a large cattle ranch in north-eastern KwaZulu-Natal, joined the staff of the Section of Helmintho- logy at the Institute under Reinecke. Horak’s studies on the conical fluke Calicophoron microbothrium
resulted in the discovery of the first highly
134 effective remedy against immature conical flukes in sheep, and in a successful experi- mental vaccine against the fluke in cattle in which irradiated metacercariae were used. He also determined the life cycle of the fluke in sheep, goats and cattle, and found that cattle appeared to be the preferred hosts.
Horak and R. (Nobby) Clark, then Pro-
fessor and Head of the Department of
Physiology at the Veterinary Faculty, pub-
lished a series of papers on the clinical
pathology of various helminth infections in
sheep, a field that at the time was only just
beginning to be researched. They found
that most acute helminth infections led to
a decrease in serum albumin concentration
because of protein seepage between the
cells of the proliferating intestinal tract
epithelium at the site of infection. Much earlier Clark, as a young state veterinarian, described the association between spring lamb paralysis and infestation with the red-legged tick R. evertsi. Horak left the Institute for the pharmaceutical industry in 1966.
P.J.S. (Blik) Anderson qualified as a veterinarian in 1954 and joined the British Colonial Service in Tanzania. Thereafter he spent some time in the pharmaceutical industry in South Africa and then joined the Section of Helminthology at the Institute in 1963. He determined the geographic distribu-
tion of lungworms in South Africa, and with Verster unravelled the life cycle of the lungworm Dictyocaulus filaria in sheep. He had a remarkable talent for wood sculpturing and held at least one public exhibition of his work.
J.A. (Jan) van Wyk qualified as a veterinarian in 1962 and thereafter was appointed as State Veterinarian in Namibia. He joined the Section of Helminthology at the OVI in 1968. He initially worked on Schistosoma in domestic livestock, focusing on the life cycle of the parasite and the disease that it produced. Thereafter he turned his attention to the cryopreserva- tion of the infective larvae of the nema- todes commonly infecting cattle and sheep. The importance of this technique lay in the fact that the infective free-living larvae of pure worm species could be frozen and thus survive for many years in this state.
They could then be thawed when required at a later occasion, particularly by the pharmaceutical industry, for anthelmintic efficacy trials.
“Ivan Horak’s studies
on the conical fluke Calicophoron microbothrium resulted in the discovery of the first highly effective remedy against immature conical flukes in sheep, and in a successful experimental vaccine against the fluke in cattle in which irradiated metacercariae were used.”
With the more or less simultaneous advent of several new anthelmintics on the market during the 1960s and thereafter van Wyk realized that anthelmintic resistance was soon to be- come a problem both for the stock farming community and the pharmaceutical indus- try and he started recording incidents of resistance in various worm species as well as the spectrum of anthelmintics against which resistance had developed. He is now recognized as a world authority in this field. It soon became obvious that the solution to the problem did not lie in increasing the dose of the remedy or in introducing novel products onto the market, but rather in a strategy of integrated management and control. With F.S. (Faffa) Malan and G.F. (Gareth) Bath he was instrumental in developing the FAMACHA© programme of selective treatment of animals exhibiting or beginning to exhibit the pathognomic sign of H. contortus (wireworm) infection, namely anaemia. By treating only those animals that require treatment the cost of treatment is reduced and the development of anthelmintic resistance by this ubiquitous nematode parasite of sheep and goats is postponed. He retired from the Institute in 1997, and
PART 3
History of Individual Disciplines
1908-2008
Years