The relation between anti-hepatitis A virus antibodies and residence water access in Rio de Janeiro, Brazil.

OBJECTIVES: The objective of this study was to analyse the relation between residence water access (water taps) and hepatitis A virus (HAV) antibodies, associated with socio-economic, environmental and demographic factors. METHODS: A logistic regression model was used for estimating the relation between residential water access (presence of water taps inside the house) and HAV antibodies, related to confounding effects of selected variables. The odds ratios estimated by the model were used as incidence density ratios (IDR) for the analysis of the water access-antibody association. Data were obtained from a cross-sectional study on the seroprevalence of hepatitis A in 3779 volunteers from Duque de Caxias city, greater Rio de Janeiro, Brazil. Participants were selected according to an age-specified random sampling survey. RESULTS: Besides water access (main variable of interest), age, monthly family income, housewife schooling, persons per room, proximity to open sewage channels and consumption water treatment were statistically associated to hepatitis A seroprevalences. An interaction between water access and proximity to open sewage channels was detected. Persons living in residences distant from an open sewage channel had a water access-antibody IDR of 2.5 (95% CI [1.4; 4.3]), in contrast to 1.1 for those living close to such channels. CONCLUSIONS: Although indirectly measured through the proxy variable water access, personal hygiene, in conjunction with the absence of open sewage channels in the proximity of the residence, was an important factor for low HAV seroprevalence study population.