Wednesday, June 3, 2009

Replies: More on Swine/A Flu

Anonymous said...
Hi Ferfal,

Any mask is better than no mask, and may stop the flu as well as an n95 mask, according to this:

Ilya said...

But this mask does not protect YOU.
It protect others from you.
It has very good protection, but it created to protect patient from surgeon breath.
Possibly, I'm not right, but my common sense tells me -- if it is not airtight -- you can inhale germs.

Good against dust, but not against biohazard.

You are right about not being airtight and thus not providing 100% protection, but it’s still MUCH better than no mask at all.
For example, when working with wood and other dusty labor, I’ve found that large amounts of dust gather in the mask where my nostrils are located, clearly stopping the particles. At least an important part of air is getting filtered.

Blackthorn D. Stick said...
Here's an interesting link you might want to check out.

Thanks for the link

Don Williams said...
Ferfal, I've been busy researching Swine Flu here in USA. Some points:

a) Our Center for Disease Control does recommend use of the N95, especially if you are in a High Risk group (e.g diabetes) and taking care of a sick relative. Best measure is to not get within 6 feet of a sick person but people can be infectious for a day or so (and transmitting flu virus) before they show noticeable symptoms. So you can't tell if that guy sitting next to you on the bus is sick.

b)However, the N95s are meant to be disposable. They filter out the small droplets created by sneezes and on which the flu viruses reside. However the flu virus itself is much smaller. I've seen reports suggesting that the N95 mask can become waterlogged (from moisture in the breath) and hence become permeable to flu viruses that have been caught on the outer surface. Obviously how soon this happens depends upon how much you are exhaling (heavy exercise vice resting) but some reports suggest they are not good for more than 2-3 hours. Also, one study concluded that there is no way to sterilize them without destroying the fine inner fibers that filter out the small items.

c) So you need a lot of N95 masks -- care of a sick relative over a week long bout would use up about 20 of them. I estimate about 100 per person would be needed for the entire flu season.

d) However, The MEDICAL N95s here in the USA disappeared quickly -- shortly after the swine flu appeared I went to 14 drug stores and found that they were all sold out. They are also very expensive ($4 per mask). However, CDC indicates that the N95
masks used in construction trades (available in paint stores, hardware stores,etc. and used while painting or sanding ) can be used as well.

e) The Medical N95 (blue colored here in USA) seems to simply have a stronger outside surface to resist drenching by body fluids (e.g, spray of blood). If you are not a surgeon or nurse inserting catheters into people, it appears that you can probably get by with the construction N95 --which is available in far greater quantities and is cheaper ($1 per mask).

f) The valve you mentioned allows easier breathing and would probably delay the mask becoming soaked with exhaled moisture. However, it costs twice as much.

g) You may also want some of the common "procedure masks" worn by doctors, dentists,etc. -- for sick relatives to wear so that they do not emit so many viruses into the air. However, they may not be able to breathe with such masks as they get sicker.

h) Note that CDC's recommendations are based upon the judgment of doctors and scientists and are based upon past experience in dealing with far more infectious diseases (measles, Tuberculosis,etc.). To my knowledge, There have not been extensive scientific tests yet of the N95's resistance to flu.

i) However, many of the US news reports that "N95 is not effective" goes counter to the CDC's recommendation. I think those news stories were put out by politicans who were panic-stricken that the US public was about to realize that the government did NOT have the 7 billion or so masks needed to protect them if the flu continued explosive growth into the USA summer season.

j) CDC recommendation is at . Note that proper fit to get an airtight seal is essential (no beard).


Some more info on N95 masks from US Food and Drug Administration (regulates use of medicines and medical equipment) and US government
(Links pointed to by US CDC)

again, the PRIMARY recommendation is to avoid contact with people. But obviously that is not always feasible.


Note that guidance to Healthcare workers caring for flu patients is to wear eye protection (goggles) and wash hands as well. It appears that flu can be contracted by viruses touching the wet membrane of the eyes --either by an infected hand rubbing them or from the air.

washing the hands removes flu viruses from the hand that might be transferred to the eyes, nose or throat.


Jedi said...
If anyone is interested in buying the real deal, here's a good one from a great company:

If you think people will look at you funny wearing an n95 mask, try wearing this thing in public. Oh well. If you ever really need it, I doubt you'll care.



Bones said...

One of the main things masks do is to KEEP YOU FROM TOUCHING YOUR OWN FACE. Most viruses are spread by touch, not by aerosol. Anything touched by an infected person can infect anyone else who touches it. It's virtually impossible to prevent contact, but by wearing a mask you greatly reduce touching your own mouth and nose thus infecting yourself. If you need to wear a mask when going out make sure you wash your hands BEFORE removing the mask. Basic hygiene is important.

Joseph said...

CDC (Center for Disease Control, here in the US) is estimating that the flu will come back more agressively in the fall. Makes sense now to stock up on masks/hand sanitizers and gloves.