Effect of city-wide sanitation programme on reduction in rate of childhood diarrhoea in northeast Brazil: assessment by two cohort studies

Abstract

SummaryBackgroundA city-wide sanitation intervention was started in Salvador, Brazil, in 1997 to improve sewerage coverage from 26% of households to 80%. Our aim was to investigate the epidemiological effect of this city-wide sanitation programme on diarrhoea morbidity in children less than 3 years of age.MethodsThe investigation was composed of two longitudinal studies done in 1997–98 before the intervention (the sanitation programme) and in 2003–04 after the intervention had been completed. Each study consisted of a cohort of children (841 in the preintervention study and 1007 in the postintervention study; age 0–36 months at baseline) who were followed up for a maximum of 8 months. Children were sampled from 24 sentinel areas that were randomly chosen to represent the range of environmental conditions in the study site. At the start of each study an individual or household questionnaire was applied by trained fieldworkers; an environmental survey was done in each area before and after introduction of the sanitation programme to assess basic neighbourhood and household sanitation conditions. Daily diarrhoea data were obtained during home visits twice per week. The effect of the intervention was estimated by a hierarchical modelling approach fitting a sequence of multivariate regression models.FindingsDiarrhoea prevalence fell by 21% (95% CI 18–25%)—from 9·2 (9·0–9·5) days per child-year before the intervention to 7·3 (7·0–7·5) days per child-year afterwards. After adjustment for baseline sewerage coverage and potential confounding variables, we estimated an overall prevalence reduction of 22% (19–26%).InterpretationOur results show that urban sanitation is a highly effective health measure that can no longer be ignored, and they provide a timely support for the launch of 2008 as the International Year of Sanitation.

Principais causas da mortalidade na infância no Brasil, em 1990 e 2015: estimativas do estudo de Carga Global de Doença

“…A positive change has occurred for diarrheal diseases, which in 1990 were the second leading cause of death, and in 2015 moved to the seventh position, with expressive rate reduction. This change indicates improvements in sanitation and nutritional conditions in the country [17][18][19] , as well as access to health care, besides the possible impact of specific actions, such as the introduction of a vaccine against rotavirus in 2006 20 , and oral rehydration therapy in primary care 21 . Respiratory conditions, and particularly whooping cough had similar results.…”

Detection of caliciviruses associated with acute infantile gastroenteritis in Salvador, an urban center in Northeast Brazil

“…However, recently, a study conducted in Salvador has demonstrated that a city-wide sanitation intervention, i.e., reducing direct exposure to unfavorable sanitation conditions, was a highly effective and sustainable measure to reduce the burden of gastroenteric infections (40). Consequently, in any decision-making process concerning the development and introduction of new vaccines, the contribution played by sanitation and other environmental improvements should be considered carefully.…”

Children's Environment in Brazil: From Domestic (Indoor) to Regional Threats

“…The factors that may have contributed to that decrease were the increase in purchasing power and consequently the betterment of living conditions [54] and the increase in the coverage of basic sanitation services [56,59]. …”