MEXICO CITY — The toll from the swine flu epidemic appears to be stabilizing in Mexico, the health secretary said yesterday, with only seven more suspected deaths. But health officials said they "fully expect" to see U.S. deaths as the virus keeps spreading around the world.

An outbreak of the virus at a New York school showed it is capable of repeated jumps between humans — meaning it can keep spreading.

The new virus is suspected in 159 deaths and 2,498 illnesses across Mexico, said Health Secretary Jose Cordova, who called the death toll "more or less stable" even as hospitals are swamped with people who think they have swine flu. And he said only 1,311 suspected swine flu patients remain hospitalized, a sign that treatment works for people who get medical care quickly.

"You can see the total of new cases," Cordova said. "In the last days, there has been a drop."

The positive news came hours after Mexico eliminated more reasons to visit the country yesterday, putting its pyramids and all other archaeological sites off limits nationwide and closing restaurants in the capital for all but takeout food.

Other countries also took tough measures. The United States stepped up checks of people entering the country and warned Americans to avoid nonessential travel to Mexico. Canada, Israel and France issued similar travel advisories.

Cuba became the first country to impose an outright ban on travel to the epicenter of the epidemic. Argentina soon followed with its own ban, and ordered 60,000 visitors who arrived from Canada, Mexico and the U.S. in the past 20 days to contact the Health Ministry.

Experts on epidemics said these kinds of government interventions are ineffective, since this flu — a never-before-seen blend of genetic material from pigs, birds and humans to which people have no natural immunity — is already showing up in too many places for containment efforts to make a difference.

Outside Mexico, confirmed cases were reported as far away as New Zealand and Israel, joining the United States, Canada, Britain, Spain and Germany. The U.S. Centers for Disease Control and Prevention said the U.S. has 66 confirmed cases in five states.

"Border controls do not work. Travel restrictions do not work," said WHO spokesman Gregory Hartl, recalling the SARS epidemic earlier in the decade that killed 774 people and slowed the global economy.

Instead, they say, governments should do more to provide medical help to people with swine flu symptoms, since the virus is proving to be treatable if diagnosed early.

FLU OUTBREAKS COMMON

U.S. officials stressed there is no need for panic, noting that flu outbreaks are quite common every year. The CDC estimates about 36,000 people in the U.S. alone died of flu-related causes each year, on average, in the 1990s.

Cordova said many of the people crowding hospital waiting rooms complaining of swine flu symptoms actually suffered from other ailments — and many of those suspected of having the virus were treated and sent home.

Only 26 cases, including seven deaths, have been definitively confirmed to be swine flu, Cordova said.

Cordova said that with U.S. help, new testing facilities in Mexico will soon have the capacity to test 150 samples a day for the new strain of swine flu. Currently, it must send samples to the CDC or Canadian labs.

Still, without a solid understanding of where the outbreak began or even how fast it is spreading in Mexico, authorities were focused on preventing people from gathering in groups where mass contagion could result.

Mexico City's mayor ordered restaurants to limit service to takeouts and deliveries, and closed gyms and swimming pools and restricted access to many government buildings.

The economic toll also spread. Even before the restaurant closings, the capital has lost 777 million pesos ($56 million) a day since the outbreak began, said Arturo Mendicuti, president of the city's Chamber of Trade, Services and Tourism.

"Of course we don't like these measures," he said. "We hope they don't last."

In the U.S., President Obama asked Congress for $1.5 billion in emergency funds to fight the illness.

"I fully expect we will see deaths from this infection," said Richard Besser, acting director of the CDC.

In New York, there were growing signs that the virus was moving beyond St. Francis Preparatory school, where sick students started lining up at the nurse's office days after some students returned from Cancun.

At the 2,700-student school, the largest Roman Catholic high school in the nation, "many hundreds of students were ill with symptoms that are most likely swine flu," said city Health Commissioner Thomas Frieden. A teacher was one of 28 confirmed cases. And a nearby school was shut down as well after more than 80 students called in sick. "It is here and it is spreading," Frieden said.

It is significant that some confirmed New York cases passed swine flu to others who had not traveled — this suggests the virus can jump from human to human, spreading through other countries, said Keiji Fukuda, assistant director-general of the World Health Organization.

"There is definitely the possibility that this virus can establish that kind of community-wide outbreak capacity in multiple countries, and it's something we're looking for very closely," Fukuda said. So-called "community" transmissions are a key test for gauging whether the spread of the virus has reached pandemic proportions.

MORE SICK IN MEXICO

Mexico opened its national naval hospital to civilians to deal with the still-mounting wave of suspected swine flu cases. Staffers wore goggles, masks and booties as they treated patients.

Scientists hope to have a key ingredient for a vaccine ready in early May, but it still will take months before any shots are available for the first required safety testing. Using samples of the flu taken from people who fell ill in Mexico and the U.S., scientists are engineering a strain that could trigger the immune system without causing illness.

"We're about a third of the way" to that goal, said Dr. Ruben Donis of the CDC.

U.S. officials said they may abandon the term "swine flu" since the virus blends genetic material from three species, and because many people mistakenly fear they can get it from meat. The outbreak has been a public relations nightmare for the pork industry, and China, Russia and Ukraine are among the countries that have banned imports from Mexico and parts of the U.S.

"It's killing our markets," said Francis Gilmore, 72, who runs a 600-hog operation in Perry, Iowa, and worries his small business could be ruined by the crisis. "Where they got the name, I just don't know."