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发表于 2009-4-27 15:40:00
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But with confirmed swine flu cases in at least six states -- and possibly as many as 14 -- the efforts seemed unlikely to stop the spread of the disease.
Particularly difficult in a metropolis as crowded as Mexico City was the embassy's advice to maintain "a distance of at least 6 feet from other persons may decrease the risk of exposure."
WHO Director-General Margaret Chan said the outbreak of the never-before-seen virus has "pandemic potential." But she said it is still too early to tell if it would become a pandemic.
"The situation is evolving quickly," Chan said in Geneva. "A new disease is by definition poorly understood."
WHO lays out three criteria necessary for a global epidemic to occur: The virus is able to infect people, can readily spread person-to-person and the global population has no immunity to it. The agency held off raising its pandemic alert level, citing the need for more information. Out of the many cases in Mexico reported, relatively few samples have been tested.
Early detection and treatment are key to stopping any outbreak. WHO guidance calls for isolating the sick and blanketing everyone around them with antiviral drugs such as Tamiflu.
Now, with patients showing up all across Mexico and its teeming capital, simple math suggests that kind of response is impossible.
Mexico appears to have lost valuable days or weeks in detecting the new virus.
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 here to the new strain, although US authorities detected an outbreak in California and Texas last week.
Perhaps spurred by the US discoveries, Mexico sent 14 mucous samples to the CDC April 18 and 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.
As recently as Wednesday, authorities 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."
"That was what led us to realize it wasn't a seasonal virus ... and take more serious preventative measures," Health Secretary Jose Cordova said.
Some Mexicans suspected the government had been less than forthcoming. "They always make a big deal about good things that happen, but they really try to hide anything bad," Mexico City paralegal Gilberto Martinez said.
Hospitals dealt with crowds of people seeking help. A hot line fielded 2,366 calls in its first hours from frightened city residents who suspected they might have the disease.
Doctors reported that anti-viral medications and even steroids were working well against the disease, noting no new deaths had been reported in the capital in the last day.
Airports around the world were screening travelers from Mexico for flu symptoms. But containing the disease may not be an option.
"Anything that would be about containing it right now would purely be a political move," said Michael Osterholm, a University of Minnesota pandemic expert.
Ahued, the capital's health secretary, said Mexico City may not even be the epicenter of the outbreak. |
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