I posted much of this yesterday, then pulled it. So if it looks familiar, that would be why.

We continue to see drastic predictions for the 2nd outbreak of H1N1 in the U.S. (an outbreak that has apparently already begun). The latest projections come from a White House advisory panel, which published findings suggesting that as much as half of the U.S. population may be affected by swine flu, with 1.8 million hospitalizations and 90,000 deaths — nearly three times the number of deaths from seasonal flu in a normal year.

The advisory panel isn’t alone with its dire predictions. Harvard professor Mark Lipsitch, who advises officials on matters such as this, told the Washington Post that, “It’s fair to say there will be tens of millions of illnesses and hundreds of thousands of hospitalizations, and tens of thousands of deaths.”

Is it really fair to say? Or are we taking a worst-case scenario and trying to talk it into reality? And exactly what kind of science is the advisory panel’s precautions based upon? I’m not an expert. I know nothing of infectious diseases. But, then, I don’t think you need to be an expert to look at some of these numbers floating around and say “Phooey!”

Sure, the H1N1 virus could mutate. But there are no indications so far that this will happen. And despite some media claims — such as one in the above-referenced WaPo story — that the virus is impacting young people more severely than the seasonal flu, that doesn’t seem to be the case. It’s impacting young people in greater numbers than seasonal flu, perhaps, but it seems to be relatively mild by comparison.

Of the folks I am familiar with who have been infected by swine flu — one includes by 3-year-old daughter and another includes someone who we’re familiar with on this blog (but I’ll not name names) — their symptoms have been typical, flu-like symptoms: Harsh, but not overly serious. My daughter ran a high fever for a couple of days and spent last weekend being doted on with ice cream, lollipops and teddy bears (all the things a little girl loves), but was otherwise none the worse for wear.

But let’s not take a couple of isolated cases and broad-brush this entire pandemic. As we all know, the flu affects different people differently. So let’s look at some numbers. The CDC estimated in June that 1 million Americans had been infected with swine flu. And, to date, there have been 522 U.S. deaths attributed to it. So let’s go conservative and cut off the CDC’s estimate at June and say that 522 people died as a result of 1 million swine flu cases. So 0.05% of everyone infected with the swine flu has died in the U.S.

Now let’s compare that with the regular ol’ seasonal flu. In a normal year, the CDC estimates that between 5% and 20% of the population is infected with the flu. That’s between 15 and 60 million. And an average of 36,000 Americans per year die of the flu. Let’s split the difference and say that 37 million people are infected with seasonal flu annually. That means that 0.09% of everyone infected with seasonal flu dies.

So can we get our broad brush back out and say that, proportionately, you’re more likely to die if you’re impacted by seasonal flu than if you’re impacted by H1N1?

Of course, the Chicken Littles will say, “Yeah, but seasonal flu impacts mostly older people with poorer immune systems, and swine flu is killing younger people.” True. Experts say the current H1N1 strain is a cousin of the Spanish Flu strain that caused the huge pandemic in 1918 and was around in some form until the 1950s, thus a lot of people over 60 alredy have an immunity to it. But swine flu is also only killing those in “high risk groups,” such as the immuno-compromised and those with pre-existing conditions such as cardiovascular disease or chronic diabetes. And, when you get right down to it, isn’t it better for swine flu to be infecting those of us in our 20s and 30s rather than the elderly, since our immune systems are generally healthier and better able to withstand the flu?

Naturally, more of us are going to be ill this winter than normal (in fact, if the first couple of weeks of school are any indication, it’s going to be a miserable winter . . . a number of bugs seem to be going around in addition to the flu). Naturally, more people will die than normal. If 1 million Americans were infected in warm weather, it is probably inevitable that this was only a sign of things to come. But it seems that a lot of folks are being misled into believing that otherwise healthy people are going to start dropping like flies.

And as for those projections that upwards of 100,000 Americans will die? Let’s look at some more numbers.

Our flu season is still a couple months away (though experts say the H1N1 outbreak could actually peak sooner than the normal flu season). But in the Southern Hemisphere, the winter season is coming to an end, and their flu season is in full swing. And while there will undoubtedly be more deaths to come, here are some figures from countries in temperate climates in the southern part of the world: Brazil, with a population of 190 million, has had 584 swine flu deaths so far. Argentina, with a population of 40 million, has had 439 swine flu deaths. There have been 147 deaths in Australia (pop. 21 million), 116 in Chili (pop. 16 million) and 16 in New Zealand (pop. 4 million).

Of those nations, Argentina — 439 deaths in a country of 40 million people — has had the highest rate of mortality by far, with 0.001% per populous dying from swine flu thus far. Brazil is the lowest, at 0.0003%, and New Zealand comes close at 0.0004%.

So let’s apply Argentina to the U.S. All other factors the same — health care, hygiene, etc. — if the U.S. had a swine flu mortality rate the same as Argentina, 3,040 Americans would die from H1N1 this winter. Let’s double it . . . What the hey, let’s triple it. No, no. Let’s say that the U.S. is the most swine-flu-prone nation in the world by far, and quadruple it. And that’s still only 12,000 deaths from swine flu.

Is it fair to compare numbers like that? Not at all. There are far too many other factors that come into play. But neither is it fair to come out and boldly say that tens of thousands will die and millions will be hospitalized. I’ll go ahead and go out on my limb and say that the death toll won’t come anywhere close to that.