Epidemiology and Molecular Diagnosis of Leprosy, Taiwan, 2002-2016

Abstract

The World Conference on Leprosy, held in 2016, reaffirmed the importance of stopping transmission, preventing disability, and detecting cases early in eradicating the disease. In Taiwan, leprosy is rare and the prevalence rate has reached the eradication criteria. Among the 133 confirmed cases in 2002-2016, 79(59.4%) were female, with 61(72.6%) imported, and the proportion of imported female cases was significant higher than that of the indigenous female cases (p ＜ 0.0001). Since M. leprae cannot be cultured in vitro, bacilli should be inoculated in BALB/c mouse's foot pads. For drug resistance testing, quantitative bacilli are inoculated within a foot pad, and the mice were fed with drug-containing food for 30 weeks. After that, the mice were sacrificed, and the amounts of bacteria were calculated. In order to improve the effectiveness of laboratory diagnosis, we establish an algorithm with molecular tests to identify M. leprae and its drug resistance since 2013. During 2013-2016, of the 47 suspected cases, 27(57.4%) cases were analyzed using the molecular tests. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 95.2%, 100%, 100%, 85.7% and 96.3%, respectively. The laboratory tests can strengthen the disease control and management.