Simplified Model to Survey Tuberculosis Transmission in Countries Without Systematic Molecular Epidemiology Programs

Area of Science:

• Microbiology
• Epidemiology
• Genomics

Background:

• Systematic molecular/genomic epidemiology for tuberculosis surveillance is challenging in many countries.
• Panama was chosen as a model to develop an alternative surveillance strategy.

Purpose of the Study:

• To evaluate an integrated approach combining MIRU-VNTR, whole-genome sequencing (WGS), and tailored PCR for tuberculosis surveillance.
• To assess the feasibility of this strategy in a setting with limited resources.

Main Methods:

• Mycobacterial interspersed repetitive unit-variable-number tandem-repeat (MIRU-VNTR) analysis was performed on Mycobacterium tuberculosis isolates.
• Whole-genome sequencing (WGS) was used to differentiate transmission clusters and identify marker single-nucleotide polymorphisms (SNPs).
• Three tailored, strain-specific PCRs targeting identified marker SNPs were prospectively applied.

Main Results:

• MIRU-VNTR analysis identified 50% of isolates in 6 clusters (A-F), with Cluster A linked to the Beijing sublineage.
• WGS distinguished recent transmission clusters (low diversity) from prevalent strains (higher diversity).
• Prospective PCR application showed 31.4% of incident cases involved strains A-C, with the Beijing strain prevalent in Colon.

Conclusions:

• An integrated approach of MIRU-VNTR, WGS, and tailored PCR offers a viable model for tuberculosis surveillance.
• This strategy can be implemented in countries lacking established molecular epidemiology programs.
• The study highlights the utility of combining different molecular techniques for effective TB surveillance.