Browsing by Author "Musisi, F.L."
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Item East Coast Fever: 3. Chemoprophylactic Immunization of Cattle using Oxytetracycline and a Combination of Theilerial Strains(1975) Radley, D.E.; Brown, C.G.D.; Cunningham, M.P.; Kimber, C.D.; Musisi, F.L.; Payne, R.C.; Purnell, R.E.; Stagg, S.M.; Young, A.S.; East African Veterinary Research Organization, Kikuyu Kenya,In the first of two experiments performed, 29 animals were immunized by chemoprophylaxis against either a combination of three theilerial strains, Theileria parva (Muguga), T. parva (Kiambu 5) and T. lawrencei (Serengeti transformed), or against one or two elements of the combination separately, and then challenged with either T. parva (Kiambu 1) or T. lawrencei (Solio KB1), both of which were known to be heterologous to T. parva (Muguga). The animals immunized against the combination had mild or inapparent reactions to challenge, whilst the susceptible control cattle and many of those immunized against one or two strains either had severe reactions of died. In the second experiment, 17 cattle immunized by chemoprophylaxis against the combination were challenged with lethal doses of three theilerial strains, T. parva (Entebbe 1), T. parva (Entebbe 2) and T. parva (Ukunda), recently isolated from two widely separated areas of East Africa. They had mild or inapparent reactions whilst 13 of 15 susceptible control cattle died. Chemoprophylaxis using a combination of theilerial strains and a limited oxytetracycline regimen was shown to be an effective means of immunizing cattle against East African theilerioses. The use of this technique as a method of immunizing cattle before exposure in the field is proposed.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.
