Mask Use, Hand Hygiene, and Seasonal Influenza-Like Illness

Journal of Infectious Diseases
15 February 2010  Volume 201, Number 4

Editorial Commentaries
Unmasking the Confusion of Respiratory Protection to Prevent Influenza-Like Illness in Crowded Community Settings
Titus L. Daniels and Thomas R. Talbot
…Fortunately, several well-designed in vivo studies have now been published that conclude there is no significant advantage of one mask type over another for respiratory protection against influenza or ILI. Loeb et al [10] conducted a noninferiority randomized, controlled study of mask use among nurses in Ontario, Canada, which demonstrated that the attack rate of laboratory-confirmed influenza was not different between those who wore facemasks and those who wore N95 respirators as respiratory protection (23.6% vs 22.9%, respectively). Although unable to demonstrate a protective benefit of mask use in households, MacIntyre et al [3] did note that adherence to mask use (face mask or N95 respirator) was associated with a reduction in ILI (hazard ratio, 0.26; 95% CI, 0.09–0.77).

Taken together with the Aiello et al [1] study, these data suggest that influenza transmission and ILI can be effectively interrupted with the use of a face mask and hand hygiene in settings of close contact. In addition, these data could inform the ongoing debate concerning respiratory protection for HCWs. Although the majority of data supporting prevention of influenza transmission with face masks has been derived from community sites, interactions between HCWs and patients are generally of a magnitude similar to what would be encountered in domestic settings. One could even argue that the household setting poses greater risk of transmission as a result of continued, prolonged exposure, whereas most HCW encounters with patients are brief, albeit possibly more frequent.

Aiello et al [1] have conducted a well-designed cluster randomized study demonstrating that use of a face mask combined with hand hygiene in a crowded community setting is helpful in preventing ILI. Although it would be difficult to extrapolate these data to the general public in noncrowded conditions (ie, nonresidential settings), these data can inform policy makers on the recommendations for mask use in community settings and perhaps other settings (eg, health care institutions)…


Mask Use, Hand Hygiene, and Seasonal Influenza-Like Illness among Young Adults: A Randomized Intervention Trial
Allison E. Aiello,1,2; Genevra F. Murray,3; Vanessa Perez,1,2; Rebecca M. Coulborn,1,2; Brian M. Davis,1,2; Monica Uddin,1,2; David K. Shay,4; Stephen H. Waterman,4 and
Arnold S. Monto,1
1Department of Epidemiology and 2Center for Social Epidemiology and Population Health, School of Public Health, University of Michigan, Ann Arbor, Michigan; 3Department of Sociology, Anthropology, and Social Work, University of South Alabama; 4Centers for Disease Control and Prevention, Atlanta, Georgia

Background.During the influenza A(H1N1) pandemic, antiviral prescribing was limited, vaccines were not available early, and the effectiveness of nonpharmaceutical interventions (NPIs) was uncertain. Our study examined whether use of face masks and hand hygiene reduced the incidence of influenza-like illness (ILI).

Methods.A randomized intervention trial involving 1437 young adults living in university residence halls during the 2006–2007 influenza season was designed. Residence halls were randomly assigned to 1 of 3 groups—face mask use, face masks with hand hygiene, or control— for 6 weeks. Generalized models estimated rate ratios for clinically diagnosed or survey-reported ILI weekly and cumulatively.

Results.We observed significant reductions in ILI during weeks 4–6 in the mask and hand hygiene group, compared with the control group, ranging from 35% (confidence interval [CI], 9%–53%) to 51% (CI, 13%–73%), after adjusting for vaccination and other covariates. Face mask use alone showed a similar reduction in ILI compared with the control group, but adjusted estimates were not statistically significant. Neither face mask use and hand hygiene nor face mask use alone was associated with a significant reduction in the rate of ILI cumulatively.

Conclusions.These findings suggest that face masks and hand hygiene may reduce respiratory illnesses in shared living settings and mitigate the impact of the influenza A(H1N1) pandemic.

Trial identifier: NCT00490633.

The Global Health System…Learning from Malaria

PLoS Medicine
(Accessed 24 January 2010)

The Global Health System: Linking Knowledge with Action—Learning from Malaria
Gerald T. Keusch, Wen L. Kilama, Suerie Moon, Nicole A. Szlezák, Catherine M. Michaud Policy Forum, published 19 Jan 2010

WHO: Pandemic (H1N1) 2009 – update 83

The WHO continues to issue weekly “updates” and briefing notes on the H1N1 pandemic at:

Pandemic (H1N1) 2009 – update 83
Weekly update
15 January 2010 — As of 10 January 2010, worldwide more than 208 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including at least 13554 deaths.

WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and member states and through monitoring of multiple sources of information.

