Association between seroprevalence and risk factors for brucellosis in small ruminants of Gujarat

A study was aimed to estimate the seroprevalence and assess the potential risk factors of brucellosis among sheep and goats in Gujarat from 2013 to 2018. Atotal of 2445 sera (goats=1373 and sheep=1072) were subjected to Rose Bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (iELISA). A total of seven important risk factors or predictor variables were identified and variables with p<0.10 were retained for univariate logistic regression analysis. The apparent and true seroprevalence were 6.70 and 7.84% in goats and 13.24 and 15.50% in sheep, respectively. In goats, univariate logistic regression analysis affirmed that only two factors i.e., history of disease (odds ratio, OR- 5.03) and larger flock size (OR-3.03) had significant (p<0.001) association with the seroprevalence of brucellosis. In addition to these two, location (OR- 2.71) was also significantly associated (P<0.001) with seroprevalence of brucellosis in sheep. Least Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) values (625.61 and 677.86) as indicators of best correlation were obtained when breed, sex, history of disease and flock size were used as predictor variables for goats. In sheep, least AIC and BIC values (688.55 and 728.36) were obtained with the model incorporating breed, history of disease, region of sampling and flock size as predictors. To conclude, in goats and sheep, three common factors viz., breed, history and flock size were significantly associated with seroprevalence of brucellosis.