Prevalence of Antibodies to Coxiella burnetii in Camel Milk in Riyadh Region, Saudi Arabia: a Comparison with Serum

Antibodies against Coxiella burnetii, the causative agent of Q-fever, were detected in lactating camels, cows and goats in Riyadh region, Saudi Arabia, using an indirect ELISA test. A total of 246 milk samples collected from 69 camels. 90 cows and 87 goats were tested. Milk samples from 43 camels (62.32%), 30 cows (33.33%) and 22 goats (25.29%) were positive for anti-C. burnetii antibodies. Serum samples collected simultaneously from the same animals and tested by ELISA revealed anti-C. burnetii antibodies in 46 camels (66.67%), 38 cows (42.22) and 14 goats (16.20%). A significant correlation between ELISA results in milk and serum was observed in the species tested. These results confirm that ELISA can be used in milk instead of serum to detect antibodies against C. burnetii in lactating camels and other animals.