Situation update:
The most intense areas of pandemic influenza virus transmission currently are in parts of North Africa, South Asia, and east and southeastern Europe….more at:

WHO Press Conference 14 January 2010
Listen to Dr Keiji Fukuda, Special Adviser to the Director-General on Pandemic Influenza [mp3 24.0Mb]
Read the transcript of the 14 January 2010 press briefing [pdf 910kb]

Interim Results: Influenza A (H1N1) 2009 Monovalent Vaccination Coverage in U.S.

The MMWR for 15 January 2010 includes:
Interim Results: Influenza A (H1N1) 2009 Monovalent Vaccination Coverage — United States, October–December 2009
Early Release   January 15, 2010 / 59(Early Release); 1-5

“…To estimate 2009 H1N1 vaccination coverage to date for the 2009–10 influenza season, CDC analyzed results from the National 2009 H1N1 Flu Survey (NHFS) and the Behavioral Risk Factor Surveillance System (BRFSS) survey, conducted during December 27, 2009–January 2, 2010, and December 1–27, 2009, respectively.

The results indicated that, as of January 2, an estimated 20.3% of the U.S. population (61 million persons) had been vaccinated, including 27.9% of persons in the initial target groups and 37.5% of those in the limited vaccine subset. An estimated 29.4% of U.S. children aged 6 months–18 years had been vaccinated. Now that an ample supply of 2009 H1N1 vaccine is available, efforts should continue to increase vaccination coverage among persons in the initial target groups and to offer vaccination to the rest of the U.S. population, including those aged ≥65 years…”

The survey reported that the uptake rate for health-care personnel was 22.3%.

Ireland announces further €1 million funding for GAVI Alliance

Ireland “reaffirmed its commitment to children in the developing world” in announcing a further €1 million in funding to the GAVI Alliance to “support GAVI’s efforts to increase and sustain vaccination rates in the world’s poorest countries against major diseases such as diphtheria, whooping cough, tetanus, Haemophilus influenzae type B, hepatitis B and yellow fever.” Peter Power, Ireland’s Minister for Overseas Development, commented,

“Children in developing countries are 10 times more likely to die from a vaccine-preventable disease than they are in wealthier nations. In 2008 alone, almost nine million children died before their fifth birthday, nearly a quarter of whom succumbed to vaccine-preventable illnesses. GAVI’s effective and strategic programme of support to the world’s poorest countries is playing a key role in stemming these unconscionable losses.”

PATH’s Malaria Vaccine Initiative (MVI) announces collaboration on transmission-blocking vaccines (TBVs)

PATH’s Malaria Vaccine Initiative (MVI) announced a new collaboration with the Johns Hopkins Bloomberg School of Public Health (JHSPH) and the Sabin Vaccine Institute (Sabin) “to initiate development toward a vaccine that may eventually help eliminate and eradicate malaria.” The collaboration “marks MVI’s first investment in transmission-blocking vaccines (TBVs),” which aim “to stop the malaria parasite from developing in the mosquito, effectively blocking transmission of malaria from mosquitoes to humans.” PATH noted that malaria kills nearly 900,000 people per year, most of them children younger than age five.

Dr. Peter Agre, Nobel Laureate and Director of the Johns Hopkins Malaria Research Institute (JHMRI), said, “Blocking transmission by novel vaccines may provide the approach needed to stop the epidemic. MVI deserves great credit for supporting potentially exciting research that would otherwise be abandoned due to lack of precedent.” Dr. Christian Loucq, Director of MVI, commented, “Although eradication is a very long-term and aspirational goal, we are excited by the potential of transmission-blocking vaccines to significantly limit the spread of malaria infection. In combination with other interventions, we believe a successful TBV would provide another important tool in the fight against malaria.”

Over the next 18 months, MVI’s partners will collaborate to produce and characterize an antigen that can activate the body’s defenses to disrupt the complex human-mosquito transmission cycle of malaria. An antigen is any substance that triggers the immune system to produce antibodies against it. The development team will identify the optimal conditions needed to manufacture clinical supplies of AnAPN1, a mosquito antigen that appears to play a major role in parasite establishment within the mosquito. Preliminary field research has shown that antibodies induced by this antigen are capable of blocking transmission of the two deadliest malaria parasites, Plasmodium falciparum and P. vivax. When a mosquito takes blood from a vaccinated person, these antibodies prevent the parasite from attaching to and invading the mosquito’s gut.

PATH noted that the collaboration—MVI’s first project focused on TBVs— “reflects MVI’s redesigned research and development strategy. The new strategy encompasses a broader outlook on malaria vaccine development and promotes early investment in a variety of approaches that have the potential to reach the malaria community’s long-term goal of a vaccine that is at least 80 percent effective against clinical disease for more than four years by 2025.”  More at: