Introduction Lepr Rev (2001) 72, 23-28 Prediction of 'highly sldn smear positive' cases among MB leprosy patients using clinical parameters JOSEPH W. LEMASTER*, TIN SHWE**, C . RUTH BUTLIN*** & PAUL W. ROCHE*** * Department oi Family Medicine, Universit o i Washington, P. O. 354696, Seattle, Washington (WA) 98195 ** Leprosy Control Division, HMG, Nepal *** Mycobacterial Research Labortor, Anandaban Leprosy Hospital, PO 151, Kathmandu, Nepal Accepted for publication 18 October 2000 Summar Although 'highly skin smear positive ' ME leprosy cases are known to be at high risk of relapse after release from treatment, and have been recommended to receive 'prolonged duration' MDT, govemment feld-based control programmes without skin smear facilities have no simple altemative method to detect such cases. This study reports a signifcant prevalence of 'highly smear positive' cases amongst 2374 new multibacillary cases recently surveyed by skn smears in Nepal, and retrospectively analyses 555 newly detected, previously untreated BL and LL cases to identify clinical and laboratory parameters that may be associated with a 'highly positive skin smear ' . While some parameters showed high sensitivity in predicting 'highly positive smear' status, none showed both high sensitivity and high specifcity simultaneously. Recent1y the WHO Expert Committee on Leprosy has conc1uded that the Iength of fxed duration muIti-drug therapy (MDT) for muItibacillary (MB) patients could be shortened to 12 months, without great1y increasing the risk of reIapse for the majority of such patients. 1 There has been much debate over this topic in the Iast year among national control programmes, who have the responsibility for impIementing this decision in their own countries. The risk of relapse among MB Ieprosy cases who have received the standard 24 months of MDT has been found to be as Iow as 0'77% 2 and as yet, there is no evidence that shorter courses of therapy will increase the risk of reIapse. 3 , 4 However, a high rate of reIapse (39%) has been reported among MB patients with 'highIy positive slit skin smears ' (bacterial index (BI) ;: 4.0+) treated with 24 months of standard MDT. 5 Pattyn in Zaire and others have suggested that the Correspondence: J. W. LeMaster (e-mail: lemaster@gateman.com) 0305-75 18/011072023+06 $ 1 .00 © Lepra 23