Menacing flu arrived as world was ready

WASHINGTON — Was the great swine-flu scare of 2009 just a big overreaction?

The answer, according to public-health and infectious-disease experts, is no.

But they acknowledged that the world has been riding a roller coaster set in motion by the emergence of a menacing pathogen at a time people have never been more primed to fight back.

"We've been getting ready for something like this for years," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "And then this comes along, and all of a sudden the alarm goes off that says: 'Oh, my God, it's here.' "

That alarm activated a network of disaster plans put in place after seemingly disparate crises and threats, including the Sept. 11 attacks, the anthrax letters, SARS, Hurricane Katrina and the ominous avian-flu virus, which has been skulking around Asia and other parts of the world for years.

"What we've seen is a combination of lessons that we've learned from these events and the alarming news we were getting out of Mexico," said Thomas Inglesby, deputy director of the Center for Biosecurity at the University of Pittsburgh. "All these things put together really set things off."

Some reactions, such as the slaughter of thousands of pigs in Egypt, were unnecessary. But many experts said the response was calibrated to aggressively protect lives without causing damaging disruptions.

Remarkably orderly

"What's remarkable is how orderly this has unfolded," said Howard Markel, a medical historian at the University of Michigan.

Two weeks after news broke about the new flu strain, there have been 46 deaths: 44 in Mexico and two in the United States. More than 2,300 are sick in 26 countries, including about 900 confirmed U.S. cases. Those are much lower numbers than were feared at the start, based on early reports of an aggressive and deadly flu in Mexico.

Experts stressed that it remains far from clear that the danger from the influenza A (H1N1) virus, as it is formally known, has passed, and they are concerned that the sharp shifts could leave the public complacent.

"I'm afraid that a kind of epidemic fatigue or the-boy-who-cried-wolf syndrome could set in," said Stephen Morse, founding director of the Center for Public Health Preparedness at Columbia University's Mailman School of Public Health. "But what's the alternative? Not to talk about it? Not to respond?"

Decades of concern

The backdrop to the roller coaster is decades of concern about influenza viruses. The microbes mutate easily and have morphed into dangerous strains. The most devastating pandemic began in 1918 and is estimated to have killed at least 50 million people worldwide.

The emergence of new microbial threats such as Ebola and AIDS, and the re-emergence of old foes in more dangerous forms, such as drug-resistant strains of tuberculosis, have highlighted the potential threats.

The Sept. 11 attacks and subsequent letters laced with anthrax spores triggered emergency planning to guard against biological threats. Most notably, the Bush administration implemented an $8 billion pandemic-flu planning program that created a detailed national blueprint and funneled millions of dollars to state and local governments to create and rehearse plans.

After the 2003 outbreak of severe acute respiratory syndrome (SARS), the World Health Organization (WHO) instituted measures that heightened the world's ability to identify and respond swiftly to outbreaks, including international regulations that call for countries to report worrisome outbreaks quickly and a revised pandemic threat-alert system.

So when reports emerged from Mexico of a new virus that most people might have no immunity against and that appeared to be spreading easily from person to person and — in an eerie echo of 1918 — was killing healthy young adults, the world went on high alert.

Even if the virus is no more severe than a typical flu, which kills about 36,000 in the United States each year, it could still take a heavy toll.

Based on previous pandemics, perhaps one-third of the world's 6 billion people — that's 2 billion — could become infected, said Keiji Fukuda of WHO, which may yet declare a full-scale pandemic if the virus takes hold in Europe or another part of the globe.

With the virus in the Southern Hemisphere, experts will be watching what happens as winter sets in.

The virus could mutate at any moment to become more lethal: The 1918 flu began with a mild spring wave followed by a devastating return in the fall for reasons that remain mysterious.

"We're dancing with this virus right now, and no one knows what will be the next step that the virus will take," Osterholm said.

Material from The Associated Press is included in this report.