Seroprevalence and associated risk factors of brucellosis in rural domestic ruminants in Zanjan province

Brucellosis is one of the most common zoonoses in Iran. Zanjan province has been categorized as a high-risk region based on annual human Brucellosis incidence reports. It seems the high prevalence of the disease is related to the morbidity of disease in the domestic animals. This cross-sectional survey was carried out between January and December 2018, to estimate the seroprevalence and related risk factors in rural domestic ruminants in Zanjan province at individual and herd levels. For this purpose, Rose Bengal, Wright and 2-Mercaptoethanol serological tests with serial interpretation were used. The results showed that the seroprevalence of the disease at individual and herd-level were 4.0% and 33.2% respectively. In 51.9% of the villages there were animals with antibody titres against Brucella. Estimating of odds ratio (OR) showed that aborted fetal and related membranes burial (Odds Ratio: OR=0.2) and daily removing of manure in Livestock breeding season (OR=0.3) were protective factors. leaving aborted fetuses, fetal placenta and embryonic layers for the dogs (OR=3.6), disposal of the organs in the environment (OR=5.2), presence of goats in the herd/flock composition (OR=9.0), Abortion history (OR=3.7), the presence of herd dogs in farm (OR=7.9) , inadequate knowledge of farmer about the disease transmission routes (OR=3.3) , introduction of new animal to the herd(OR=5.0) and lack of vaccination history against brucellosis(OR=3.7) were significant risk factors. Therefore, it is essential to define and execute specified measures in order to strengthen protective factors and also weaken the risk factors of the disease in the province.