Narrator: This is Science Today. Public health officials have wondered whether another influenza outbreak could reach such deadly proportions as the 1918 epidemic, which killed half a million people. Now, demographer Andrew Noymer of the University of California, Berkeley, has findings suggesting that undetected tuberculosis may have caused much of the mortality in 1918.
Noymer: My results do not show that we are invulnerable to another influenza epidemic. But what they do show is slightly encouraging - that in the United States, where TB death rates are much, much more lower than they were in 1918, that there is a risk factor that has potentially been ignored until now that was TB co-infection.
Narrator: Victims of the 1918 influenza epidemic died of a very severe, secondary bacterial pneumonia, which can be caused by TB infection.
Noymer: There is some plausibility to this story in so far as when people have pulmonary tuberculosis, cavities form in the lungs and they become a breeding ground for bacteria.
Narrator: For Science Today, I'm Larissa Branin.