Nontuberculous mycobacteria (NTM) are an important cause of disease and death, most often in the form of progressive lung disease. A new Oregon-based study has found that women have higher rates of NTM disease than men, including pulmonary disease. Pulmonary NTM was originally described in men, and until recent decades, thought to be less common among women. However, this study is the first population-based study of pulmonary NTM disease, and the first to document higher rates among women.
NTM-related pulmonary disease prevalence in women was 6.4 per 100,000 vs. 4.7 per 100,000 for men. The researchers believe that their findings are in line with published reports from experts who assert that the epidemiology of this disease has changed during the last several decades to affect women more frequently than men. They also found higher rates of NTM disease in those aged 51 and over and in residents of the Western, more urban part of Oregon. The latter may be due to the existence of large, municipal water systems in which water is standing for prolonged periods, which can attract bacteria, note the researchers.
Of the 933 patients with NTM isolated by culture, 56 percent met the microbiologic criteria for NTM disease. The annualized case rate of NTM disease was 7.2 cases per 100,000 persons. Pulmonary cases predominated with a case rate of 5.6 per 100,000, 85 percent of which was caused by Mycobacterium avium complex. Skin/soft tissue infections were the second most common cases, with a rate of 0.9 per 100,000. In comparison, Oregon's rate of tuberculosis (TB) was 2.8 and 2.2 cases per 100,000 persons for 2005 and 2006, respectively, suggesting that NTM disease causes more illness than TB in the State. The study was conducted under Oregon's special studies statute and was funded, in part, by the Agency for Healthcare Research and Quality (HS17552).
See "Nontuberculous mycobacterial disease prevalence and risk factors: A changing epidemiology," by P. Maureen Cassidy, M.P.H., Katrina Hedberg, M.D., Ashlen Saulson, B.S., and others in the December 15, 2009, Clinical Infectious Diseases 49, pp. e124-e129.