From the third week on, both the mask only and mask/hand sanitizer interventions showed a significant or nearly significant reduction in the rate of influenza-like illness symptoms in comparison to the control group. The observed reduction in rate of flu-like symptoms remained even after adjusting for gender, race/ethnicity, hand washing practices, sleep quality, and flu vaccination.
Non-pharmaceutical interventions such as hand washing and masks---especially in a pandemic flu outbreak---are critical to study because pharmaceutical interventions such as vaccinations and antivirals may not be available in sufficient quantity for preventing and controlling pandemic influenza outbreaks.
In February 2007, the Centers for Disease Control and Prevention and the U.S. Department of Health and Human Services in collaboration with other federal agencies, education, businesses, healthcare and private sectors developed an interim planning guide on the use of Non-Pharmaceutical Interventions (NPIs) to mitigate an influenza pandemic.
The measures include voluntary home quarantine, isolation and treatment of cases, social distancing, personal protection such as face masks and hand hygiene, and school dismissal.
"Although a few of these measures can be evaluated during seasonal influenza outbreaks, many are difficult or impossible to evaluate in advance of a pandemic," Monto said. "However, use of face masks and hand hygiene interventions can be evaluated now, during seasonal influenza outbreaks, which can provide concrete evidence for decision makers."
Further studies are needed to confirm whether mask use may be an effective means of reducing influenza in shared living settings. Since it was not possible to blind subjects, knowledge of the intervention may have influenced influenza-like symptom reporting and therefore the results
|Contact: Laura Bailey|
University of Michigan