Face Mask Use and Control of Respiratory Virus Transmission in Households

Many countries are stockpiling face masks for use as a nonpharmaceutical intervention to control virus transmission during an infl uenza pandemic.We conducted a prospective cluster-randomized trial comparing surgical masks, non-fi ttested P2 masks, and no masks in prevention of infl uenzalike illness (ILI) in households.Mask use adherence was self-reported.During the 2006 and 2007 winter seasons, 286 exposed adults from 143 households who had been exposed to a child with clinical respiratory illness were recruited.We found that adherence to mask use signifi cantly reduced the risk for ILI-associated infection, but <50% of participants wore masks most of the time.We concluded that household use of face masks is associated with low adherence and is ineffective for controlling seasonal respiratory disease.However, during a severe pandemic when use of face masks might be greater, pandemic transmission in households could be reduced. H ighly pathogenic avian infl uenza virus A (H5N1) con-tinues to spread globally, posing a serious human pandemic threat.In the event of an infl uenza pandemic or other emerging respiratory disease such as severe acute respira- Face Mask Use and Control of Respiratory Virus Transmission in Households