Prevalence and herd-level risk factors associated with Brucella infection in smallholders keeping large ruminants

Brucellosis is a disease that poses a higher risk of transmission to animals and people who have close interactions with them, such as farmers. Therefore, the present study was designed to determine the seroprevalence of bovine brucellosis and associated risk factors in Kasur, Punjab, Pakistan. One hundred pooled milk samples from 100 smallholder mixed herds of cows and buffaloes with a total study population of 425 animals (277 cattle and 148 buffalos) with a range of up to seven animals in each herd were collected and tested through a milk ring test (MRT). Blood samples were collected from the animals of MRT-positive herds and then subjected to an indirect enzyme-linked immunosorbent assay (i-ELISA) for the presence of antibodies against Brucella abortus. Of the 100 herds, 16 % (n = 16) were MRT-positive. In MRT-positive herds, 77 animals (43 female cattle, three male cattle, 21 female buffaloes, and ten male buffaloes) were present; 32 (41.6 %) were i-ELISA seropositive, with the highest seropositivity (54.8 %) observed in buffaloes as compared to cows (32.6 %). Almost 38 % of the farmers were unaware of brucellosis. Herd-level risk factors indicated Brucella seropositivity increased in herds with recent abortion history and bull exchange during breeding. Conversely, herds with veterinary assistance exhibited a decreased Brucella seropositivity. The findings highlight the need for a government-led awareness campaign emphasizing routine screenings, especially for breeding bulls, to stop further disease spread. Early detection and management can enhance animal health, milk production, and livestock holders' economic well-being.