Coxiella burnetii antibodies in some Nigerian dairy cows and their suckling calves.

Dairy cows and their suckling calves kept at institutional and governmental farms under semi-intensive husbandry and dual purpose Fulani nomadic herds with extensive management system around Zaria, Nigeria were screened for antibodies against Coxiella burnetii using the capillary agglutination test (CAT). An antibody prevalence of 59.8% detected among 306 dairy cows under both management systems was significantly (P less than 0.01, X2) higher than was found among their suckling calves where 41.0% of 205 calves tested were seropositive. At institutional herds, 61.4% of 176 dairy cows, 47.3% of 110 suckling calves and 43.2% of 44 milk samples contained antibodies to C. burnetii. However, within Fulani nomadic herds, 57.7% of 130, 33.7% of 95 and 62.5% of 40, dairy cows, suckling calves and milk samples respectively, were positive for C. burnetii antibodies. Antibody titres of seropositive cows were similar for both systems as 82 (62.7%) of 122 tested sera had titres of 1:64 or above. It is concluded that milkborne C. burnetii infections could be a health hazard to consumers of raw or unpasteurized milk in this environment, based on high prevalence rates and titres, as some cows could be shedding the organism. The role of management practice in the transmission of C. burnetii is also discussed.