You are here:
Nontuberculous mycobacteria: Reports of clinical laboratory isolation in a three county area, North Carolina, 2006 -2010
Citation:
HILBORN, E. D., M. S. Murphy, K. Messier, E. E. HUDGENS, A. J. GHIO, J. M. Maillard, S. Pfaller, AND J. Stout. Nontuberculous mycobacteria: Reports of clinical laboratory isolation in a three county area, North Carolina, 2006 -2010. Presented at International Conference on Emerging Infectious Diseases, Atlanta, GA, March 11 - 14, 2012.
Impact/Purpose:
Laboratory reports of mycobacteria isolation and identification are created during the clinical diagnostic process to differentiate Mycobacterium tuberculosis from nontuberculous mycobacteria (NTM). NTM isolation rates are expected to exceed rates of true NTM infections.
Description:
Background: Laboratory reports of mycobacteria isolation and identification are created during the clinical diagnostic process to differentiate Mycobacterium tuberculosis from nontuberculous mycobacteria (NTM). NTM isolation rates are expected to exceed rates of true NTM infections. Methods: We collaborated with North Carolina tuberculosis control personnel and diagnostic laboratories to identify and collect reports of NTM isolation among residents of three counties during 2006 -2010. Data included: patient age, gender, race, NTM species, anatomic site of isolation, and location of patient residence when present in the report. We performed descriptive analyses of data, and calculated rates of isolation by county, race, and age group using 2010 USCensusdata. We mapped patient residence to evaluate environmental risk factors for infection. Results: We identified 559 individuals with at least one report of isolation of NTM, 50% were female, 64% white; 22% African American and 14% 'other' race. Isolation rates per 100,000 were higher among white females than white males, however African American and 'other' race males had higher rates of isolation than females. Median age of isolation was 56 years (range: <1-107 years). Isolations from anatomic sites included: 415 (74%) from respiratory specimens; 40 (7%) from sterile sites or blood culture; 30 (5%) from dermal sites; and 74 (13%) from 'other' sites. Of 505 NTM isolates identified to species or complex, 371 (74%) were slow growing NTM, and M. avium complex was identified in 302 (60%). The rate of isolations per 100,000 persons varied among counties; county 'A': 24.4; county 'B': 11.5; county 'C': 5.4. Isolation rates among all ages were 8.6/100,000 persons. Rates per 100,000 persons increased with age: ranging from 2.5 for those less than 20 years, to 27.5 for those persons age 60 and older. Conclusions: We found NTM isolations rates were modified by gender and race. Slow-growing NTM isolations predominated. Isolations were more frequent among older persons. Isolation rates varied among counties, with higher rates in a county with less favorable environmental conditions for NTM occurrence suggesting a potential diagnostic bias. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.