In LA

I was just watching Real Time with Bill Maher and Mr. Maher was discussing bird flu with CNN’s Dr. Sanjay Gupta. It was more of a debate than a discussion, with Dr. Gupta stressing how big a deal the bird flu could be and that it makes sense to get freaked out about a disease that “kills 1 in 2 people”. Bill Maher, on the other hand, was really enthusiastically pushing the idea that the pharmaceutical companies are evil (yeah, there’s some truth to that) and that people should have healthier lifestyles (yeah, there’s some truth to that), and that somehow improving our lifestyles and diets would boost our immunity so that we can’t catch things like the bird flu (uh, no. I’m not aware of any evidence that olympic athletes catch significantly fewer viruses than couch potatoes, although they do probably have less chronic back pain).

But getting back to Dr. Gupta’s statement about the possibility that bird flu has killed 1 out of every 2 people infected with it. This 50% mortality rate meme rears its head in almost every sensational article about bird flu, and I think this number is not such a reasonable assumption. The real statistic, the way it should be discussed in a responsible press, is that out of all the confirmed human cases of H5N1 infection, 50% of them ended in death. But that sounds much less sensational and is thus a much less likely bit of information to spread so easily. My presumption is that the “50% mortality rate” may be wrong because it’s not unlikely that there are many unconfirmed — it may be likely that the vast, vast majority of people who come down with the avian flu think they just have a bad case of the normal flu and don’t die and don’t go to the hospital and are hence, not confirmed cases. My doubt is fueled by the fact that there is no recorded incidence of any influenza virus that caused anywhere near a 50% human mortality rate, even considering past flu epidemics that killed millions.

For an example of a more easily believable mortality rate, check out one of the more recent and dramatic flu epidemics, the 1918 Spanish flu, which killed 25-50 million people worldwide. It is estimated to have had a 2-5% mortality rate. The common flu varieties have mortality rates around %0.004 (PDF - I may be wrong in my math, but it’s at least somewhere below %1). So even if the avian flu has the same mortality rate as the 1918 flu epidemic that would be a huge jump above the normal rate and enough to be worthy of some level of panic.

I could be very wrong about this, and I’d even bet that the odds that I’m wrong are much higher than the real human mortality rate of H5N1.

This entry was posted on Tuesday, November 8th, 2005 at 7:45 am and is filed under China, Geeky. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.