The effectiveness of hand hygiene interventions for preventing transmission or acquisition of viral infections in the community: Findings from a systematic review

Introduction: The World Health Organization recommends improving hand hygiene (HH) practices of the general public as one aspect of controlling the transmission of novel coronaviruses and influenza virus epidemics or pandemics. Objectives: To systematically review the evidence on the effectiveness of HH interventions for preventing transmission or acquisition of viral infections in the community. Methods: PubMed, MEDLINE, CINAHL and Web of Science databases were searched for empirical studies published between 2002-May 2020, on HH in the general public and acquisition or transmission of novel coronavirus infections or influenza. Study selection, data extraction and quality assessment were conducted by one reviewer, with all decisions checked by another. We conducted a sub-set analysis of intervention studies included in this review, by calculating the effect estimates. Results: The review identified four intervention studies, all of which used cluster randomised designs evaluating the effectiveness of HH education paired with provision of HH products or hand washing with soap and water (HW) against influenza transmission or acquisition amongst the populations of schoolchildren (n = 2) or the general public (n = 2). Three indicated a protective effect of HH interventions (Figure);yet, this effect was significant for only one school-based intervention, which consisted of the provision of HH education and performing HW twice a day (OR: 0.64;95% CI 0.51, 0.80). However, the risk of bias of this study was assessed as unclear;whereas the remaining three studies were assessed as high risk. Conclusion: There is some limited evidence demonstrating that hand hygiene interventions were effective in preventing influenza in school children. Thus, whilst provision of HH education to school children will be beneficial from a public health perspective, it's impact on influenza transmission is unclear. Research is needed to evaluate the effectiveness of HH interventions for prevention of respiratory infections, including SARS-CoV-2, amongst more diverse groups of the general public populations.