Identifying risk factors for tungiasis and heavy infestation in a resource-poor community in northeast Brazil.

Tungiasis is a neglected parasitic skin disease caused by penetration of female sand fleas into the epidermis. The ectoparasitosis is widespread in resource-poor communities in South America, the Caribbean and sub-Saharan Africa. To identify risk factors for the presence of sand fleas and severe infestation in an endemic community, we examined the entire population of a traditional fishing village for the presence of embedded sand fleas and determined the number and type of lesions. Demographic, behavioural and environmental characteristics of the population were assessed using a structured questionnaire. Multivariable analysis showed that both occurrence of tungiasis and heavy infestation were significantly related to poor housing conditions (odds ratio [OR]=4.7, 95% CI 1.4-15.8), lack of health education (OR=4.1, 95% CI 2.0-8.6) and presence of animals on the compound (OR=1.9, 95% CI 1.1-3.4). Contrary to common belief, a protective effect of frequent use of closed footwear could not be demonstrated. Based on the population attributable fractions calculated for the major risk factors identified, we conclude that several low-cost interventions would have a considerable impact on the occurrence of tungiasis and heavy infestation.