Variant Influenza Viruses in Humans
Swine flu viruses do not normally infect humans. However, sporadic human infections with influenza viruses that normally circulate in swine and not people have occurred. When this happens, these viruses are called “variant viruses.” They also can be denoted by adding the letter “v” to the end of the virus subtype designation. Human infections with H1N1v, H3N2v and H1N2v viruses have been detected in the United States.
Information for Specific Groups
CDC data on the most current case counts for variant flu virus infections in humans reported in the United States.
MorePrint Materials
- Graphic: Flu Can Spread Between Pigs and People [1.2 MB, 2 pages] | Spanish [1.2 MB, 2 pages]
- Key Facts for People Exhibiting Pigs at Fairs [545 KB, 2 pages]
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- Educational Poster [389 KB, 1 page]
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More Information
- Current and Past Reports of Human Infections with Variant Viruses
- Medscape Commentary: CDC Guidance for Swine Influenza Virus Infection
- Infectious Disease News: ‘Common-Sense’ precautions reduce risk for variant flu at fairsResource Repository- Youth in Agriculture
- Zoonotic Influenza: Detection, Response, Prevention, and Control Reference Guide
Flu Can Spread Between Pigs and People
Page last reviewed: August 9, 2022
