This new strain of swine-origin influenza A H1N1 is substantially different from human influenza A H1N1 viruses; therefore, a large proportion of the population might be susceptible to infection and the seasonal influenza vaccine H1N1 strain likely will not provide protection
Calling this the H1N1 virus, as the Obama administration has decreed, is inaccurate, because this virus is not the same as the human H1N1 virus. It also muddies the waters since some will believe that the flu shot they got last year might offer some protection. According to CIDRAP and the CDC, it won't.
Infected persons are assumed to be shedding virus from the day prior to illness onset until resolution of symptoms. Persons with swine-origin influenza A H1N1 virus infection should be considered potentially contagious for up to 7 days following illness onset.
This means that you could be feeling perfectly fine, but be contagious. That makes containment nearly impossible to achieve. We can expect to see cases of this flu spreading for quite awhile yet.
Available data suggest that airborne transmission does not play a major role in the spread of influenza viruses
A mask will only help you if you are close enough, within 3 feet, for an infected person to sneeze or cough on you. And in that case, direct transfer of the virus may still take place. ON the other hands, masks work very well for the already infected person, containing the virus from sneezes etc. So runningdowm to Home Depot for a face mask isn't going to help you, but if it makes you feel better, go for it.
An outbreak of swine-origin influenza was recognized in early 1976 among military personnel at Fort Dix, New Jersey. Thirteen clinical cases occurred with one death; the cause of the outbreak remains unknown, and no exposure to pigs was identified (see References: Gaydos 2006). Retrospective serologic testing subsequently demonstrated that up to 230 soldiers had been infected with the novel virus, which was an H1N1 strain. The outbreak did not spread beyond Fort Dix.
Morbidity and mortality rates are difficult to determine since many cases of the flu go unreported as the symptoms are very mild. Speaking very roughly, morbidity describes the percentage of the population that has the disease while mortality describes the percentage of the affected population that will die from the disease. Without knowing the manning levels at Fort Dix, it's hard to determine morbidity, but out of 230 soldiers known to have been exposed to swine flu, only 13 cases were serious enough to need medical treatment, and only 1 died. That gives us a mortality rate of 0.4%. That sounds comfortingly small; the problem is that the garden variety of flu we battle every year has a mortality rate of somewhere around 0.1% or so, and it still takes out over 50,000 people annually. If the two types of flu are transmitted similarly, as the CDC believes, then we can expect as many as 200,000 deaths in the US from a widespread outbreak of the swine flu, jumping from the eighth to the third leading cause of death, just behind cancer and ahead of stroke.
This brings up the question, How come the mortality numbers from Mexico are so much higher? The answer is simple. They haven't done the testing to discover the hundreds or thousands of people who were exposed but didn't get sick enough to go to the hospital. Consider that if we used the 13 soldiers from Ft. Dix who got sick enough to go to the doctor in our mortality calculation, we'd show a rate of about 7.7%, which is very close to what we are seeing in Mexico right now.
So, let's put this all together. If the current patterns hold true, then the worst case scenario is that 200,000 people die from this flu that wouldn't have died otherwise. Given that 2.5 million people die each year (rough approximation using data from 2005), we're looking at an increase in the US death rate from 0.83% to 0.90%. 3 times as many people will die fron heart disease. 2.5 times as many will die from cancer. Accidents will claim almost half as many. Going another step, 200,000 is the worst case right now; it's very likely that the outbreak will not be as widespread as the standard seasonal flu. Our behavior patterns are different during the warmer months, and our immune systems are under less stress, accounting for the seasonal variations in flu infection rates. I'm guessing that we won't see anywhere near 200,000 deaths from the swine flu in the US. I doubt we'll even reach the seasonal flu number of 50,000. Yes, we need to take action to minimize these numbers, but the panic and hysteria we are seeing from governmental agencies is ridiculous. The swine flu simply isn't that dangerous.
If something changes, if we start seeing infection rates far above what we expect for the seasonal flu, or for some reason the mortality rate spikes, then there will be cause for alarm, but right now, talk of closing borders and shutting down travel and wearing masks in public is fear driven over-reaction.