MEXICO CITY — 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 Sunday it may soon be time to reopen businesses and schools in the nation where the outbreak probably 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 U.S. Centers for Disease Control and Prevention, said swine flu is spreading just as easily as regular winter flu.

"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."

On Sunday, health officials raised the number of confirmed U.S. 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 late Sunday that the virus has killed 22 people in Mexico, raising the toll from 19. The last confirmed death occurred April 29, he said.

Cordova said the virus had sickened at least 568 and apparently peaked in Mexico between April 23 and April 28. A drastic nationwide shutdown appears to have helped prevent the outbreak from becoming more serious, he said.

"The evolution of the epidemic is now in its declining phase," Cordova said. He said officials would decide today whether to extend the shutdown or let schools and businesses reopen Wednesday.

Pablo Kuri, an epidemiologist advising Cordova, said Sunday that tests have confirmed a swine flu death in Mexico City on April 11, two days earlier than what had been believed to be the first death.

He also said there have been no deaths among health care workers treating swine flu patients in Mexico, indicating that the virus may not be as contagious or virulent as initially feared.

The closed events made for a surreal Sunday in Mexico, as parishioners celebrated Mass via television; camera operators were the only ones in stadium bleachers; and parks, museums, restaurants, theaters and other attractions were closed.

Sunday also marked the official start of campaigning for July 5 congressional elections – but all public campaigning was banned to prevent gatherings where the virus could spread.

Gabriela Cuevas Barron of the conservative National Action Party claimed she was launching Mexico's first virtual campaign, promising in a webcast to work for a cleaner and safer Mexico City – for now, through Twitter, Facebook and YouTube. Meanwhile, the leftist Democratic Revolution Party was already up with a Facebook page for its candidates.

The United States said it had sent 100,000 protection kits worth $1 million to Mexico for use by first responders. The kits include respiratory masks, protective goggles and overalls. The U.S. has sent $16 million in aid to Mexico since the emergency began, the U.S. Embassy said.

New Mexico officials announced Sunday that 14 schools in four towns were being closed for at least a week after the state's first swine flu case was confirmed. The New Mexico Activities Association suspended all athletic and activity programs until further notice at member schools across the state.

In Arizona, all 10 public schools in the border city of Nogales canceled classes this week after a student tested positive for swine flu.

California officials, meanwhile, suspended all prison visitations pending results of tests on an ill Centinela State Prison...