April 29, 2009: Wearing a protective face mask, a woman and her child leave the emergency area of a hospital in Mexico City.
April 28, 2009: A nurse shows how to perform a test for swine flu virus with her colleague at the Malmo Academic Hospital in Malmo, Sweden.
April 28, 2009: A thermal scanner shows the heat signature of passengers from an international flight arriving at Incheon airport, west of Seoul.
April 28, 2009: A pig is fed inside its enclosure at a farm in Spain's central town of Burgos.
April 28, 2009: A statue of San Judas Tadeo, the saint petitioned for "lost causes", wears a mask during a pilgrimage in his honor in Mexico City.
April 28, 2009: Passengers wear protective masks as they ride Mexico's city subway.
April 25: Hiram Diaz, 8, left, gives his 6-year-old sister Adely Diaz a ride on the pegs of his bicycle while wearing protective masks in Mexico City.
April 25: St. Francis Preparatory School is seen in the Queens borough of New York.
The World Health Organization has raised its pandemic alert for swine flu to the second highest level, meaning that it believes a global outbreak of the disease is imminent.
WHO Director-General Margaret Chan made the decision Wednesday to raise the alert level from phase 4 — signifying transmission in only one country — after reviewing the latest scientific evidence on the outbreak.
"Influenza pandemics must be taken seriously precisely because of their capacity to spread rapidly to every country in the world," Chan said. “New diseases by definition are poorly understood and influenza viruses are notorious for their rapid mutation and unpredictable behavior.”
In Mexico, where the flu is believed to have originated, officials said Wednesday the disease is now confirmed or suspected in 159 deaths, and nearly 2,500 illnesses.
"The good news is that we are better prepared for an influenza pandemic than anytime in our history," she said, adding "it really is all of humanity that is under threat in a pandemic."
She said all countries should immediately activate their pandemic preparedness plans and remain on high alert for unusual outbreaks of influenza-like illness and severe pneumonia.
Phase 5 alert means there is sustained human to human spread in at least two countries. It also signals that efforts to produce a vaccine will be ramped up.
WHO has confirmed human cases of swine flu in Mexico, the United States, Canada, Britain, Israel, New Zealand and Spain. Mexico and the U.S. have reported deaths.
The change comes as the fast-moving flu spreads to at least 10 U.S. states from coast to coast Wednesday and swept deeper into Europe, extending its global reach as President Barack Obama mourned the first U.S. death, a Mexican toddler who had traveled with his family to Texas. Total American cases have surged to nearly 100, and Obama said wider school closings might be necessary.
The cases include 51 in New York, 14 in California and 16 in Texas. Two cases have been confirmed in Kansas, Massachusetts and Michigan, while a single cases have been reported in Arizona, Indiana, Nevada and Ohio, according to the Centers for Disease Control and Prevention.
Maine reported three confirmed cases Wednesday, which are not included in the CDC figures.
And the U.S. government says the first shipments of the drug Tamiflu from the federal stockpile arrived in New York state, New York City and Indiana Wednesday morning, and all states will get their share by Sunday.
As a precaution, the government has decided to ship to the states enough medication to treat 11 million people — just in case the new swine flu takes off.
Labor union president Colleen Kelley said Wednesday the government should allow border officers to wear protective gear at all times and to take frequent breaks to wash their hands, a precaution recommended by health experts.
A Mexican boy died at Texas Children's Hospital in Houston Monday night from a variant of H1N1 swine flu.
He was about 2 years old. Houston officials said he was 23 months old, but state officials said he was 22 months old and could not immediately explain the discrepancy.
Health officials say a family member and others who had contact with the child are not sick. The child lived in Matamoros, on the Mexican border with Texas, an official said.
Kathy Barton, a spokeswoman for the Houston Health and Human Services Department, said Wednesday that the child had traveled with family from Mexico to Brownsville in south Texas.
He had underlying health problems when he traveled to the Texas border town to visit relatives. They did not specify what underlying health issues the boy had before arriving in the U.S.
The cause of death was pneumonia caused by the flu virus, Cameron County Judge Carlos Cascos said.
Health officials in Brownsville are trying to trace his family's trip to find out how long they were in the area, who they visited and how many people were in the group, Cascos said.
He was admitted to a Houston hospital a few days after developing a fever and other flu symptoms and died on Monday night.
