Exposure Risk for Infection and Lack of Human-to-Human Transmission of Mycobacterium ulcerans Disease, Australia

: We conducted epidemiologic and genetic analyses of family clusters of Mycobacterium ulcerans (Buruli ulcer) disease in southeastern Australia. We found that the incidence of M. ulcerans disease in family members was increased. However, the risk for exposure appeared short-term and not related to human-human transmission.