Characterization of some Theileria parva stocks from Zambia using monoclonal antibodies.

Theileria parva parasites have been isolated from different location in Zambia where malignant theileriosis has been recorded. A total of 16 bovine lymphocytic cell lines infected with T. parva schizonts were characterized using a panel of anti-schizont monoclonal antibodies (MAbs). Comparison of the Theileria stocks isolated before (old) and after (new) the Muguga cocktail of T. parva from Kenya was used to vaccinate cattle against theileriosis in Zambia revealed differences in their reactivity against MAbs. The new isolates are showing MAb profiles similar to that exhibited by the Muguga cocktail which was used to vaccinate cattle in these areas between 1983 and 1989. These results suggest that the use of the Muguga cocktail to vaccinate animals against theileriosis in Zambia may have introduced Theileria stocks of different antigenic properties.