Pandemic influenza: The latest new, ideas and debates
Friday, May 1, 2009
More on face masks
I just ran across a very helpful article on the use of face masks to prevent the transmission of influenza-like illness in the home. The researchers asked parents who had children with respiratory illness to wear either surgical masks, non-fit tested P2 masks (= N-95 masks), or no mask to see if the masks protected them against infection.
The key findings were:
"We estimated that... the relative reduction in the daily risk of acquiring a respiratory infection associated with adherent mask use (P2 or surgical) was in the range of 60%–80%." (emphasis added)
"Adherent" in this context means that the people actually wore the mask most or all of the time. And...
"... [less than] 50% of those in the mask use groups reported wearing masks most of the time."
You can't win if you don't play, folks. The take home message here is: Masks help... but only if you use them consistently.
Interestingly, the authors also found no significant difference in adherence between P2 (N-95) mask users and surgical mask users, despite the widespread opinion that N-95 masks are more uncomfortable than surgical masks.