Global flu epidemic fear grows, more U.S. cases

Mexico has said the flu had killed 20 people and could be to blame for 48 more deaths. In all, more than 1,000 suspected cases have been reported nationwide. Most of the dead were aged 25 to 45, a worrying sign because a hallmark of past pandemics has been high fatalities among healthy young adults.

The new flu strain -- a mixture of swine, human and avian flu viruses -- is still poorly understood.

Mexico has shut schools and museums and canceled hundreds of public events in the capital to prevent further infections.

A significant worsening of the outbreak could hit tourism and consumer spending in a country already weakened by the global economic crisis and an army-led war on drug cartels.

Calderon reassured Mexicans that the flu was "curable", while Mexico City Mayor Marcelo Ebrard said his goal was to slow the spread of the virus in the capital.

No countries or global bodies have issued travel bans to Mexico, but some countries alerted travelers to check websites for information on the flu outbreak.

The WHO says the virus from 12 of the Mexican patients is genetically the same as a new strain of swine flu, designated H1N1, seen in eight people in California and Texas. All of the eight have recovered.

(Additional reporting by Jonathan Lynn in Geneva, Mica Rosenberg, Catherine Bremer and Alistair Bell in Mexico City, Maggie Fox in Washington and Tan Ee Lyn in Hong Kong; Editing by Eric Walsh)