The World Health Organization this morning raised the H1N1 virus pandemic alert level to Phase 6, its highest level, making the swine flu the first declared global flu epidemic in 41 years.

"Spread in several countries can no longer be traced to clearly defined chains of human-to-human transmission," said Dr. Margaret Chan, WHO director-general, in a prepared statement. "Further spread is considered inevitable."

Nearly 30,000 confirmed cases have been reported in 74 countries. The agency raised the alert level based on the geographical spread of the virus, not the number of confirmed cases. The pandemic is only "moderate in severity," according to the agency, which cautioned against overreactions to the increased alert level.

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