Sensitivity and specificity of methods of classification of leprosy without use of skin-smear examination

The classification of leprosy is closely linked to chemotherapy as seen in the premultidrug therapy (MDT) era, when the Ridley-Jopling system ((9)) was used to determine the duration of dapsone therapy. The introduction of MDT in 1982 included a revised and simplified classification into two groups, multibacillary (MB) and paucibacillary (PB) ((16)). MB was classified using skin-smear results when the bacterial index (BI) was greater than or equal to 2+, This was revised by the World Health Organization (WHO) Ex pert committee in 1988 ((13)) so that the finding of a positive smear at any site led to MB classification. In 1993 the WHO Study Group suggested that clinical methods alone could be used for classification where facilities for skin smears were unavailable or unreliable ((15)).