Why Future Flu Pandemics May Be Much More Lethal

How does it feel to be a pandemic? Fairly addictive, in fact. In the Flash-based Web game Pandemic 2, players take on the identity of a deadly disease trying to wipe out the earth's population. Using preset options, players create an illness designed for a maximum body count: will the disease be a virus, bacteria or a fungal pathogen? Will it be resistant to moisture? Cause coughing or sneezing? Be carried by rats or insects? If players make the symptoms too apparent, doctors will treat their disease before it spreads; too contagious and the airports close down before it can jump to other countries.

It's an engrossing game, and an eerie one in light of the rapid global spread of the swine flu. But though this particular flu is causing a certain level of hysteria, public-health doctors appear to be cautiously optimistic that Americans have the training, resources and advance warning needed to keep the virus under control. Still, both the real pandemic and the virtual versions in the game reflect important questions: what will the next global health crisis look like—and what can we do to stop it?

The potential epidemics that most worry epidemiologists and public-health experts fall into three main categories: diseases formerly found in animals that have mutated to cause human infection (mad-cow disease, avian flu) diseases spread beyond their country of origin thanks to globalization (West Nile virus, SARS) and diseases resistant to existing medication (MRSA, tuberculosis). It's tempting to write off these fears as public-health hand-wringing. But is a potentially devastating pandemic really possible? "The answer is absolutely yes. There are something on the order of 1,500 microbes that infect humans. Over the last 15 years we've seen many … that were either new to the geographic range or new to humans," says Dr. David Weber, a doctor of infectious-disease medicine at the University of North Carolina, Chapel Hill, and a member of the Centers for Disease Control and Prevention's influenza working group.

Today's swine flu--already an evolved virus—may be just a precursor to some future disease that combines all of these potentially deadly components. Think of it as flying-pig flu. What we call avian flu, the virus that struck in Asia in 2003, is incredibly deadly but not too contagious; most of the people killed were those who had direct contact with animals. What we're currently referring to as swine flu is spreading quickly, but—at least in the U.S.—leaves the majority of its victims with only a few days of fever and coughing. A new virus that's a combination of these two—deadly like bird flu, fast-moving like swine flu—could have devastating consequences.

"The issue of pandemic influenza with a severe presentation of disease and ease of transmission is, to me, one of the most worrisome potentials for the world in terms of public health," says Dr. Robert Kim-Farley, director of communicable disease control and prevention at the Los Angeles County Department of Health Services and an epidemiology professor at the University of California, Los Angeles. Should conditions like this arise, Kim-Farley says there are estimates of 50 million deaths.

Because viruses mutate so quickly and so often, there are several ways such a superflu might be created: A version of bird flu could mutate on its own to create a more spreadable version. A pig could contract avian influenza at the same time it has human influenza. (Just days ago it was revealed that a farmer in Canada may have given 20 pigs swine flu that he picked up in Mexico. "A person themselves could come across avian influenza and at the same time have seasonal influenza," says Kim-Farley. "You end up with a new strain that has easy transmissibility."

These animal viruses are most easily passed on to humans in places where pigs, poultry and people share close quarters. But because of easy, globalized travel and trade, a new virus could rapidly spread to more industrialized areas the same way the current swine-flu virus made its way to New York City.

The global economy plays another role in creating superviruses: The demands of feeding industrialized nations leads to small towns packed with antibiotic-resistant pigs, cows and chickens (the current swine flu may have first presented in the town of La Gloria, Mexico, site of an industrial pig farm owned by the U.S. company Smithfield Foods). The increase in urbanization means that farmers who once lived on large fields are now sharing apartments with their agriculture. "You have situations in Asia where people are sleeping with the flocks and keeping pigs underneath the house," says Kim-Farley. "Then, within 24 hours, you can go from a village in Southeast Asia to Los Angeles."

Finally, there is the issue of drug resistance. The more people infected, the more people treated—and that can make the treatment less effective in the long run. "We're very happy that H1N1 [the current swine-flu virus] has susceptibility to [medications like] Tamiflu and Relenza," says Dr. Ann Marie Kimball, professor of health services and epidemiology at the University of Washington Medical Center and author of "Risky Trade: Infectious Disease in the Era of Global Trade." "But the more you use these drugs, you will start seeing a resistance. That's why the second focus of this particular epidemic will be on finding a vaccine."

Developing a vaccine is one way to help stop a superflu, though it's tough to predict how a vaccine created in response to the current strain of swine flu would react to a newer incarnation down the road. If the spread and severity of swine flu is controlled in the U.S., the current crisis may turn out to be something of a blessing in the future. It's given hospitals the chance to re-evaluate emergency treatment plans and prepare for the next pandemic.

"For 20-30 years we've permitted the public-health infrastructure to quietly whither," says Dr. William Schaffner, chairman of the department of preventive medicine at Vanderbilt University School of Medicine in Nashville. "Highways, tourism, public safety—these things always take precedence. A pandemic threat illuminates the issue and reminds us all that we really need to enhance the public health resources."

Still, in the end, the best protection may still be common sense: basic hygiene like hand washing and cough-covering may still be one of the most effective lines of defense against catching a spreading viruses. Even the superflus players create in Pandemic 2 can't do much harm if nobody passes them along.

Why Future Flu Pandemics May Be Much More Lethal | Culture