Drug resistance in Nepali leprosy patients.

Although multidrug therapy (MDT) was introduced into Nepal in 1983, the MDT coverage only recently exceeded 67%. In view of the large number of patients who were still receiving dapsone monotherapy, it is relevant to investigate the current levels of dapsone and rifampin resistance. The study was undertaken at a leprosy referral hospital near Kathmandu. Over a 5 1/2-year period, 157 leprosy patients with a bacterial index (BI) > or = 2.0 were investigated for drug resistance according to the method of Rees. Among previously untreated cases, 6% of 88 isolates showed low-dose dapsone resistance; among previously treated patients with a presumed relapse, 47% of 34 isolates demonstrated dapsone resistance. In the remaining 35 cases there was no growth in control mice. Rifampin resistance was not confirmed in any case.