Investigation of tuberculosis transmission in Canadian Arctic Inuit communities using DNA fingerprinting.

OBJECTIVE: To understand the transmission of tuberculosis in Inuit communities in the Baffin region of the Canadian Arctic. METHODS: Twenty-one isolates of Mycobacterium tuberculosis from 19 Inuit patients diagnosed with tuberculosis between February 1991 and September 1993 were analyzed by DNA fingerprinting. The DNA fingerprints were achieved by the standard restriction fragment length polymorphism (RFLP) technique, with subsequent probing using the repetitive insertion segment IS6110. RESULTS: The isolates could be divided into three DNA types. The DNA types generally corresponded to the geographic origins of the patients. In most instances only one DNA type of M. tuberculosis was identified in each community. This suggests that a single case was the start of each of the three clusters, most likely due to reactivation. CONCLUSIONS: The results show that molecular typing of M. tuberculosis was useful in determining the mode of transmission of tuberculosis in a remote area of the Canadian Arctic where the disease is endemic. In addition, the information provides useful information for planning interventions in this setting.