What Is Bird Flu?

Bird flu is extremely rare in humans, but could pose a threat

Bird flu, or avian flu, is a type of influenza A that occurs naturally in wild birds and can be spread to domesticated birds. In extremely rare cases it can affect humans.

There are many strains of bird flu, but when most people talk about bird flu they’re referring to viruses that originate in Asia, specifically H7N9 or H5N1, the classic bird flu. In the past, both of these have caused small outbreaks globally, but neither has ever been detected in the United States.

Here’s what you should know about avian flu, including risks, symptoms, and prevention. 

What to Know About Bird Flu

Verywell / Juoles Garcia

Avian Flu in Birds vs. Humans 

Bird flu occurs naturally in wild birds and can also spread to livestock poultry. However, transmission to humans is very rare. Avian flu is passed through contact with the saliva, mucus, or feces of a bird that has the virus. For a human to contract the virus, a substantial amount of the virus must enter their eyes, nose, or mouth. Almost everyone who contracts avian flu gets it after close contact with infected birds. 

Human-to-human transmission has only been detected in extremely rare situations. However, global health officials monitor avian flu because the virus has a high mortality rate (rate of death). If the virus mutates, or changes, to be able to spread more easily from human to human, it would become even more dangerous.

Current Risk of Transmission 

The risk of getting bird flu, especially in the United States, is extremely low. Globally, 1,568 people have been infected with H7N9 since 2013. Since 2003, about 862 people around the globe have contracted H5N1. Very rarely, other strains of bird flu are diagnosed in the United States, but the more serious strains have never occurred in humans or birds in this country.

Bird Flu Symptoms 

In humans, the symptoms of bird flu are the same as seasonal influenza. Some cases are mild, while others are severe. Avian flu has a much higher mortality rate than seasonal influenza. Roughly 53% of people diagnosed with H5N1 and 50% of people diagnosed with H7N9 have died.

Symptoms include:

  • Fever
  • Cough
  • Sore throat and runny nose
  • Aches, including headache
  • Fatigue
  • Conjunctivitis (pink eye)
  • Trouble breathing

Risk Factors 

People who live or work in close proximity to birds are at the highest risk of contracting bird flu. The avian flu is more common in certain areas of the globe, especially Asia, and risk increases if you have recently traveled to a country that is experiencing bird flu.

Among people who contract bird flu, people who are pregnant, those who are immunocompromised (have a weakened immune system), or people ages 65 and older are at higher risk for serious complications. 

Bird Flu Prevention

To further reduce the risk of contracting bird flu, the Centers for Disease Control and Prevention (CDC) recommends that people:

  • Avoid contact with wild birds.
  • Stay away from domestic birds that are sick or dead.
  • Avoid any contact with bird feces, whether wild or domestic.
  • Report dead wild birds to state agencies and never handle them with bare hands.
  • If traveling, avoid farms and poultry markets in countries affected by bird flu.

Food Preparation Tips 

There has never been a documented case of a human contracting bird flu through uncooked or undercooked food. However, scientists know that other viruses can pass through substances like blood that are found in uncooked food.

To be extra cautious, the CDC recommends that people cook poultry and eggs thoroughly and wash their hands after preparing them. When traveling in countries affected by bird flu, the CDC recommends not preparing poultry or eggs. 

Bird Flu Diagnosis and Treatment 

Bird flu cannot be diagnosed with symptoms alone, it must be diagnosed with a lab test. To conduct the test, doctors will swab your nose and analyze the mucus. It’s important to tell your doctor if you have recently travelled to a country that experiences avian flu, or if you’ve been in contact with birds. 

Bird flu can be treated using antiviral medications. If you believe you’ve been exposed to bird flu, these medications might also prevent you from contracting the illness.

Flu Shot Vaccine for Bird Flu 

The seasonal flu vaccine does not offer protection against bird flu. However, getting the vaccine might help prevent severe illness that could occur if you contracted the seasonal flu and bird flu at the same time. 

There isn’t currently a publicly available vaccine for bird flu. However, the U.S. government has a stockpile of vaccines for H5N1, which could be deployed if the virus ever began spreading easily between humans.


Bird flu is concerning because of its high mortality rate. However, it is extremely rare in humans. Although avian flu occurs in birds around the world, fewer than 2,500 people have been infected since 2003. However, it’s still important to limit contact with birds and bird droppings, and to tell your doctor if you become sick after visiting a country with active bird flu. 

A Word From Verywell

The COVID-19 pandemic has left many people on edge. Bird flu is concerning, but it’s important to remember that it’s exceedingly rare in humans. The two most dangerous strains of bird flu—H5N1 and H7N9—have never been detected in birds or humans in the United States. As always, focusing on overall health, practicing good hygiene, and keeping up to date on vaccines can help keep you safe. 

Frequently Asked Questions

  • Which countries have had bird flu outbreaks in the past?

    Bird flu cases occur naturally in bird populations around the world. Cases of the severe H5N1, or classic bird flu, have occurred in Asia, Europe, Africa and on Pacific Islands. In 2014 the only North American case of H5N1 occurred in Canada in a person who had recently returned from China. 

  • Is there a vaccine specifically for avian flu?

    There is not a publicly available bird flu vaccine. However, the federal government has a stockpile of vaccines against the H5N1 bird flu virus, which would be distributed if the virus ever began passing from human to human. 

  • When was the first documented case of bird flu in humans?

    The first human case of H5N1, the classic bird flu, was diagnosed in Hong Kong in 1997. In 2014, Canada experienced the first case of H5N1 in the Americas. A human case has never been reported in the United States. 

  • What is the bird flu mortality rate?

    Bird flu has a much higher mortality rate than seasonal influenza. Roughly 53% of people diagnosed with H5N1 and 40% of people diagnosed with H7N9 have died. 

  • Are pet birds at risk of getting the avian flu?

    Pet birds have a very low risk of contracting bird flu as long as they are kept indoors and out of contact with wild birds. However, domestic birds, including poultry, are at higher risk for bird flu. Occasionally outbreaks of North American bird flu occur in poultry in the United States, but H5N1 has never occurred in birds in America. 

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Agriculture Association. Global AIV with zoonotic potential situation update.

  2. Centers For Disease Control and Prevention. Outbreaks of North American lineage avian influenza viruses

  3. Centers for Disease Control and Prevention. Influenza A virus infections in humans.

  4. Food and Agriculture Association. H7N9 situation update.

  5. The Vaccine Alliance. The next pandemic: H5N1 and H7N9 influenza?.

  6. MedlinePlus. Bird flu.

  7. Centers for Disease Control and Prevention. Prevention and treatment of avian influenza A viruses in people.

By Kelly Burch
Kelly Burch is has written about health topics for more than a decade. Her writing has appeared in The Washington Post, The Chicago Tribune, and more.