Clinical significance of nontuberculous mycobacteria isolates in elderly Taiwanese patients

Abstract

The aim of this study was to investigate the clinical significance of nontuberculous mycobacteria (NTM) isolates in elderly Taiwanese patients. From 2004 through 2008, patients >65 years old with NTM isolation were identified. The definitions of NTM disease followed the American Thoracic Society and Infectious Disease Society of America (ATS/IDSA) criteria. Among the 3,175 NTM isolates, Mycobacterium avium complex (MAC; n = 1,118, 35.2%) was the most prevalent species, followed by M. abscessus (n = 545, 17.2%). Among the 1,633 elderly patients with NTM isolates, the most prevalent NTM species were MAC (n = 592, 36.3%) and M. fortuitum complex (n = 311, 19.0%). NTM colonization was found in 1,339 (80.4%) patients and only 326 (19.6%) patients had NTM diseases. During the study period, the annual incidence rates (per 100,000 inpatients and outpatients) of NTM colonization and disease both increased significantly (p < 0.0001) from 10.5 to 15.8 and from 2.1 to 4.3, respectively. Isolated pulmonary NTM infections compromised 294 (90.2%) of the 326 elderly cases of NTM disease. In conclusion, this study found an increasing trend in the incidence of both NTM isolates and NTM diseases among elderly Taiwanese patients. MAC and M. abscessus were the most frequent species causing various types of NTM disease.

Increased risk of pulmonary tuberculosis in patients with previous non-tuberculous mycobacterial disease

“…8,20,21 In Taiwan, Lai et al reported an incidence rate of NTM disease of 2.23/100 000 outp atients 22 and 4.3/100 000 elderly patients (aged ⩾65 years), whereas their NTM colonisation rate was 15.8 in 2008. 23 Our results demonstrate a mean annual incidence of NTM disease of 1.9/100 000, in line with previous reports.…”

Management of nontuberculous mycobacterial infection in the elderly

“…The American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) have established guidelines to aid physicians in making the diagnosis of NTM. These guidelines indicate that in order to diagnose pulmonary NTM disease, clinical, radiological, and microbiological evidence of the disease should be met [5]. Table 3 shows criteria for diagnosing NTM according to ATS/IDSA guidelines.…”

“…Table 1 shows the most common NTM that cause infection in the elderly. They represent a diverse group of environmental organisms that can be isolated from water sources, soil, animals, and food [4, 5]. Human NTM infection is mainly acquired from environmental exposures [6, 7], although potential human-to-human transmission was recently suggested.…”

Update on the Epidemiology of Pulmonary Nontuberculous Mycobacterial Infections

“…65 years of age from 2004 to 2008 and found that, of 1,339 patients with NTM isolates, 19.6% met ATS/IDSA criteria for disease. 24 MAC and M. abscessus were most common. Another single medical center report looked specifically at MAC in Taiwan and identified 22% as meeting ATS/IDSA diagnostic criteria.…”