Study Design, Outcome Measurement, and Parameter Estimation for the Evaluation of an Ultraviolet Based Household Water Treatment and Safe Storage Intervention

Globally, diarrhea is one of the leading causes of morbidity and mortality. Populations living in developing countries disproportionally experience the burden of diarrhea; in these areas contaminated drinking water remains one of the primary environmental pathways for the transmission of diarrheagenic pathogens. Centrally treated "piped" water is largely recognized as the best method to provide human populations with consistent access to safe drinking water. Piped water requires little additional input from end users, and therefore has few additional barriers to the adoption and sustained consumption of water that is free of microbial contamination. In areas where the construction of piped water systems is not feasible due to capital or maintenance costs, or dispersed rural populations, the promotion of household water treatment and safe storage (HWTS) strategies have been recommended as the best method to deliver to safe water to households that lack affordable alternatives.Several HWTS strategies have been tested in field efficacy trials, including treatment by chlorine, filtration, boiling and solar disinfection. While various meta-analyses of these trials have suggested that HWTS strategies improve drinking water quality, and reduce diarrhea, there is some concern that: 1) the design and implementation of these trials may have biased results, and relatedly; 2) that these strategies themselves are not being used by target populations outside the context of these intensive trials. Specifically, each of the HWTS strategies listed above comes with small barriers to use: chlorine changes the taste and odor of the water and is not effective against spore forming pathogens (e.g., cryptosporidium), filters are slow and are have limited effectiveness against viruses, boiling changes the temperature of water and requires significant time and fuel inputs, and solar disinfection requires significant time inputs from end users to effectively produce safe water. In efficacy t