Waterless hand hygiene in Dar es Salaam, Tanzania: A field study of microbial efficacy and user perceptions

The act of handwashing with soap has been found to effectively reduce diarrheal and respiratory illness, both leading causes of death for children under 5 in developing countries. However, effective handwashing with soap requires reliable access to high quality water supplies, to which more than 1 billion people lack access. This research addresses the challenge of improving hand hygiene within water-constrained environments. We assessed the microbial efficacy of alcohol-based hand sanitizer (ABHS), a waterless hand hygiene method used in hospitals and health clinics in industrialized countries, in comparison to the efficacy of handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. A total of 205 participants, including mothers, nurses, students, and teachers, were interviewed and hand sampled before and after the use of ABHS, handwashing with soap and water, or no hand hygiene agent. All hand samples were analyzed by membrane filtration for concentrations of the fecal indicators enterococci and E.coli. Current hand hygiene practices and user perceptions were also documented. In a head-to-head efficacy test of handwashing with soap and water versus hand sanitizer with adult mothers, hand sanitizer performed significantly better than handwashing with soap and water when enterococcus was used as the test indicator. No significant difference in efficacy of the two methods was observed when comparing log reductions of E.coli. The results of this study indicate that ABHS is at least as effective at reducing bacteria levels on hands as handwashing with soap and water in field conditions. The efficacy of ABHS should be further evaluated in a variety of field settings, and the feasibility and potential health benefits of promoting ABHS as an alternative hand hygiene option for water-constrained environments assessed.