Germany confirmed three cases of swine flu on Wednesday, becoming the third European country hit by the disease that has upended life in Mexico. New Zealand's swine flu total rose to 14 and the World Health Organization called for an immediate scientific review of the disease.

Germany's national disease control center, the Robert Koch Institute, said the three cases include a 22-year-old woman hospitalized in Hamburg; a man in his late 30s being treated at a hospital in Regensburg, north of Munich, and a 37-year-old woman from another southern town. All three had recently returned from Mexico.

Britain and Spain already have confirmed cases of the disease.

Related: 10 Ways to Protect Yourself From Swine Flu

Swine flu is suspected of killing more than 150 people in Mexico and sickening over 2,400 there. WHO has confirmed 105 cases in seven countries, not yet including Germany. Over half of those are in the United States, but Mexico is the only country where deaths have been confirmed.

In Geneva, the U.N. health body was holding an emergency "scientific review" of the swine flu outbreak Wednesday to collect what is known about how the disease spreads,how it affects human health and how it can be treated.

Experts will take part via telephone from the United States, Mexico and other countries where people have been infected. A report will be published shortly after the meeting ends.

New Zealand's number of cases rose to 14 Wednesday, including one person not among a school group who recently returned from Mexico. Officials say the swine flu strain infecting the students is the same as that in Mexico. All were responding well to treatment with antiviral drugs and in voluntary quarantine at home.

New Zealand has 44 other possible cases, with tests under way.

Mexico was taking drastic measures to fight the outbreak. It closed all archaeological sites Tuesday and allowed restaurants in the capital to only serve take-out food in an aggressive bid to stop gatherings where the virus can spread. Schools remained closed until at least May 6.

A regional Beach Soccer championship in Mexico was postponed and all Mexican first-division football games this weekend will be played behind closed doors.

Other countries have reacted by avoiding Mexico. While the U.S., the European Union, and other countries have discouraged nonessential travel to Mexico, Cuba banned flights to and from Mexico and Argentina suspended flights arriving from Mexico.

Cruise lines are avoiding Mexican ports and holiday tour groups are canceling holiday charter flights there.

In Australia, officials were testing more than 100 people with flu symptoms for the virus. It has been ruled out in at least 10 cases.

Health Minister Nicola Roxon told Australian Broadcasting Corp. radio Wednesday that the government had granted health authorities wider powers to contain contagious diseases as a precaution.

Those powers ranged from "using disinfectants on planes or at ports through to the far more extreme ... making sure that people are isolated and perhaps detained if they don't cooperate and are showing symptoms of this disease," she said.

The World Health Organization has raised its alert level to 4 — out of a possible 6 — but has not called for travel restrictions or border closures.

No cases of the disease have been confirmed in Asia, where governments were rushing to try to hold back the virus from the continent and taking strict precautions with travelers at airports.

Treating/Preventing Swine Flu

Besser said Monday people can best protect themselves against the swine flu threat by taking precautions they were taught as kids, like frequently washing their hands and covering their mouths when coughing.

He said there is no reason for Americans to begin wearing face masks as residents of some Mexican states are now doing.

There is no vaccine available to prevent the new swine flu. However, there are antiflu drugs that do work once someone is sick.

Scientists hope to have a key ingredient for a vaccine ready in early May, but it still will take a few 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.

But if a vaccine eventually is ordered, the CDC already has taken a key preliminary step — creating what's called seed stock of the virus that manufacturers would use.

In the meantime, the virus appears responsive to the antiviral drugs, like Tamiflu and Relenza, which can be used to reduce the severity of the flu if used within two days of the appearance of symptoms.

Dr. Robert A. Salata, chief of the Division of Infectious Disease at University Hospitals Case Medical Center in Cleveland, told FOXNews.com that the fact that the severity of the virus can be weakened by antiviral drugs is encouraging.

"This past flu season, all of the influenza type A viruses like this one, were resistant to Tamiflu," said Salata, who is also a professor at Case Western Reserve University. "These viruses appear to be sensitive to all four antiviral drugs on the market."

Roughly 12 million doses of Tamiflu will be moved from a federal stockpile to places where states can quickly get their share if they decide they need it, Homeland Security Secretary Janet Napolitano said.

Salata said people should be cautious, but not panic.

New York Worst Hit State

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 nation, "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.

Meanwhile, President Barack Obama asked Congress for $1.5 billion in emergency funds to fight the illness.

The U.S. 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.

For all the government intervention, health officials suggested that efforts to contain the flu strain might prove ineffective. Around the world, officials hoped the outbreak would not turn into a full-fledged pandemic, an epidemic that spreads across a wide geographical area.

The pork industry was dealing with a public relations nightmare over the virus, which is a never-before-seen hybrid of human, swine and bird influenza that is widely called swine flu.

Public health officials have said people cannot get sick from eating pork, but some countries, such as China, Russia and Ukraine, have banned imports from Mexico and parts of the U.S.

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The Associated Press, Reuters and FOXNews.com's Marrecca Fiore contributed to this report.