Keywords: M. lepromatosis, molecular test
Leprosy is a chronic, infectious, mycobacterial disease mainly affecting the skin, peripheral nerves, mucosal surfaces and eyes. About 160 countries across the world share their national leprosy data, of which, India accounts for more than half (56.6%) of the global new leprosy case burden. (1,2) M. leprae was thought to be the only causative agent of leprosy until M. lepromatosis was identified as another causative agent of the disease in 2008.3 The genome of M. leprae (3.27 Mb) is larger than M. lepromatosis (3.21 Mb) and there is a significant sequence difference of 9.1% between the two. (3) M. leprae is prevalent in most countries, while M. lepromatosis has been reported from Mexico, Canada, Brazil, Singapore and Myanmar. (4-6) Though India is the largest contributor to the global leprosy burden, there is not a single case of M. lepromatosis reported from India till date. Molecular methods play an important role in the laboratory confirmation of leprosy. Routine molecular diagnosis for leprosy in India focuses on identification of M. leprae, and antimicrobial resistance (AMR) detection, completely ignoring the newer agent. The current study was carried out to find the proportion of M. lepromatosis in the clinical specimens of leprosy patients received at a tertiary care leprosy institute, located in South India.
A descriptive study was conducted utilizing Slit Skin Smear (SSS) and skin biopsy specimens: retrospective frozen specimens from 2005-2018 (89 cases) and prospective specimens from January 2019 to April 2021 (20 cases). Approval...