Some observations on the sero-prevalence of heartwater and tick infestation in Zambian goats.

A survey was carried out to define the distribution of heartwater in goats that originated from six districts in communal grazing semi-arid areas of Zambia. A total of 181 samples (40.1%) out of 451 serum samples from adult goats were positive for Ehrlichia ruminantium antibodies after screening using indirect MAP-1B antigen ELISA technique with statistically significant differences (P < 0.01) between the six districts. Out of 1 036 adult goats examined for tick infestation, 105 were infested by ticks, with Amblyomma species being the most dominant tick encountered. Amblyomma variegatum, which is the vector for heartwater transmission in Zambia constituted 42.4% of the tick species, identified. The overall tick infestation rate was 10% while the tick:goat ratio was 2.1:1. Amblyomma variegatum appears to be widespread throughout the study area, as are antibodies to E. ruminantium.