X stands for eXtinction

A prominent physician warns that we could go the way of the dinosaurs if we don't face up to the threat of killer viruses.

Published March 21, 1997 8:00PM (EST)

AIDS, Ebola, Mad Cow Disease, "flesh-eating" disorders, "superviruses," antibiotic-resistant bacteria. Just when modern science thought it had defeated most life-threatening plagues, new ones -- the stuff of nightmares and Hollywood movies -- are emerging. Even old epidemics, like tuberculosis, malaria and bubonic plague, are making a comeback.

How much is hype, how much is real? In "Virus X: Tracking the New Killer Plagues" (Little, Brown), Frank Ryan says there really is reason to be concerned. Ryan, a fellow of Britain's Royal College of Physicians, wrote about the return of tuberculosis in his previous book, "The Forgotten Plague." In "Virus X," Ryan warns of the possibility of lethal new viruses breaking out of a particular geographical "hot zone" and aggressively spreading across the world.

Salon corresponded with Dr. Ryan via e-mail from his home in Sheffield, England.

There have been a slew of scary "virus books" published recently -- Richard Preston's "The Hot Zone," Laurie Garrett's "The Coming Plague," Richard Rhodes' "Deadly Feasts" and your "Virus X." Are we unnecessarily scaring ourselves?

It's true that there is a degree of "viral fatigue" caused by all these books and films like "Outbreak." But there really is a problem out there. I'm afraid there really are new plagues on the way.

And "Virus X" is one of them? What is "Virus X"?

The title of my book, "Virus X," means a virus that threatens human extinction. The X stands for "eXtinction." I should add that most of the book is devoted to less terrible, scary but interesting, scenarios. But it would be foolish not to face the worst-case scenario, which I discuss in the book.

There were fears that AIDS might fit that description. Is it because of international transportation and ease of travel that these viruses have become so threatening?

Yes. Human behavior has greatly changed the natural goal posts with regard to the threat of new plague viruses. Take AIDS, for example. According to my hypothesis, in the past a band of hunters might have been bitten or scratched by chimpanzees harboring the virus; the result would have been a lethal attack localized to the hunter band -- or at worst their home village.

Today, thanks to the global village, a new plague virus could perambulate the globe at the speed of a passenger jet. Then a new step in the plague scenario would take place in the massively populated cities -- they would become viral "amplification zones."

So it's modern civilization -- jet planes and big cities -- that will spread the killer virus.

It's important for Americans to realize how an airborne plague would actually evolve. If a deadly virus arrived in American cities and towns, it would be too late at this stage to stop it; can you imagine the spread of pandemic flu without a vaccine? Since the advent of the "global village," some of the most deadly viruses known to science have emerged -- but none of them, thank God, have spread by the airborne route. The future is threatened by plagues. Maybe in time science can treat any viral illness or very quickly produce a vaccine for any new virus. But as we have seen with AIDS, this is not now the case.

You use the term "aggressive symbiosis" to describe how these viruses become so virulent. What does the term mean?

Viruses cannot be thought of merely as predators acting on their own. I collected evidence that points to the fact that viruses "co-evolve" with a "host" species in nature -- whether animal or plant -- and over time create an evolutionary paradigm where each contributes to the survival of the other. A mutual benefit of this kind is termed "symbiosis." The contribution made by the host is obvious -- it gives the virus a niche in which to survive and replicate.

But what does the virus do for the host in return? I believe there is a natural selection pressure for viral strains that not only co-evolve toward an utterly benign relationship toward the host but also an extremely aggressive behavior toward evolutionary rivals of the host. If I am right -- and fellow scientists are already agreeing with me -- then the potential for new plagues is much greater than was hitherto thought. For example, a species such as chimpanzees are likely to harbor many different strains of immunodeficiency virus, just as the host of Ebola (probably a bat or a rodent) will be harboring many new strains of Ebola viruses. In fact, every species of life on earth is harboring one or more symbiotic viruses.

Are they also harboring new strains of tuberculosis, cholera and malaria -- which were supposed to have been wiped out years ago but are coming back to haunt us?

No, it's quite different. Bacterial plagues are returning for a number of complex and interrelated reasons. Firstly, we became complacent and abused the miracle of the antibiotic discoveries. The result was the emergence of antibiotic-resistant germs. Secondly, we ignored the anguish of the developing world, so we are now importing their problems. Thirdly, we compartmentalized microbes, expecting they would never change, when in fact they are the oldest forms of life on earth.

Bacteria were the first age of life on earth -- some 3 billion years ago -- and unlike the dinosaurs they never became extinct. The reason is they have a fantastic capacity to change in response to environmental stress. Antibiotics and our disease control measures are interpreted by the bacteria's "genomic intelligence" -- a term I conceived -- as environmental stresses, and they have fought back in time-honored ways, through mutation, hybridization and a number of other mechanisms.

That sounds almost as threatening as a new virus.

Bacterial diseases are the ones we meet every day in hospitals, so antibiotic resistance is the most important problem doctors face in their day-to-day management. In terms of a global -- or species -- threat, new plague viruses, or "emerging viruses," are the bigger problem. The reason is they usually have no treatment and no vaccine. Therefore they pose a potential global disaster.

Are we doomed -- or is there anything we can do to protect ourselves?

There are a lot of things we can do to reduce the risk. The single most vital thing is awareness. I mean public and media awareness. This will force politicians to pay for the next most vital step -- global surveillance. And unless something is done about this -- and done soon -- the risk is serious.

So, "virus X" may be a political issue as much as a scientific one?

Protecting society from the threat of new plagues goes beyond the ambit of scientists. You want an example? When AIDS began in America, two scientists at the Centers for Disease Control, Jim Curran and Don Francis, tried to get a small amount of money to study its means of spreading. If they had gotten that money, the spread of AIDS by blood products and sexual intercourse, whether homosexual or heterosexual, would have been documented long before it actually was. Politicians refused them the money. The result was the AIDS epidemic as we know it. Scientists do not control the money, but they do need it for what is essentially "insurance" against new scenarios.

I see my book, and this article, as trying to educate the public in this light. I am afraid that I, too, am likely to be equally unsuccessful.


By Lori Leibovich

Lori Leibovich is a contributing editor at Salon and the former editor of the Life section.

MORE FROM Lori Leibovich


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