Brucella bacteria cause brucellosis, an infection associated with unpasteurized dairy products.
Brucella is a genus of small Gram-negative bacteria that infect mammals. Humans can acquire brucellosis by consuming contaminated milk or cheese, handling infected animals or tissues, or inhaling contaminated aerosols. The disease commonly causes recurring fever, sweating, fatigue, and joint or muscle pain.
Different Brucella species are associated with different animal hosts. Brucella melitensis is strongly linked to goats and sheep, while Brucella abortus is associated with cattle. Brucella suis is associated with pigs, and Brucella canis with dogs.
Pasteurization greatly reduces the risk from dairy products by killing Brucella and other pathogens. Brucellosis is sometimes called undulant fever because its fever may rise and fall. The genus name honors David Bruce, who investigated Malta fever.