In related news, Texas officials are postponing all public high school athletic and academic competitions until May 11 because of the swine flu outbreak. Some private schools are planning to continue with their athletic and academic competitions.
In California, dozens of Marines are in confinement after one came down with the disease.
South Carolina health officials have identified eight additional 'probable' cases of swine flu, bringing the total number to 10. Rhode Island was added to the states that have suspected cases.
Health officials say two probable swine flu cases have been found in Milwaukee, and four of the city's public schools have been ordered closed.
A Massachusetts health official says two siblings in that state have tested positive for swine flu after traveling to Mexico. The children from Lowell — about 35 miles northwest of Boston — are the first confirmed cases in New England. Health officials have not released the names or ages of the siblings, but said they are not hospitalized and are recovering.
State public health officials in Illinois said Wednesday that more than one case is being sent to federal authorities for confirmation.
An IDPH spokeswoman Melaney said one case is located at a North Side Chicago school. A Chicago Public Schools spokeswoman confirms that the school is being closed.
President Barack Obama said Wednesday that wider school closings in the U.S. may be necessary, adding that local schools across America should consider temporarily shutting down if conditions worsen.
Dr Keiji Fukuda, WHO's Assistant Director-General ad. Interim for Health Security and Environment, said it is clear at this point that the virus is continuing to spread from person to person with no evidence of slowing down at this point.
“As the outbreak evolves, it’s clear that we are moving closer to a Phase 5 alert, which is a significant milestone,” said Fukuda, speaking during a late morning news conference.
The WHO called an emergency meeting Wednesday to assess the global outbreak of swine flu and to reassess whether it should move up its pandemic alert level from 4 to 5. The current level is two levels below the threshold for a full pandemic.
Fukuda said as soon as the WHO concludes that there is sustained transmission of the virus in two or more countries it will raise the level to one level below a full pandemic.
There is no vaccine to prevent infection but U.S. health officials aim to have a key ingredient for one ready in early May, the big step that vaccine manufacturers are awaiting. But even if the World Health Organization ordered up emergency vaccine supplies — and that decision hasn't been made yet — it would take at least two more months to produce the initial shots needed for human safety testing.
"We're working together at 100 miles an hour to get material that will be useful," Dr. Jesse Goodman, who oversees the Food and Drug Administration's swine flu work, told The Associated Press.
Obama asked Congress for $1.5 billion in emergency funds to help build more drug stockpiles and monitor future cases, as well as help international efforts to avoid a full-fledged pandemic.
In Washington, Homeland Security Secretary Janet Napolitano was questioned closely by senators about whether the U.S. should close its border with Mexico, repeated the administration's position that questioning of people at borders and ports of entry was sufficient for now and said closing borders "has not been merited by the facts."
In a bit of good news, Mexico's health secretary, Jose Cordova, late Tuesday called the death toll there "more or less stable."
Swine Flu vs. Seasonal Influenza
“The illness is consistent with seasonal influenza and has generally the same symptoms of seasonal influenza,” Fukuda said. “Our information to date shows that the infection can range from very mild, requiring no hospitalization and recovering after a few days, to fatal, which is also in keeping with seasonal influenza."
Fukuda said there is no evidence that the virus is spreading from pigs or that it is unsafe to eat pork.
Authorities sought to keep the crisis in context: Flu deaths are common around the world. In the U.S. alone, the CDC says about 36,000 people a year die of flu-related causes.
Children, especially those younger than age 5, are particularly vulnerable to flu and its complications, and every year children die from seasonal flu.
According to the CDC, more than 20,000 children younger than age 5 are hospitalized every year because of seasonal flu. In the 2007-08 flu season, the CDC received reports that 86 children nationwide died from flu complications.
As of April 11, CDC had received reports of 53 seasonal flu-related deaths in children during the current seasonal flu season.
Still, the CDC calls the new strain a combination of pig, bird and human viruses for which people may have limited natural immunity.
Hence the need for a vaccine. 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. The hope is to get that ingredient — called a "reference strain" in vaccine jargon — to manufacturers around the second week of May, so they can begin their own laborious production work, said CDC's Dr. Ruben Donis, who is leading that effort.
The first doses of a swine-flu vaccine could be available about 15 weeks after the World Health Organization decides what kind of vaccine it wants companies to produce, Sanofi-Aventis SA's chief executive said in an interview with the Wall Street Journal.
The Associated Press and Reuters contributed to this report.