Single lesion as an indicator to monitor the leprosy trend to elimination in hyperendemic areas

Abstract

INTRODUCTION: Prevalence and detection rates of leprosy are not sufficient to show the real magnitude of changes in epidemiological patterns. OBJECTIVES: Evaluate the feasibility and usefulness of the proportion of new leprosy patients with a single skin lesion (SSL) as a potential indicator of the elimination of leprosy. METHODS: We conducted a retrospective study based on secondary data analyzing newly reported cases of leprosy between 1997 and 2002, in the city of Palmas, Tocantins, Brazil. Patients with a single lesion were compared to remaining patients, and the odds ratio was used as measure of association. RESULTS: Out of the 1,303 new cases of leprosy, 481 (36.9%) had a SSL. An increasing time-trend was observed in the proportion of new cases detected with a single lesion, which grew from 20.3% in 1999 to 49.1% in 2002 (linear trend p<.001) while a reduction in the number of new cases was observed simultaneously after 1999. The proportion of patients with a single lesion was higher in women, young age, paucibacillary, tuberculoid and indeterminate clinical forms, residents of urban areas, those with negative baciloscopy, with macular lesions, without physical disabilities, and mainly detected in primary health care units. CONCLUSIONS: These findings confirm that the proportion of patients with a SSL can be used as a sensitive and feasible indicator to assess the progress of the elimination of leprosy in hyperendemic areas.