There's a fast-spreading avian flu virus killing millions of chickens in Asia, and it has mutated into one that is transmitted among humans. People start falling ill in Southeast Asia, but it takes weeks to recognize what is happening. An American businessman from Chicago completes a deal in Hanoi and flies back to O'Hare, the busiest airport in the world. O'Hare has one of only 11 stations in the U.S. capable of quarantining sick international travelers, but everyone on this flight seems fine. In any case, there have been no reports of a flu outbreak in Vietnam.
The businessman heads first to the office and then home. Meanwhile, one of his seatmates on the plane has flown on to Denver, another to New York. In a few days the businessman develops a high fever that drugs can't quell and is admitted to a hospital. Within a week, his lungs fail and he dies. Doctors assume a severe case of flu. Only after the pathologist's report comes back a week later do they learn he was infected with H5N1, the deadly virus that causes avian flu. It's easily spread through the air, and currently there's no vaccine.
One week later, Chicago has thousands of avian flu cases and the city is drawing down the nation's supplies of Tamiflu, a drug made in Switzerland by Hoffmann-La Roche Inc. that's the only antidote. The U.S. has enough Tamiflu for only a few million patients -- none of it stored in Chicago. By now there are outbreaks in New York, in Denver, and dozens of other regions across the nation. Fear of contagion has slowed the nation's transportation network to a crawl, and health-care workers in particular are rapidly succumbing.
As many as 50% of those stricken are dying, and half are ages 18 to 40. The U.S. can't turn to other nations for help -- the disease is speeding around the globe, and the media is comparing it to the 1918-19 Spanish flu pandemic, which killed up to 40 million worldwide.
The comparison would be on target. The Centers for Disease Control & Prevention estimates that 25% of the U.S. population, 67 million victims, might fall ill in an avian flu pandemic. Even if a vaccine is developed, it would take six months to produce one tailored to the viral strain causing the pandemic, and the world's extremely limited vaccine production capacity means only 14% of the global population could be inoculated within a year of the outbreak. "The difference between this and a hurricane is that all 50 states will be affected at the same time," says Michael T. Osterholm, an infectious disease expert at the University of Minnesota. "And this crisis will last a year or more. It will utterly change the world."
The change would spread far beyond the number of deaths. Most experts predict that an avian flu outbreak in the U.S. would overwhelm hospitals, decimate workforces, and throw transportation and supply chains into chaos. Because of the wide use of just-in-time inventory control and dependence on medical supplies made overseas, drug and food shortages would arise almost instantly. The nonprofit Trust for America's Health estimates that the economic impact of a moderate-size flu pandemic on the U.S. could reach $166.5 billion from death and lost productivity alone. That figure excludes "other disruptions to commerce and society."
Unlike some other types of disasters, prevention is close to impossible. A recent computer model prepared by Emory University suggests that rapid treatment and containment of patients at the site of the first outbreak, almost certainly in Southeast Asia, would delay its spread long enough to produce more vaccine -- but only if those measures were instituted within 21 days. Since Thailand is the only country in the region that has a pandemic plan, that scenario is unlikely.
Once a flu virus starts spreading, quarantines do little good, says Marc Lipsitch, a Harvard University epidemiology professor, because the flu infects dozens of people within minutes by a cough or sneeze. People who acquired SARS, a far less contagious disease that hit Asia and Canada two years ago, did not become infectious themselves for at least a week. Carriers of a flu virus become infectious within two to four days, often before they develop symptoms.
Chicago officials have been meeting with federal and state authorities to develop better plans for handling such disasters. "We're not sitting back on our heels," says Dr. Pamela S. Diaz, infectious disease director at Chicago's Dept. of Public Health. Yet the many drumbeats warning of an imminent avian flu outbreak are growing louder. On Sept. 7, a World Health Organization official cautioned that we may be at the last stage before a pandemic virus emerges. "Whether the avian influenza pandemic will occur, that is not the question any more," said Dr. Jai P. Narain, the director of WHO's communicable diseases department. The consensus among infectious disease experts stems from the fact that a flu pandemic has emerged every 25 to 30 years for centuries.
Not all virus strains are as virulent as the Spanish flu, which killed 500,000 Americans. A flu outbreak in 1957-58 killed 70,000 in the U.S., and the relatively mild Hong Kong flu outbreak of 1968-69 caused 37,000 deaths. It's possible that H5N1 could mutate into a benign virus that causes little harm to humans. But most experts believe that this strain will lean toward the deadlier end of the scale.
So far, the virus has killed approximately half of the 109 humans it has infected in Asia -- presumably through contact with infected birds. This summer, H5N1 was found in pigs, which often act as incubators for a human infection. "This organism is following the historical playbook step by step," says Dr. Georges C. Benjamin, head of the American Public Health Assn.
Right now, the U.S. has no national pandemic preparedness plan, either for treating large numbers of patients or for dealing with the resulting economic and social disruptions. "We can't handle a pandemic flu," asserts Dr. Redlener of the National Center for Disaster Preparedness. "We don't have enough capacity in our health care system. We can't handle hundreds of people a day dying." His dire assessment is based on the fact that U.S. public health authorities have been woefully underfunded for decades.
Washington is starting to get the message. Earlier this year, WHO called on member nations to pony up at least $100 million to develop an international response. Congress quickly pledged $25 million and funded the purchase of 3 million courses of Tamiflu, adding to the 2.3 million already on hand. Senator Barack Obama (D-Ill.) hopes to establish a national pandemic influenza preparedness committee.
On the treatment front, the National Institutes of Health is racing to test experimental vaccines. And world governments have been meeting regularly over the past year to figure out how to increase global vaccine capacity. WHO believes that the world has a chance of preventing a catastrophe because it has had plenty of notice about the pandemic. Now, it's up to the nations to act on that warning.
By Catherine Arnst, with Arlene Weintraub in New York, Joseph Weber and Michael Arndt in Chicago, and Stan Crock in Washington