Masks may be just as effective as respirators in preventing flu in health care workers
THURSDAY, Oct. 1 (HealthDay News) -- Surgical masks may be no less effective than N95 respirators in preventing influenza in health care workers, according to a study published online Oct. 1 in the Journal of the American Medical Association.
Mark Loeb, M.D., of McMaster University in Hamilton, Canada, and colleagues randomly assigned 446 nurses in emergency departments, medical units, and pediatric units in eight tertiary care hospitals in Ontario, Canada, to wear a surgical mask or a fit-tested N95 respirator when providing care to patients who had febrile respiratory illness during the flu season of 2008/2009.
The researchers found that 23.6 percent of nurses in the surgical mask group and 22.9 percent in the N95 respirator group were infected with influenza (absolute risk difference, −0.73 percent), demonstrating non-inferiority of the surgical mask. In addition, 8 percent in the surgical mask group and 11.9 percent in the N95 respirator group had at least a four-fold rise in serum titers of the 2009 H1N1 strain. Non-inferiority for this H1N1 strain was demonstrated between the two groups (absolute risk difference, 3.89 percent).
"The major implication of this study is that protection with a surgical mask against influenza appears to be similar to the N95 respirator, meeting criteria for non-inferiority. Our findings apply to routine care in the health care setting. They should not be generalized to settings where there is a high risk for aerosolization, such as intubation or bronchoscopy, where use of an N95 respirator would be prudent," the authors write.