# 2703
One of the big unknowns, when it comes to using NPI's - or Non Pharmaceutical Interventions - during a pandemic is how protective ordinary surgical masks would be from the virus.
We're not talking about N95 respirators here, but regular surgical facemasks. These are loose-fitting, disposable masks that cover the nose and mouth such as the one shown below.
Facemasks, while not believed to be as protective as N95 respirators, have the advantage of being easier to wear for long periods of time, and are a fraction of the cost of the more expensive respirator.
The unanswered question, however, is how effective are they?
We get a partial answer to that question in the upcoming issue of Emerging Infectious Diseases. The study, entitled Use of Face Masks to Control Respiratory Virus Transmission in Households, is due to be published in the February 2009 issue. It is not online yet.
During the winter flu seasons of 2006 and 2007, adults in 143 Australian families were asked on a random basis to either wear, or not wear, facemasks when a child was sick at home with a respiratory illness.
Those adults that wore a facemask were four-times less likely to become infected by their sick children.
I've long advocated that individuals stockpile, and use facemasks during a pandemic (see Who Was That Masked Man? and Any Mask In A Viral Storm) even though the scientific evidence of their efficacy was limited.
For me it came down to something is better than nothing.
I'm pleased to see that we are now starting to get some scientific evidence to back that assumption up.
This report from the Times.
From The Times
January 26, 2009
Facemasks can protect against flu - if only people keep them on
Mark Henderson, Science Editor
Protective facemasks can guard against respiratory infections such as flu, and could play an important part in defending against a pandemic, according to research.
Persuading people to wear a mask and to fit it properly, however, is a difficult task that could limit their effectiveness, British and Australian scientists have found. In a clinical trial of the effectiveness of masks, researchers at Imperial College London and the University of New South Wales studied 280 adults from 143 families living in Sydney during the winter flu seasons of 2006 and 2007.
When a child in the household was ill with flu, the volunteers were asked either to wear a mask or not, on a random basis. Those who wore a mask while their children were sick were four times less likely than non-wearers to become infected by their sick children. Details of the research are published in the journal Emerging Infectious Diseases.
Neil Ferguson, director of the MRC Centre for Outbreak Analysis and Modelling at Imperial College, who led the study, said that the findings indicated strongly that masks could be useful in protecting against flu infections, and could be important in a pandemic. “In a severe influenza pandemic, there may be limited availability of vaccines in the first few months,” he said. “In that context, masks are a potentially important additional weapon.”
In an Interim guidance on the use and purchase of facemasks and respirators by individuals and families for pandemic influenza preparedness the American public has been given a much stronger recommendation for the home stockpiling, and use, of facemasks and respirators than we've seen before.
Some excerpts from this guidance:
Although not all households will have someone who becomes ill with influenza during a pandemic, because one cannot predict in which households an infection will occur, it would be reasonable for each household to stockpile some respirators that can be used, if needed, when caring for an ill family member.
With proper precautions, a single caregiver can use the same respirator several times over a day for brief care visits with the same ill person in the household,[2] so a stockpile of 20 respirators per household would be reasonable.
<snip>
Pandemic outbreaks in communities may last 6 to 12 weeks.[3] Persons who cannot avoid commuting on public transit may choose to purchase 100 facemasks for use when going to and from work.
An additional supply of facemasks also could be purchased for other times when exposure in a crowded setting is unavoidable or for use by an ill person in the home when they come in close contact with others.[4]
The CDC maintains a web page on face mask and respirator use called:
