Non-tuberculous mycobacteria isolation from presumptive tuberculosis patients in Lambaréné, Gabon

Trop Med Int Health. 2022 Apr;27(4):438-444. doi: 10.1111/tmi.13736. Epub 2022 Feb 27.

Abstract

Objective: The prevalence of clinical cases of pulmonary non-tuberculous mycobacteria (NTM) is increasing worldwide. The aim of this study was to determine the proportion and the NTM species isolated from presumptive tuberculosis patients in Lambaréné, Gabon.

Method: From January 2018 to December 2020, sputum samples from presumptive TB patients were analysed at the tuberculosis reference laboratory of the Centre de Recherches Médicales de Lambaréné. Two sputum samples were collected per patient, and culture was performed using Bactec MGIT 960. The GenoType Mycobacterium CM/AS was used for NTM isolates confirmation and species differentiation.

Results: Among 1363 sputum samples analysed, 285 (20.9%) were Auramin acid fast bacilli (AFB) smear-positive. NTM were isolated in 137/1363 (10%) of the samples. The most prevalent NTM species was Mycobacterium intracellulare (n = 74; 54%).

Conclusion: These results show the presence of NTM among presumptive TB patients in Gabon, which could potentially complicate TB diagnosis. This presents a new public health challenge, and emphasises the need to consider NTM in planning the prevention and management of tuberculosis control.

Keywords: Mycobacterium intracellulare; CM/AS genotype; Gabon; non-tuberculous mycobacteria; prevalence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gabon / epidemiology
  • Humans
  • Mycobacterium Infections, Nontuberculous* / epidemiology
  • Nontuberculous Mycobacteria / genetics
  • Sputum / microbiology
  • Tuberculosis* / diagnosis
  • Tuberculosis* / epidemiology
  • Tuberculosis, Pulmonary* / diagnosis
  • Tuberculosis, Pulmonary* / epidemiology
  • Tuberculosis, Pulmonary* / microbiology