Swine flu (swine influenza) is a respiratory disease caused by viruses (influenza viruses) that infect the respiratory tract resulting in nasal secretions, a barking cough, decreased appetite, and listless behavior.
Swine influenza virus was first isolated from pigs in 1930 in the U.S. and has been recognized by pork producers and veterinarians to cause infections in pigs worldwide. In a number of instances, people have developed the swine flu infection when they are closely associated with pigs (for example, farmers, and pork processors).
Swine flu is transmitted from person to person by inhalation or ingestion of droplets containing virus from people sneezing or coughing; it is not transmitted by eating cooked pork products.
In year 2009 H1N1 flu virus was first detected in Mexico, causing some deaths among a "younger" population. It began increasing during the summer 2009 and rapidly spread to the U.S. and to Europe and eventually worldwide. The WHO declared it first fit their criteria for an epidemic and then, in June 2009, the WHO declared the first flu pandemic in 41 years.
There was a worldwide concern and people began to improve in hand washing and other prevention methods while they awaited vaccine development. By late December to January, a vaccine against H1N1 was available in moderate supply worldwide.
The numbers of infected patients began to recede and the pandemic ended. However, a strain of H1N1 was incorporated into the yearly trivalent vaccine for the 2010-2011 flu season because the virus was present in the world populations.
Symptoms of swine flu are similar to most influenza infections: fever (100 F or greater), cough, nasal secretions, fatigue, and headache, with fatigue being reported in most infected individuals. Some patients may also get a sore throat, rash, body aches, headaches, chills, nausea, vomiting, and diarrhea. It's not necessary to see a doctor if you're generally healthy and develop flu signs and symptoms, such as fever, cough and body aches.
Call your doctor, however, if you have flu symptoms and you're pregnant or you have a chronic disease, such as emphysema or a heart condition.