Tb Genomics for Public Health

ABSTRACT

Mycobacterium tuberculosis complex (MTBC), the causative organisms of tuberculosis (TB), has afflicted man for millennia. TB was declared a global health emergency by the World Health Organization in 1993. Before the 2020 Covid pandemic, it was responsible for 10 million new cases annually and was the leading infectious disease killer worldwide. MTBC strain typing represents an important complementary tool to guide TB control measures. TB programmes can use genotyping results in combination with epidemiological information to determine if recent transmission has likely occurred, and hence identify outbreaks that require targeted public health action. MTBC genotyping also can differentiate between relapse or re-infection, detect false-positive cases, and identify and monitor the circulating TB strains in the population over time. Restriction Fragment Length Phenotyping (RFLP), introduced in the 1990s, was labour intensive, required large amounts of DNA and was not easily comparable between laboratories. These disadvantages are overcome by the PCR-based MIRU-VNTR and spoligotyping methods. More recently, whole genome sequencing (WGS) of MTBC has been shown to provide high resolution identification of recent transmission chains and their direction, as well as drug resistance prediction. Its increasing reliability and affordability has enabled this technology to transition from the research arena to clinical care and public health functions. Its application in high TB burden countries will hopefully revitalize global TB control efforts which have set back by the Covid pandemic.Copyright © 2023