Message #142295

[Bianca]

A team from the Centers for Disease Control had arrived in Mexico to help set up detection testing
for the swine flu strain, something Mexico previously lacked.

Health authorities started noticing a threefold spike in flu cases in late March and early April, but
they thought it was a late rebound in the December-February flu season.

Testing at domestic labs did not alert doctors to the new strain. Health Secretary Jose Cordova acknowledged Mexican labs lacked the necessary profiling data to detect the previously unknown
strain.

The first death occurred in southern Oaxaca state on April 13, but Mexico didn't send the first of 14 mucous samples to the CDC until April 18, around the same time it dispatched health teams to
hospitals looking for patients with severe flu or pnuemonia-like symptoms.

Those teams noticed something strange: The flu was killing people aged 20 to 40. Flu victims are
usually either infants or the elderly. The Spanish flu pandemic, which killed at least 40 million people worldwide in 1918-19, also first struck otherwise healthy young adults.

Even though U.S. labs detected the swine flu in California and Texas before last weekend, Mexican authorities as recently as Wednesday were referring to it as a late-season flu.

But mid-afternoon Thursday, Mexico City Health Secretary Dr. Armando Ahued said, officials got a call "from the United States and Canada, the most important laboratories in the field, telling us this
was a new virus."

Asked why there were so many deaths in Mexico, and none so far among the U.S. cases, Cordova
noted that the U.S. cases involved children — who haven't been among the fatal cases in Mexico, either.

"There are immune factors that are giving children some sort of defense, that is the only explanation
we have," he said.

Another factor may be that some Mexican patients may have delayed seeking medical help too long, Cordova said.

Others are forced to work and leave their homes despite health concerns.

Wearing two dirty, blue surgical masks she says she found and a heavy coat, Daniela Briseno swept garbage early Sunday morning from the streets in Mexico City.

"This chill air must be doing me harm. I should be at home but I have a family to support," the 31-
year-old said.

Scientists have warned for years about the potential for a pandemic from viruses that mix genetic material from humans and animals.

A "seed stock" genetically matched to the new swine flu virus has been created by the CDC, said
Dr. Richard Besser, the agency's acting director. If the government decides vaccine production is necessary, manufacturers would need that stock to get started.

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Associated Press Writers

David Koop
in Mexico City;

Frank Jordans
in Geneva;

Mike Stobbe
in Atlanta;

Malcolm Ritter
in New York; and

Maria Cheng
in London

contributed to this report.