Efficacy of waterless hand hygiene compared with handwashing with soap: a field study in Dar es Salaam, Tanzania

Abstract

Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed.

Figure 1.

Box and whisker plots showing baseline levels of Escherichia coli and fecal streptococci (FS) per hand of respondents. The line within each box represents the median, the top and bottom of the box represent the 75th and 25th percentiles, and the top and bottom whisker extend to the 90th and 10th percentiles, respectively.

Figure 2.

Box and whisker plots of reductions in concentrations (calculated as log colony-forming units [CFU]/hand before − log CFU/hand after) of Escherichia coli and fecal streptococci (FS) on hands after the use of hand sanitizer, after handwashing with soap and water, or after no hand hygiene method.