Face Masks Can Help Limit Influenza Spread

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Face Masks and Hand Hygiene Can Help Limit Influenza's Spread, Study Finds.

ScienceDaily (Jan. 26, 2010) — Ordinary face masks and hand hygiene can

effectively reduce the transmission of influenza-like illness during flu season.

The finding comes from a new study, now available online, published in the Feb.

15 issue of The Journal of Infectious Diseases. In an influenza pandemic,

vaccination may not be initially available, and antiviral prescribing may be

limited, which is why scientists need to understand how effective other measures

are in preventing influenza.

For the study, researchers from the University of Michigan School of Public

Health, led by E. Aiello, PhD, recruited more than 1,400 college

students living in university residence halls during the 2006-2007 influenza

season. Participants were assigned to one of three groups: those who wore face

masks, those who wore masks and used alcohol-based hand sanitizer, or a control

group who received no intervention. Students were monitored for influenza-like

symptoms for six weeks. All participants viewed a basic hand hygiene

instructional video. Subjects in the hand hygiene and mask group were given an

alcohol-based hand sanitizer and written instructions regarding proper face mask

and hand sanitizer use. Those in the mask group received written instructions on

face mask use only. The students began using the measures just after laboratory

confirmation of influenza on the University of Michigan campus had been made.

The investigators observed significant reductions in the incidence of

influenza-like symptoms starting after three weeks in the hand sanitizer/mask

group and in the mask group compared with the control group. In the hand

sanitizer/mask group, Dr. Aiello and researchers found a reduction of

influenza-like symptoms ranging from 35 to 51 percent when compared with the

control group. The incidence of symptoms between the hand sanitizer/mask group

and the mask-only group were not statistically different, suggesting that the

use of hand sanitizer did not substantially contribute to reducing symptoms.

The findings " have implications for guidelines and recommendations for mask use

in the community setting, " the authors wrote. Mask use during this study was

proven to have a protective effect even when worn moderately during the day.

Additionally, the use of face masks and hand hygiene may reduce respiratory

illnesses in community settings and lessen the impact of the H1N1 pandemic, the

authors noted.

An accompanying editorial agreed with the researchers and suggested that use of

a face mask and hand hygiene can be effective in reducing transmission of

influenza and influenza-like illness. The editorial's lead author, Titus

s, MD, MPH, of Vanderbilt University, pointed out that the Centers for

Disease Control and Prevention (CDC) currently recommends the use of a face mask

only for individuals at increased risk for influenza or where H1N1 is

circulating in the community setting. " These data can inform policymakers on the

recommendations for mask use in the community and perhaps other settings, " such

as health care institutions, the editorial said.

Journal Reference:

1. Aiello et al. Mask Use, Hand Hygiene, and Seasonal Influenza-Like Illness

among Young Adults: A Randomized Intervention Trial. The Journal of Infectious

Diseases, 2010; 100120134621007 DOI: 10.1086/650396.

http://www.sciencedaily.com/releases/2010/01/100121135907.htm