Mexican Health Minister said Monday that swine flu has killed 149 people and up to 1,995 people had been hospitalized across the country. The government has ordered all schools to close till May 6th.

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Meanwhile, World Health Organization announced that it is raising its pandemic alert level from Phase 3 to Phase 4, which signifies that the new swine flu virus can cause sustained outbreaks and is adapting itself to spread among humans.

The US declared a public health emergency Sunday while

?the total number of swine flu cases throughout the country rose to 48 Monday. The WHO spokesman said that effort had been made by the US to produce swine flu vaccine.

Countries and regions from around the world are?stepping up safety measures as the number of confirmed and suspected cases surfaced in Europe and Asia.

Chinese government banned the import of pork and pork products from Mexico on Monday. Up until now no swine flu case has been reported on the Chinese mainland.

The swine flu is a respiratory disease that infects pigs. There are no signs that people can get the swine flu from eating pork.