Systematic Review of Studies In Sub-Saharan Africa Aims to Consolidate Data on Pulmonary NTM

MRCG’s systematic review of several studies in sub-Saharan Africa aimed to consolidate existing data on pulmonary NTM in sub-Saharan Africa, review the existing gaps in our knowledge of pulmonary NTM and identify future research priorities was published in Scientific Reports on the 20th of September 2017. According to lead author Catherine Okoi, the findings suggested that a substantial proportion of patients in sub-Saharan Africa suspected of having pulmonary TB or multi-drug resistance TB may actually have had pulmonary NTM disease that was not detected in routine laboratory analysis. Thus, understanding the proportions of NTM and MTBC in the patients with tuberculosis-like disease is critically needed for proper evaluation of the disease, and planning appropriate interventions.

Pulmonary tuberculosis-like disease caused by non-tuberculous mycobacteria (NTM) has gained attention, in part, because of its increased recognition especially in the elderly and immunocompetent population. This is an emerging problem of public health significance. With the increasing incidence from case reports and series from diverse countries and regions of the world, the distribution of NTM species isolated from clinical samples appear to vary significantly by region. However, very little is known about the contribution of NTM to tuberculosis-like disease, and significant knowledge gaps exist regarding their geographical distribution, clinical and molecular epidemiology in low and middle-income countries (LMIC) where there is a high burden of disease caused by Mycobacterium tuberculosis complex (MTBC). Given the similarity on the clinical manifestation of pulmonary diseases caused by NTM and MTBC, one implication of the inability to identify NTM in pulmonary samples hitherto is that the prevalence of diseases ascribed to MTBC could be faulty.

Going forward, a comprehensive multi-country surveillance of NTM is needed to better understand the magnitude of the burden of pulmonary NTM in carriage and disease in sub-Saharan Africa, and to design strategic action plans for effective laboratory diagnostics of NTM pulmonary disease and carriage to inform appropriate case management. Finally, given the increasing incidence of pulmonary NTM colonisation and disease registered around the globe, epidemiological and surveillance data should be obtained through the reporting of pulmonary NTM infections for Public Health decision making.


Mrs. Catherine Okoi is a Molecular Microbiologist working with Professor Martin Antonio and Dr Kwambana Adams Brenda in the Vaccines and Immunity Theme, at MRC Unit The Gambia (MRCG), and has a strong interest in the accurate diagnosis of infectious diseases. Since joining MRCG in 2011, Mrs. Okoi has worked and contributed immensely to the success of several projects in The Unit including The Gambia Survey of Tuberculosis Prevalence (sponsored by Global Fund), Next Generation Molecular Diagnostic Techniques for Developing Countries project (sponsored by Bill and Melinda Gates Foundation) and Invasive Bacteria Disease Surveillance project (sponsored by World Health Organisation).

She also won a Seed Grant award from Institute of Tropical Medicine (ITM) Antwerp in 2015 to support her MPhil programme. Articles co-authored by Mrs. Okoi include A tuberculosis nationwide prevalence survey in Gambia, 2012; Impact of the Mycobacterium africanum West Africa 2 lineage on TB Diagnostics in West Africa: decreased sensitivity of rapid identification tests in The Gambia; An outbreak of pneumococcal meningitis among older children (≥5 years) and adults after the implementation of an infant vaccination programme with the 13-valent pneumococcal conjugate vaccine in Ghana and Use of quantitative molecular diagnostic methods to identify causes of diarrhoea in children: a reanalysis of the GEMS case-control study. Mrs. Okoi currently manages and coordinates the laboratory activities of the Research Molecular Microbiology Group in Professor Martin Antonio’s group.