21 October 2005

The Killer Flu

Forrest M. Mims III

Influenza has always been a killer. Every year it kills thousands, especially the elderly.

In a typical year, several tens of millions of Americans catch the flu, and around 36,000 die from it or its complications. The death rate seems high at first glance, but it's only around a tenth of one percent.

Occasionally a much deadlier strain of flu arrives and millions die. This happened in 1918.

The 1918 pandemic killed an estimated 50 million people around the world. It did so with great speed, for a person might notice symptoms in the morning and be dead that night.

The 1918 pandemic spread rapidly around the world. According to the US Department of Health & Human Services, from 20 to 40 percent of people in affected countries caught this dangerous flu. In some countries more than 50 percent of the population was infected.

The 1918 flu virus, like some others, came from birds. Scientists confirmed that recently when they produced living flu viruses from frozen tissue samples of people who died from the killer flu.

There is concern that scientists have brought a killer virus back to life. How are they protecting the deadly virus? Could a scientist become accidentally infected and spread the virus?

These concerns pale in the face of a far greater threat, for a new kind of bird flu is on the loose in Southeast Asia. It kills a much higher percentage of its victims than its 1918 cousin.

So far fewer than 100 people in Vietnam, Thailand and Indonesia are known to have died from the new strain of bird flu. The most significant fact is that around half of those who have contracted the disease have died. Many scientists feel that it is only a matter of time before the new bird flu develops the ability to be transmitted directly between people.

Should this occur, health experts claim the world could be at the edge of the next great pandemic. Modern transportation systems will allow the disease to be spread around the world much faster than the 1918 pandemic. The death rate could dwarf that of killers like AIDs and malaria.

But then again, it might not. In the face of scary warnings from the World Health Organization and government officials, some experts say there is insufficient information to make predictions at this point. They also point out that a version of the new flu that can be passed between people, which has to appear, might be less lethal than the variety acquired directly from birds.

You can learn more about the scary side of the bird flu by reading "The Next Killer Flu," the cover story of the October issue of National Geographic magazine. The web version is here.

In "False Alarm: The Truth About the Epidemic of Fear," Physician Marc Siegel makes the case that reason is more important than fear when responding to unknown threats.

The web also has many information sources about bird flu. Begin your search at the Centers for Disease Control flu page. You can find many more pages by searching on "avian influenza CDC."

Forrest M. Mims III and his science are featured online at www.forrestmims.org.

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise, Seguin, Texas. The column is written for a general audience.


 
Figure 1. Flu patients filled this emergency hospital at Camp Funston, Kansas, during the 1918 influenza epidemic. Image courtesy of the National Museum of Health and Medicine of the Armed Forces Institute of Pathology.
   
Copyright 2005 by Society for Amateur Scientists