[Evaluation of the clinical classification of new cases of leprosy. Study conducted at the Marchoux Institute in Bamako, Mali]

Abstract

Introduction: The difficulties related to the bacilloscopic diagnosis of leprosy, providing a more reliable classification of cases, in 1995 led the WHO to recommend the use of a new classification, in endemic countries, based on clinical criteria alone, in order to simplify the poly-chemotherapeutic regimens. According to our experience in the Marchoux Institute, this classification may lead to errors in diagnosis through overzealous or mis-interpretation of the two forms of leprosy. The aim of our study was to evaluate the concordance between this clinical classification and that based on a bacilloscopic examination.

Patients and methods: We conducted a descriptive study of new cases of leprosy seen at the Marchoux Institute, without distinction in gender or age, from January to December 2000. All the patients included underwent clinical examination and a bacilloscopic exploration to provide a double classification. The concordance between the two classifications was assessed using the Kappa test.

Results: Two hundred new cases of leprosy were included. Out of 126 clinically multi-bacillary cases, 61 were confirmed bacteriologically, and 65 were false positives. Out of 74 clinical cases with few bacilli, 2 were bacteriologically multi-bacilli. The concordance between the two classifications was average (Kappa=0.40). There was a significant difference between the percentages of multi-bacilli observed in both classifications (p<10(-8)).

Discussion: The clinical classification may well overestimate the multi-bacillary form. In the absence of a reliable bacilloscopic apparatus, a more detailed clinical classification of leprosy forms must be developed.