Public Health and Economic Importance of Bovine Brucellosis: An Overview

Brucellosis is an important infectious re-emerging bacterial zoonosis of public health and economic significance. It affects the health and productivity of livestock as well as that of their owners and can have a deep economic impact. Brucellosis in cattle is usually caused by bio-vars of Brucella abortus. In some countries, particularly in southern Europe and western Asia, where cattle are kept in close association with sheep or goats, infection can also be caused by B. melitensis. Occasionally, B suis may cause a chronic infection in the mammary gland of cattle, but it has not been reported to cause abortion or spread to other animals. Humans are almost exclusively exposed to brucellosis through contact with animals and food of animal origin, transmitted via human contact with secretions, predominantly through calving and abortions. The disease can also be spread through the consumption of contaminated, unpasteurized dairy products. Globally, 500000 cases of human brucellosis are reported annually. The prevalence of human brucellosis differs between areas and has been reported to vary with standards of personal and environmental hygiene, animal husbandry practices, and species of the causative agent and local methods of food processing. The most common signs and symptoms of human brucellosis are fever, asthenia, myalgia, arthralgia, sweats, lymphadenopathy, hepatomegaly and splenomegaly. Endemic brucellosis in low-income countries of sub-Saharan Africa and South Asia has multiple economic implications across agriculture and public health and broader socio-economic development sectors. It is an economically important disease of livestock causing reproductive wastage through infertility, delayed heat, loss of calves, reduced meat and milk production, culling and economic losses. Microscopic examination of stained smears can be useful for a presumptive diagnosis, particularly if the direct examination supported by other tests. Mass vaccination is the mainstay of brucellosis control in livestock, but should be combined with other measures that limit the spread of the pathogen, allow identification of animals and herds, and increase community participation. Human brucellosis is usually prevented by controlling the infection in animals; Pasteurization of dairy products is an important safety measure where this disease is endemic.