Simple Measures Effective in Reducing Transmission of Flu Virus
From Medscape Medical News
News Author: Laurie Barclay, MD
“Our 2007 Cochrane review showed that physical interventions (personal hygiene, barriers, and distancing) are highly effective,” write Tom Jefferson, MD, from the Acute Respiratory Infections Group, Cochrane Collaboration, in Rome, Italy, and colleagues. “However, the current mainstay of pandemic interventions still seems to be vaccines and antiviral drugs, with no evidence supporting their widespread use, especially against a seemingly mild threat such as the novel H1N1 virus.”
Physical measures were highly effective in the prevention of transmission of severe acute respiratory syndrome, according to a meta-analysis of 6 case-control studies. The interventions included the following:
- Hand-washing more than 10 times daily
- Wearing surgical masks
- Wearing N95 masks
- Wearing gloves
- Wearing gowns
- Hand-washing, masks, gloves, and gowns combined
The combination of hand-washing and use of masks, gloves, and gowns also effectively interrupted influenza transmission within households. In younger children and within households, hygienic measures can prevent respiratory tract virus transmission, according to results from the highest-quality cluster randomized trials.
There was limited evidence that the more uncomfortable and expensive N95 masks were more effective than simple surgical masks, but they caused skin irritation. Any additional benefit of adding virucidals or antiseptics to normal hand-washing was uncertain, and global measures, such as screening at entry ports, were not properly assessed.
It appeared that social distancing might be effective if used in relationship to the risk for exposure (the higher the risk, the longer the distancing period), but evidence was limited.
“Routine long term implementation of some of the measures to interrupt or reduce the spread of respiratory viruses might be difficult,” the review authors write. “However, many simple and low cost interventions reduce the transmission of epidemic respiratory viruses. More resources should be invested into studying which physical interventions are the most effective, flexible, and cost effective means of minimizing the impact of acute respiratory tract infections.”
Limitations of this study include methodologic limitations of the included studies.
“In situations of high risk of transmission, barrier measures should be implemented such as wearing gloves, gowns, and masks with a filtration apparatus, and isolation of likely cases,” the study authors conclude. “Most effort should be concentrated on reducing transmission from young children through regular education at school on hygiene. In addition, society should invest in more comfortable and better designed face masks and barrier apparatus, which would increase compliance with their use.”
The National Health Service research and development program and the National Health and Medical Research Council of Australia supported this study. The review authors have disclosed no relevant financial relationships.
BMJ. 2009;339:b3675.
