What is avian influenza?

Avian influenza (aka avian flu or bird flu) is a type of influenza that primarily infects birds but can sometime cause infection in mammals like cows, and rarely humans.

How widespread is avian flu?

Wild birds: Avian flu has been found worldwide in wild birds including waterfowl, gulls and shorebirds since 2022. There has been an uptick in the number of wild birds infected in both the Lehigh Valley and New Jersey in the past month.

Domestic poultry: Avian flu has also been causing outbreaks in domestic poultry and dairy cattle in some areas of the U.S. Pennsylvania had its first case of avian flu in a commercial chicken flock in Lehigh County last month. So far, there have been no cases of avian flu in cattle in Pennsylvania, and no cases in poultry or cattle in New Jersey.

Cats: Since 2024 dozens of cats have also contracted avian flu, including barn and feral cats, indoor cats and big cats in zoos and in the wild (e.g., mountain lions, tigers, leopards and bobcats). Infection is thought to be largely related to exposure to unpasteurized milk and raw or undercooked meat in food.

Humans: There have been 67 confirmed human cases of avian flu in the U.S. since 2024, including one death. There have been no reported human cases of avian flu in New Jersey or Pennsylvania. Ninety-six percent of cases in the United States have been linked to animal exposures. There have been no documented cases of human-to-human spread.

What are symptoms of avian flu?

Most human cases of avian flu in the US have been mild. Symptoms have included eye redness and irritation (this has been the predominant symptom), mild fever, cough, sore throat, runny or stuff nose, muscle or body aches, headaches and fatigue.

How is avian flu spread?

Almost all cases of avian flu in humans have been caused by close contact with infected live or dead birds. There have been rare cases of spread to humans from infected mammals like cows. So far, there has been no known human-to-human spread of avian flu. The avian flu virus has also been detected in unpasteurized (raw) cow’s milk. While there have been no cases of human avian flu directly linked to raw milk, it could be still be a potential source of infection.

What is the incubation period of avian flu?

The time from when a person is exposed to avian flu to when they develop symptoms is about three days but can range from two to seven days. Eye symptoms such as redness and irritation can be one of the earliest symptoms, occurring one to two days after exposure.

How do we test for avian flu?

Patients with avian flu will test positive for influenza with our current PCR tests. Further specialized testing could then be performed to confirm the avian flu strain in people with risk factors for exposure.

How is avian flu treated?

Our current medications for influenza (i.e., Tamiflu) have activity against avian flu.

Does the annual influenza vaccine protect against avian flu?

No, but there is an approved avian flu vaccine for humans that is being held in the national stockpile in case it would be needed.

How can people avoid becoming infected with avian flu?

The most important prevention measure is to avoid direct contact with sick or dead wild birds, poultry and other animals, or anything that may have been contaminated by them.

Hunters who handle wild birds should dress game birds in the field when possible and wear appropriate protection including gloves, an N95 or surgical mask, and eye protection.

Backyard poultry and livestock owners should take measures to avoid avian flu infection in their animals following USDA guidelines. They should also follow good hand hygiene and wear appropriate protection when caring for their animals.

Visitors to livestock fairs and shows should follow good hand hygiene and wear appropriate protection when in close contact with animals or consider avoiding these events altogether.

Pet owners should avoid feeding unpasteurized milk or raw meat to their pets and should always wash their hands thoroughly after handling any pet food.

Is it safe to eat chicken and eggs?

It is safe to eat chicken and eggs if they are thoroughly cooked. Hands and surfaces that come in contact with raw chicken or eggs should be thoroughly cleaned.

Is it safe to consume raw milk?

Avian flu has been detected in unpasteurized (raw) milk. While there have been no cases of human avian flu directly linked to raw milk or raw milk products like soft cheese, ice cream and yogurt, they can still pose a risk for avian flu as well as other serious infections. Pasteurization is the safest way to kill bacteria and viruses like avian flu in milk.

Overall, how concerned should I be about avian flu?

The risk from avian flu to the general public at the point remains low, but public health and agricultural officials continue to monitor the situation. We will continue to provide updates as we learn more information.