What New Things Are Going To Kill Me?

By Richard Preston

Remember in the movie Aliens when Hudson asked, "Is this gonna be a stand-up fight, sir, or another bug hunt?" Well, the 21st century is going to be one hell of a bug hunt. There's no doubt that eerie new infectious diseases will appear, and the struggles against some of them will make the fight against the AIDS virus look like the opening battle of a war. Of course, by then there will probably be a vaccine for AIDS, and the shot will cost a few dollars or be given for free.

Today new viruses are coming out of nature and "discovering" the human species, while in hospitals and in jungle clinics exceedingly powerful mutant bacteria are emerging that can't be treated with antibiotics. In the past decade, at least 50 new viruses have appeared, including Ebola Ivory Coast, Andes virus, hepatitis G, Fakeeh, Pirital, Whitewater Arroyo, Hendra virus, Black Lagoon virus, Nipah and Oscar virus. This summer West Nile virus showed up for the first time in the western hemisphere, when it was discovered in New York City.

Viruses are moving into the human species because there are more of us all the time. From a virus' point of view, we look like a free lunch that's getting bigger. My grandfather was born in 1899, on the eve of a new century, when there were 1.5 billion people on earth. He died in 1995, and by then there were almost 6 billion people. Thus in one lifetime the population quadrupled, and it's heading for 9 or 10 billion. In nature, when populations soar--and become densely packed--viral diseases tend to break out; then the population drops. This is nature's population-control mechanism. It happens with rodents, insects and even plants. There is no reason to think the human race is exempt from the laws of nature.

Giving these laws an extra push will be the rise of tropical megacities--huge, densely packed cities in less developed nations. A U.N. study predicts that by the year 2015, there will be 26 extremely big cities on the planet, and 22 of them will be in less developed regions. The megacities will include Bombay (26 million people by 2015), Lagos (24 million), Dhaka (19 million) and Karachi (19 million). By 2030, almost 60% of the world's people will live in urban areas. By then, some megacities could have 30 million or more people. The population of California today is 35 million. Take all of California, cram those people into one city, remove most doctors and medical care, take away basic sanitation and hygiene, and what you have is a ticking biological time bomb. Now make eight or 10 such bombs and plant them around the world.

Now wire the bombs together. People travel rapidly by airplane, carrying diseases with them as they fly. The human species has become a biological Internet with fast connections. The bionet will only get faster in the next century--that is, more people will travel by air more often, increasing the speed at which diseases move. If a tropical megacity gets hit with a new virus, New York City and Los Angeles will see it days or weeks later.

Then there are the biological weapons. The 20th century saw the creation of great weapons based on the principles of nuclear physics; the 21st century will see great weapons based on the knowledge of DNA and the genetic code. During the 1980s, the Soviet Union used rudimentary genetic engineering to create incurable strains of Black Death (bubonic plague) that were resistant to drugs. This biotech Black Death was loaded into missile warheads aimed at the U.S. As biotechnology becomes more supple and powerful and as the genetic code of more organisms is unraveled, biologists will learn how to mix genes of different bugs to create deadly, unnatural strains that can be turned into deadly, effective weapons.

Scientists have found a type of bacterium that is virtually indestructible. It's called Deinococcus radiodurans ("terrible berry that survives radiation"). This bug can live in a blast of gamma rays that is the equivalent of thousands of lethal human doses--radiation so strong it cracks glass. Scientists have found "dead" radiodurans spores in Antarctica that have baked in UV light for 100 years. Yet when placed in a nutrient bath, the bug's DNA reassembles itself and proliferates. If radiodurans genes could be put into anthrax, they might produce an anthrax that's virtually impossible to kill. From a bioweaponeer's point of view, the future is bright.

Biological weapons are a disgrace to biology. Most biologists haven't wanted to talk or even think about them. For years leading U.S. biologists were assuring themselves and the public that bioweapons don't work and aren't anything to worry about. It was a naive dream from the childhood of biology. The physicists lost their innocence when the first nuclear bomb went off in 1945. The biologists will lose their innocence when the first biological weapon spreads through the human species.

Yet the 20th century lived with the nuclear bomb, and there was great economic and scientific progress and much human happiness. The same can be true in the next century. Our tools for defending against new diseases are improving all the time. Vaccines are getting better. Drugs to fight bugs are advancing. And new devices are coming that will identify an infectious agent in seconds.

Our greatest weapon against the bugs will always be our mind. Dr. Jeffrey Koplan, director of the Centers for Disease Control and Prevention, predicts that in the end, the fight will come down to the same old sleuthing methods that disease hunters have always used to find bugs and stop them. "Shoe-leather epidemiology" is what Koplan calls it. "You wear out your shoes investigating an outbreak," he says. "You go around identifying the source of the disease and figuring out how it's being spread, and then you remove the source. Even if it's Vibram-soled epidemiology, we'll do it."

No matter how great our technology, we'll still have to go mano a mano with the microbes. We may not completely win the 21st century bug hunt, but I am confident that we won't lose it.

Richard Preston, best-selling author of The Hot Zone and The Cobra Event, is working on a book about microscopic life forms