United States raw milk debate prior to symptom onset." Milk collected or stored in unsanitary conditions may harbor a host of disease-causing organisms (pathogens), such as "tuberculosis" (Mycobacterium bovis), the bacteria "Campylobacter" (Campylobacteriosis), "Escherichia" E. coli O157:H7), "Listeria" (Listeriosis), "Salmonella" (Salmonellosis), "Yersinia" (Yersinia enterocolitica), and "Brucella" (Brucellosis). Pasteurization consistently removes all of these pathogens, though they can be reintroduced if the product is handled carelessly. Thus dairy farms that pasteurize their milk can have unsanitary facilities without the attendant outbreaks of disease that would occur if a raw milk dairy kept its herds in similar unsanitary conditions. People with weakened immune systems, such as elderly,
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