Don't Be Taken In By Stylish Dismissal of the Threat of Pandemic Flu

Some people become overly catastrophic at the slightest hint of threat. That is a bad thing. On the other hand, some people err in the opposite direction, and that is a bad thing as well.

It is stylish to be dismissive of concerns raised by the media. Such a dismissive attitude can be seen in an opinion piece by Wesley Pruden, appearing in The Washington Times on Tuesday, April 28. Mr. Pruden, editor emeritus of the paper, pointed out that, in recent years, the media alerted people to threats that did not, in fact, kill everyone in sight, threats like "AIDS, SARS, bird flu, poisoned peanut butter," and so on.

There is much to criticize in Mr. Pruden's op-ed piece, such as the way he mocks the caution with which global and national health authorities have qualified their warnings. (Well, of course they have to use words like "may" and "might," in reference to this threat. If we wait until a pandemic definitely develops before we raise warnings, then it will be too late to do anything; that would be the medical equivalent of the way the federal government dealt with Hurricane Katrina.) However, I would like to focus on the very worst section of Mr. Pruden's piece, the part most likely to cause actual harm. As he put it:

About 2,000 persons in Mexico are down with flu, and about 150 have died. That's a mortality rate of about 7 percent. Sad, even tragic, but not exactly the most lethal flu virus we've ever seen.

The lordly manner with which this op-ed piece dismisses the apparent mortality rate seen in the recent Mexican flu cases disguises a monumental misunderstanding of the medical significance of these statistics. It is a misunderstanding that has potentially lethal consequences.

The most lethal flu pandemic of which we have certain knowledge is the so-called Spanish flu of 1918. The low-end estimates of the number of people killed by this flu pandemic are 40 million around the world--in a single year. As noted in probably the best book on this pandemic, John M. Barry's The Great Influenza, the mortality rate of the Spanish flu was 2%. (Mr. Barry repeats this statistic in his own op-ed piece, which also appeared on April 28, in The New York Times.) At 2%, the Spanish flu showed a much higher mortality rate than the normal annual flu, which has a mortality rate that is a fraction of 1%. That, in addition to the Spanish flu's relatively high infection ratio (it infected one-quarter or more of those exposed to the virus), made the Spanish flu the worst pandemic disease killer of recorded history, beating out the Black Death of Europe.

Yes, there are worse mortality rates, for agents like the Ebola virus--but Ebola and the like have never become pandemic. (Good thing, too, as then we'd be in Stephen King, end-of-civilization territory.) The Spanish flu, with it's 2% mortality rate, wins the prize for deadliest pandemic virus.

But 2% does not hold a candle to 7%, now does it? Actually, a mortality rate of 7% really would be the most lethal flu virus we've ever seen, and by a very large margin, at that.

The figures coming out of Mexico are more than a bit sketchy. It will take at least a few more days to clarify the actual infection rate and mortality rate of the new swine flu seen in Mexico. However, if--and may the Divine Powers in heaven forbid this--if the new swine flu does indeed have a mortality rate of 7%, then it will have over three times the mortality rate of the Spanish flu, the worst flu pandemic of recorded history until now, all without the necessity of the virus mutating from what it is today.

This is why the health authorities of the globe are so concerned. This is why they are taking serious steps, even in the early stages when the available data are still so sketchy. This is why Mr. Pruden's op-ed is so irresponsible, and dangerous--for by misrepresenting the meaning of the very statistics he quotes, he encourages people to ignore this threat.

One might expect Mr. Pruden to know the meaning of these statistics. After all, he does cite the Spanish flu; his piece even features a photograph of Seattle in the grip of the Spanish flu (above). However, having taught dozens of class sections of statistics at the college level myself, I can understand how easy it is to misunderstand the impact of these statistics. (Think about this for a minute. Seven percent is about one person in fifteen. Have you ever experienced an illness that killed one person out of every 15 infected? That's worse than the mortality rate from combat for the Union troops in the Civil War.)

But now you know that impact. I hope that, over the course of the next few days, we'll come to know the true mortality rate of the new swine flu. If it is well below 1%, that will mean one thing. On the other hand, if it is 2%, or worse, then we are in Spanish flu range, and that worked out quite badly for the unprepared world of 1918. If it is actually 7%--frankly, we would be in a lot of trouble. Let's hope (and pray) for a lower number--but let us prepare for a worse scenario.

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-----UPDATE

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The Washington Times published my response to Mr. Pruden as a Letter to the Editor in their May 1 issue. I did not choose the title ("Fear the Flu"); I write this blog so that you won't do that. But at least a response is in print.

(The photo, of Seattle during the 1918 pandemic, was obtained from the website of The Washington Times. The photo itself is in the public domain.)