Um novo método para avaliação rápida da tungíase em áreas endêmicas

Abstract

Rapid assessment methods are needed to delimitation of risk communities and to enable implementation and evaluation of impact interventions. Objective: To develop and assess a rapid epidemiologic method to estimate the overall prevalence of tungiasis and severity of disease in endemic communities with distinct demographic, socio-cultural and environment characteristics. Material and Methods: Analysis data from ten population-based surveys on tungiasis, performed in five endemic communities – three in Brazil (secondary data) and two Nigeria (primary data) – between 2001 and 2008. In all surveys, tungiasis was clinically diagnostic by presence of Tunga penetrans into epidermis of participants. To elaborate rapid assessment method six topographic sites of the feet were selected as potential infestation indicator in community level. Linear regression analyses were performed as well strength of associations (R2) and p values were calculated. Estimated prevalences were calculated for each of the ten surveys and compared to true prevalences. The most useful topographic localization to define a rapid assessment method was select based on the strength of association and operational aspects. Result: In total, 7121 individuals of the five communities were examined. Prevalence of tungiasis varied between 21.1% and 54.4%. In the two Nigerian communities the combined overall prevalence was 47% (142/302; 95% confidente intervale: 41%-53%). Tungiasis were more common in males than in females (51,5% vs. 46,3%; p=0,2). Children prevalence (<14 years) was statistically higher then adolescents and adults prevalence (60% vs. 33%, p<0,0001). In the ten surveys, all strength coefficients were high for the six localizations (ranged between 70% and 96%) and p values were significant (all <0,002). The presence of periungual lesions on the toes showed the highest strength coefficient (R2=96%; P<0.0001) and it was identified as the most useful and rapid localization to estimate the prevalence of tungiasis. Estimating prevalence of tungiasis by equation [estimated prevalence] = 1,12 x [prevalence on periungual sites] + 5,0), the mean absolute error was 1,9%. Tungiasis on this topographic site also reliably estimated prevalence of severe disease (>20 lesions) using the equation [estimated prevalence] = 0,24 x [prevalence on periungual sites] – 3,4); mean absolute error was 0,9%. Conslusion: Tungiasis is a public health problem in the fishing communities in Nigeria. Identification of T. penetrans in the periungual area of the feet can be used as a rapid and reliable method to assess the epidemiological situation of endemic areas. This approach will help to delimit endemic communities and to plan control measures aimed at the reduction of tungiasis. Key-words: Tungiasis; Tunga penetrans; Epidemiology; Rapid assessment method; Public Health; Africa; Brazil