The swine flu epidemic spread deeper into the United States, Europe and Latin America - and in Canada, back to pigs - even as Mexico's health chief hinted it may soon be time to reopen businesses and schools in the nation where the outbreak likely began.
The virus spread to Colombia in the first confirmed case in South America, worrisome because flu season is about to begin in the Southern Hemisphere. More cases were confirmed in Europe and North America; health officials said at least 999 people have been sickened worldwide.
Dr Richard Besser, acting chief of the US Centers for Disease Control and Prevention, said swine flu is spreading just as easily as regular winter flu.
"The good news is when we look at this virus right now, we're not seeing some of the things in the virus that have been associated in the past with more severe flu," Besser said. "That's encouraging, but it doesn't mean we're out of the woods yet."
Yesterday, health officials raised the number of confirmed US swine flu cases to 244 in 34 states. The new number, up from 160 on Saturday, reflects streamlining in federal procedures and the results of tests by states, which have only recently begun confirming cases, said Dr Anne Schuchat of the CDC.
Mexican Health Secretary Jose Angel Cordova said that the virus that has killed 22 people in Mexico, raising the toll from 19.