N95 Masks Can Help Prevent Spread of H1N1 Flu
H1N1 flu continues to be a concern as “regular” flu season nears. The normal influenza season in the Northern hemisphere usually runs from October through May, with a peak mid-February. Approximately 5-20% of the US population is infected by influenza each flu season. Without taking H1N1 flu into account, historically nearly 200,000 people are hospitalized with the flu each year, and on average 36,000 will die either from influenza or its complications.
In an attempt to lessen the spread of H1N1 flu, the Centers for Disease Control and Prevention (CDC) recommended guidelines for protection of health-care workers during an outbreak includes the use of N95 respirators for those in close contact with people who have H1N1 flu.
The reason for this recommendation is due to the the droplet mode of influenza transmission. Any influenza virus can be transmitted by droplet when someone coughs or sneezes. Extremely fine droplets are aerosolized into the air around the person who sneezed or coughed. If these droplets come in contact with your nose, mouth, throat, or lungs, it is possible for you to become infected by the viruses in those droplets.
The second way influenza can be spread is either through direct contact or through an intermediate like a doorknob, known as a “fomite.” The virus can survive for minutes to days depending on the surface, and if you touch that surface then your mouth or nose, again, it is possible that you can become infected. This is why frequent hand washing is so important.
The N95 respirator masks fit more snuggly around the mouth and nose than loosely fitted surgical masks. They also have filters that can block about 95 percent of the flu virus.
Tests done by the Institute of Medicine showed that the protection provided by N95 masks was eight to 12 times greater than that offered by surgical masks. Surgical mask can provide some protection, but there is a wide variation in how much of the virus is filter out (from 4% to 90%).
The general public should continue to use basic precautions:
* Wash your hands often with soap and water.
* Use waterless alcohol-based hand gels (containing at least 60% alcohol) when soap is not available and hands are not visibly dirty.
* Cover your mouth and nose with a tissue when you cough or sneeze. Try to cough or sneeze into your elbow / upper sleeve rather than your hand. If you use a tissue, dispose of it in a wastebasket and then wash your hands.
* Follow all local health recommendations. For example, you may be asked to put on a surgical mask to protect others.
Institute of Medicine: http://www.iom.edu
President’s Council of Advisors on Science and Technology (PCAST): www.ostp.gov/cs/pcast
For more information on H1N1 swine flu, visit the Flu.Gov.