Wednesday, August 19, 2009

The Flu Epidemic Panic

There's a rumblin' in the e-heard this morning. The Ticker Guy captures the concern nicely with the title, "Depression Assured? Maybe (Swine Flu)." And offers this quote from some backwoods mononzine:

The Centers for Disease Control has predicted a 2.1 percent to 3.3 percent death rate among those who come down with swine flu this fall, which translates into an additional 52,000 to 86,000 deaths in the city over a three-month period, Kasdan said.

So, are we all gonna get sick and die this fall and winter from the pig flu?! Specifically, H1N1. Well you don't need to follow the heard and get all-a-twitter worrying, you can do some simple digging on the intertubes yourself and find out the facts.

The CDC has been so kind as to use our tax money to post some simple facts about the normal influenza mortality. That's right Karl, people get the flu every single year and some die from flu related complications, sadly enough. But how many? I typed, "how many people die from the flu each year" into google and this CDC site came up immediately. Here's the relevant bit for our purposes,

Each flu season is unique, but it is estimated that, on average, approximately 5% to 20% of U.S. residents get the flu, and more than 200,000 persons are hospitalized for flu-related complications each year. About 36,000 Americans die on average per year from the complications of flu.

Here's the site for hospitalizations, with more details on the variability from year to year:

During the 1990s, the average number of people hospitalized was over 200,000 but individual seasons ranged from a low of 157,911 in 1990-91 to a high of 430,960 in 1997-98.

SO, given the first quote, with an average hospitalization rate of about 200,000 and an average annual mortality rate of about 35,000, we get about 17.5 deaths per 100 hospitalizations for complications associated with the normal ol' flu bug.

Well, how about H1N1?! Turns out that the CDC has been tracking this carefully since the outbreak and --- what a wonderful world this is!--- posts their data on the intertubes!

According to the most recent reports (August 13, 2009), only 7511 people have been hospitalized with H1N1 complications in the United States -- remember that in an average year about 200,000 people in the United States are hospitalized for normal influenza complications, if we annualize the 7511 number we only get to 10,000 (I know ... the flu is worse in the fall and winter than summer and spring, so we will have to watch closely). Still, 10,000 is a far cry from the 200,000 hospitalizations we get from the normal flu on average. Even at 100,000 H1N1 related hospitalizations, it would be a rather wimpy flu season (that's assuming exponential growth in rates of H1N1 related illnesses this fall and winter.

The CDC reports that about 477 deaths have been attributed to H1N1 so far this year. That's a rate of about 6 deaths per 100 hospitalizations ((477/7511)*100) -- or only about ONE THIRD the rate of a normal flu season!

Um ... so... sorry Ticker Guy, no Flu Pandemic from wimpy little H1N1.

The heard may go back to its regularly scheduled anxiety over the pending 2012 end of the world stuff*.

*Note: um the Mayan world ended well before the planned 2012 date (about 900 AD). Looks like their calendar had the last laugh!