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.

Quality of reporting in clinical trials of preharvest food safety interventions and associations with treatment effect.

Randomized controlled trials (RCTs) are the gold standard for evaluating treatment efficacy. Therefore, it is important that RCTs are conducted with methodological rigor to prevent biased results and report results in a manner that allows the reader to evaluate internal and external validity. Most human health journals now require manuscripts to meet the Consolidated Standards of Reporting Trials (CONSORT) criteria for reporting of RCTs. Our objective was to evaluate preharvest food safety trials using a modification of the CONSORT criteria to assess methodological quality and completeness of reporting, and to investigate associations between reporting and treatment effects. One hundred randomly selected trials were evaluated using a modified CONSORT statement. The majority of the selected trials (84%) used a deliberate disease challenge, with the remainder representing natural pathogen exposure. There were widespread deficiencies in the reporting of many trial features. Randomization, double blinding, and the number of subjects lost to follow-up were reported in only 46%, 0%, and 43% of trials, respectively. The inclusion criteria for study subjects were only described in 16% of trials, and the number of animals housed together was only stated in 52% of the trials. Although 91 trials had more than one outcome, no trials specified the primary outcome of interest. There were significant bivariable associations between the proportion of positive treatment effects and failure to report the number of subjects lost to follow-up, the number of animals housed together in a group, the level of treatment allocation, and possible study limitations. The results suggest that there are substantive deficiencies in reporting of preharvest food safety trials, and that these deficiencies may be associated with biased treatment effects. The creation and adoption of standards for reporting in preharvest food safety trials will help to ensure the inclusion of important trial details in all publications.

Impacto do uso da água de cisternas na ocorrência de episódios diarréicos na população rural do agreste central de Pernambuco, Brasil / The impact of the use of water from water-tanks on the occurrence of diarrhea in the rural population of the Central Agreste region of the Brazilian State of Pernambuco

OBJETIVOS: avaliar o impacto do uso da água de cisternas na ocorrência de episódios diarréicos comparando o número e a duração de episódios entre moradores de domicílios com e sem cisternas, numa mesma área geográfica. MÉTODOS: estudo longitudinal prospectivo aninhado a um estudo de corte transversal com dois grupos de comparação (domicílios com e sem cisternas) realizado, em 21 municípios do Agreste Central de Pernambuco, em 2007. O período de coleta foi de 60 dias, e incluiu 1765 indivíduos. Para análise descritiva utilizou-se modelos mistos hierárquicos, Mann-Whitney e Kaplan-Meyer com nível de significância de 5 por cento. RESULTADOS: entre os 949 indivíduos com cisternas, obteve-se uma redução no risco de ocorrência de episódios diarréicos de 73 por cento quando comparados aos 816 indivíduos sem cisternas (RR=0,27; p<0.001). O número médio de episódios registrados nos residentes de domicílios sem cisternas foi de 0,48 (DP=1,17), contra 0,08 (DP=0,32) nos domicílios com cisternas(z=-10,26; p<0,001). A duração média dos episódios foi 1,5 vezes maior nos domicílios sem cisternas (χ²=8,99; p=0,003). CONCLUSÕES: os achados deste estudo destacam a importância do acesso à água potável na redução de doenças. A ocorrência de diarréia, bem como, seus indicadores de gravidade - número de episódios e duração da diarréia foram consistentemente maiores nos residentes de domicílios sem cisternas.

OBJECTIVES: to evaluate the impact of the use of water-tanks on the occurrence of episodes of diarrhea, comparing the number and duration of episodes among the residents of households with and without water-tanks in the same geographical area. METHODS: a longitudinal prospective study, nested in a cross-section study comparing two groups (households with and without water-tanks), was carried out in 21 municipalities in the Central Agreste region of the Brazilian State of Pernambuco, in 2007. Data was gathered over 60 days and included 1,765 individuals. Descriptive analysis was carried out using mixed hierarchical models, Mann-Whitney and Kaplan-Meyer with the level of significance set at 5 percent. RESULTS: among the 949 individuals with water-tanks, there was a reduction in the risk of the occurrence of episodes of diarrhea of 73 percent compared with the 816 individuals without water-tanks (RR=0.27; p<0.001). The mean number of episodes registered among residents of households without water-tanks was 0.48 (SC=1.17), compared with 0.08 (SC=0.32) among households with water-tanks (z=-10.26; p<0.001). The mean during of episodes was 1.5 times greater in households without water-tanks (χ2=8.99; p=0.003). CONCLUSIONS: the findings of this study point to the importance of access to drinking water for the reduction of disease. The occurrence of diarrhea and its concomitant severity indicators-number of episodes and duration-were consistently higher among residents of households without water-tanks.