This document provides interim guidance and will be updated as needed.
Detailed background information and recommendations regarding the use of masks and respirators in non-occupational community settings may 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” http – //www.pandemicflu.gov/plan/community/maskguidancecommunity.html
Information on the effectiveness of facemasks1 and respirators2 for the control of influenza in community settings is extremelylimited. Hence, it’s difficult to assess their potential effectiveness in controlling swine influenza A (H1N1) virus transmission in these settings.
In the absence of clear scientific data, the interim recommendations below have been developed based on public health judgment and the historical use of facemasks and respirators in other settings.
In areas with confirmed human cases of swine influenza A (H1N1) virus infection, the risk for infection may be decreased 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 actions include frequent handwashing, covering coughs, and having ill persons stay home, except to seek medical care, and minimize contact with others in the household.
Additional measures that can limit transmission of a new influenza strain include voluntary home quarantine of members of households with confirmed or probable swine influenza cases, reduction of unnecessary social contacts, and prevention whenever possible of crowded settings.
When it is absolutely necessary to enter a crowded setting or to have close contact3 with persons who may be ill, the time spent in that setting ought to be as short as possible.
When used correctly, facemasks and respirators may help reduce the risk of getting influenza, but they should be used along with other preventive measures, such as avoiding close contact and maintaining good hand hygiene.
A respirator that fits snugly on your face can filter out small particles that may be inhaled around the edges of a facemask, but compared with a facemask it’s harder to breathe through a respirator for long periods of time. More information on facemasks and respirators may be found at www.cdc.gov/swineflu.
When crowded settings or close contact with others cannot be avoided, the use of facemasks1 or respirators2 in areas where transmission of swine influenza A (H1N1) virus has been confirmed should be considered as follows –
1. Whenever possible, rather than relying on the use of facemasks or respirators, close contact with individuals who may be ill and being in crowded settings ought to be avoided.
2. Facemasks1 should be considered for use by person who enter crowded settings, both to protect their nose and mouth from other individuals ‘s coughs and to reduce the wearers’ likelihood of coughing on others; the time spent in crowded settings should be as short as possible.
3. Respirators2 ought to be considered for use by person for whom close contact with an communicable person is unavoidable. This can include selected person who must care for a sick person (e.g., family member with a respiratory infection) at home.
These interim recommendations will be revised as new information about the use of facemasks and respirators in the current setting becomes available.
For more information about human infection with swine influenza virus, visit the CDC Swine Flu website.
1 Unless otherwise specified, the term “facemasks” refers to disposable masks cleared by the USA Food and Drug Administration (FDA) for use as medical devices. This includes facemasks labeled as surgical, dental, medical procedure, isolation, or laser masks. Such facemasks have several designs.
One kind is affixed to the head with two ties, conforms to the face with the aid of a flexible adjustment for the nose bridge, and may be flat/pleated or duck-billed in shape. Another kind of facemask is pre-molded, adheres to the head with a single elastic band, and has a flexible adjustment for the nose bridge.
A third type is flat/pleated and affixes to the head with ear loops. Facemasks cleared by the FDA for use as medical devices have been determined to have specific levels of protection from penetration of blood and body fluids.
2 Unless otherwise specified, “respirator” refers to an N95 or higher filtering facepiece respirator qualified by the U.S. National Institute for Occupational Safety and Health (NIOSH).
3 Three feet has often been used by infection control specialists to define close contact and is based on studies of respiratory infections; nevertheless, for practical purposes, this distance may range up to 6 feet.
The World Health Organization uses “approximately 1 meter”; the U.S. Occupational Safety and Health Administration uses “within 6 feet.” For consistency with these estimates, this document defines close contact as a distance of up to 6 feet.