Are Leprosy Case Numbers Reliable?

The most recent WHO leprosy statistics 1 WHOGlobal leprosy update, 2016: accelerating reduction of disease burden. Wkly Epidemiol Rec. 2017; 92: 501-520 PubMed Google Scholar show that new cases increased worldwide from 210 758 in 2015, to 214 783 in 2016, representing an increase of 4025 (2%) cases. Multidrug treatment was initiated in the mid-1980s, and by 2001, effective global leprosy elimination campaigns sponsored by WHO had reduced the prevalence from around 5·3 million cases in 1985, to 597 035 (89% reduction). 2 WHOLeprosy. Global situation. Wkly Epidemiol Rec. 2002; 77: 1-8 PubMed Google Scholar This decrease seems like a tremendous success, but the reduction in prevalence needs some historical context.