Identification of a familial cluster of pulmonary Mycobacterium bovis disease.

SETTING: Local public health department. DESIGN: Retrospective review of a cluster of three pulmonary Mycobacterium bovis cases occurring in a family, with genotyping of M. bovis strains isolated from the family members. RESULTS: The genotypes of the M. bovis isolates were identical, as determined by three different methods: IS6110 restriction fragment length polymorphism, spoligoytping and mycobacterial interspersed repetitive units-variable number tandem repeat analyses. CONCLUSION: The identification of three acid-fast bacilli (AFB) smear-positive pulmonary M. bovis cases, presenting in a single family and caused by an identical strain, suggests that person-to-person transmission of this organism may have occurred, although infection of one or more family members through ingestion of a contaminated dairy product could not be excluded.