Swine flu

With the coverage of the swine flu, I've been thinking about an arcane fact I was told once about the epidemic of 1918.

A friend I went to college with went on to study demography in graduate school. At that time (early 1970's), the way you got a PhD in demography was to study the "demographic transition" (when people get prosperous enough to consider children an expense instead of an asset) somewhere. We lived in Rhode Island, so he studied it in Rhode Island.

This meant that he looked at essentially all the death certificates issued in the first few decades of the twentieth century. And one of the things he and other demographers noticed about the spike in deaths from Spanish Influenza in 1918 was that it led to a decline in deaths from tuberculosis over the next decade or so.

So the theory at that point was that the people who died from the flu tended to be people who already had low-grade tuberculosis.

So if the current flu coming out of Mexico is anything like the 1918 flu, and if the theory based on death certificates in the twentieth century has any validity, then we might be in better shape than some people are worried about. I'd be very surprised if the level of low-grade tuberculosis, at least in developed countries, isn't a lot lower now than in 1918.

Of course, further research may well have invalidated the theory about the 1918 deaths, and there may be very little resemblance between the viruses in 2009 and the ones in 1918.

Related posts:

1. Swine flu II
2. I’m back, and what’s next