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Worries and Questions Mount as Disease Goes Global

Racing to keep up with swine flu’s spread, health agencies warned this morning that the number infected is changing hourly, and the World Health Organization is eyeing an upgrade to pandemic level 5 if it sees sustained person-to-person transmission in at least two countries. Mexico is there already, WHO says, and it’s keeping a close watch on New York City, where the swine flu has spread through at least one school. The WHO alert level was raised from 3 to 4 on Monday.

Even as cases of the disease are confirmed in more and more countries—Germany and Austria have just been added to the list—the flu’s severity is in question. “We don’t have a handle on this right now,” said Keiji Fukuda, WHO’s assistant director-general for health security and environment, at a conference call with journalists this morning.

But at the European Centre for Disease Prevention and Control, which held its own briefing an hour before WHO, Angus Nicoll, head of the agency’s influenza program, said he was seeing “something that looks more like an ordinary influenza, with a lot of people infected, but very few people being sick enough to end up in hospital or die.” Mexico, he noted, has reclassified some deaths attributed to swine flu as due to other causes.

The first death outside Mexico, in a Mexican toddler who traveled to Texas several weeks ago, was reported this morning. Outside the United States and Mexico, most cases so far are in individuals who recently traveled to Mexico. As of today, the United States has 91 confirmed cases in 10 states. Six of these people, including the child who died, have been hospitalized. Richard Besser, acting director of the U.S. Centers for Disease Control and Prevention, said at a press conference today that “we have a number of suspect cases that have been hospitalized.”

Questions remain about whether the flu in Mexico, the nexus of all flu-related deaths except the toddler’s, is really more severe, or whether, as health officials increasingly seem to believe, there were simply many undiagnosed flu cases there, making the death rate much smaller than it seems at first glance.

Officials also worry whether a second or third wave of swine flu will hit later this year with more severity than the first. That’s what happened in 1918, said Nicoll, when the flu pandemic first presented as mild before receding and resurging, killing millions. WHO officials will soon face a tricky choice of whether to urge vaccine manufacturers to ramp up stores of seasonal influenza vaccine, as they do every year, or to focus their efforts on a swine flu vaccine. It’s also possible that the swine flu strain could be added to next year’s seasonal vaccine. “There isn’t enough information to make that decision yet,” said Nicoll. Indeed, right now, the warning to the public from those in charge seems to be: Don’t count on what we’re telling you now, because it’s likely to change tomorrow.