ALEX CHADWICK, host:
I'm Alex Chadwick. This is DAY TO DAY. Time now for our regular look at health news. This winter the whole world is concerned about avian flu, hoping it doesn't become a pandemic. Researchers studying how the flu spreads and mutates look to past epidemics for clues and recent research has uncovered an interesting tidbit about one particular flu outbreak from the 1970s. It turns out to have been a man-made epidemic. Madeline Brand got details from Dr. Sydney Spiesel. He's a pediatrician and professor at the Yale Medical School. He spoke with Madeline earlier.
MADELINE BRAND, reporting:
So the incident we're talking about took place in 1977, it was called the red flu and tell us about that.
Dr. SYDNEY SPIESEL (Yale Medical School): The red flu first appeared in Northeastern Russia and China and certainly anything that would appear there in those days was called red, which is how it got to be called the red flu.
BRAND: Because they were Communist countries.
Dr. SPIESEL: Exactly right. And it spread all over the world.
BRAND: Now, tell us how this became, as I hinted at earlier, a man-made epidemic.
Dr. SPIESEL: Well, this flu was very similar in structure to a flu which had occurred in the middle '50s, called H1N1, which was related to the Spanish flu, but it had gotten milder over time. After 1957 it just disappeared from the world completely, until 1977. And suddenly it reappeared and it turned out to be very, very similar in structure to a flu last identified in 1950.
One of the things that we've learned, and this is the thing that later molecular biology has told us, is that flu changes very easily, and it would've been impossible for these two flu's to be identical in nature. If they passed from person to person or animal to animal there would have been a small accumulation of changes and mutations. And to have these two flu's that were just identical, that was not possible to happen naturally.
And we also have learned that when corpses are frozen, the flu virus deteriorates and it deteriorates fairly quickly. We know that because we tried to recover flu from people who had died in the 1918 epidemic to study it. And that deterioration would have prevented that from being a source of infection. So there was only one possibility, which is one to make us a little bit nervous.
That flu must have come from a laboratory freezer where the temperatures are cold enough so that stored virus can remain viable and unchanging. And I think it was probably accidentally released at that point.
BRAND: Well, that's pretty scary. Have laboratory security measures been improved since then?
Dr. SPIESEL: They have been improved completely since then. We have, now we've learned a lot about confining dangerous viruses to very highly protected environments, and we even have different levels of protection that are required. The flu that's being studied now, you can't imagine, for example, how well protected we are.
The thing that makes us a little bit nervous about all this stuff is that this flu that reemerged in 1977 was in fact a direct descendant of the Spanish flu epidemic of 1918. The flu of 1918 was also an avian flu that entered the human community. It was devastating and very highly virulent, both for birds and for humans. I think that that's why we're studying flu and every aspect of flu with such great attention.
BRAND: Dr. Sydney Spiesel writes the Medical Examiner column for the online magazine Slate. Thank you for joining us.
Dr. SPIESEL: Thank you.
CHADWICK: And thanks to my colleague Madeline Brand for that interview. Transcript provided by NPR, Copyright NPR.
