Surgical masks don't block swine -- or any other -- flu

Surgical masks have become a common sight, particularly in Asia, as people try to prevent becoming infected with the infectious agent of the day, be it SARS, seasonal flu or the new pandemic H1N1 influenza virus. But a new study of 1,936 healthcare workers conducted in Beijing during last winter's flu season found that the masks are, for all practical purposes, useless. Dr. Raina MacIntyre of the University of New South Wales in Sydney, Australia, reported the results Tuesday at an infectious diseases society meeting in San Francisco, according to the Bloomberg news service.

Even the N95 masks that the government recommends for protection blocked only 75% of viruses,according to the article, perhaps because they were not fitted properly. The main problems with them are that they cost as much as 10 times the price of a regular surgical mask, they have to be fitted correctly and they can become uncomfortable after prolonged wearing.

-- Thomas H. Maugh II

Photo credit: Mark Baker / Associated Press

Comments

[cybele]

Okay, so they don't block you from getting the flu. Is it possible that they block some ability for you to transmit it?

(Also, don't some folks get colds & flus because they touch their face, if the mask is on, aren't they less likely to?)

[Max]

now i can just walk into a bank and hold it up and no one will notice

[Mike]

I always thought those mask wearing oddballs were just that...

Now I have reason to chuckle even more.

[Ron Williams]

So then why do doctors wear them?

[Chris Falcone]

I live in Minnesota and have been wearing a mask (the so-called uncomfortable N95 variety) for protection and will continue to do so until 2 weeks after immunization—and please note I am not a health care worker. Because masks could come into short supply I would take anything negative on masks with a grain of salt. Bottom line about viruses in general is that they, like every other substance that can prove deadly, has a LD50, which means an amount of agent that can function as a Lethal Dose in 50% of the host population. Granted all it takes is one H1N1 virus to set up shop in a cell capable of replicating the virus to become infected. However, we know that the pneumonia caused by H1N1 can be purely viral and from my extensive medical training my best guess is that those that suffer and or die from a purely viral pneumonia most likely had the virus first touch down in their lower respiratory tract (i.e., the lungs). Once the virus lands and infects one cell it then all boils down to math--how fast can the virus spread BASED ON THE INITIAL DOSE. I would much rather be exposed to a few virus particles (because the mask helped lower my exposure level) rather than a small airborne glob of phlegm that is teaming with literally millions of virus particles—wouldn’t you?-----Masks may not be preventing many health care workers from becoming sick but I would wager they are helping save some of their lives by minimizing their H1N1 exposure.

[dobbs]

Can't imagine how gross the inside of the mask would be after a person had been wearing it all day. Surely you should wear a fresh one every morning? But if they're expensive, people will re-use them. Ick.

[Paul]

Surgical masks are okay for people to wear in the community. The reason why they don't work in a health care setting is due to the very high levels of virus in the air in the hospitals. Hundreds of sick patients with H1N1, or any flu virus for that matter, spewing out millions of viral particles will overcome any surgical mask's ability to filter it out. Besides, they are only designed to help limit the ability of sick people to spread their coughs and sneezes.

Surgical masks are good for sick people to wear until they get better, so they won't spread their secretions caused by sneezing and coughing. They work best that way.

N95 masks are the gold standard. I've never caught an influenza virus or cold virus, even when sitting in the same car with someone sick as a dog and coughing/sneezing without covering his mouth. (sitting right next to him)

I have asthma though, so this is the reason why I wear an N95 mask when I go out to the hospital, mall or airport. It's never let me down but I make sure it fits me well by adjusting the metal clip on the bridge of the nose and breath heavily through it several times to test for air leaks. When fit properly, I then go out and carry alcohol-based hand sanitizer with me.

I am allergic to eggs and cannot receive the flu vaccine anyway. Nurses won't give it to me out of fear I might go into shock from anaphylaxis due to my severe egg allergy. The flu vaccine is made from chicken embryos and they try to clean as much egg protein off as they can, but it can still cause an allergic reaction in some people. I won't take a chance with that.

I don't like wearing masks, but other people are not very considerate. Never do I see anyone covering their mouths properly or sneezing into their elbow. People who are sick, generally don't care who they infect. They only care about themselves. That's just the way society is though unfortunately.

[Paul]

Surgical masks (and N95) also prevent you from touching your face. This is another way they help prevent disease. Even wearing masks though, if you don't wash your hands and then rub your eyes, you can easily infect yourself, so hand washing is a must.. even when donning a mask.

[Larry Lefkowitz]

There is a new mask available that uses advanced nanotechnology to neutralize germs (surgical and N95 masks filter germs).

Also, it's bi-directional, so it neutralizes germs from both environment and wearer.

Unlike other masks, it can be worn up to 24 hours, and has a special shape so that it is more comfortable for extended use. It neutralizes germs that would normally cause odor after a short period of time.

You can learn more at www.BeyondN95Mask.com