SACRAMENTO, Calif. -- As poultry farms and dairies across California battle bird flu outbreaks, some are wondering if their food is safe to eat.

Since highly pathogenic avian influenza surfaced in the United States in January 2022, the virus has been detected in wild birds and domestic poultry, according to the federal Centers for Disease Control and Prevention.

HPAI was detected at a Merced County turkey farm in September and infected chickens at a Tulare County ranch about a month later, leading to the destruction of hundreds of thousands of birds, The Fresno Bee previously reported.

Meanwhile, avian flu has sickened cows more than 130 dairies across California, as well as 15 dairy workers.

The Bee talked to a Fresno-based infectious disease expert to learn more about the virus — and how it affects food safety.

What is bird flu?

According to the U.S. Food and Drug Administration, highly pathogenic avian influenza — also known as bird flu or H5N1 — is a highly contagious and often deadly disease primarily found in poultry.

It is “caused by highly pathogenic avian influenza A (H5) and A (H7) viruses,” the agency said on its website.

HPAI can spread from wild birds to domestic poultry and other animals. The virus can also infect humans in rare cases.

“It is important to note that ‘highly pathogenic’ refers to severe impact in birds, not necessarily in humans,” the agency said.

How is avian influenza spread to humans?

Unlike seasonal influenza viruses, which are typically contracted through human-to-human transmission, avian influenza viruses are spread by infected birds through saliva, mucus and feces, according to the CDC.

The virus can also be present in the respiratory secretions, organs, blood, or body fluids of other infected animals — including milk.

Human infections occur when the virus enters the eyes, nose or mouth, or is inhaled through airborne droplets, aerosol particles or dust. It can also be transmitted by touching contaminated surfaces and then touching the face.

“Illness in humans from avian influenza virus infections have ranged in severity from no symptoms or mild illness to severe disease that resulted in death,” the CDC said.

Can I get bird flu by drinking milk?

“There is no evidence that the virus can be transmitted to humans through properly prepared food,” the U.S. Food and Drug Administration said on its website.

Pasteurized milk and other dairy products are safe to consume, according to Hebah Ghanem, infectious disease specialist at University of California San Francisco, Fresno.

“The most important thing that it has to be pasteurized, because the virus is killed with heat,” Ghanem told The Bee.

“Pasteurization of milk was adopted decades ago as a basic public health measure to kill dangerous bacteria and largely eliminate the risk of getting sick,” the FDA said on its website.

Will eating eggs make me sick?

All egg products are pasteurized as required by the U.S. Department of Agriculture.

“This means that they have been rapidly heated and held at a minimum required temperature for a specified time to destroy bacteria,” the agency said.

However, eggs that are still in their shells aren’t required to be pasteurized, leading to potential health risks if eaten raw or uncooked.

What about chicken?

Chicken is safe to eat if it’s properly cooked, according to Ghanem.

During an avian flu outbreak, “The chance of infected poultry or eggs entering the food chain is low,” the FDA said on its website in April, “because of the rapid onset of symptoms in poultry as well as the safeguards in place, which include testing of flocks and federal inspection programs.”

“When food is properly prepared and stored, the risk of consumers becoming infected with HPAI is reduced even further,” the FDA said.

How contagious is avian flu?

“There have not been any human-to-human transmission cases yet” during the recent bird flu outbreak, Ghanem said.

“The transmission is from animal to human,” she added.

According to Ghanem, people usually only get infected with highly pathogenic avian influenza if they come in contact with an infected animal or its bodily fluids.

“That’s why most of the cases (involve) the people who are working with animals,” Ghanem explained.

“Because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, monitoring for human infection and person-to-person spread is extremely important for public health.” the CDC said on its website.

How dangerous is HPAI for humans?

The California dairy workers infected with avian flu so far have experienced mild flu-like symptoms, The Bee previously reported.

“All the cases that we have here in California are very mild,” Ghanem said. “They haven’t needed hospitalization.”

What are avian flu symptoms?

According to the CDC, avian flu symptoms in humans may include:

•Fever or feeling feverish or chillsEye redness or irritation

•Cough

•Sore throat

•Runny or stuff nose

•Muscle or body aches

•Headaches

•Tiredness

What should I do if I’m exposed to bird flu virus?

If you get exposed to the avian flu virus, Ghanem said, you must follow these steps.

1. Observe yourself to see if you develop any symptoms

2. Let the CDC know, so you can get tested

3. Isolate in case you have the virus

4. Start treatment if you test positive for HPAI or have any symptoms

Doctors can test for bird flu by “collecting a swab from the upper respiratory tract (nose or throat) of the sick person,” the CDC said. “Testing is more accurate when the swab is collected during the first few days of illness.“

Avian flu is treated with an antiviral medication such as Oseltamivir (Tamiflu) or Zanamivir (Relenza), according to the CDC.

“Antiviral treatment works best when started as soon as symptoms begin,” the CDC said.

How can I prevent spread of virus?

To prevent the spread of highly pathogenic avian influenza, people should avoid exposure to dead animals, Ghanem said. That includes wild bird, poultry, other domesticated birds and cows.

People should also avoid exposure to animal feces as well as fluids.

Here are other tips from Ghanem:

•Wash your hands

•Avoid contaminated surfaces and any other material that has been touched or is close to the infected animal

•Don’t drink raw milk.

•Eat pasteurized cheese.

•Monitor yourself for symptoms

She also recommends getting vaccinated against influenza.

“While getting a seasonal flu vaccine only prevents seasonal flu and will not protect against H5N1 bird flu,” the CDC said on its website, “it is important that people who may have frequent exposure to infected or potentially infected birds or other animals get a seasonal flu vaccine — ideally two weeks before their potential exposure.”

“This is because it can reduce the prevalence and severity of seasonal flu and might reduce the very rare risk of co-infection with a human seasonal virus and an avian virus at the same time,” the agency said.

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