Factors predicting incidence of nontuberculous mycobacteria in an era of climate change and altered ecosystems in the United States.

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause chronic pulmonary disease. Incidence patterns have risen globally over the last several decades. Prior studies suggest that climate change may have a role in increasing incidence patterns.

METHODS

We analyzed NTM incidence from two US-based populations: Medicare beneficiaries and persons with cystic fibrosis (pwCF). We identified predictors of NTM incidence with time-lagged meteorological and severe weather event covariates across US climate zones.

FINDINGS: The average annual incidence of NTM was 30.4 per 100,000 for the Medicare population and 2071.4 per 100,000 pwCF, with both populations showing rising incidence over the study period. We found that several factors predicted NTM incidence risk for the Medicare population and pwCF. In the Southeastern US particularly, floods were predictors of NTM incidence risk and across the mid-latitude US, dust storms were predictors of incidence. Air pressure, cloud cover, precipitation, and the number of days above various temperature thresholds were consistent predictors of NTM incidence across climate zones. The lag time between predictive meteorological variation or weather events and NTM incidence varied by zone and population studied.

INTERPRETATION: Geographic heterogeneity exists in the meteorological and severe event factors predictive of NTM incidence, evidenced by data from two high-risk study populations in the US. The role of continued climate change in the spatial and temporal distribution of NTM incidence merits further research.