Cross-sectional sero-survey, molecular identification, and associated risk factors of brucellosis in Saudi farm animals

Background Brucellosis, caused by different Brucella species , is an important disease affecting both humans and animals worldwide, including Saudi Arabia. In animals, a successful control program of brucellosis requires knowing herd seroprevalence, brucella spp . circulated, and associated risk factor identification. To the best of the author's knowledge, there is no serosurvey at the national herd level. Thus, the objectives of this study were to determine the seroprevalence of brucellosis, species identification, and its associated risk factors in 13 main administrative regions in Saudi Arabia. A cross-sectional serological survey was designated, and five thousand three hundred eighty-four serum samples and eighty-seven representative whole blood samples were collected from four animal species, including camel, cattle, sheep, and goat. The samples were analyzed using competitive Enzyme Linked Immunosorbent Assay (cELISA) and real-time polymerase chain reaction (rtPCR) to determine sero-epidemiology of brucellosis and the endemic two species of Brucella abortus and Brucella melitensis . Univariate analysis of chi-square (χ2) was used initially to determine the significance of overall brucella seroprevalence and the associated significant risk factors at α < 0.25, then multivariate analysis of logistic regression was used at α < 0.05 to exclude the confounder of those risk factors using SPSS version 20. Results The overall brucella seroprevalence was 6.8% (366/5384). The seroprevalence of brucellosis in camels, cattle, goats, and sheep was (63/1571) 4%, (28/660) 4.2%, (121/1597) 7.6%, and (154/1556) 9.9%, respectively. The highest brucella seroprevalence was in the Albaha region, 21.7% (59/272), where there was no brucella seroprevalence in the Jazan and Al-Jouf areas. The percentages of Brucella spp. in randomly selected seropositive samples were (29/87) 33.3% and (25/87) 28.7% for Brucella melitensis and Brucella abortus, respectively, while 37.9% (33/87) of the samples were negative for Brucella speciation. Univariate analysis reveals that regions, species, and age persist to show statistically significant P  < 0.25. Likewise, on multivariate analysis, only regions, species, and age were statistically significant at P  < 0.05. Conclusion The disease is region, species, and or age dependent in Saudi Arabia. Thus, it is important to carry out appropriate control measures and create awareness of public zoonotic transmissions of brucellosis, especially in the regions where the prevalence of contagious Brucella spp. is high and prevails un-pasteurized milk drink.