What Is Bird Flu? Tips to Stay Safe During the Outbreak

As avian influenza A virus ('bird flu') strikes dairy cows across states, including Texas, where it has been transmitted to a human, concerns about a possible pandemic arise. This article explores the outbreak's origins, its implications for human health, and safety measures individuals can take to protect themselves during this challenging time.

Is there a bird flu pandemic?

The Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) are currently tracking an outbreak of a strain of avian influenza A virus ('bird flu') in dairy cows. As of April 11, 2024, states like Idaho, Kansas, Michigan, New Mexico, Ohio, Texas, North Carolina, and South Dakota have reported this strain of bird flu in livestock, all of which are dairy milking cows. The clinical signs of infection in the cows include decreased milk production and low appetite.

A person in Texas who had worked with the infected dairy cows tested positive for the same strain of bird flu (H5N1) as found in the cows. The infected person, who is now recovering, first reported redness (conjunctivitis) as their only symptom. There is no evidence of human-to-human transmission at the moment.

This case is unique because it is the second time that the H5N1 bird flu has been transmitted from an animal to a human. The single previous case of human infection with H5N1 bird flu in the U.S. was in Colorado in April 2022. The person had been involved with culling a flock of chickens infected with H5N1 and reported fatigue for a few days as their only symptom.

A different strain of bird flu (H7N2) was passed from a cat in 2016. The NYC veterinarian had been handling sick cats without protection and experienced mild flu symptoms. Since 2022, the H5N1 virus has been detected in more than 200 mammals, such as outdoor cats on dairy farms, and most recently, in goats and cows.

What causes bird flu?

The strain of bird flu detected in the cows — highly pathogenic avian influenza A H5N1, Eurasian lineage goose/Guangdong clade 2.3.4.4b — is similar between the cows and connected with wild birds. The virus sequence has been tested and currently, there do not appear to be changes in the virus that would make it more likely to be passed to humans.

Another type of highly pathogenic avian influenza (H7N9) has also caused human infections in the past. Similar to H5N1, the range of symptoms in humans has varied widely.

It is important to note that the scientific name of the virus (highly pathogenic avian influenza) is determined by experimental tests in poultry. The strains are categorized as 'low' vs. 'high' based on these laboratory tests. The low vs. highly pathogenic terminology is used to distinguish between the bird flu strains, but it has no bearing on the severity of illness in a human.

How does bird flu spread?

Bird flu spreads among wild birds via saliva, mucous, and feces. Unprotected close contact with poultry during handling and equipment cleaning may provide the right opportunity for a human to come in contact with the virus.

Can humans get bird flu?

Humans can catch bird flu if the virus is breathed in or contacts mucous membranes, such as the eyes, nose, or mouth. Previous human cases of bird flu have been associated with infected birds and poultry, not mammals. However, it is also possible that transmission from mammals to humans has happened, but has simply not been detected.

Human cases of H5N1 bird flu are rare, and only 880 cases have been detected worldwide since 2003. Most commonly, human cases are associated with close contact with infected birds. The virus may be transferred by touching contaminated surfaces and then touching the eyes, nose, or mouth, or breathing in dust or droplets. The CDC is monitoring this outbreak among cows carefully and believes the risk to humans remains very low.

Is human-to-human transmission possible?

Very rarely, cases of avian influenza have been passed from one family member to another after prolonged, very close, unprotected household contact. A few cases have been transmitted following close contact with a very sick family member who was hospitalized.

Bird flu symptoms

The range of symptoms is wide, from no symptoms at all or mild illness to severe illness and death. When symptoms are present, they resemble typical flu symptoms: fever or feeling feverish (a fever may not be present), cough, runny nose, body aches, headaches, sore throat, and fatigue. More severe cases may experience difficulty breathing, diarrhea, nausea, vomiting, or seizures, although these are not common.

The symptoms of avian flu in birds include closed and runny eyes, a swollen head, and death. As with seasonal influenza, the possible complications of avian influenza include pneumonia and acute respiratory distress syndrome.

