Nontuberculous mycobacterial lung disease in a high tuberculosis incidence setting in Brazil

Abstract

Objective:The incidence of lung disease caused by nontuberculous mycobacteria (NTM) has been increasing worldwide. In Brazil, there are few studies about nontuberculous mycobacterial lung disease (NTMLD), and its prevalence is yet to be known. Our objective was to determine the specific etiology of the disease in the state of Rio Grande do Sul, Brazil, as well as the frequency and diversity of NTM species in our sample of patients. Methods:This is a retrospective analysis of the medical records of patients diagnosed with NTMLD treated in a referral center located in the city of Porto Alegre, Brazil, between 2003 and 2013. Results:Our sample comprised 100 patients. The most prevalent NTM species were Mycobacterium avium complex (MAC), in 35% of the cases; M. kansasii, in 17%; and M. abscessus, in 12%. A total of 85 patients had received previous treatment for tuberculosis. Associated conditions included structural abnormalities in the lungs, such as bronchiectasis, in 23% of the cases; COPD, in 17%; and immunosuppressive conditions, such as AIDS, in 24%. Conclusions:MAC and M. kansasii were the most prevalent species involved in NTMLD in the state, similarly to what occurs in other regions of Brazil. Data on regional epidemiology of NTMLD, its specific etiology, and associated conditions are essential to establish appropriate treatment, since each species requires specific regimens. Most patients with NTMLD had received previous tuberculosis treatment, which might lead to development of resistance and late diagnosis.

Nontuberculous mycobacteria in patients registered in a tuberculosis control program in Southwestern Colombia, 2014-2017

“…In one study in Brazil, common comorbidities of patients diagnosed with nontuberculous mycobacteria infection were bronchiectasis, chronic obstructive pulmonary disease, cardiovascular disease, and HIV. Surprisingly, 85% of the patients received tuberculosis treatment (8). In our study, diabetes and previous tuberculosis were common, and HIV coinfection was detected in 9.3% of patients.…”

“…There is a global increased attention on nontuberculous mycobacteria as the causative agents of disease in humans. Which is demonstrated by the emergence of reports from different regions and countries (3,(7)(8)(9)(10)(11). Several studies on the epidemiology of nontuberculous mycobacteria-related diseases in low and middleincome countries support this trend (5).…”

“…Brazil reported increasing from 2007 to 2013 number of pulmonary disease cases produced by nontuberculous mycobacteria. This is partly explained by a higher awareness of nontuberculous mycobacteria in the health community and/or better laboratory capacity (7,8).…”

“…Nevertheless, it should be noted that rapidly growing mycobacteria were more frequently isolated in contrast to the global trend of nontuberculous mycobacteria distribution that shows slowly growing mycobacteria and particularly Mycobacterium avium complex (MAC) as the most frequent species (7)(8)(9)(10)(11). In order to obtain a better picture of distribution of nontuberculous mycobacteria in Colombia and to conduct future studies on the clinical significance of circulating species producing pulmonary disease, it is necessary to strengthen laboratory capacity for the isolation and identification of nontuberculous mycobacteria through currently recommended methods like PCR and partial sequencing of genes like rpoB and hsp65 (10).…”

“…The likelihood of nontuberculous mycobacteria to cause lung disease increases with previous tuberculosis infection and HIV (5,8,9). In one study in Brazil, common comorbidities of patients diagnosed with nontuberculous mycobacteria infection were bronchiectasis, chronic obstructive pulmonary disease, cardiovascular disease, and HIV.…”