Swine Flu is also known as influenza A/H1N1, a new flu subtype with genetic material from the swine flu subtype, the avian flu subtype, and the A/H3N2 subtype. It began in Mexico and has quickly spread to countries across the globe.
Influenza is a contagious respiratory illness (bronchia, lungs) caused by influenza viruses. There are a number of different types of influenza viruses, designated by type - A, B or C - further broken down into subtypes that characterize the virus' coat proteins or their primary vectors (animals they infect).
Influenza A viruses are divided into subtypes based on two surface coat proteins: the hemagglutinin [H] and the neuraminidase [N]. There are 16 different hemagglutinin subtypes and 9 different neuraminidase subtypes. The current outbreak of swine flu is designated A/H1N1, and the primary flu strain in the 2008-2009 flu season just past was A/H3N2. The Avian flu that has caused illnesses in Southeast Asia and Indonesia is A/H5N1.
Viruses are not a cellular life form. They are basically bundles of DNA covered with a protein coat that attaches to cell walls and injects the DNA, which then uses the host's replication machinery to reproduce itself. Eventually the cell ruptures and releases the replicated virus particles that go on to infect more cells.
Influenza viruses mutate, recombine, sometimes pick up pieces of host genomes and otherwise change at a rapid rate. This is why influenza vaccines must be created annually to combat the expected strain that accounts for the most infections, and why sometimes the available influenza vaccine proves ineffective against the flu strain that does become prevalent during flu season. The CDC [Centers for Disease Control] estimates than more than 200,000 people are hospitalized in the U.S. every year from flu-related complications, primarily pneumonia or bronchial pheumonia. CDC further estimates that 36,000 people die in the U.S. from flu-related causes every year.
The current outbreak of A/H1N1 swine flu that began in Mexico and has quickly spread to countries across the globe is a new subtype with genetic material from the swine flu subtype, the avian flu subtype, and the A/H3N2 subtype. The World Health Organization is closely monitoring the cases as they are confirmed, and has advised national health organizations that this new virus is resistant to two of the 4 developed antiviral drugs available. It responds to oseltamivir (Roche's Tamiflu), and standby stockpiles of the drug in Switzerland and the United States are being made available.
The annual human influenza strains tend to be more dangerous to the very young or very old and people with compromised immune systems. But pandemic influenzas - strains like the Spanish flu that caused at least 50 million deaths worldwide in 1918 - are particularly dangerous because they tend to strike healthy adults with adequate immune systems. The age range of the ~108 people confirmed to have died of this new strain so far in Mexico has officials all over the world concerned about the possibility of a new pandemic.
This new strain of swine flu is passed person to person, just the way that seasonal flu strains are passed. It cannot be spread by eating pork, so long as the pork has been properly handled and cooked. People in affected areas have been advised to avoid crowds and public places (restaurants, theaters, etc.), and to wear a disposable surgical mask over the mouth and nose if they must go out. People are advised to avoid touching surfaces like doorknobs and such in public places, to keep their hands away from their face (flu viruses enter primarily through eyes, nose and mouth) and wash hands with soap and hot water often. Alcohol-based hand sanitizers are also recommended.
To further reduce your chances of getting sick, get plenty of sleep, the full recommended 8 hours per night if possible. Do not neglect daily exercise and drink plenty of fluids and eat fresh, nutritious foods.