Delated Type Hypersensitivity Theilerin Test in Cattle Vaccinated against Theileria annualata infection
2000
Hashemi-Fesharaki, R., Razi Vaccine and Serum Research Institute. Tehran. Iran | Habibi, G.H., Razi Vaccine and Serum Research Institute. Tehran. Iran | Ahourai, P., Razi Vaccine and Serum Research Institute. Tehran. Iran
Theileriosis due to Theileria annualata is a disease causing drastic losses of cattle in Iran. Fortunately, and effective vaccine has been produced since 1973 for pure-bred and across-bred cattle, which are highly at risk. Although the results clearly indicated that cell-mediated immune responses against. T.annualata are important, there is not yet an accurate and quick test, neither in vitro nor in vivo for checking protective immunity in vaccinated cattle. Since the determination f specific delayed hypersensitivity responses continue to be the most efficient clinical and epidemiological tools for the study of other pathogenic protozoa like leishmania it is whorth while to evaluate the effectiveness of delayed hypersensitivity theilrerin test on.annulata infection. Theilerin was prepared and its total nitrogen was determined at level of 1mg /ml.72 holstein friesian cattle recovered from acute theilerios is or vaccinated received 0.1ml of theilerin intradermally at normal concentration of total nitrogen or other dilutions (1/10 and 1/100). Some 60% of calves and 66.67% of milking cows receiving normal theilerin showed more than 1mmincrease in skin thickness at the site of inoculation (mean value of 1.86mm for calves and 3.46mm for milking cows). The pathological examination of the inoculation site showed infiltration of lymphocytes. No changes of general condition were observed in animals under study. The result indicated that the test is positive and could be used for checking immunity in vaccinated animals.
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