The future in diagnostic tools for TB outbreaks: A review of the approaches with focus on LAMP and RPA diagnostics tests

Tuberculosis (TB) is still the most frequent cause of morbidity and mortality in the world caused by Mycobacterium tuberculosis (MTB). Due to slow diagnostic and treatment options, the disease is a major concern for public health and also increases the burden on the global economy. Rapid, sensitive, and cheaper TB diagnosis test is urgent to lower their rates by point of care testing (POCT). Therefore, molecular detection techniques like recombinase polymerase assay (RPA) and Loop-mediated isothermal amplification (LAMP) play a significant role in this regard as they work on the principle of isothermal nucleic acid amplification. RPA and LAMP bridge the research gap between the previous PCR-based detection tool and other reported isothermal tools for MTB. In this review, we endeavor to provide an overview of the assay that will be a novel approach toward a rapid amplification and visualization of DNA by the naked eye in natural light. RPA and LAMP can prove to be a highly specific pathogen detection technique in combination with lateral flow (LF) strips and SYBR Green I. Optimization of amplification conditions also made the assay ideally suited to the resource-limited field application at POCT. Additionally, RPA and LAMP have paved the way for meeting a key component of the POC diagnosis of TB like universal drug susceptibility testing. However, RPA is more suitable at the POC level than LPA as it requires a lower amplification temperature of around 37-42 °C and a simpler primer design.