Epidemiology and spatial exploratory analysis of leprosy in the district of Toliara, Madagascar

Abstract

Objectives: As leprosy case-notification is plateauing worldwide, a more targeted approach including contact tracing and possibly treating hotspots becomes necessary. This study aims to provide an update on the epidemiology of leprosy in the District of Toliara by comparing the local leprosy indicators to national data, along with a geographical exploration of patients origin and identification of hotspots. Results: A cohort of 87 patients who started polychemotherapy (PCT) in 2013–2014 was identified at the principle hospital of Toliara. When compared with national findings, two-tailed z scores for proportions (95% confidence interval) indicate a significantly lower proportion of MB cases (79%, P = 0.01), a higher proportion of females (39%, P = 0.001) and a lower proportion of PCT completion in MB patients (59%, P = 0.00001) in this cohort. Two maps were generated illustrating origin of patients by municipality and hotspots in the urban area and coastal rural regions along the Route Nationale 9 (RN9). Conclusions: This study demonstrates the differences in leprosy indicators when comparing Toliara district to Madagascars national data with a significantly low PCT completion rate in this patient cohort. A geographical exploration on patients provenance reveals the appearance of hotspots especially in easily accessible municipalities. In interpreting hotspot analysis and eventually selecting appropriate strategies/interventions, care should be taken to take account of possible underestimation of leprosy burden in rural and difficult-to-reach areas.