Indigenous Transmission of Mycobacterium africanum in Canada: A Case Series and Cluster Analysis

Complexities and benefits of adopting next-generation sequencing-based tuberculosis diagnostics: a qualitative study among stakeholders in low and high-income countries

OBJECTIVES

To clarify perceived benefits, barriers and facilitators of Mycobacterium tuberculosis next-generation sequencing implementation in Madagascar and Canada, towards informing implementation of this diagnostic technology in public health agencies and clinical settings in and beyond these settings.

DESIGN

This qualitative study involved conducting semistructured interviews with key stakeholders engaged with next-generation sequencing implementation in Madagascar and Canada. Team-based descriptive analysis supported by Nvivo V.12.0 was used to identify key themes.

SETTING

The study was conducted with participants involved at the clinical, diagnostic and surveillance levels of tuberculosis (TB) management from Madagascar and Canada.

PARTICIPANTS

Eighteen participants were interviewed (nine Madagascar and nine Canada) and included individuals purposively sampled based on involvement with TB surveillance, laboratory diagnosis and clinical management.

RESULTS

The following five themes emerged in the analysis of Malagasy and Canadian interviews: (1) heterogeneity in experience with established TB diagnostics, (2) variable understanding of new sequencing-based diagnostics potential; (3) further evidence as being key to expand adoption; (4) ethical arguments and concerns; (5) operational and system-level considerations.

CONCLUSION

There persists important lack of familiarity with TB next-generation sequencing (TB NGS) applications among stakeholders in Canada and Madagascar. This translates into skepticism on the evidence underlying its use and its true potential value added within global public health systems. If deployed, TB NGS testing should be integrated with clinical and surveillance programmes. Although this is perceived as a priority, leadership and funding responsibilities for this integration to happen remains unclear to clinical, laboratory and public health stakeholders.

Tuberculosis caused by Mycobacterium africanum: Knowns and unknowns

Tuberculosis (TB), one of the deadliest threats to human health, is mainly caused by 2 highly related and human-adapted bacteria broadly known as Mycobacterium tuberculosis and Mycobacterium africanum. Whereas M. tuberculosis is widely spread, M. africanum is restricted to West Africa, where it remains a significant cause of tuberculosis. Although several differences have been identified between these 2 pathogens, M. africanum remains a lot less studied than M. tuberculosis. Here, we discuss the genetic, phenotypic, and clinical similarities and differences between strains of M. tuberculosis and M. africanum. We also discuss our current knowledge on the immune response to M. africanum and how it possibly articulates with distinct disease progression and with the geographical restriction attributed to this pathogen. Understanding the functional impact of the diversity existing in TB-causing bacteria, as well as incorporating this diversity in TB research, will contribute to the development of better, more specific approaches to tackle TB.