Nationwide Seroprevalence of Coxiella burnetii Infection in Saudi Farm Animals: Implications for Public Health.

Q fever, caused by the intracellular bacterium Coxiella burnetii, is a significant zoonotic disease for which ruminants are the main reservoir. This cross-sectional study aimed to assess the seroprevalence of C. burnetii in farm animals (sheep, goats, cattle, and camels) across Saudi Arabia. A total of 7760 serum samples were collected from 2253 sheep, 2224 goats, 1111 cattle, and 2172 camels, representing various regions of the country. The samples were screened for C. burnetii antibodies using an enzyme-linked immunosorbent assay (ELISA). The findings revealed significant regional and species-specific differences. The findings revealed notable regional and species-specific variations in seroprevalence. In goats, seropositivity was detected in 92% of the tested herds; however, only 48% of the individually tested animals were found to be positive. Similarly, camels exhibited herd-level seropositivity of 92.9% of the examined herds, with only 46.7% of the individually examined animals testing positive. For sheep, 80% of the examined sheep flocks were positive, while 30.2% of the individually tested animals were positive. Cattle showed a significantly lower seroprevalence, since only 27.6% of the screened herds were found to be positive, and only 8.2% of the individually tested animals were positive. In conclusion, the results indicate that C. burnetii infection is widespread among livestock in Saudi Arabia, with goats, camels, and sheep posing a particularly elevated risk of zoonotic transmission. The observed regional disparities and species-specific infection rates highlight the need for comprehensive surveillance and targeted control strategies to mitigate the spread of Q fever in Saudi Arabia.