Bovine tuberculosis is similar to human tuberculosis, and it can infect humans.
Infection by eating or drinking dairy products is relatively uncommon in the United States, Ficht notes. So far, the scientists have used so-called DNA fingerprinting to identify about 300 isolates of the bovine TB bacterium in cattle from across Texas. Identifying specific strains of the bacterium is made difficult because its DNA varies only in subtle ways. About three samples in 10 can be identified as different, and about seven in 10 are indistinguishable from one another by DNA analysis, he says. If they are indistinguishable, then transmission remains a possibility.