Ofloxacin resistance in multibacillary new leprosy cases from Purulia, West Bengal: A threat to effective secondary line treatment for rifampicin resistant leprosy cases.
OBJECTIVE: Purulia is one of the high endemic districts for leprosy in West Bengal [Eastern part of India]. The annual new case detection rate (ANCDR) of leprosy in West Bengal is 6.04/100000 (DGHS 2019-20). Our earlier report has already provided the evidence of presence of secondary drug resistance in relapse cases of leprosy. The primary aim of the study was to find out primary drug resistance pattern for dapsone, rifampicin and ofloxacin among new leprosy patients from Purulia, West Bengal. to find out the emergence of primary drug resistance to any of these drugs.
METHODS: In the present study, slit- skin smear samples were collected from 145 newly diagnosed leprosy cases from TLM Purulia hospital during the duration between 2017-2018. DNA was extracted from these samples and were analyzed for the genes associated with drug resistance in M. leprae genome by PCR and was followed by Sanger sequencing. Wild-type strain (Thai-53) and mouse footpad-derived drug-resistant (Z-4) strain was used as reference strains.
RESULTS: Out of 145 cases; 25 cases had shown mutation in any of the three genes of rpoB, folP and gyrA associated with rifampicin, dapsone and ofloxacin resistance as described by WHO respectively by Sanger sequencing. Among these 25 cases; 16 cases had shown the mutations in ofloxacin, 2 cases had shown the mutation in combination of ofloxacin and rifampicin, 4 cases had shown the mutation only in rifampicin, 1 case had shown mutation in combination of rifampicin and dapsone and 2 cases had shown mutation only in dapsone.
DISCUSSION AND CONCLUSION: Results from this study indicated the emergence of resistance to anti-leprosy drugs in new cases of leprosy. As ofloxacin is the alternate drug for the treatment of rifampicin resistant cases, the emergence of new cases with resistance to ofloxacin indicates that ofloxacin resistant M. leprae strains are actively circulating in endemic region i. e. Purulia, West Bengal of India and poses a concern about the effective treatment of rifampicin resistance cases.