Performance of leprosy case-contact surveillance: a space-time analysis in Bahia State, Northeast Brazil

Abstract

The aim was to analyze the space-time trend in the proportion of contacts examined among those recorded, according to demographic profile of new leprosy cases in the State of Bahia, Brazil, in the 2003-2014 cohort. This was a state population-based ecological study with temporal and spatial analyses of the proportion of contacts examined among those recorded, according to characteristics of the reference leprosy case, based on the Information System for Notifiable Diseases of the Brazilian Ministry of Health. The time trend analysis was based on Poisson regression (Joinpoints). Spatial analysis used spatial autocorrelation by local indicators of spatial association. Over the course of the historical series, 52.9% (55,116/104,142) of the recorded contacts were examined, with lower proportions in persons < 60 years of age, indigenous individuals, and residents of large cities (especially the state capital Salvador). There was an upward trend in the proportion of contacts examined, less evident when the reference leprosy case was a male, black, living in the rural area, and in small towns or the state capital. Spatial distribution showed that the majority of the municipalities showed precarious performance, with clusters identified in the North and Far South of the state. Bahia shows precarious performance on contact surveillance, particular in conditions of greater social vulnerability. Additional strategies should be implemented in order to overcome the operational obstacles to contact surveillance, considered essential for interrupting leprosy transmission in the state.