A socioenvironmental composite index as a tool for identifying urban areas at risk of lymphatic filariasis.

OBJECTIVE: To describe the spatial distribution of lymphatic filariasis and its relationship with the socioenvironmental risk indicator, thus identifying priority localities for interventions in endemic urban areas. METHODS: The study area was the municipality of Jaboatão dos Guararapes, State of Pernambuco, Brazil. The data sources were a parasitological survey and the 2000 demographic census. From these data, a socioenvironmental composite risk indicator was constructed using the 484 census tracts (CT) as the analysis units, based on the score-formation technique. Census tracts with higher indicator values presented higher risk of occurrences of filariasis. RESULTS: Six thousand five hundred and seven households were surveyed and 23 673 individuals were examined, among whom 323 cases of microfilaremia were identified. The mean prevalence rate for the municipality was 1.4%. The indicator showed that 73% (237/323) of the cases of microfilaremia were in high-risk areas (third and fourth quartiles) with worse socioenvironmental conditions (RR = 4.86, CI = 3.09-7.73, P < 0.05). CONCLUSIONS: The socioenvironmental composite risk indicator demonstrated sensitivity, since it was able to identify the localities with greater occurrence of infection. Because it can stratify spaces by using official and available data, it constitutes an important tool for use in the worldwide program for eliminating lymphatic filariasis.

The socio-demographic, environmental and reservoir factors associated with leptospirosis in an urban area of north-eastern Brazil.

In an ecological study based on the 18 microregions that form the city of Recife, the capital of the Brazilian state of Pernambuco, associations between socio-demographic, environmental and reservoir factors and the incidence of leptospirosis in the city were investigated. Incidence over a 5-year period (2001-2005) and 14 variables were analysed, using central trend and dispersion measurements, Pearson's correlation and multiple linear regression. Variables relating to education, income, housing type, sewage system, rubbish collection and hydrographic factors were found to be significantly correlated with leptospirosis incidence (P<0.05 for each). Just two variables - the proportion of heads of households with incomes less than or equal to the legal minimum (U.S.$83.55/month), and the proportion of households from which rubbish was dumped in skips, lakes, rivers or the sea or on vacant land - explained 60% (P=0.017) of the differences in disease risk observed between the various areas of the city.

The use of socioeconomic factors in mapping tuberculosis risk areas in a city of northeastern Brazil.

In Brazil the challenge of meeting the needs of those living in deprived areas has generated discussions on replacing the existing approach to epidemiological surveillance with an integrated public health surveillance system. This new approach would supplant the traditional focus on high-risk individuals with a method for identifying high-risk populations and the areas where these persons live. Given the magnitude of the problem that tuberculosis (TB) poses for Brazil, we chose that disease as an example of how such a new, integrated public health surveillance system could be constructed. We integrated data from several sources with geographic information to create an indicator of tuberculosis risk for Olinda, a city in the Brazilian state of Pernambuco. In order to stratify the urban space in Olinda and to check for an association between the resulting TB risk gradient and the mean incidence of the disease between 1991 and 1996, we applied two different methods: 1) a "social deprivation index" and 2) principal component analysis followed by cluster analysis. Our results showed an association between social deprivation and the occurrence of TB. The results also highlighted priority groups and areas requiring intervention. We recommend follow-up that would include treating acid-fast bacilli smear-positive pulmonary TB cases, tracing of these persons' contacts, and monitoring of multidrug-resistant cases, all in coordination with local health services.

[Surveillance of endemic diseases in urban areas: the interface between census tract maps and morbidity data]. / Vigilância de doenças endêmicas em áreas urbanas: a interface entre mapas de setores censitários e indicadores de morbidade.

In this article we discuss the methodological issues associated with the creation of a surveillance system for endemic diseases in urban areas based on analysis of populations at risk and on spatially referenced epidemiological indicators. We comment on the system's basic requirements, selection criteria for socioeconomic variables, and methodological steps to combine these variables so as to construct a census-based deprivation index. We also present the ways we solved some operational problems related to generation of digitized census tracts maps and linkage of morbidity data from different sources. This approach, spatial organization into account in surveillance of endemic diseases, exemplified here by tuberculosis and leprosy, allows for the interaction of several official data sets from census and health services in order to geographically discriminate inner-city risk strata. Criteria for constructing these risk strata were considered a useful tool for health planning and management activities for the control of endemic diseases in cities.