Countries with bird flu outbreaks

Bird flu is found globally, carried by wild aquatic birds such as ducks and geese, and then picked up by domesticated or commercial bird populations. The World Health Organization (WHO) tracks cases of bird flu. Cases have been reported from 23 countries worldwide since 2003. Most recently, cases have been reported in Chile and Vietnam.

If traveling to a country with a known outbreak, avoid poultry farms and live animal markets. All travelers should wash their hands thoroughly with soap and water prior to eating. Monitor travel information provided by the CDC prior to making plans.

Vaccines for bird flu

There are currently no animal or human vaccines for bird flu, and seasonal human flu vaccination does not protect against bird flu. However, the CDC is working on several vaccine candidates that are a good match to the circulating bird flu strain. This candidate vaccine could be used to create a human vaccine, and preliminary data suggests it works well in birds and other animals.

How to stay safe during the bird flu outbreak

You can stay safe during the bird flu outbreak by following the same health and hygiene practices that you follow every day.

1. Avoid contact with wild birds and poultry

The best way to protect yourself is to limit contact with potentially infected wild birds, poultry, or livestock. Use common sense by wearing gloves when in a close and prolonged exposure situation, such as when cleaning equipment and animal housing. Do not touch surfaces that might be contaminated with feces or raw milk from infected birds or livestock.

2. Practice good hygiene

Washing your hands with soap and water is the best defense against infection. Avoid touching your nose, mouth, or eyes with your hands unless you have thoroughly washed them.

3. Use protective gear

People who work in higher-risk occupations, such as on a poultry or dairy farm, animal rescue facilities, or raising backyard flocks, should take sensible precautions when handling animals.

Using protective gear, such as gloves, a well-fitting mask, and eye protection (e.g., goggles) may be important if you are in close quarters, such as a confined area with poor ventilation, while handling wild birds or poultry or potentially infected livestock.

Hunters should recognize the potential for infection when dressing wild birds such as ducks, geese, or turkeys. Field dressing while wearing protective gear may be advisable.

4. Avoid cross-contamination

Changing your clothes after handling potentially infected birds or animals is important prior to handling healthy domestic poultry or animals. Throw out used gloves and masks when moving between flocks to prevent transmitting infection.

5. Report illness in your backyard flock or animals

The U.S. has a massive poultry population serving as an important food source. Biosecurity is, therefore, everyone’s responsibility.

If you have a backyard flock or raise dairy cattle, be alert for potential illness and report unusual bird or animal deaths through your state veterinarian. You can also call the USDA’s toll-free number 1-866-536-7593.

6. Cook poultry thoroughly and use pasteurized eggs

Ensuring poultry is cooked thoroughly is crucial. According to the Egg Safety Center, pasteurized eggs can be safely used in recipes without cooking when raw eggs are required, such as in Caesar salad, mayonnaise, meringues, eggnog, or ice cream.

7. Seek medical attention if symptomatic

If you have influenza-like symptoms, stay home and rest, drink plenty of fluids, monitor your symptoms, and consult your doctor for testing if your symptoms worsen or if you have risk factors for severe illness.

If you have recently handled sick animals or birds, it is important to contact your clinician for proper testing.

8. Vaccinate poultry

Poultry vaccination programs help protect against a variety of diseases, including Marek’s disease, bronchitis, and bursal disease. These vaccines can be delivered via a spray, drinking water, and injecting the egg (the developing chick receives the vaccine).

The CDC is conducting a robust investigation in coordination with the FDA. You can stay informed by following the CDC’s Current situation.

In summary, bird flu is only rarely passed to humans. Just as in seasonal influenza, bird flu symptoms vary widely — from no symptoms at all to mild illness, severe disease, or death. If you have been in contact with wild birds or infected poultry or dairy cattle and become sick with flu-like symptoms, call a medical professional and seek guidance about testing. It is safe to continue eating chicken and eggs and drinking milk. Avoid raw milk and use pasteurized eggs in recipes calling for raw eggs.