In the event of a flu pandemic, will the use of masks by the public help? It's not completely clear. We know that N95-style respirators are recommended in the health care setting. And research is ongoing to assist in answering the many questions that are raised. So, for now, here's some guidance from the transcript of today's CDC press conference by Dr. Julie Gerberding:
"But in the short run, we just want to make sure that those people who are already thinking about this, have the best possible information that we have and kind of our sense of what makes sense from a practical standpoint to do - to add to that preparedness kit that we hope everyone already is working on at home.
And just as a reminder of what that includes, it includes your food and water supply for up to two weeks, your medications, your pet food and water as well as any pet medications. Some materials that you need to be able to run your radio without electricity and the other kinds of things that can be found on the web site to assure your family can take care of itself, not only in the flu pandemic, but in any kind of disaster emergency that might occur in your community."
Here is some important background:
An influenza pandemic will likely cause illness in large numbers of people in almost every community worldwide. Influenza is thought to be transmitted from person to person by close contact (within 6 feet) with individuals who are infected with influenza virus (e.g., via exposure to respiratory secretions). It is unclear to what extent inhalation of small particles or direct exposure to larger droplets contributes to this close-range transmission of influenza viruses. Experience with influenza viruses transmitted from person to person in institutional settings indicates that most transmission occurs over short distances; long-distance transmission through the air (e.g., via ventilation systems) has not been demonstrated. For a more detailed discussion of influenza virus transmission, see Appendix A of Interim Guidance on Planning for the Use of Surgical Masks and Respirators in Healthcare Settings during an Influenza Pandemic (www.pandemicflu.gov/plan/healthcare/maskguidancehc.html).
For many respiratory infections other than influenza, transmission occurs primarily during the later stages of illness when infected persons are likely to stay home or seek medical care. In contrast, influenza tends to be most infectious during the early stages of illness, especially just after the onset of coughing and sneezing. Therefore, much influenza transmission during a pandemic is likely to occur in non-healthcare settings, such as schools, public gatherings, and households. Although it is not possible to completely avoid all risk of becoming infected while continuing to interact with others in the community, individuals and households can use various strategies, including those described in this document and elsewhere (see below), to help limit the risk of exposure to themselves and their families.
Vaccination is generally considered the most effective way to prevent seasonal influenza. However, unlike the typical situation with seasonal influenza, an effective vaccine may not be available for all people early in a pandemic. Thus, current U.S. pandemic preparedness and planning efforts have included the coordinated use of nonpharmaceutical interventions to help reduce the spread of influenza. This approach is described in Interim Pre-Pandemic Planning Guidance: Community Strategy for Pandemic Influenza Mitigation in the United States — Early, Targeted, Layered Use of Nonpharmaceutical Interventions (www.pandemicflu.gov/plan/community/commitigation.html), which would be used in conjunction with this interim guidance for facemask and respirator use.
The bolded represents the advice to classify pandemics like hurricanes (category 5 pandemics are worse than category 1 pandemics) and to consider closing schools, working from home and otherwise avoiding people when possible in the event of a category 4 or 5 pandemic. Scan through this H5N1 tag for more.
And the part about masks?
When it is absolutely necessary to enter a crowded setting or to have close contact with persons who might be infectious, the time spent in that setting should be as short as possible. If used correctly, facemasks and respirators may help prevent some exposures, but they should be used along with other preventive measures, such as social distancing and hand hygiene. When crowded settings or close contact with others cannot be avoided, the use of facemasks or respirators should be considered as follows:
- Whenever possible, rather than relying on the use of masks or respirators, close contact and crowded conditions should be avoided during an influenza pandemic.
- Facemasks should be considered for use by individuals who enter crowded settings, both to protect their nose and mouth from other people's coughs and to reduce the wearers' likelihood of coughing on others; the time spent in crowded settings should be as short as possible.
- Respirators should be considered for use by individuals for whom close contact with an infectious person is unavoidable. This can include selected individuals 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 setting of pandemic influenza becomes available. For up-to-date information about pandemic influenza, visit www.pandemicflu.gov.
Or, visit Flu Wiki Forum for more discussion.
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