Knowledge of Brucellosis, Health-Seeking Behaviour, and Risk Factors for Infection Amongst Workers on Cattle Farms in Gauteng, South Africa

Brucellosis in humans is under-detected and underreported in sub-Saharan Africa. Risk factors associated with infection and health seeking behaviour in response to brucellosis-like symptoms, amongst cattle farm workers and veterinary officials in South Africa, are unknown. Farm workers and veterinary officials ( = 230) were screened for brucellosis using commercial Rose Bengal Test (RBT), IgM Enzyme-linked Immunoassay (ELISA), IgG ELISA and the BrucellaCapt test. Knowledge of brucellosis and risk factors for exposure to were also investigated. Seroprevalence varied according to test used: 10.1% (RBT), 20.9% (IgG ELISA) and 6.5% (BrucellaCapt). Only 22.2% (6/27) of veterinary officials opt to visit a clinic, doctor, or hospital in response to self-experienced brucellosis-like symptoms, compared to 74.9% (152/203) of farm workers ( < 0.001). Of the BrucellaCapt seropositive participants, 53% (7/15) did not visit a clinic in response to brucellosis-like symptoms. Weak evidence of an association between the handling of afterbirth or placenta and infection of a short evolution (RBT, IgM ELISA and IgG ELISA seropositive) was found (OR = 8.9, 95% CI: 1.0-81.1, = 0.052), and strong evidence of an association between this outcome and the slaughter of cattle (OR = 5.3, 95% CI: 1.4-19.6, = 0.013). There was strong evidence of a positive association between inactive/resolved infection and veterinary officials vs. farm workers exposed to seropositive herds (OR = 7.0, 95% CI: 2.4-20.2, < 0.001), with a simultaneous negative association with the handling of afterbirth or placenta (OR = 3.9, 95% CI: 1.3-11.3, = 0.012). Findings suggest a proportion of undetected clinical cases of brucellosis amongst workers on cattle farms in Gauteng.