Already France, Hong Kong, New Zealand and Spain have reported about potential new cases in which people had been infected with swine flu and Canada confirmed several new cases. In the U.S., where 20 such infections have been confirmed, federal health officials declared a public-health emergency and are preparing to distribute to state and local agenciesa quarter of the country's 50 million-dose stockpile of antiviral drugs. Time.com reported. Meanwhile, in hard-hit Mexico, where more than 80 people have died from what is believed to be swine flu, the government closed all public schools and canceled hundreds of public events in Mexico City. 
First of all is this a flu pandemic?
The influenza virus is constantly mutating. That's why we can't get full immunity to the flu, the way we can to diseases like chicken pox, because there are multiple strains of the flu virus and they change from year to year. However, even though the virus makes us sick, our immune systems can usually muster enough of a response so that the flu is rarely fatal for healthy people.
But every once in awhile, the virus shifts its genetic structure so much that our immune systems offer no protection whatsoever. (This usually happens when a flu virus found in animals - like the avian flu still circulating in Asia - swaps genes with other viruses in a process called reassortment, and jumps to human beings.) A flu pandemic occurs when a new flu virus emerges for which humans have little or no immunity and then spreads easily from person to person around the world. In the 20th century we had two mild flu pandemics, in 1968 and 1957, and the severe "Spanish flu" pandemic of 1918, which killed an estimated 40 to 50 million people worldwide.
The WHO has the responsibility of declaring when a new flu pandemic is underway, and to simplify the process, the U.N. body has established six pandemic phases. Thanks to H5N1 avian flu, which has killed 257 people since 2003 but doesn't spread very well from one human to another, we're currently at phase 3. If the WHO upgraded that status to phase 4, which is marked by a new virus that begins to pass easily enough from person to person that we can detect community-sized outbreaks, such a move would effectively mean that we've got a pandemic on our hands.
The truth is that every outbreak is unpredictable, and there's a lot we don't know yet about the new swine flu. There hasn't been a flu pandemic for more than a generation, and there hasn't been a truly virulent pandemic since long before the arrival of mass air transit. We're in terra incognito here. Panic would be counterproductive - especially if it results in knee-jerk reactions like closing international borders, which would only complicate the public-health response. But neither should we downplay our very real vulnerabilities. As Napolitano put it: "This will be a marathon, not a sprint." Be prepared.
Outside of Mexico, the swine flu hasn't looked too serious yet - unlike during the SARS outbreaks of 2003, when an entirely new virus with no obvious treatment took the world by surprise. In the U.S., the normal flu season is winding down, which should make it easier for public-health officials to pick out swine flu cases from run-of-the-mill respiratory disease. And there are simple things that people can do to protect themselves, like practicing better hygiene (wash hands frequently and cover mouth and nose when sneezing) and staying away from public places or traveling if they feel sick. "There's a role for everyone to play when an outbreak is ongoing," said Besser.
But the truth is that every outbreak is unpredictable, and there's a lot we don't know yet about the new swine flu. There hasn't been a flu pandemic for more than a generation, and there hasn't been a truly virulent pandemic since long before the arrival of mass air transit. We're in terra incognito here. Panic would be counterproductive - especially if it results in knee-jerk reactions like closing international borders, which would only complicate the public-health response. But neither should we downplay our very real vulnerabilities. As Napolitano put it: "This will be a marathon, not a sprint." Be prepared.
via Time.com
Is Swine Flu Pandemic
Swine Influenza
According World Health Organisation the United States Government has reported seven confirmed human cases of Swine Influenza A/H1N1 in the USA (five in California and two in Texas) and nine suspect cases. All seven confirmed cases had mild Influenza-Like Illness (ILI), with only one requiring brief hospitalization. No deaths have been reported. 
A strain of flu never seen before has killed up to 60 people in Mexico and also appeared in the United States.
Mexico's government said at least 20 people have died of the flu and it may also be responsible for 40 other deaths.
It shut down schools and canceled major public events in Mexico City to try to prevent more deaths in the sprawling, overcrowded capital. Authorities said they had enough antiviral medicine to treat about 1,000 suspected cases reported so far.
The World Health Organization said tests showed the virus from 12 of the Mexican patients was the same genetically as a new strain of swine flu, designated H1N1, seen in eight people in California and Texas.
Wikipadia wxplanes H1N1 virus as a subtype of the species Influenza A virus. The "H" refers to the Hemagglutinin protein, and the "N" refers to the Neuraminidase protein. H1N1 has mutated into various strains including the Spanish Flu strain (now extinct in the wild), mild human flu strains, endemic pig strains, and various strains found in birds. A variant of H1N1 was responsible for the Spanish flu pandemic that killed some 50 million to 100 million people worldwide from 1918 to 1919.[1] A different variant exists in pig populations.
There are everyday actions people can take to stay healthy.
Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hands cleaners are also effective.
Avoid touching your eyes, nose or mouth. Germs spread that way.
Try to avoid close contact with sick people.
Influenza is thought to spread mainly person-to-person through coughing or sneezing of infected people.
If you get sick, CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.