How Does a Person Catch Swine Flu?

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What is swine flu, and how is swine flu different from other kinds of flu? How does a person catch swine flu?

Swine flu is a respiratory illness caused by influenza viruses that infect the respiratory tract of pigs; these viruses can occasionally infect humans. The disease first came to attention in 1976 with an army recruit's death from swine flu. Widespread fear then led to an often-criticized mass-inoculation program in the United States that resulted in illnesses and deaths. In spring 2009, numerous cases of swine flu affecting humans were reported, first in San Diego, Calif. Investigators decided the 2009 swine flu strain, first seen in Mexico, should be termed novel H1N1 flu since it was mainly found infecting people and is a mixture of flu viruses from human flu strains, avian (bird) strains, and swine strains. The newest swine flu virus that has caused swine flu is influenza A H3N2v (commonly termed H3N2v) that began as an outbreak in 2011. The "v" in the name means the virus is a variant that normally infects only pigs but has begun to infect humans. There have been small outbreaks of H1N1 since the pandemic.

Medically Reviewed by a Doctor on 2/23/2015