H1N1 Flu: Facemask and Respirator Use

September 24, 2009 10:00 AM ET

This document has been updated in accordance with the CDC Recommendations for the Amount of Time Persons with Influenza-Like Illness Should be Away from Others . This document provides interim guidance and will be updated as needed

This document provides updated interim guidance on the use of facemasks and respirators for decreasing the exposure to  2009 influenza A (H1N1) virus. This guidance replaces other CDC guidance on mask and/or respirator use that may be included in other CDC documents in regards to the outbreak of 2009 H1N1 virus. No change has been made to guidance on the use of facemasks and respirators for health care settings. This document includes guidance on facemask and respirator use for a wider range of settings than was included in previous documents and includes recommendations for those who are at increased risk of severe illness from infection with the 2009 H1N1 virus compared with those who are at lower risk of severe illness from influenza infection.For more information about human infection with 2009 influenza A (H1N1) virus, visit the CDC H1N1 Flu website. Other CDC 2009 H1N1 guidance will be updated with the information contained in this document as soon as possible.

Detailed background information and recommendations regarding the use of facemasks and respirators in non-occupational community settings can be found on PandemicFlu.gov in the document Interim Public Health Guidance for the Use of Facemasks and Respirators in Non-Occupational Community Settings during an Influenza Pandemic. Information on the use of facemasks and respirators in health care settings can be found at http://www.cdc.gov/h1n1flu/guidelines_infection_control.htm.

Information on the effectiveness of facemasks and respirators for decreasing the risk of influenza infection in community settings is extremely limited. Thus, it is difficult to assess their potential effectiveness in decreasing the risk of 2009 influenza A (H1N1) virus transmission in these settings. In the absence of clear scientific data, the interim recommendations below have been developed on the basis of public health judgment, the historical use of facemasks and respirators in other settings for preventing transmission of influenza and other respiratory viruses, and on current information on the spread and severity of the 2009 influenza A (H1N1) virus.

In areas with confirmed human cases of 2009 influenza A (H1N1) virus infection, the risk for infection can be reduced through a combination of actions. No single action will provide complete protection, but an approach combining the following steps can help decrease the likelihood of transmission. These recommended actions are:

• Wash hands frequently with soap and water. If soap and water are not available, use an alcohol-based hand rub*
• Cover your mouth and nose with a tissue when coughing or sneezing.
• Avoid touching your eyes, nose and mouth
• People who are sick with an influenza-like illness (ILI) (fever plus at least cough or sore throat and possibly other symptoms like runny nose, body aches, headaches, chills, fatigue, vomiting and diarrhea) should stay home and keep away from others as much as possible, including avoiding travel, for at least 24 hours after fever is gone except to get medical care or for other necessities. (Fever should be gone without the use of fever-reducing medicine). 
   
• Avoid close contact (i.e. being within about 6 feet) with persons with ILI.

In addition, influenza antiviral medications are an important tool for the treatment and prevention of influenza, including 2009 H1N1. Also see Guidance on the use of antiviral medications.

Facemasks and Respirators

Recommendations for the uses of facemasks and/or respirators are listed in Table 1 below for different settings where a person may be exposed to 2009 H1N1 virus. These recommendations also differ based on whether the person exposed to 2009 H1N1 is in a group at increased risk for severe illness from influenza infection. More information on preventing influenza transmission in health care settings can be found in the Interim Guidance for Infection Control for Care of Patients with Confirmed or Suspected 2009 Influenza A (H1N1) Virus Infection in a Healthcare Setting.

In community and home settings, the use of facemasks and respirators generally are not recommended.  However, for certain circumstances as described in Table 1, a facemask or respirator may be considered, specifically for persons at increased risk of severe illness from influenza.