New Virus Spurs Experts to Rethink Definition of Pandemic

Influenza experts are acknowledging that they were almost completely surprised by the way the current swine flu outbreak unfolded, so much so it is forcing the world to rethink what a pandemic is and what pandemic preparedness means.

Virtually every assumption made since planning for a pandemic began in earnest after the deadly "bird flu" outbreak of 2004 in Southeast Asia has been contradicted by the six-week history of swine-origin influenza A (H1N1).

Although they acknowledged there might be alternative scenarios, nearly every expert assumed that the next pandemic strain would jump from birds to human beings someplace in Asia. They also assumed that, like the H5N1 bird flu virus, which is lethal in 60 percent of people who catch it, the new strain would be recognized immediately and would have to be fought with drastic measures.

Instead, the virus emerged in North America, appears to have come from pigs, had spread widely by the time it was noticed, and kills less than 1 percent of the people it infects.

The world expected a fastball pitcher throwing smoke. Instead, it got a junk-baller who is throwing everyone off balance.

"Everyone was thinking about H5N1 and the possibility that we would be in for partial global population collapse," said David S. Fedson, a physician, influenza expert and former drug company executive who has written extensively on pandemic planning. "We never addressed severity, because we knew it would be severe. And now we have this funny virus coming out of pigs."

The consequence is that, despite five years and hundreds of millions of dollars spent on getting ready, the world is oddly unprepared for the incipient pandemic of H1N1 swine flu it now confronts. As of Friday, there had been 15,510 confirmed cases and 99 deaths in 53 countries.

In the United States, plans to "limit non-essential passenger travel in affected areas" were never invoked, and an aggressive school-closing policy was quickly revised when it became clear that the virus did not travel like wildfire, and in all but a few cases caused only mild illness.

In Europe, many countries are using a public health strategy that is likely to miss many of the new flu cases rather than find as many as possible -- exactly opposite the strategy typically invoked in the early stage of a pandemic.

Some experts think there has been a reluctance to document "community spread" of the swine flu virus in countries such as Britain and Spain because it would force the World Health Organization to declare Phase 6 -- a global pandemic -- and tag those nations with triggering what seems like an unnecessarily loud alarm.

The most obvious manifestation of the world's second thoughts was the WHO's announcement last Tuesday that it will convene a conference of experts by e-mail and videophone over the next two weeks to consider changing the very definition of pandemic.

The purpose is to add measurement of the disease's severity to the criteria for moving to Phase 6, which declares "that a global pandemic is under way."