Avian influenza (also known as bird flu or avian flu) usually attacks birds rather than humans. Although the virus poses a low risk to the public’s health overall, the U.S. Centers for Disease Control and Prevention (CDC) confirmed the first case of severe bird flu in the country on Dec. 13, 2024. Since April 2024, there have been 61 reported cases of bird flu in humans in the United States. The CDC continues to monitor the current situation.
Furthermore, on Dec. 18, 2024, the California governor declared a state of emergency over a bird flu outbreak in cattle. More than 300 dairy herds tested positive in the past month.
This article provides an overview of the bird flu, its symptoms, and treatment and prevention.
Cause of Bird Flu
Bird flu is a general term for an infection caused by influenza A viruses, which occur naturally among birds. Wild birds carry the virus in their intestines but do not get sick. However, the virus is very contagious and can make domesticated birds (e.g., chickens, ducks and turkeys) very sick and kill them. There have also been reported cases of pigs being infected. Avian influenza A viruses are common in these animal species or groups: wild waterfowl, domestic poultry, swine, horses, dogs and bats.
The virus is passed through saliva, nasal secretions and feces. Infection occurs when coming into contact with any of these substances.
Avian Influenza A (H5N1)
A highly pathogenic strain of bird flu, H5N1, is deadly to wild waterfowl and domestic poultry. It’s transmitted from birds to humans infrequently, but when a human is infected, the resulting illness is often fatal. Humans have virtually no immunity to the highly pathogenic H5N1 avian influenza.
Human Infection
The risk of human infection with bird flu is generally low, but confirmed cases have been reported since 1997. Most cases have resulted from contact with infected poultry or surfaces contaminated with secretion or excretions from infected birds. The spread of the disease from one person to another is very rare.
While the H5N1 virus had only been found in humans in Asia, Europe, the Near East and Africa, the CDC recently confirmed the first instance of severe illness in the United States. The first U.S. patient was likely exposed to the virus from a backyard flock, which is also the first time such a flock has been associated with a bird flu infection.
Symptoms
Unfortunately, it is not always possible to tell if live poultry is infected with bird flu. Most symptoms are undetectable or mild (such as low egg production or ruffled feathers).
In humans, bird flu symptoms have ranged from typical flu-like signs (e.g., fever, cough, sore throat and muscle aches) to eye infections, pneumonia, severe respiratory diseases, and other severe or life-threatening complications.
Prevention
The best way to prevent bird flu is to avoid exposure whenever possible. Infected birds transmit the virus in their saliva, mucus and feces. Other infected animals may shed the avian influenza A virus in respiratory secretions and other bodily fluids (e.g., unpasteurized cow milk).
Food Consumption
Eating uncooked or undercooked poultry or beef can cause illness. Pasteurization kills bacteria and viruses, including avian influenza A, in milk. As such, unpasteurized milk and related products can also cause illness. Consider the following tips from the CDC for safely preparing or consuming food:
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Wash your hands with soap and warm water for at least 20 seconds before and after handling any food.
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Clean cutting boards and other utensils with soap and hot water immediately after use.
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Separate raw meat from cooked foods to prevent cross-contamination.
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Use a food thermometer to ensure meat is cooked to the appropriate internal temperature:
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Poultry: 165 degrees Fahrenheit
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Ground beef: 160 degrees Fahrenheit
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Whole cuts of beef: 145 degrees Fahrenheit
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Choose pasteurized milk and products made with pasteurized milk, including soft cheese, ice cream and yogurt.
Good hand hygiene continues to be critical to protecting oneself against viruses of any type, so be sure to wash your hands after coughing or sneezing.
Traveling
Currently, the CDC doesn’t recommend against travel to any countries due to avian influenza A viruses. However, travelers in countries or states with bird flu outbreaks should follow these recommendations from the CDC:
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Do not visit poultry farms, bird markets or other places where live poultry is raised, kept or sold. If you must visit, wear personal protective equipment (PPE) and avoid touching poultry and other birds.
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Do not visit dairy farms with sick cows unless you’re wearing PPE.
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Do not eat raw or undercooked poultry products. Wash your hands thoroughly after touching any uncooked poultry.
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Visit a doctor if you become sick during or after travel.
Treatment
If you think you have bird flu, you’ll be advised to stay home, or if the illness is severe, you’ll be isolated from other patients in the hospital. Some antiviral medications, such as oseltamivir and zanamivir, are used to treat bird flu. However, as with any influenza, the virus may eventually become resistant to these drugs, so additional studies are ongoing. Also, keep in mind that there are no approved vaccines for the bird flu; standard flu shots are different.
Summary
As the bird flu infects wild birds, poultry and some mammals, it could create additional opportunities for humans to be exposed to the virus. The risk of influenza A viruses spreading from birds to people has not increased; however, there could be an increase in sporadic human infections when people are exposed to infected birds and animals.
Although people with job-related or recreational exposure to infected birds or animals are at a greater risk of contracting the H5N1 virus, the CDC expresses that the current risk to the general public from bird flu viruses is low.
Visit the CDC’s website to learn more about the bird flu.
This article is for informational purposes only and is not intended as medical advice. For further information, please consult a medical professional. © 2024 Zywave, Inc. All rights reserved.