Mycobacterium leprae: Pathogenesis, diagnosis, and treatment options

Mycobacterium leprae is known to cause leprosy, a neurological and dermatological disease. In the past 20 years, 16 million leprosy cases have been recorded and more than 200,000 new cases were registered each year, indicating that the disease is still progressing without hindrance. M. leprae, an intracellular bacterium, infects the Schwann cells of the peripheral nervous system. Several types of leprosy have been described, including indeterminate, tuberculoid, borderline tuberculoid, mid-borderline, borderline lepromatous and lepromatous, and three different forms of leprosy reactions, namely type 1, 2 and 3, have been designated. Microscopic detection, serological diagnostic test, polymerase chain reaction and flow tests are employed in the diagnosis of leprosy. The recommended treatment for leprosy consists of rifampicin, dapsone, clofazimine, ofloxacin and minocycline and vaccines are also available. However, relapse may occur after treatment has been halted and hence patients must be educated on the signs of relapse to allow proper treatment and reduce severity. In this review, we depict the current understanding of M. leprae pathogenicity, clinical aspects and manifestations. Transmission of leprosy, diagnosis and treatment are also discussed.