Solar disinfection of drinking water in the prevention of dysentery in South African children aged under 5 years: the role of participant motivation.

ABSTRACT

Solar disinfection (SODIS) effectively improves the microbial quality of drinking water for preventing diarrhea; however, the effect of participant motivation has not been studied. This 1-year randomized controlled trial investigated the effect of SODIS of drinking water and motivation on the incidence of dysentery and nondysentery diarrhea among children of age 6 months to 5 years living in periurban communities in South Africa.We compared 383 children in 297 households using SODIS with 335 children in 267 households with no intervention. At baseline 62.4% of the study households had stored water which met World Health Organization guidelines for zero thermotolerant coliforms per 100 mL. Dysentery was recorded using a pictorial diary. Incidence of dysentery was significantly associated with higher motivation, defined as 75% or better completion of diarrhea data. Incidence rates were lower in those drinking solar disinfected water (incidence rate ratio 0.64, 95% CI 0.39 - 1.0, P = 0.071) but not statistically significant. Compared with the control, participants with higher motivation achieved a significant reduction in dysentery (incidence rate ratio 0.36, 95% CI 0.16 - 0.81, P = 0.014). However, there was no significant reduction in risk at lower levels of motivation. Solar disinfection was not significantly associated with nondysentery diarrhea risk overall (P = 0.419). A statistically significant reduction in dysentery was achieved only in households with higher motivation, showing that motivation is a significant determinant for measurable health gains. Failure of three-quarters of participants to achieve a significant reduction in dysentery suggests that research into effective implementation is required.