WASHINGTON - Federal officials warned on Tuesday that swine-flu related deaths were likely in the United States as the disease that killed scores in Mexico continued to spread across the world and governments intensified steps to battle the outbreak.
The number of confirmed cases in the United States was raised to 66, but states and cities were reporting more suspected cases. In New York, the city's health commissioner said "many hundreds" of schoolchildren were ill at a school where some students had confirmed cases.
President Barack Obama asked Congress for $1.5 billion in emergency funds to fight the disease. So far, no deaths linked to the disease have been confirmed outside Mexico.
But Richard Besser, acting director of the Centers for Disease Control and Prevention, said in Atlanta: "I fully expect we will see deaths from this infection.
That was echoed by U.S. Homeland Security Secretary Janet Napolitano. "It is very likely that we will see more serious presentations of illness and some deaths as we go through this flu cycle," she said.
Napolitano added that in a normal seasonal influenza season, about 35,000 deaths are linked to the flu.
The Centers for Disease Control and Prevention said the United States has 66 confirmed cases in five states.
In New York, there were growing signs that the virus was moving beyond St. Francis Preparatory school, where sick students started lining up last week at the nurse's office. The outbreak came just days after a group of students returned from spring break in Cancun.
At the 2,700-student school, the largest Roman Catholic high school in the country, "many hundreds of students were ill with symptoms that are most likely swine flu," said Health Commissioner Thomas Frieden. The cases haven't been confirmed.
Twelve teachers reported flu-like symptoms as well, said the principal, Brother Leonard Conway.
A nearby public school for special education students was shut down after more than 80 students called in sick. Frieden said that some of the students have siblings at St. Francis.
"It is here and it is spreading," Frieden said.
Some of the New York students who tested positive for swine flu after a trip to Mexico passed it on to others who had not travelled - a significant fact because it suggests the strain suspected in dozens of deaths in Mexico can also spread through communities in 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.
Fukuda warned, however, against jumping to the conclusion that the virus has become firmly established in the United States.
Meanwhile, swine flu was ruled out as the cause of one of two recent deaths being investigated by the Los Angeles County coroner's office. Coroner's Assistant Chief Ed Winter said Tuesday that lab testing is still pending in the case of the second fatality, but that swine flu is not now suspected.
Obama's request for $1.5 billion in emergency funds would help build drug stockpiles and monitor future cases as well as help international efforts. White House spokesman Robert Gibbs said the flu outbreak requires "prudent planning" and not panic.
But with the virus spreading, the United States stepped up checks of people entering the country and warned Americans to avoid nonessential travel to Mexico.
"We anticipate that there will be confirmed cases in more states as we go through the coming days," Napolitano said on NBC's "Today" show on Tuesday.
On Capitol Hill, a Senate panel held an emergency meeting on the disease.
"Based on the pattern of illness we're seeing, we don't think this virus can be contained. ... But we do think we can reduce the impact of its spread, and reduce its impact on health," Rear Admiral Anne Schuchat, the CDC interim science and public health deputy director, told a Senate Appropriations health subcommittee.
"There's a lot of anxiety right now across the country," subcommittee Chairman Tom Harkin (D-Iowa) said.
"It's important for people to know there's a lot that we can do," Schuchat told Harkin. "The investments that have been made in preparedness are making a difference."
Still, she warned, not only might the disease get worse, "it might get much worse."
"We don't have all the answers today," she added.