9 Frequently Asked Questions Answered by Health Experts

As its name suggests, bird flu is another variant of the flu virus that commonly infects birds.

“The influenza virus is capable of infecting multiple species, so not just humans, but also birds and other mammals,” says Sharon Nachman, the head of the pediatric infectious disease division at Stony Brook Children’s Hospital. “Each time it infects another species, there’s a chance it will change some of its outer proteins, rendering protective antibodies from a previous infection worthless.”

Current concerns center on a strain of bird flu known as H5N1. According to the CDCthe first case of H5N1 was detected in domestic waterfowl in 1996 in southern China.

“H5N1 is named because of the surface proteins present on the virus and is a type of bird flu,” says Jason Zucker, MDinfectious disease specialist at NewYork-Presbyterian/Columbia University Irving Medical Center.

Yes, Nachman says bird flu can spread to mammals, including humans. Between 1996-97, 860 people have been infected with the virus, with outbreaks occurring in China and Hong Kong.

Yet, you may never have heard of this virus. There is a reason for this.

“Bird flu rarely spreads to humans,” says Zucker. “When it does, it mainly occurs through close contact with an infected animal. Although human-to-human transmission is reported, it is rare and most often occurs with people living in the same household.

Zucker says the infection is spread from an animal, usually a bird, to a human by:

• saliva
• stool
• nasal secretions

“The reported symptoms resemble those of the common flu, and just like the flu, we know they range from mild illness…to more severe illness,” Zucker says.

Common symptoms of bird flu can include:

• cough
• fever
• sore throat
• muscle aches
• headache
• difficulty breathing

Experts say it’s not clear.

“[When H5N1 was first discovreed]scientists feared it would cause a flu pandemic,” says Jay Varma, MD, Kroll’s Chief Medical Advisor, Fellow of the Kroll Institute and Director of the Weil Cornell Center for Pandemic Prevention and Response. “Since then it has mainly circulated among birds and occasionally infected mammals – everything from tigers to foxes to seals – and relatively small numbers of humans.”

But one recent report noted an outbreak of H5N1 in farmed mink in Spain in October. A preprint that has not been peer-reviewed reported a potential summer 2021 outbreak in seals in New England.

What’s different now?

“Scientists believe it mainly spreads to different parts of the world and to different animals when birds fly long distances and come into contact with other animals or birds are eaten by animals,” Varma says. “But they still don’t understand all of the factors, from the virus itself to environmental conditions, that determine how this virus spreads.”

This is something that experts are watching closely but still don’t know. According to the CDC, the H5N1 epidemic in 1996-97 had a mortality rate of more than 50%. But that doesn’t mean the virus will have the same effect more than two decades later.

“It’s too early to tell how deadly any specific flu virus variant will be,” Nachman says. “Usually this virus has seasons where it derives serotypes and rarer seasons where it changes serotypes. A drift means there is a small change from year to year, so if you had the flu last year you are less likely to get very sick when you see the drift variant this year.

The caveat: ‘If it’s a staggered virus, you’re less likely to have antibodies that will help protect you, and therefore you’ll be more likely to get sick,’ says Nachman .

In other words, officials are still not sure.

You may have been hoping that we were at the end of “sickness season”. Now the news of bird flu is worrying. Nachman uttered a familiar refrain in response to questions about the seasonality of bird flu.

“It’s a matter of waiting and seeing what comes around, then following the science,” Nachman says.

Varma agrees, adding, “Because there are northern and southern hemispheres that experience opposite seasons, there is always a possibility that bird flu is circulating somewhere in the world.”

Zucker notes that there is was not a confirmed case of bird flu in humans in 2023. But outbreaks in mink and potentially other animals like seals marked the first major outbreaks of H5N1 “driven by mammal-to-mammal transmission,” according to a JAMA report. released on Monday. The authors noted “renewed concerns that H5N1…may be on the verge of spreading to humans.”

“This is a large outbreak, affecting multiple species, and we are seeing confirmed mammal-to-mammal transmission in animals like mink, bringing it closer to humans,” says Zucker.

It is fear. Is it possible? Maybe, but it’s still too early to tell.

“This will require careful monitoring, and we don’t know if or how it will affect humans, but it’s important to remain vigilant,” Zucker said.

To reduce the risk of you or an animal catching bird flu, the CDC recommended :

• avoid direct contact with wild animals, including those that appear ill or ill
• policies on handling dead birds vary by state and locality. If local authorities ask you to dispose of a carcass in the trash, put on gloves or a returned plastic bag
• get vaccinated against the seasonal flu

“And, as always, good hand hygiene is important,” says Zucker.