This is a bacterial disease that affects man, domestic and wild animals (commonly known as undulating fever or bang disease in humans and animals respectively). Brucellosis is still prevalent in the tropics. It is a costly disease as it leads to infertility and culling. In cattle, it causes inflammation of the uterus and cervix and causes repeat breeding. The disease is commonly referred to as a professional hazard for farmers and veterinarians. Brucellosis is spread from vaginal discharge of infected cow or from aborted feotus. Breeding bulls can get or spread the disease during mating. In man, it is spread through oral ingestion of bacteria in milk of infected cow; the bacteria can also be transmitted through skin, wounds, mucus membranes of the eye, nose and teat opening in animals. In a pregnant cow, brucellosis causes abortion which characteristically occurs between 5th and 8th month. People who handle aborted feotus without proper protection or drink milk from infected cows can get infected. Sometimes the dead feotus can be retained in the womb and will be mummified or macerated. In cases where calves are born from infected mothers, they will be weak and prone to diarrhoea and will in most instances die at infancy. The aborting cows are sources of infection to other animals and man as they shade the infection into pastures, buildings and drinking water. The disease is diagnosed in cows using simple milk tests but has no treatment. The disease can only be prevented through vaccination, use of artificial insemination instead of bulls and screening of new animals to minimise introduction of the disease into farms.

Eradication can be achieved through a rigorous test and slaughter strategy/policy of infected cows. Countries that have eradicated the disease like Denmark, UK, Netherlands and Romania have employed this strategy. In humans, the disease is treatable but cases of misdiagnosis for malaria and typhoid are common.