MEXICO CITY (Reuters) - Mexico voiced hope on Friday it might be getting control of an outbreak of a new flu strain that has killed up to 176 people there, shut down large parts of the country and raised fears of a global epidemic.
The U.S. Centers for Disease Control and Prevention said Mexico's outbreak of the new H1N1 swine flu virus may not be as severe as it looked at first, citing many mild cases that were not immediately noticed.
Worldwide, 15 countries have confirmed cases. South Korea confirmed its first case at the weekend, a day after Hong Kong reported the first H1N1 patient in Asia. Almost all infections outside Mexico have been mild, and only a handful of patients have required hospital treatment.
In Mexico, many businesses were closed for a five-day break on a presidential order to help slow the spread of the disease. The capital's mayor, Marcelo Ebrard, said emergency measures against the virus were bringing results.
"This has led us to a situation where the numbers are getting better every day," he said. "I'm not saying we should let our guard down ... I'm telling you so you know where we stand."
Mexican public hospitals that treat roughly half the country admitted just 46 patients with severe flu symptoms on Thursday, down from 212 patients on April 20.
In Hong Kong, authorities sealed off a hotel where a 25-year-old Mexican visitor had been staying. He became the first verified case in Asia.
The United States, which has the most confirmed infections outside Mexico, now has 145 cases across 22 states after two people fell sick in Florida and one in Connecticut.
The CDC said in a new report Friday it had confirmed 97 cases and seven out of up to 176 deaths in Mexico blamed on the H1N1 strain. Only one person has died outside Mexico: a toddler from Mexico who traveled to the United States.
U.S. President Barack Obama praised efforts to fight the virus. "I think that those who have been on top of this have done an extraordinary job. I'm optimistic that we're going to be able to manage this effectively but we still have more work to do," he said after a Cabinet meeting.
A WHO expert said there was no doubt a successful vaccine could be made against the virus reasonably soon.
Much of Mexico shut down until Wednesday to help contain the outbreak. Building sites, car plants, factories, corporate and government offices will let workers stay home and extend a long weekend that began with the May 1 holiday.
The Labor Ministry said it would fine or forcibly close companies that stay open Monday and Tuesday as a major factory association and many small businesses say they plan to.
"As far as I know we're coming to work next week. Unless someone comes from the government to tell us to close," said Victor Barracas, a bookstore employee in central Mexico City.
Restaurants that would normally cater to families off work were shut as far north as the border city of Tijuana. Ice cream vendors at shuttered parks rued a dearth of clients.
Many families canceled long-weekend trips to beach resorts like Acapulco. But some felt relieved the death toll seemed to be stabilizing after a week of people wearing face masks, avoiding public gatherings and washing hands frequently.
"When they announced the virus it was a blow. We are going to keep taking precautions but I feel a little less worried now," said Jessica Santiago, 29, an optometrist walking her dog beside the deserted Chapultepec Park, normally packed with families strolling or rowing boats on a big lake.
U.S. Commerce Secretary Gary Locke urged China and Russia to end restrictions placed on U.S. pork after the outbreak, noting the flu cannot be spread by food.
Experts have struggled to explain why so many deaths have occurred in Mexico and nowhere else. On Friday, the CDC suggested a simple explanation: there are many cases in Mexico, most are mild, and just the bad ones have been seen so far.
It said case-finding had focused on patients seeking care in hospitals and noted: "A large number of undetected cases of illness might exist in persons seeking care in primary-care settings or not seeking care at all."
Scientists hope to get a clearer picture with data from test kits the CDC sent to Mexico to measure the extent of the illness. Even common seasonal influenza kills an estimated 250,000 to 500,000 people globally every year.
The World Health Organization did not hold a meeting of its emergency committee on Friday, so its level 5 alert remained in force and was not raised to a full 'phase 6' pandemic alert.
The WHO has said it would call the new virus strain Influenza A (H1N1), not "swine flu," since there is no evidence that pigs have the virus or can transmit it to humans. Pork producers had said consumers were shunning their product.
Most markets have shrugged off flu fears and focused on whether a U.S. recession may be nearing an end.
Additional reporting by Jason Lange, Helen Popper, Lewis Krauskopf, Karen Jacobs, Maggie Fox, Donny Kwok, Robin Emmott; editing by Mohammad Zargham