Non-Tuberculous Mycobacteria: Single Center Analyses of Risk Factors, Management and Mortality Outcomes of Adults...

In sub-Saharan Africa, there is paucity of data regarding non-tuberculous mycobacterial (NTM) infections, leading to underappreciation of disease burden. Consequently, fewer resources are allocated, leading to potential adverse outcomes. This study examines long-term mortality and risk factors of South African patients with positive NTM samples.

We conducted a retrospective analysis of clinical isolates of NTMs between 1 January 2010 and 30 June 2017. We retrieved and thoroughly reviewed the corresponding medical records of patients treated at Charlotte Maxeke Johannesburg Academic Hospital. Outcomes were compared between patients who underwent different therapy regimens, including macrolide-based regimens and 'watchful waiting'.

A total of 123 patients were followed for a median of 1 year (interquartile range [IQR], 0.5-4.5). The median age was 39 years (IQR, 31-51) with male predominance, 58%. The common comorbid conditions were HIV (encountered in 78%) and previous TB (58%). Pulmonary disease due to Mycobacterium avium complex (MAC-PD) was found in 74% of patients, M. fortiutum in 5%, and M. gordonae in 4%. The mortality relative risk for patients on initial macrolide-containing therapy was 0.54 (95% confidence interval [CI], 0.22-1.36), p = 0.194, while that for macrolide-free antimicrobials was 1.38 (95% CI, 0.57-3.34), p = 0.471. The adjusted hazard rate for mortality with low CD4 counts < 50 cells/mm³ was 2.79 (95%, 1.20-6.50), while that for unknown CD4 counts was 4.01 (95% CI, 1.17-13.77), compared to CD4 counts > 50 cells/mm³.

Among HIV patients, NTM-PD predominated, and not disseminated disease. MAC-PD was the most common infection. Low CD4 counts was a significant risk factor for early death, while sex, NTM species, macrolide therapy, and previous TB were not.