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A2604 - Municipal Drinking Water Treatment Practices and Risk of Nontuberculous Mycobacterial Infection
Author Block: L. Caverly1, N. Kotlarz2, M. Zimbric2, J. Errickson2, L. Raskin2, J. J. LiPuma2; 1Pediatric Pulmonology, University of Michigan, Ann Arbor, MI, United States, 2University of Michigan, Ann Arbor, MI, United States.
RATIONALE: Nontuberculous mycobacterial (NTM) pulmonary infections are increasing in prevalence in the United States and result in significant morbidity, mortality, and health care costs. NTM infections are primarily acquired from environmental sources, including soil and water exposed surfaces. While relationships between NTM infection and municipal drinking water treatment practices are unclear, higher levels of NTM have been detected in drinking water disinfected with chloramine compared to chlorine. We hypothesized that prevalence of NTM infection would be greater in recipients of drinking water treated with chloramine compared to drinking water treated with chlorine. METHODS: We performed a retrospective review of all NTM diagnostic tests (i.e., acid-fast bacillus smear and culture) performed at Michigan Medicine from January 2000 through September 2015. Data obtained included NTM test results, patient demographics, and clinical data. Information on municipal water treatment practices in Michigan cities was obtained from the US Environmental Protection Agency. Logistic regression modeling was used to examine relationships between NTM infection, subject characteristics, and city characteristics, including municipal water treatment practices. RESULTS: Of the 29,789 patients tested for NTM over the study period, 4.1% had a test positive for NTM at least once. The majority (66%) of NTM-positive tests were from a pulmonary source. Patient diagnosis of immune deficiency or lung disease, and older patient age were significantly associated with increased risk of an NTM positive test (p = 0.04 and 0.03, respectively). Municipal water disinfectant type (chloramine) was not significantly associated with NTM infection (p = 0.24). However, the use of surface water as opposed to groundwater as the primary drinking water source was significantly associated with NTM infection (p = 0.04). CONCLUSIONS: In this cohort, chloramine-treated drinking water treatment was not associated with increased risk of NTM infection compared to chlorine-treated drinking water. The positive relationship between a surface water source of municipal drinking water and NTM infection implies the potential for higher NTM abundance in surface water relative to groundwater, and suggests municipal drinking water as a potentially modifiable risk factor to reduce incidence of NTM infection.