The number of confirmed human swine flu cases in the United States has risen to 64, with at least seven patients having been hospitalized, while President Barack Obama asked Congress for US$1.5 billion to enhance US and global capacity to respond to the potential spread of swine flu.

"I fully expect we will see deaths from this infection," as swine flu cases are investigated, said Richard Besser, acting director of the US Centers for Disease Control and Prevention in Atlanta on Tuesday.

According to Besser, the hospitalizations include three in California and two in Texas. Their ages ranged from seven to 54. Later, New York said two people had been hospitalized.

However, the CDC reported no new infection sites beyond five states already afflicted. Besser said there are 45 confirmed cases in New York city, 10 in Califronia, six in Texas, two in Kansas and one in Ohio. However, at least four other cases have been reported by states.

"We are in a pre-pandemic period," the official said, adding that the CDC is stepping up laboratory cultivation of the swine flu virus for an eventual vaccine.

Based on the latest lab analysis, Besser said new flu infections are still occurring. He noted, by comparison, that ordinary human flu accounts for about 36,000 deaths every year in the United States.

The White House has asked Congress for US$1.5 billion to fight a swine flu outbreak that has killed scores of people in Mexico. President Barack Obama sent a letter to lawmakers on Tuesday, asking them for a supplemental spending plan to build drug stockpiles and monitor future cases.

Obama said in a letter to Congress read out by spokesman Robert Gibbs that the request was made "out of an abundance of caution" in order to "enhance our nation's capability to respond to the potential spread of this outbreak."

He assured Congress that the administration was "cooperating with international organizations and health officials around the globe."

"Among the uses of these funds could be supplementing anti-viral stockpiles, developing a vaccine, supporting the monitoring, diagnostic and public health response capabilities and assisting international efforts to stem this outbreak," he said.

California Governor Arnold Schwarzenegger declared a state of emergency on Tuesday in response to the growing concern about the spread of swine flu, freeing up resources to combat the possible outbreak across the state.

The declaration came two days after US health officials declared a public health emergency on Sunday related to the swine flu outbreak. There are 64 confirmed cases across the country as of Tuesday.

In issuing the statewide emergency declaration, which would "cut government red tape" and free up health resources, Schwarzenegger stressed that there was no need for general alarm.

Meanwhile, California became the first in the country on Tuesday with the ability to conduct its own swine flu testing without having to send samples to the Centers for Disease Control in Atlanta.

In Los Angeles, public health officials were investigating two recent deaths that are possibly related to swine flu, and would be the first reported deaths in the United States from the outbreak if confirmed.

New York Mayor Michael Bloomberg said on Tuesday that the city's confirmed swine flu cases could be much higher than 45 as reported by the CDC.

All the confirmed cases so far are from one high school in the city's Queens district, though authorities are probing a second school nearby for possible cases.

Bloomberg warned that the number of confirmed cases in St. Francis Preparatory School could go much higher if all of the more than 100 students there were tested.

"We can get a lot more by just testing everybody at St. Francis," the mayor told a press conference. "You'll be shocked if out of the other 100 plus students who have a cough and a fever don't have it."

US Trade Representative Ron Kirk and the head of the Department of Agriculture, Tom Vilsack, insisted on Tuesday that US food supply is safe and pork meat does not transmit the swine influenza virus.

"The American food supply is safe," they said in a statement.

In their statement, Kirk and Vilsack cited references from the World Health Organization (WHO) and the CDC statements that there was no evidence of swine flu being transmitted by meat.

"Swine influenza viruses are not spread by food. You cannot gets wine influenza from eating pork or pork products," the statements said. "Eating properly handled and cooked pork products is safe."

Stressing potential concerns about the safety of US pork and pork products, Vilsack stated that "while there is no evidence at this time that swine has been infected with this virus, the science is clear that consuming or handling pork, consistent with safe handling practices, is of no risk to consumers."

Kirk, the top US trade negotiator, urged all trading partners to base any food safety measures taken to protect their populations on scientific evidence and in accordance with their international obligations.

"Restrictions on US pork or pork products or any meat products from the United States resulting from the recent outbreak do not appear to be based on scientific evidence and may result in serious trade disruptions without cause," Kirk said.

Swine flu refers to influenza caused by any strain of the influenza virus that is endemic in pigs. Till now, more than 150 people have died in Mexico in an outbreak of the virus. Dozens of other cases have been confirmed worldwide.

The WHO raised its pandemic alert level on Monday from Phase 3 to Phase 4, which means the swine flu virus can cause sustained human-to-human transmission and "community-level outbreaks."

(Xinhua News Agency April 29, 2009)