What disease is caused by the bacterium Brucella melitensis?

Brucella melitensis causes brucellosis, a zoonotic infection also known as Malta fever.

The bacterium is especially associated with goats and sheep, where infection can cause abortion, stillbirths, infertility, inflammation of the reproductive tract, and reduced milk production. People may become infected by consuming unpasteurized dairy products or through contact with infected animals, placentas, or other secretions.

The organism’s medical history reaches back to Malta. In 1887, British physician David Bruce isolated the bacterium—then called Micrococcus melitensis—from the spleen of a soldier who had died of the disease. The genus was later renamed Brucella in Bruce’s honor.

A common mix-up is Q fever, another livestock-associated disease, but Q fever is caused by Coxiella burnetii. Brucellosis is caused by Brucella species, with B. melitensis among the most important causes of severe human disease.