Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 2 - Hand hygiene and other hygiene measures: systematic review and meta-analysis.

Lubna A Al-Ansary; Ghada A Bawazeer; Elaine Beller; Justin Clark; John Conly; Chris Del Mar; Elizabeth Dooley; Eliana Ferroni; Paul Glasziou; Tammy Hoffman; Tom Jefferson; Sarah Thorning; Mieke van Driel; Mark Jones

The combined effect of the trials is small, but highly statistically significant. There is also considerable variation across trials, suggesting a different impact across implementation methods and settings. More research is urgently needed into the sources of variability of these effects. However, given the low cost and minimal disruption from good hand washing behaviour, we believe this small effect warrants continued promotion as part of a combined strategy to reduce the spread of respiratory viruses. No single strategy -other than prolonged isolation of the entire population -can block an epidemic spread. The alternative is combining multiple, partially effective interventions, such as hand washing, crowd reduction, or self-isolation of symptomatic patients, etc. This model is used in medical error reduction, where a common analogy is the "Swiss cheese model" whereby enough slices of cheese are needed to prevent the holes lining up, and an error occurring. Hand washing is clearly not a complete solution but adds one important layer of a combined strategy to reduce respiratory viral transmission. the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.