Mycobacterium bovis tuberculosis: from animal to man and back.

Rare cases of tuberculosis due to Mycobacterium bovis have been described in humans who have been exposed to cattle or other infected animals. We report a case of tuberculosis in cattle exposed to a patient infected with M. bovis, where the strain isolated in the cattle and the patient were identical. As the patient is reported to have been exposed and contaminated during childhood, this seems to be the first documented case of transmission of M. bovis from animal to man and back to animal.