Seasonal Influenza (Flu)

Avian Flu: H7N9 Virus—Electron Micrograph Images of H7N9 Virus from China
CDC Influenza Application—for Clinicians and Health Care Professionals
FluView Interactive—Influenza Surveillance Data the Way You Want it!
FluVaxView—How many people got their flu vaccination early this season?
CDC Communications to Clinicians—Activity updates and current recommendations.

The 2012-2013 flu season started early and activity was intense compared to previous recent seasons for which data are available. While the 2012-2013 season has ended, sporadic flu activity can occur year-round and vaccination is still recommended for institutional outbreak control, for children needing their second dose and for some travelers. All seasonal influenza vaccine for the 2012-2013 season will expire by June 30, 2013. Vaccine for the 2013-2014 season will be available in the fall.

Click here for updates on Avian Influenza A (H7N9) Virus »

Flu Basics

Symptoms, How Flu Spreads, Higher Risk Groups, Past and Current Flu Season…

Prevention - Flu Vaccine

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PHIL Influenza Images

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Avian

There are many different influenza A viruses; some are found in humans and others in animals such as avian flu in birds and poultry.

H7N9

A new avian influenza A (H7N9) virus has been detected in China. CDC is following this situation closely and coordinating with domestic and international partners.

H3N2v

Influenza viruses that normally circulate in pigs are called “variant” viruses when they are found in people. Influenza A H3N2 variant viruses (also known as “H3N2v” viruses) with the matrix (M) gene from the 2009 H1N1 pandemic virus were first detected in people in July 2011.

Swine

There are many different influenza A Viruses; some are found in humans and others in animals such as swine flu in pigs.

Pandemic

CDC’s pandemic preparedness efforts include ongoing surveillance of human and animal influenza viruses, risk assessments of influenza viruses with pandemic potential, and the development and improvement of preparedness tools that can aid public health practitioners in the event of an influenza pandemic.

Bat

Bat influenza refers to influenza A viruses found in bats. Laboratory research at CDC suggests these viruses would need to undergo significant changes to become capable of infecting and spreading easily among humans. Little yellow shouldered bats are not native to the continental United States, but are common in Central and South America.

Canine

Dog flu is a contagious respiratory disease in dogs caused by a specific Type A influenza virus referred to as a “canine influenza virus.” This is a disease of dogs, not of humans.

Other

Influenza A viruses are found in humans and many different animals, including ducks, chickens, pigs, whales, horses and seals. Additional information on 2009 H1N1 influenza, Flu.gov, and Nonpharmaceutical Interventions (NPIs).