MEXICO CITY - As Mexico struggled against the odds Saturday to contain a strange new flu that has killed as many as 68 and perhaps sickened more than 1,000, it was becoming clearer that the government hasn't moved quickly enough to head off what the World Health Organization said has the potential to become a global epidemic.
The World Health Organization said the outbreak has become a "public health emergency of international concern" and asked countries around the world to step up reporting and surveillance of the disease and implement a coordinated response to contain it.
But Mexicans were dying for weeks, at least, before U.S. scientists identified the strain -- a combination of swine, bird and human influenza that people may have no natural immunity to. Now, even controlling passengers at airports and bus stations may not keep it from spreading, epidemiologists say.
The disease has already reached Texas, California and Kansas, and 24 new suspected cases were reported Saturday in Mexico City alone, where authorities suspended schools and all public events until further notice. More than 500 concerts, sporting events and other gatherings were canceled in the metropolis of 20 million.
Health teams noticed something strange: The flu was killing people aged 20 to 40. Flu victims are usually either infants or the elderly.
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."
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.
Scientists have warned for years about the potential for a pandemic from viruses that mix genetic material from humans and animals. The WHO held off on raising its pandemic alert level, citing the need for more information.
Another reason to worry is that authorities said the dead so far don't include vulnerable infants and elderly. The Spanish flu pandemic, which killed at least 40 million people worldwide in 1918-19, also first struck otherwise healthy young adults.
