SOLAR DISINFECTION OF DRINKING-WATER AND DIARRHEA IN MAASAI CHILDREN - A CONTROLLED FIELD TRIAL

Background Solar radiation reduces the bacterial content of water, and may therefore offer a method for disinfection of drinking water that requires few resources and no expertise. Methods We distributed plasti c water bottles to 206 Maasai children aged 5-16 years whose drinking water was contaminated with faecal coliform bacteria. Children were in structed to fill the bottle with water and leave it in full sunlight o n the roof of the hut (solar group), or to keep their filled bottles i ndoors in the shade (control group). A Maasai-speaking fieldworker who lived in the community interviewed the mother of each child once ever y 2 weeks for 12 weeks. Occurrence and severity of diarrhoea was recor ded at each follow-up visit. Findings Among the 108 children in househ olds allocated solar treatment, diarrhoea was reported in 439 of the 2 -week reporting periods during the 12-week trial (average 4.1 [SD 1.2] per child). By comparison, the 98 children in the control households reported diarrhoea during 444 2-week reporting periods (average 4.5 [1 .2] per child). Diarrhoea severe enough to prevent performance of duti es occurred during 186 reporting periods in the solar group and during 222 periods in the control group (average 1.7 [1.2] vs 2.3 [1.4]). Af ter adjustment for age, solar treatment of drinking water was associat ed with a reduction in all diarrhoea episodes (odds ratio 0.66 [0.50-0 .87]) and in episodes of severe diarrhoea (0.65 [0.50-0.86]). Interpre tation Our findings suggest that solar disinfection of water may signi ficantly reduce morbidity in communities with no other means of disinf ection of drinking water, because of lack of resources or in the event of a disaster.