Avian Influenza ("Bird Flu")

Influenza (often called "flu") is an illness caused by the influenza virus. Symptoms, in humans, include fever, cough, muscle aches, headache, runny nose, sore throat, nausea, vomiting, eye redness and irritation, and general weakness. These symptoms can range from mild to severe. Flu can be serious in the very young, the very old, and people who have other health problems.

Birds can also develop influenza, called avian influenza. The influenza viruses that affect birds typically do not affect humans. Influenza in birds may also cause a range of symptoms ranging from mild to severe, including death.

Pandemic influenza ("pandemic flu") is a worldwide outbreak of a new type of influenza virus. The new virus is able to spread from person to person. and can cause widespread serious illness because most people are not immune and can get sick.

All birds are vulnerable to bird flu. Migratory birds, such as wild ducks or geese, can carry the virus. Domestic birds, such as chickens and ducks, can get avian influenza through direct contact with an infected bird's saliva, nasal secretions, or droppings (poop). 

In the current US outbreak of avian influenza, a large number of dairy cows have been infected with avian influenza. Cats, sea lions, wolves, and other mammals can also be infected with bird flu. 

Although rare, humans can become infected with avian influenza. Most human infections happen through close direct contact with live or dead infected poultry or other infected animals.  

Transmission of avian influenza from person to person is extremely rare, and there have been no cases of person to person transmission during the current US outbreak of H5N1. Because bird flu viruses can change over time and become more easily passed between people, the city, state, and federal authorities closely monitor bird flu activity. 

There is currently an outbreak of H5N1 bird flu among wild birds across the US, as well as among domesticated poultry and cattle in some parts of the country. In Massachusetts, H5N1 avian influenza has been circulating intermittently among wild birds since 2022, and is currently causing widespread illness among wild birds in Eastern Massachusetts. There have been several dozen cases of human infection with H5N1 in the US during the current outbreak, mostly among poultry and cattle workers. There have been no human infections to date in Boston.  

In the U.S., it is safe to eat properly handled and cooked poultry. Always wash your hands after handling raw poultry. Cook all poultry and poultry products (including eggs) thoroughly before eating. A safe internal cooking temperature for poultry is 165°F.