BMJ  2008;336:77-80 (12 January), doi:10.1136/bmj.39393.510347.BE (published 27 November 2007)

Research

Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review

Tom Jefferson, coordinator1, Ruth Foxlee, trials search coordinator2, Chris Del Mar, dean3, Liz Dooley, review group coordinator4, Eliana Ferroni, researcher5, Bill Hewak, medical student3, Adi Prabhala, medical student3, Sree Nair, professor of biostatistics6, Alex Rivetti, trials search coordinator1

1 Cochrane Vaccines Field, Alessandria, Italy, 2 Cochrane Wounds Group, Department of Health Sciences, University of York, 3 Faculty of Health Sciences and Medicine, Bond University, Gold Coast, 4229, Qld, Australia, 4 Cochrane Acute Respiratory Infections Group, Faculty of Health Sciences and Medicine, Bond University, 5 Public Health Agency of Lazio Region, Rome, 6 Department of Statistics, Manipal Academy of Higher Education, Manipal, India

Correspondence to: C Del Mar cdelmar{at}bond.edu.au

Objective To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.

Data extraction Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies.

Data synthesis Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study quality was poor for the three randomised controlled trials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn.

Conclusion Routine long term implementation of some physical measures to interrupt or reduce the spread of respiratory viruses might be difficult but many simple and low cost interventions could be useful in reducing the spread.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to StumbleUpon StumbleUpon   Add to Technorati Technorati    What's this?

Relevant Articles

Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review
Tom Jefferson, Chris Del Mar, Liz Dooley, Eliana Ferroni, Lubna A Al-Ansary, Ghada A Bawazeer, Mieke L van Driel, Ruth Foxlee, and Alessandro Rivetti
BMJ 2009 339: b3675. [Abstract] [Full Text] [PDF]

A/H1N1 influenza update
Adrian O’Dowd
BMJ 2009 339: b2977. [Extract] [Full Text]

How well are we managing the influenza A/H1N1 pandemic in the UK?
Roy M Anderson
BMJ 2009 339: b2897. [Extract] [Full Text]

A/H1N1 influenza: questions and answers
Rebecca Coombes
BMJ 2009 338: b1849. [Extract] [Full Text]

Reason for optimism
Peter Doshi
BMJ 2008 336: 172. [Extract] [Full Text] [PDF]

Next to cleanliness
Fiona Godlee
BMJ 2008 336: 0. [Extract] [Full Text]

Using physical barriers to reduce the spread of respiratory viruses
Martin Dawes
BMJ 2008 336: 55-56. [Extract] [Full Text] [PDF]

Measuring inconsistency in meta-analyses
Julian P T Higgins, Simon G Thompson, Jonathan J Deeks, and Douglas G Altman
BMJ 2003 327: 557-560. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

  • Cowling, B. J., Chan, K.-H., Fang, V. J., Cheng, C. K.Y., Fung, R. O.P., Wai, W., Sin, J., Seto, W. H., Yung, R., Chu, D. W.S., Chiu, B. C.F., Lee, P. W.Y., Chiu, M. C., Lee, H. C., Uyeki, T. M., Houck, P. M., Peiris, J. S. M., Leung, G. M. (2009). Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households: A Cluster Randomized Trial. ANN INTERN MED 151: 437-446 [Abstract] [Full text]  
  • Jefferson, T., Del Mar, C., Dooley, L., Ferroni, E., Al-Ansary, L. A, Bawazeer, G. A, van Driel, M. L, Foxlee, R., Rivetti, A. (2009). Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ 339: b3675-b3675 [Abstract] [Full text]  
  • Mossad, S. B. (2009). Influenza in long-term care facilities: Preventable, detectable, treatable. Cleveland Clinic Journal of Medicine 76: 513-521 [Abstract] [Full text]  
  • Anderson, R. M (2009). How well are we managing the influenza A/H1N1 pandemic in the UK?. BMJ 339: b2897-b2897 [Full text]  
  • MOSSAD, S. B. (2009). The resurgence of swine-origin influenza A (H1N1). Cleveland Clinic Journal of Medicine 76: 337-343 [Abstract] [Full text]  
  • Embil, J. M., Dyck, B., Plourde, P. (2009). Prevention and control of infections in the home. CMAJ 180: E82-E86 [Full text]  
  • MOSSAD, S. B. (2008). 2008-2009 Influenza update: A better vaccine match. Cleveland Clinic Journal of Medicine 75: 865-870 [Abstract] [Full text]  
  • Parrish, C. R., Holmes, E. C., Morens, D. M., Park, E.-C., Burke, D. S., Calisher, C. H., Laughlin, C. A., Saif, L. J., Daszak, P. (2008). Cross-Species Virus Transmission and the Emergence of New Epidemic Diseases. Microbiol. Mol. Biol. Rev. 72: 457-470 [Abstract] [Full text]  
  • Doshi, P. (2008). Reason for optimism. BMJ 336: 172-172 [Full text]  
  • Dawes, M. (2008). Using physical barriers to reduce the spread of respiratory viruses. BMJ 336: 55-56 [Full text]  

Rapid Responses:

Read all Rapid Responses

When fear trumps science: a case study for finding alternative research methods
Joshua L. Jacobs, et al.
bmj.com, 8 Dec 2007 [Full text]
Reason for optimism
Peter Doshi
bmj.com, 9 Dec 2007 [Full text]
Minimising virus spread
Alex J. Elliot, et al.
bmj.com, 18 Jan 2008 [Full text]
Re: When fear trumps science: a case study for finding alternative research methods
Offie C. Wortham
bmj.com, 14 Feb 2009 [Full text]



Access jobs at BMJ Careers
Whats new online at Student 

BMJ