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Avian Influenza A Virus

Highly pathogenic avian influenza A (H5N1) virus infection reported in a person in the U.S.

The CDC (Centers for Disease Control and Prevention) confirmed on April 1, 2024, that a person in the U.S. has tested positive for highly pathogenic avian influenza A (H5N1). The CDC says risk to the general public remains low. For more information on this positive test, visit the CDC Highly Pathogenic Avian Influenza A (H5N1) Virus Infection Reported in a Person in the U.S.

Wisconsin actively monitors for human cases of avian influenza and has plans in place to respond, if necessary. Currently, there is no imminent threat to Wisconsin since there is little evidence of sustained human-to-human spread of the bird flu in other parts of the world. It is difficult to predict if a bird flu virus will become a pandemic, but Wisconsin has plans in place to respond to that possibility, regardless of the source. You may also visit the Influenza (Flu) home for more information on how to protect yourself against the flu.

What is avian influenza?

Avian influenza occurs naturally among birds and is caused by influenza viruses. It can also spread to other animals. Animals carry the viruses in their intestines but usually do not get sick from them. However, avian influenza is very contagious among birds and other infected animals and can make some domesticated birds, including chickens, ducks and turkeys, very sick and can kill them.

Infected animals act as hosts to influenza viruses by carrying the virus in their intestines and shedding it in bodily fluids, such as saliva, nasal secretions and feces. Other animals become infected when they come in contact with these fluids. 

Humans can become infected through contact with infected animals, animal products, or contaminated fluids. Avian flu can spread from birds to people and cause serious illness and even death.

Avian influenza has not mutated to a point where it could easily spread from person-to-person. It's difficult to predict if – or when – that might happen, or if it will result in an influenza pandemic. 

People who have gotten sick with avian influenza have been in direct contact with infected animals.

Symptoms of avian influenza in humans range from typical influenza-like symptoms (fever, cough, sore throat, muscle aches) to eye infections, pneumonia, acute respiratory distress, viral pneumonia and other severe and life-threatening complications.

Health care providers will tell patients how to treat their illness, depending on the severity of their symptoms. Treatment may include hospitalization, supportive care and/or the use of antivirals. 

Studies have shown that one antiviral drug called Tamiflu (oseltamivir) may possibly protect against the H5N1 strain of influenza.

Yes, it is safe to eat animal products that have been fully cooked. It is not safe to drink unpasteurized (raw) milk. General precautions should always be taken when handling any raw meat, including raw eggs, to avoid possibly spreading germs. These measures include:

  • Washing hands and surfaces before and after food preparation.
  • Avoiding using the same utensils on raw meat as on other foods, even cooked meat.
  • Cooking raw meat thoroughly.

Note: The U.S. bans imports of animal products from areas where birds are infected with the H5N1 virus.

Thomas Haupt, Influenza Surveillance Coordinator
DHS Division of Public Health
Bureau of Communicable Diseases
Phone 608-266-5326
Fax 608-261-4976

Wisconsin Local Health Departments - Regional offices – Tribal agencies

Last revised April 8, 2024