Social deprivation index and lymphatic filariasis: a tool for mapping urban areas at risk in northeastern Brazil

This paper describes the construction and application of a social deprivation index that was created to explore the relationship between lymphatic filariasis and socioenvironmental variables in the municipality of Jaboatão dos Guararapes, Pernambuco, Brazil, thereby contributing towards identifying priority areas for interventions. This indicator was obtained from principal-component factor analysis. Variables available from the national census representing socioenvironmental conditions, household characteristics and urban services were used. Epidemiological data came from a parasitological survey on lymphatic filariasis. 23 673 individuals were examined and 323 were positive (1.4%). Two factors that together explained 80.61% of the total variance were selected. The social deprivation strata were capable of indicating a risk gradient, with 74.9% of the microfilaremia cases situated in the high-risk stratum. Principal-component factor analysis was shown to be sensitive for selecting indicators associated with the risk of lymphatic filariasis transmission and for detecting areas potentially at risk. The capacity of the social deprivation index for picking up social inequalities qualifies it as a new tool for use in planning interventions aimed at controlling lymphatic filariasis in urban spaces.