Browsing by Author "Cunnigham, M.P."
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Item East Coast Fever: Challenge if Immunised Cattle by Prolonged Exposure to Infected Ticks(1975) Radley, D.E.; Brown, C.G.D.; Cunnigham, M.P.; Kimber, C.D.; Musisi, F.L.; Purnell, R.E.; Stagg, S.M.; East African Veterinary Research Organization, Muguga, PO Box 32, Kikuyu, KenyaBos taurus steers, previously treated with acaricide but washed before the trial commenced, were introduced sequentially to a paddock with a high level of T. parva infected ticks. The 12 animals exhibited macroschizonts in lymph nodes at 7-12 days, a febrile response at 9-13 days, and died at 14-21 days. Tick counts were highest on ears (the maximum level was 330), and the build-up of tick attachment correlated with time to death. Four steers immunized three months previously with tick-derived T. parva stabilate material plus Terramycin ECF were kept in the paddock throughout the experiment (60 days). Prepatent period was 10-15 days, but despite high levels of tick attachment (peaks of 500 on ears), there were minimal symptoms and only a slight transient rise in antibody titre on day 40. A few macroschizonts were detected in lymph nodes during the first week of infection and they reappeared from days 34-38. A few piroplasms were seen intermittently in blood smears.Item A Method for the Measurement of the Infectivity of Trypanosome Suspensions(1963) Lumsden, W.H.R.; Cunnigham, M.P.; Webber, W.A.F.; Hoeve, Van K.; East African Agricultural And Forestry JournalA method, based on serial dilution and inoculation of several dilutions into groups of test animals. for the estimation of the infectivity of trypanosome suspensions is described and discussed. The theoretical considerations important in interpreting the results of such experimentation are considered, and a simple method of computing end points and their standard errors is described. The results of an experiment are described; 10 replicate estimations of the trypanosome numbers in, and of the infectivity of, a suspension were made. It is concluded that the method for the estimation of infectivity is a valid one. The results obtained being in accordance with the theoretical model used.Item Theileriosis: The Exposure of Immunised Cattle in Atheileria Lawrencei Enzootic Area(1974) Cunnigham, M.P.; Brown, C.G.D.; Burridge, M.J.; Irvin, A.D.; Kirimi, I.M.; Purnell, R.E.; Radleys, D.E.; Wagner, G.G.; East African Veterinary Research Organization, Muguga, P.O. Box 32, Kikuyu, KenyaThree groups of steers were exposed to field challenge in a T. lawrencei-enzootic area of Kenya. Four out of five ECF-susceptible steers and four out of five steers immunised against T. parva (Muguga) died of theileriosis, the surviving animals experiencing severe reactions. On the other hand, all five steers immunised against T. parva (Muguga) and a strain of theileria probably homologous with the one present in the area of exposure, survived and only experienced mild reactions. These results indicated that immunisation of cattle with T. parva (Muguga) may not necessarily protect them against field challenge with certain T. lawrencei-type strains, but that immunisation with an apparently homologous strain of theileria may well do so.
