Swine flu is the common name for the new strain of H1N1 influenza first identified by the Centers for Disease Control and Prevention (CDC) in April 2009. New cases were subsequently identified in several different countries around the world, prompting the World Health Organization to declare a pandemic on June 11, 2009. As of October 2009, CDC surveillance data indicate that most cases of influenza in the United States are caused by the new virus.
Origin
Swine flu is a new variant of the influenza A H1N1 virus that combines genes from flu viruses that circulate in pigs in Europe and Asia, birds and humans. Other kinds of influenza A H1N1 viruses have been circulating for years.
Cause for Alarm
When a swine flu outbreak was first identified in 2009, CDC laboratory studies indicated that no children and very few adults under 60 had antibodies to the virus. In addition, although about one-third of adults over 60 had some antibodies to the virus, it was unclear how effective those antibodies would be in protecting against severe disease.
Symptoms
Symptoms of swine flu include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A June 2009 report by the CDC's "Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team," published in the New England Journal of Medicine, indicates that vomiting and diarrhea are more common with swine flu than other kinds of flu: Approximately 40 percent of people with swine flu complained of one or both.
Vaccine
The swine flu virus was first identified in April 2009 after strains for the 2009-2010 seasonal flu vaccine had already been selected. Therefore, the FDA approved a second, supplementary vaccine solely to combat H1N1 flu. For the 2010-2011 flu season, the seasonal flu vaccine provides protection against swine flu.
Treatment
The CDC advises that most people with swine flu get better without treatment. People who are severely ill from swine flu, people over 65, children under 5, women who are pregnant, mothers who are up to two weeks postpartum and other people with certain kinds of medical problems may require one of two antiviral drugs, Tamiflu or Relenza, which are FDA-approved for the treatment of swine flu.
References
- CDC: 2009 H1N1 Flu ("Swine Flu") and You
- CDC: Morbidity and Mortality Weekly Report--Influenza Activity in the United States--Aug. 30 2009 to Jan. 9, 2010
- New England Journal of Medicine; "Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans; Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team"; June 18 2009
