Prevalence of non-tuberculous mycobacterial disease among patients evaluated for pulmonary tuberculosis in Iraq 2015-2018

Abstract

Background: Nontuberculous Mycobacteria (NTM) are an important cause of morbidity and mortality in the progressive lung diseases. Clinical presentation of Mycobacterium tuberculosis complex (MTBC) and NTM may or may not be the same, but the treatment regimen is always different for both the infections. This study aims at highlighting the burden of NTM pulmonary disease (NTM-PD) among patients evaluated for pulmonary Tuberculosis (PTB). Methods: This study reviewed the registers of NRL for the period 2015-2018 looking for detected NTM among sputum samples drawn from patients evaluated for PTB. These samples were cultured on solid media. Cultures with rapid or slow growth are tested by line probe assay (LPA) to detect NTM. Taking into consideration that drainage of patients or their samples to NRL is from all Iraq for performing LPA to confirm the diagnosis. Results: During the four years period, 22 NTM-PD were observed out of 1416 patients evaluated for PTB with solid culture media for sputum samples with a rate of 1.6% (1.0%-2.4%). Male to female ratio was 2:1. NTM-PD was distributed almost equally through years with prevalence rates of 1.7% in 2015, 1.1% in 2016, 1.6% in 2017, and 1.9% in 2018. Observed types of NTM were: M.kansassi (11 or 50%), M.intracellulare (6 or 27.3%), M.gordonae (2 or 9.1%), and (1 or 4.5%) for each of M.fortiutum, M.abscessus and M.chelonae. Conclusions: NTM-PD presented in a rate of 1.6% out of patients evaluated for PTB with a male to female ratio of 2:1 and the dominant subtype is M.kansassi (50%).