The animals people depend on for food and income can also carry infections across the boundary between farms and homes. In South Africa, that boundary looked quiet for one disease—but not for all of them. Diseases that pass between animals and people are responsible for 2.5 billion human cases globally and approximately 2.7 million deaths annually.

That makes contact with livestock a public-health question, not only a farming question. Surveillance of animal handlers and livestock contributes to understanding the true disease burden and risk factors within a community.

This study therefore looked at cattle, farm workers, and exposure linked to their work. The study compared two ways of farming: communal or backyard subsistence farming and large-scale commercial farming. It investigated infection in cattle and farm workers, along with the factors linked to risk.

It also set out to document occupational and environmental exposure to three infection groups: Brucella species, Leptospira species, and hantaviruses, across South Africa’s Free State province. The testing covered cattle across two municipal regions in South Africa’s Fezile Dabi district, including dairy and beef farms and a community cattle enclosure.

That spread matters because the results reflect several different cattle-keeping settings, not just one farm. The study followed workers who had occupational exposure to animals and cattle. The farms already had cattle scheduled for routine screening for bovine tuberculosis and brucellosis through the provincial surveillance program.

Farm workers on those farms were then screened for signs of tuberculosis-causing bacteria and for antibodies showing exposure to brucellosis, and they completed a questionnaire. Among the cattle checked, three of fifty-one in Maokeng and four of thirty-three on farm A were classified as suspected reactors by the study’s screening test.

But in the cattle tested, the study detected no positive bovine tuberculosis results at or above its stated threshold of twenty. So the first picture is not of widespread cattle tuberculosis. The results available from the screening did not identify a clear positive result at that threshold.

Signs of exposure to brucellosis were detected in all occupations. Among the farm workers, antibodies were found in Maokeng community farmers and in one worker from farm B. Signs of exposure to leptospirosis and hantaviruses were mainly detected in abattoir workers and stable groomsmen.

The risk was not evenly distributed across every job. The cattle tuberculosis prevalence detected in this study was 0.7 percent, representing two animals, and both came from commercial dairy farm B. The researchers say the result was lower than reports from several other sub-Saharan countries.

The findings are consistent with potentially effective control schemes lowering cattle tuberculosis transmission at the study site. But wildlife can also spread this infection to nearby livestock where the two meet. Hantaviruses are usually transmitted through environmental exposure, but their presence in South Africa has not been confirmed.

The study’s antibody findings were similar to those in other studies, yet the researchers say this limited study cannot establish a conclusion. Because possible rodent hosts are present in Africa, the researchers say these infections could occur and should be investigated among people at risk.

A large proportion of people in South Africa depend on animals for food, trade, companionship, or services. That is why the study encourages a One Health approach: understanding human and animal health together. More emphasis should go to populations at higher risk of zoonotic infection in epidemiological investigations, especially in a country where many people depend on animals for food, trade, companionship, or services.

The study found different risks in different farming communities: tuberculosis in cattle was uncommon, while signs of several other infections appeared among people and animals. Safer farming depends on watching both sides together.