Epidemiology of Pulmonary Nontuberculous Mycobacterial Disease, Japan1

To the Editor: Incidence of pulmonary nontuberculous mycobacterial disease (PNTMD) is reportedly increasing globally (1,2). Although such an increase is expected in Japan (3,4), the epidemiologic situation is unclear. The most recent survey, which used the 1997 American Thoracic Society diagnostic criteria, reported that the incidence rate for PNTMD in 2007 was 5.7 cases per 100,000 personyears (5). To update the data, we performed a nationwide hospital-based survey in Japan.