Hand Hygiene to Reduce Transmission of Influenza
Hand Hygiene to Reduce Transmission of Influenza
Please cite this paper as: Warren-Gash et al. (2012) Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12015.
Hand hygiene may be associated with modest protection against some acute respiratory tract infections, but its specific role in influenza transmission in different settings is unclear. We aimed to review evidence that improving hand hygiene reduces primary and secondary transmission of (i) influenza and (ii) acute respiratory tract infections in community settings. We searched Medline, Embase, Global Health and Cochrane databases up to 13 February 2012 for reports in any language of original research investigating the effect of hand hygiene on influenza or acute respiratory tract infection where aetiology was unspecified in community settings including institutions such as schools, and domestic residences. Data were presented and quality rated across outcomes according to the Grading of Recommendations Assessment, Development and Evaluation system. Sixteen articles met inclusion criteria. There was moderate to low-quality evidence of a reduction in both influenza and respiratory tract infection with hand hygiene interventions in schools, greatest in a lower–middle-income setting. There was high-quality evidence of a small reduction in respiratory infection in childcare settings. There was high-quality evidence for a large reduction in respiratory infection with a hand hygiene intervention in squatter settlements in a low-income setting. There was moderate- to high-quality evidence of no effect on secondary transmission of influenza in households that had already experienced an index case. While hand hygiene interventions have potential to reduce transmission of influenza and acute respiratory tract infections, their effectiveness varies depending on setting, context and compliance.
Hand hygiene is a simple, low-cost, non-pharmaceutical intervention that was recommended by local, national and international health agencies to prevent influenza transmission during the 2009 H1N1 influenza pandemic. Although evidence suggests that hand hygiene reduces diarrhoea episodes by around a third, the specific effect on influenza transmission is unclear. One previous review suggested that hygienic measures including hand washing, especially around young children, could reduce spread of respiratory tract viruses in general. Two earlier reviews estimated that hand hygiene may reduce transmission of respiratory tract infections by 16% and 21%, although these figures were pooled across studies with different designs, settings and outcome measures. Results may also have been biased by poor quality of included studies.
It is biologically plausible that enhanced hand hygiene would interrupt influenza transmission, predominantly through reducing contact and some droplet spread rather than through effects on aerosol transmission. However, it is unclear whether effects are likely to differ in different community settings, for example, in schools compared with households or in high versus low–middle-income countries. These questions are likely to be of interest to governments and policymakers developing preparedness strategies for the next influenza pandemic and were the focus of our review.
We anticipated that interest in the 2009 pandemic may have stimulated new research into non-pharmaceutical interventions for influenza. We systematically reviewed the latest evidence from both intervention and observational studies to investigate whether hand hygiene practised in the community protected against influenza or acute respiratory tract infection in children and adults. We included studies based in both institutional non-healthcare settings, for example schools, and in domestic residences. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to present data and rate quality of evidence.
Abstract and Introduction
Abstract
Please cite this paper as: Warren-Gash et al. (2012) Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12015.
Hand hygiene may be associated with modest protection against some acute respiratory tract infections, but its specific role in influenza transmission in different settings is unclear. We aimed to review evidence that improving hand hygiene reduces primary and secondary transmission of (i) influenza and (ii) acute respiratory tract infections in community settings. We searched Medline, Embase, Global Health and Cochrane databases up to 13 February 2012 for reports in any language of original research investigating the effect of hand hygiene on influenza or acute respiratory tract infection where aetiology was unspecified in community settings including institutions such as schools, and domestic residences. Data were presented and quality rated across outcomes according to the Grading of Recommendations Assessment, Development and Evaluation system. Sixteen articles met inclusion criteria. There was moderate to low-quality evidence of a reduction in both influenza and respiratory tract infection with hand hygiene interventions in schools, greatest in a lower–middle-income setting. There was high-quality evidence of a small reduction in respiratory infection in childcare settings. There was high-quality evidence for a large reduction in respiratory infection with a hand hygiene intervention in squatter settlements in a low-income setting. There was moderate- to high-quality evidence of no effect on secondary transmission of influenza in households that had already experienced an index case. While hand hygiene interventions have potential to reduce transmission of influenza and acute respiratory tract infections, their effectiveness varies depending on setting, context and compliance.
Introduction
Hand hygiene is a simple, low-cost, non-pharmaceutical intervention that was recommended by local, national and international health agencies to prevent influenza transmission during the 2009 H1N1 influenza pandemic. Although evidence suggests that hand hygiene reduces diarrhoea episodes by around a third, the specific effect on influenza transmission is unclear. One previous review suggested that hygienic measures including hand washing, especially around young children, could reduce spread of respiratory tract viruses in general. Two earlier reviews estimated that hand hygiene may reduce transmission of respiratory tract infections by 16% and 21%, although these figures were pooled across studies with different designs, settings and outcome measures. Results may also have been biased by poor quality of included studies.
It is biologically plausible that enhanced hand hygiene would interrupt influenza transmission, predominantly through reducing contact and some droplet spread rather than through effects on aerosol transmission. However, it is unclear whether effects are likely to differ in different community settings, for example, in schools compared with households or in high versus low–middle-income countries. These questions are likely to be of interest to governments and policymakers developing preparedness strategies for the next influenza pandemic and were the focus of our review.
We anticipated that interest in the 2009 pandemic may have stimulated new research into non-pharmaceutical interventions for influenza. We systematically reviewed the latest evidence from both intervention and observational studies to investigate whether hand hygiene practised in the community protected against influenza or acute respiratory tract infection in children and adults. We included studies based in both institutional non-healthcare settings, for example schools, and in domestic residences. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to present data and rate quality of evidence.