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

A recent study from a designated COVID-19 hospital in Wuhan, China, suggested that contact was one of the major routes of transmission of SARS-CoV-2 [69] . They found that poor hand hygiene, despite the use of full PPE, was independently associated with a risk of SARS-CoV-2 HCW transmission using multivariate logistic regression in a retrospective cohort study with a relative risk (RR) of 3.07 (95% CI 1.14-5.15) and 2.45 ( 95% CI1.45-4.03), respectively, in a high risk and low risk clinical unit, which supports the overall findings of our review with specific reference to the COVID-19 virus. [69] Strengths and weaknesses of the study This update of our review focused on the evidence from RCTs, providing a higher level of certainty, compared with the previous version, which also meta-analysed observational studies. However, many of the trials were small and hence underpowered, and at high or unclear risk of bias due to poor reporting of methods, and lack of blinding. The populations, outcomes, comparators and interventions tested were heterogeneous. Interventions were often complex in their implementation (e.g. handwashing education aimed at different stakeholders with specific instructions) and adherence was often modest or not reported.