Pediatric Pulmonology 52:324–330 (2017) Household Proximity to Water and Nontuberculous Mycobacteria in Children With Cystic Fibrosis Jennifer M. Bouso, MD, MSPH, 1,2 * James J. Burns, MD, MPH, 1 Raid Amin, PhD, 3 Floyd R. Livingston, MD, 4 and Okan Elidemir, MD 1,2 Summary. Background: Nontuberculous mycobacteria (NTM) have a particular affinity for patients with cystic fibrosis (CF). Recent studies suggest a possible relationship between acquiring NTM and the level of environmental water in a given area. We sought to determine if there is an association between household proximity to water and NTM in children with CF. Materials and Methods: An IRB-approved retrospective chart review was completed on 150 children with CF in Florida. Inclusion criteria required regular follow-up, at least two acid-fast bacilli cultures, and a consistent home address over a 3-year period. The distance from each patient’s home to the nearest body of water was measured using ArcMap 1 , a Geographic Information System, and the mean distance to water for NTM-positive and NTM-negative groups were compared. A stepwise backwards logistic regression was used to evaluate for predictors of NTM- positivity. Results: Of the 150 CF patients, 65 met inclusion criteria and 21 (32.3%) tested positive for NTM. Comparison of the mean distance to water for NTM-positive versus NTM-negative groups revealed a cutoff of 500 meters. On the logistic regression, CF patients who lived within 500 meters of water were 9.4 times more likely to acquire NTM (P ¼ 0.013). Other significant predictors included a history of Aspergillus fumigatus (OR 7.9, P ¼ 0.011) and recent history of Pseudomonas aeruginosa (OR 2.5, P ¼ 0.007). Conclusions: In the regions studied, children with CF who live closer to water are more likely to acquire nontuberculous mycobacteria. Future studies in other geographic areas are needed to determine if these results are generalizable. Pediatr Pulmonol. 2017;52:324–330. ß 2017 Wiley Periodicals, Inc. Key words: cystic fibrosis; infections (pneumonia TB viral); infectious disease; atypical mycobacteria; nontuberculous mycobacteria; water; children; pediatric pulmonology. Funding source: none reported. 1 Pediatric Residency Program at Sacred Heart Hospital, University of Florida, Pensacola, Florida. 2 Department of Pediatric Pulmonology, Nemours Children’s Specialty Care, Pensacola, Florida. 3 Department of Mathematics and Statistics, University of West Florida, Pensacola, Florida. 4 Department of Pediatric Pulmonology, Nemours Children’s Specialty Care, Orlando, Florida. Conflict of interest: None of the authors have any financial/nonfinancial disclosures or conflicts of interest to report. Ethics statement: This study was conducted in accordance with the amended Declaration of Helsinki. Nemours Children’s Clinics IRB Board approved the research protocol, IRB# 73570–2. Prior abstract presentation: Initial results from the Pensacola CF center were presented as an oral presentation by Dr. Jennifer Bouso in the Pulmonary and Critical Care Session at the Southern Regional Meeting in New Orleans, LA on February 19th, 2016. The abstract related to this meeting was not published. Final results were presented in poster format at the North American Cystic Fibrosis Conference in Orlando, Florida on October 27, 2016. Ã Correspondence to: Jennifer M. Bouso, MD, MSPH, University of Florida, Pediatric Residency Program at Sacred Heart Hospital, 5153N. 9th Ave. Pensacola, FL 32504. E-mail: bousoj86@ufl.edu Received 22 July 2016; Revised 6 October 2016; Accepted 17 November 2016. DOI 10.1002/ppul.23646 Published online 30 January 2017 in Wiley Online Library (wileyonlinelibrary.com). ß 2017 Wiley Periodicals, Inc.