Access to a piped supply of safe drinking water has benefits for health. Although intermittent water supply carries a higher risk of contamination, the health effects of an uninterrupted water supply have been less well documented and were assessed by 2 recent studies in PLoS Medicine.
December 15, 2015
One study showed an association between interruptions in the availability of tap water and an increase in cases of suspected cholera in the city of Uvira in the Democratic Republic of Congo, where cholera is endemic (Jeandron A et al. PLoS Med. 2015;12:e1001893). The international team of investigators examined the daily incidence of diarrhea in patients older than 5 years admitted to a cholera treatment center from 2009 to 2014 in relation to daily variations in the volume of water supplied by the town’s water treatment plant. In a 12-day period after a day without tap water, the suspected cholera incidence rate was predicted to increase by 155%, compared with admissions after a day with optimal water supply. The results showed that 23.2% of suspected cholera cases over this period were potentially attributable to irregular tap water supply.
In a separate study, researchers from the United States and Kenya compared health outcomes in areas with an intermittent water supply with those with a continuous water supply in Hubli-Dharwad, India (Ercumen A et al. PLoS Med. 2015;12:e1001892). In this matched cohort study, the researchers found that having a continuous water supply was not associated with a reduction in diarrhea or weight in children younger than 5 years. However, a continuous water supply was associated with a 37% lower prevalence (1.6% vs 2.5% with intermittent supply) of bloody diarrhea among children younger than 5 years who were living in the poorer households. Relative to intermittent supply areas, areas with continuous water supply were also found to have 42% fewer households with at least 1 reported case of typhoid fever (58/1711 vs 103/1690).
These studies suggest that the potential health benefits of piped water can be negated if an uninterrupted water supply is not maintained.