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

Krpasha Govindasamy; Eric M C Etter; Bernice N Harris; Jennifer Rossouw; Darrell A Abernethy; Peter N Thompson

doi:10.3390/pathogens10111484

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

Pathogens. 2021 Nov 14;10(11):1484. doi: 10.3390/pathogens10111484.

Authors

Krpasha Govindasamy¹, Eric M C Etter^{1

2

3}, Bernice N Harris⁴, Jennifer Rossouw⁵, Darrell A Abernethy^{6

7}, Peter N Thompson¹

Affiliations

¹ Department of Production Animal Science, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa.
² Centre de Cooperation Internationale en Recherche (CIRAD), UMR Joint Research Unit, Animals Health Territories Risks Ecosystems (ASTRE), 34070 Montpellier, France.
³ CIRAD, Institut national de la recherche agronomique (INRA), University Montpellier, 34070 Montpellier, France.
⁴ School of Health Systems and Public Health, University of Pretoria, Pretoria 0031, South Africa.
⁵ Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Sandringham, Johannesburg 2192, South Africa.
⁶ Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa.
⁷ Aberystwyth School of Veterinary Science, Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Penglais, Aberystwyth SY23 3FL, UK.

Abstract

Brucellosis in humans is under-detected and underreported in sub-Saharan Africa. Risk factors associated with Brucella 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 (N = 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 Brucella 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 (p < 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, p = 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, p = 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, p < 0.001), with a simultaneous negative association with the handling of afterbirth or placenta (OR = 3.9, 95% CI: 1.3-11.3, p = 0.012). Findings suggest a proportion of undetected clinical cases of brucellosis amongst workers on cattle farms in Gauteng.

Keywords: B. abortus; Brucella; BrucellaCapt®; IgG ELISA®; IgM ELISA®; RBT®; South Africa; bovine; brucellosis; human.