tetano
Editor, Senior Moderator
This page contains background information about swine influenza virus infections in humans, now called ?variant virus infections in humans.?
What is Swine Influenza?
Swine influenza (swine flu) is a respiratory disease of pigs caused by type A influenza viruses that regularly cause outbreaks of influenza in pigs. Swine flu viruses can cause high levels of illness in swine herds, but usually cause few deaths. Common signs in sick pigs include fever, depression, coughing (barking), discharge from the nose or eyes, sneezing, breathing difficulties, eye redness or inflammation, and going off feed. However, influenza-infected pigs also may not appear ill or be only mildly ill. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks of seasonal influenza in humans.
What is a variant influenza virus?
When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a ?variant influenza virus.? For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an ?H3N2 variant? virus or ?H3N2v? virus. This naming convention was first announced in a January 6, 2012 Morbidity and Mortality Weekly Report entitled Update: Influenza A (H3N2)v Transmission and Guidelines ? Five States, 2011. (See Box)
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http://www.cdc.gov/flu/swineflu/keyfacts-variant.htm
What is Swine Influenza?
Swine influenza (swine flu) is a respiratory disease of pigs caused by type A influenza viruses that regularly cause outbreaks of influenza in pigs. Swine flu viruses can cause high levels of illness in swine herds, but usually cause few deaths. Common signs in sick pigs include fever, depression, coughing (barking), discharge from the nose or eyes, sneezing, breathing difficulties, eye redness or inflammation, and going off feed. However, influenza-infected pigs also may not appear ill or be only mildly ill. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks of seasonal influenza in humans.
What is a variant influenza virus?
When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a ?variant influenza virus.? For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an ?H3N2 variant? virus or ?H3N2v? virus. This naming convention was first announced in a January 6, 2012 Morbidity and Mortality Weekly Report entitled Update: Influenza A (H3N2)v Transmission and Guidelines ? Five States, 2011. (See Box)
..
http://www.cdc.gov/flu/swineflu/keyfacts-variant.htm