Bird flu: Where we are now and what to know about prevention

Bird flu, or avian influenza, is a viral infection that primarily affects birds but can be transmitted to humans. With ongoing outbreaks and evolving research, it's important to understand the risks, how the virus spreads, and what you can do to stay safe. Here's what we know about bird flu in February 2025.

What is bird flu?

Bird flu is a disease caused by avian influenza A viruses that primarily affect birds. Though uncommon, these viruses can spread to humans, leading to serious illness and, in some instances, death.

Certain bird flu strains are particularly worrisome because they can cause severe respiratory illness, and have a high mortality rate in humans when transmission occurs.

Can humans get bird flu?

Avian influenza is a zoonotic disease, meaning it can be transmitted from animals to humans. However, the CDC considers the current risk of H5N1 to the general public to be low. Certain groups are more vulnerable due to their exposure to infected animals. Those at higher risk include:

• individuals who work closely with infected birds or animals, such as farmers, poultry workers, and backyard flock owners
• veterinarians and wildlife facility staff
• public health responders handling infected animals
• hunters and bird watchers with recreational exposure to wild birds.

Symptoms of bird flu in humans can range from mild respiratory illness (such as fever, cough, and sore throat) to severe pneumonia and even death.

Bird flu cases

While several bird flu strains have infected humans, H5N1 and H7N9 are the most notable. Between 2003 and 2023, the World Health Organization (WHO) reported 878 human cases of H5N1, with a 52% fatality rate across 23 countries. H7N9 has caused outbreaks in China since 2013, leading to over 1,500 cases and a 40% fatality rate.

More recently, H5N1 has made a resurgence in the U.S., with 68 confirmed human cases since March 2024, according to the Centers for Disease Control and Prevention (CDC). Recent outbreaks in early 2025 have affected poultry farms worldwide, leading to large-scale culling of birds to prevent the spread.

There has only been one documented human death in the U.S. from the recent outbreak; most cases have been mild.

How bird flu spreads

Avian influenza viruses can easily evolve and adapt to new host environments. These viruses naturally circulate in wild birds like ducks and geese, which often carry them without symptoms. They can spread to domestic poultry and dairy cows through direct contact or contaminated water and surfaces.

Infected poultry, such as chickens and turkeys, release large amounts of the virus through feces, saliva, and respiratory secretions. Humans can become infected through:

• direct contact with sick birds
• exposure to contaminated environments, like live bird markets
• handling raw poultry without proper precautions.

As of now, there have been no reports of bird flu spreading from person to person. Experts continue to study the virus for potential changes.

Can you get bird flu from your cat?

There have been reports of domestic cats contracting bird flu after eating infected birds. While the risk to pet owners is low, Dr. Michelle Chan, an infectious disease physician at Beth Israel Deaconess Medical Center and an instructor in medicine at Harvard Medical School, explains, "Avian flu can spread to household pets, such as cats and dogs, if they hunt outdoors or are exposed to infected animals like wild birds."

She further notes that "pet food containing unpasteurized dairy or raw meat can also be a source of infection." To reduce your risk, it's a good idea to keep cats indoors in areas experiencing bird flu outbreaks, and avoid pet food containing raw meat or unpasteurized dairy.

Bird flu prevention

To prevent bird flu, Dr. Chan advises "avoiding contact with sick or dead animals, as well as potentially contaminated surfaces and water. If you notice sick or dead wildlife, report it to the appropriate authorities. The highest risk of infection is among those working closely with animals, such as on farms. If you fall into that category, wear gloves, masks, and eye protection to help prevent infection. Washing hands after touching contaminated surfaces is also crucial — touching the eyes, nose, or mouth increases the risk of spread."

It's also important to follow food safety guidelines. To reduce the risk of infection, avoid raw dairy and undercooked poultry or beef. Cooking meat and eggs to the proper temperature and choosing pasteurized dairy products help eliminate harmful bacteria and viruses, including avian influenza.

If you're exposed to bird flu, antiviral medications like oseltamivir (Tamiflu) can lower the risk of infection.

If you develop symptoms that could be bird flu or think you've been exposed, contact your doctor right away for guidance on testing and treatment.

Is it safe to eat eggs?

It is safe to eat eggs if they are properly cooked. According to the United States Department of Agriculture (USDA), poultry and eggs that are handled and cooked correctly do not pose a risk for avian influenza or other harmful bacteria. Cooking eggs to an internal temperature of 160° F (71° C) kills the virus and makes them safe to eat. Avoid raw or undercooked eggs, especially during outbreaks.

Is it safe to eat poultry?

Properly cooked poultry is safe to eat. The USDA recommends cooking poultry to an internal temperature of 165° F (74° C) to eliminate any potential virus. Handling raw poultry with care — washing hands, cleaning surfaces, and preventing cross-contamination — further reduces risk.