Physical interventions to interrupt or reduce the spread of respiratory viruses (Review)
Date of this Version
Background: Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a world-wide threat. Antiviral drugs and vaccinations may be insufficient to prevent catastrophe.
Objectives: To systematically review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.
Search Strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2); MEDLINE (1966 to May 2009); OLDMEDLINE (1950 to 1965); EMBASE (1990 to May 2009); and CINAHL (1982 to May 2009).
Selection Criteria: We scanned 2958 titles, excluded 2790 and retrieved the full papers of 168 trials, to include 59 papers of 60 studies. We included any physical interventions (isolation, quarantine, social distancing, barriers, personal protection and hygiene) to prevent transmission of respiratory viruses. We included the following study designs: randomised controlled trials (RCTs), cohorts, case controls, cross-over, before-after, and time series studies.
Data collection and analysis: We used a standardised form to assess trial eligibility. RCTs were assessed by: randomisation method; allocation generation; concealment; blinding; and follow up. Non-RCTs were assessed for the presence of potential confounders, and classified into low, medium, and high risks of bias.
Main Results: The risk of bias for the four RCTs, and most cluster RCTs, was high. The observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis. The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children.
This document has been peer reviewed.