Environmental Risk Factors for Mycobacterium avium Complex (Mac) Lung Disease in HIV-(-) Adults

EPA Grant Number: FP916956
Title: Environmental Risk Factors for Mycobacterium avium Complex (Mac) Lung Disease in HIV-(-) Adults
Investigators: Ashworth, Maegan
Institution: University of Alabama at Birmingham
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2008 through June 30, 2010
RFA: STAR Graduate Fellowships (2008) RFA Text |  Recipients Lists
Research Category: Academic Fellowships


This project will be a population-based case-control study of lung disease caused by members of the Mycobacterium avium complex (MAC).

MAC are residents of soil, water and animal hosts, and occasionally cause disease in humans. There is evidence that the incidence of MAC lung disease is increasing in humans without apparent immune defects. Some clinical and biologic traits of the host have been identified as risk-factors, but less is known about how disease risk is affected by pathogen traits, environmental factors, and ways that potential hosts interact with pathogens in the environment. The objective of this research is to identify features of the home water supply, features of potting and gardening soil, ways that individuals interact with water and soil, and subgroups of MAC (species, subspecies, clades, or specific strains) that are associated with risk of MAC pulmonary disease.


MAC pulmonary disease patients will be invited to participate via pulmonary and infectious disease doctors in the state of Washington. Control subjects will be recruited via cases. Information regarding water use, soil use, and potential confounding factors will be collected via face-to-face interview in the subject’s home. During the same home-visit, samples of soil and water will be collected. Members of the MAC will be detected and identified from these samples. Associations between hypothesized risk-factors and case-control status will be compared using by calculating odds ratios (Ors). ORs will be estimated by means of Mantel-Haenszel methods and multiple logistic regression.

Expected Results:

It is expected that case-status will be associated with a history of engaging in behaviors that generate aerosols of soil and water in the home. It is also expected that traits of the water supply, traits of soil, and specific subgroups of MAC identified will differ between cases versus controls. This will help identify behavioral modifications or changes to disinfection practices in water systems they may reduce the risk of MAC lung disease.

Supplemental Keywords:

opportunistic diseases, waterborne diseases, mycobacterium avium, nontuberculous, epidemiology, lung disease, pulmonary disease, emerging diseases, environmental mycobacteria,

Progress and Final Reports:

  • 2009
  • Final