Comparison of the burden of diarrhoeal illness among individuals with and without household cisterns in northeast Brazil.

BACKGROUND: Lack of access to safe and secure water is an international issue recognized by the United Nations. To address this problem, the One Million Cisterns Project was initiated in 2001 in Brazil's semi-arid region to provide a sustainable source of water to households. The objectives of this study were to determine the 30-day period prevalence of diarrhoea in individuals with and without cisterns and determine symptomology, duration of illness and type of health care sought among those with diarrhoea. A subgroup analysis was also conducted among children less than five years old. METHODS: A face-to-face survey was conducted between August 20th and September 20th, 2007 in the Agreste Central Region of Pernambuco State, Brazil. Households with and without a cistern that had at least one child under the age of five years were selected using systematic convenient sampling. Differences in health outcomes between groups were assessed using Pearson's Chi-squared and two-way t-tests. Demographic variables were tested for univariable associations with diarrhoea using logistic regression with random effects. P-values of 0.05 or less were considered statistically significant. RESULTS: A total of 3679 people from 774 households were included in the analysis (1863 people from 377 households with cisterns and 1816 people from 397 households without cisterns). People from households with a cistern had a significantly lower 30-day period prevalence of diarrhoea (prevalence = 11.0%; 95% CI 9.5-12.4) than people from households without a cistern (prevalence = 18.2%; 95% CI 16.4-20.0). This significant difference was also found in a subgroup analysis of children under five years old; those children with a cistern had a 30-day period prevalence of 15.6% (95% CI 12.3-18.9) versus 26.7% (95% CI 22.8-30.6) in children without a cistern. There were no significant differences between those people with and without cisterns in terms of the types of symptoms, duration of illness and health care sought for diarrhoea. CONCLUSIONS: Our results indicate that the use of cisterns for drinking water is associated with a decreased occurrence of diarrhoea in this study population. Further research accounting for additional risk factors and preventative factors should be conducted.

The use of socioeconomic factors in mapping tuberculosis risk areas in a city of northeastern Brazil / Uso de factores socioeconómicos en la localización de áreas con riesgo de tuberculosis en una ciudad del nordeste de Brasil

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

En Brasil, el reto de satisfacer las necesidades de los residentes en zonas pobres ha generado discusiones sobre la sustitución del actual abordaje de la vigilancia epidemiológica por un sistema integrado de vigilancia de la salud pública. Este nuevo abordaje debería sustituir el tradicional enfoque en los individuos de alto riesgo por un método destinado a identificar las poblaciones de alto riesgo y las zonas en las que viven. Dada la magnitud del problema de la tuberculosis en Brasil, elegimos esta enfermedad como un ejemplo de cómo se podría concebir este nuevo sistema integrado de vigilancia de la salud pública. Se reunieron los datos de varias fuentes y la información geográfica para crear un indicador del riesgo de tuberculosis en Olinda, ciudad del estado de Pernambuco. Con el fin de estratificar el espacio urbano de Olinda y de buscar una asociación entre el gradiente del riesgo de tuberculosis y la incidencia media de la enfermedad entre 1991 y 1996, se aplicaron dos métodos diferentes: 1) un "índice social de pobreza", y 2) un análisis de componentes principales seguido de un análisis por grupos. Los resultados obtenidos revelaron una asociación entre la pobreza y la aparición de la tuberculosis y también señalaron grupos y zonas prioritarias que requerían intervención. Se recomienda un seguimiento que debería incluir el tratamiento de los casos de tuberculosis pulmonar con baciloscopia positiva, la identificación de los contactos de estos individuos y el control de los casos resistentes a múltiples fármacos, todo ello en coordinación con los servicios de salud locales.