In-house contamination of drinking-water is a persistent problem in developing countries. This study
aimed at identifying critical points of contamination and determining the extent of recontamination
after water treatment. In total, 81 households were visited, and 347 water samples from their current
sources of water, transport vessels, treated water, and drinking vessels were analyzed. The quality
of water was assessed using
Escherichia coli
as an indicator for faecal contamination. The concentration
of E. coli increased significantly from the water source [median=0 colony-forming unit (CFU)/100 mL,
interquartile range (IQR: 0-13)] to the drinking cup (median=8 CFU/100 mL; IQR: 0-550; n=81, z=-3.7,
p<0.001). About two-thirds (34/52) of drinking vessels were contaminated with
E. coli. Although boiling
and solar disinfection of water (SODIS) improved the quality of drinking-water (median=0 CFU/100 mL;
IQR: 0-0.05), recontamination at the point-of-consumption significantly reduced the quality of water in
the cups (median=8, IQR: 0-500; n=45, z=-2.4, p=0.015). Home-based interventions in disinfection of water
may not guarantee health benefits without complementary hygiene education due to the risk of posttreatment
contamination.
