Influenza in Animals
CDC has compiled two tables that showing the different hemagglutinin and neuraminidase subtypes and the species in which they have been detected.
Influenza A viruses are found in many different animals, including ducks, chickens, pigs, whales, horses, seals and cats.
Influenza B viruses circulate widely only among humans.
Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: the hemagglutinin (H) and the neuraminidase (N). There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes. All known subtypes of influenza A viruses have been found among birds, except subtype H17N10 and H18N11 which have only been found in bats.
While it is unusual for people to get influenza infections directly from animals, sporadic human infections and outbreaks caused by certain avian influenza A viruses have been reported.
- Weekly U.S. Influenza Surveillance Report Friday, April 19, 2019
- What CDC Does About Novel Flu: Outbreak Investigations Wednesday, April 17, 2019
- Upcoming 2019-2020 Influenza Season Thursday, March 28, 2019
- CDC Health Advisory: Influenza Season Continues with an Increase in Influenza A(H3N2) Activity Thursday, March 28, 2019
- CDC Study Describes New Lab Method to Test Flu A(H3N2) viruses, Has Potential to Improve Flu Vaccine Strain Selection Wednesday, March 27, 2019