From the Journals

Non-TB mycobacteria infections rising in COPD patients



Veterans with chronic obstructive pulmonary disease (COPD) have seen a sharp increase since 2012 in rates of non-TB mycobacteria infections, which carry a significantly higher risk of death in COPD patients, according to findings from a nationwide study.

Dr. George Kubica/CDC

Petri culture plate that had been used to cultivate colonies of the saprotrophic bacteria Mycobacterium avium, which is commonly found in water and soil.

For their research, published in Frontiers of Medicine, Fahim Pyarali, MD, and colleagues at the University of Miami, reviewed data from Veterans Affairs hospitals to identify non-TB mycobacteria (NTM) infections among more than 2 million COPD patients seen between 2000 and 2015. Incidence of NTM infections was 34.2 per 100,000 COPD patients in 2001, a rate that remained steady until 2012, when it began climbing sharply through 2015 to reach 70.3 per 100,000 (P = .035). Dr. Pyarali and colleagues also found that, during the study period, prevalence of NTM climbed from 93.1 infections per 100,000 population in 2001 to 277.6 per 100,000 in 2015.

Hotspots for NTM infections included Puerto Rico, which had the highest prevalence seen in the study at 370 infections per 100,000 COPD population; Florida, with 351 per 100,000; and Washington, D.C., with 309 per 100,000. Additional hotspots were identified around Lake Michigan, in coastal Louisiana, and in parts of the Southwest.

Dr. Pyarali and colleagues noted that the geographical concentration of cases near oceans and lakes was “supported by previous findings that warmer temperatures, lower dissolved oxygen, and lower pH in the soils and waters provide a major environmental source for NTM organisms;” however, the study is the first to identify Puerto Rico as having exceptionally high prevalence. The reasons for this should be extensively investigated, the investigators argued.

The mortality risk was 43% higher among NTM-infected patients than in COPD patients without an NTM diagnosis (95% confidence interval, 1.31-1.58; P less than .001), independent of other comorbidities.

Though rates of NTM infection were seen rising steeply in men and women alike, Dr. Pyarali and colleagues noted as a limitation of their study its use of an overwhelmingly male population, writing that this may obscure “the true reach of NTM disease and mortality” in the general population. The average age of NTM diagnosis remained steady throughout the study period, suggesting that rising incidence is not attributable to earlier diagnosis.

Dr. Pyarali and colleagues reported no outside sources of funding or financial conflicts of interest.

SOURCE: Pyarali F et al. Front Med. 2018 Nov 6. doi: 10.3389/fmed2018.00311.

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