SARS Wars

Having seen all the news reports on the outbreak of Severe Acute Respiratory Syndrome, or SARS, I sat down with two physician colleagues of mine who specialize in infectious diseases and asked them the obvious: Are we all going to die?

“Yes,” they answered in unison and without hesitation. “Of course everyone dies,” Dr. Dan Anderson explained helpfully. He and Dr. Jason Sanchez work in Abbott Northwestern’s Infection Control department. “We just don’t know when or what from.”

Maybe this SARS thing is becoming an epidemic of hysterical proportions? “There’s some of that,” said Dr. Sanchez. “A patient asked me if they should cancel their trip to Washington D.C., so people do take leaps. The lay public is afraid to travel here in the U.S., and I don’t think anybody has told them to be. People came to those conclusions on their own,” he added. “But it is a serious, front-page issue.”

Definitely serious. It’s an infection with lethal potential, after all. But not even the World Health Organization is giving us any sense of proportion. Right now, the talk is all numerator, not denominator, and you need both to calculate risk. “There have been 80 or 90 deaths now, out of almost 4,000 suspected cases. But that’s 4,000 people who got sick enough to come to somebody’s attention,” noted Dr. Anderson. “But maybe it’s 90 deaths out of 10 million this year; no one knows.”

Here’s what the experts do know: The SARS virus is a member of the coronavirus family, whose members generally cause only mild respiratory illnesses. So why is SARS acting more like a Gambino family virus? “Take influenza for example,” Dr. Sanchez said. “Some of the major pandemics in the past are not just from minor mutations in the virus, what we call antigenic drift, but from a major re-assortment of the virus’ DNA that the population will not have immunity to. That’s called antigenic shift.”

So a few weeks back, maybe a coronavirus somewhere in China slipped into a genetic Glamour Shots, got a complete make-over, and walked out the door nearly unrecognizable to our immune system. If that happened, it would give a virus like SARS the chance to really get going before our bodies’ defenses could react.

But antigenic drift—the reshuffling of the genetic deck—has been going on since the beginning of time. What’s really revolutionized the infection world is, of course, the travel industry. More people flying more often to more places. Viruses are hitchhikers, and hitching a ride—a really fast ride—has never been easier. A SARS offspring can catch a 5 p.m. flight out of Hong Kong and be touching down at Heathrow by day’s end. That beats a sneeze of just about any magnitude.

“Read The Demon in the Freezer by Richard Preston,” suggested Dr. Anderson. “Part of it reviews how people like D.A. Henderson eradicated small pox in the 1960s and 70s. When they identified a case, they would treat or isolate everyone who had had contact with that person in the last two weeks. In Pakistan, in the late 1960s, how far might that net be cast—15 miles, 50 miles? And how far might that be today?”

Until we develop more rapid ways to identify new viruses (or the airline industry tanks, and we all agree to travel on foot), global health alerts, travel restrictions, and a bit of fear and loathing are here to stay. If the SARS virus does end up getting to the Pandemic Hall of Fame, we’ll have antigenic drift, the Wright brothers, and your local travel agent to thank for it.—Craig Bowron