Seroprevalence of <i>Brucella</i> infection in cattle and small ruminants in South Omo zone, southern Ethiopia

Abstract

A cross-sectional study was conducted in selected districts of the South Omo Zone to estimate the seroprevalence of brucellosis and its associated risk factors. Additionally, the knowledge, attitude, and practices (KAP) of livestock keepers about the disease were also assessed. A total of 1349 sera samples were collected from 450 cattle and 899 small ruminants (450 goats and 449 sheep) kept under an extensive production system. Rose Bengal Plate Test was used for screening and ELISA as a confirmatory test for the detection of antibodies against Brucella species. Based on confirmatory tests, the overall seroprevalence of brucellosis was 2.2 % (95% CI: 1.1 – 4.1%) in cattle, 2.0% (95% CI: 0.9, 3.8%) in goats and 1.3% (95% CI: 0.5, 2.9%) in sheep with higher seropositivity in cattle compared to small ruminants. Seropositivity did not vary significantly (p> 0.05) with agroecology, age, and sex groups in cattle. However, a higher seroprevalence of 2.7% was detected in male cattle compared to 1.6% for females. Seroprevalence was higher in small ruminants from the lowland agroecology (3.0%) than those from the midlands (0.8%). Study respondents had a low level of knowledge on brucellosis with only 43% of them having some information about the disease. Most of the respondents have routinely engaged in practices that can expose them to infections such as assisted delivery (65%), contact with after-birth materials (50%), and handling aborted materials (15%) without any protection. High consumption of unpasteurized dairy products (93%) such as raw whole milk and traditionally fermented dairy product is also common. This study provides information on the occurrence f brucellosis in major livestock species kept at cross-border marginal areas with limited disease information. The existence of various exposure practices implies the need for creating awareness among livestock keepers on general disease transmission and its zoonotic role.