Brucella include arthritis or epididymo-orchitis, spondylitis, neurobrucellosis, liver abscess formation, and endocarditis, the latter potentially fatal. Human brucellosis is usually not transmitted from human to human; people become infected by contact with fluids from infected animals (sheep, cattle, or pigs) or derived food products, such as unpasteurized milk and cheese. Brucellosis is also considered an occupational disease because of a higher incidence in people working with animals (slaughterhouse cases). People may also be infected by inhalation of contaminated dust or aerosols, and as such, the CDC has labeled "Brucella" species as highly weaponizable. Human and animal brucellosis share the persistence of
Brucellosis a "calfhood" vaccination. Most cattle receive a tattoo in one of their ears, serving as proof of their vaccination status. This tattoo also includes the last digit of the year they were born. The first state–federal cooperative efforts towards eradication of brucellosis caused by "Brucella abortus" in the U.S. began in 1934. Brucellosis was originally imported to North America with non-native domestic cattle ("Bos taurus"), which transmitted the disease to wild bison ("Bison bison") and elk ("Cervus canadensis"). No records exist of brucellosis in ungulates native to America until the early 19th century. Antibiotics such as tetracyclines, rifampin, and the