Potential risk factors associated with herd level seroprevalence of brucellosis based on a univariate random effects model with strata forced in as a fixed effect and site as a random effect.

Sero-prevalence: Having or not at least one animal testing positive by Elisa-test within the herd (1 or 0). Strata: Stratum in which the investigations took place (Urban, Periurban, Rural). Site: Means the village, hamlet or the district selected for the study within the different strata. Herd: Herd surveyed within the different sites. Ref.: reference group.