H5 bird flu, a type of bird flu, has infected dozens of people in the U.S. and spread to seven states and Canada this year. As more human cases emerge, concerns are growing about whether the virus could lead to another pandemic or lockdown.

Oregon announced its first human case last week, with health officials describing the illness as mild.

The patient, who has fully recovered, is linked to a previously reported outbreak in birds at a commercial poultry farm, the Oregon Health Authority announced Friday.

But a teenager in Canada with no ties to a farm was in critical condition and was being treated for acute respiratory distress at a children’s hospital in British Columbia after testing positive for H5N1 bird flu, that country’s first human case, the reported. CBC last week. .

The patient — whose gender, age and identity have not been released — “was previously a healthy teenager” with no underlying conditions, the province’s health officer, Dr. Bonnie Henry, said at a news conference.

After symptoms started in early November, the youngster’s decline was “pretty rapid,” Henry said.

“It’s a reminder that in young people this is a virus that can evolve and cause quite serious illness,” she noted.

The teen had not been exposed to birds or other farm animals, but had been around dogs, cats and reptiles, she added. The source of contamination is being investigated.

Tests confirmed the patient had H5N1, the Public Health Agency of Canada announced, the strain that infects birds, poultry, mammals and humans.

Could bird flu cause the next pandemic? Here’s what you need to know:

What is bird flu?

Like humans, birds can get the flu, and the bird flu viruses that make birds sick can sometimes infect other animals, such as cows and, rarely, humans, the National Library of Medicine explains.

H5 is a family of bird flu viruses. It has caused widespread flu among wild birds worldwide and is causing outbreaks in poultry and American dairy cows, according to the Centers for Disease Control and Prevention. Some farm workers exposed to these animals have also become ill.

H5 has nine subtypes, including H5N1, the strain responsible for the recent diseases.

Is there an outbreak of bird flu?

According to the CDC, there have been 52 confirmed human cases in the US during the 2024 outbreak. They were reported in California, Colorado, Michigan, Missouri, Oregon, Texas and Washington state.

“We do have an outbreak of human infections with H5N1,” said Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security and spokesperson for the Infectious Diseases Society of America.

Almost all patients had contact with infected livestock or poultry. The one exception – a patient in Missouri – had no known exposure to animals. There is no confirmed person-to-person spread.

The current public health risk from H5 bird flu is low, the CDC says. The flu monitoring systems currently show no signs of unusual flu activity in humans, including the H5N1 virus, or any unusual flu-related trends in emergency room visits.

But the agency is “carefully monitoring” the situation – as are experts in the field.

Dr. Ian Lipkin, an expert on emerging viral threats, calls it a major health problem.

“Emerging infectious diseases are unpredictable. If you had told me 20 years ago that we were going to have big problems with coronaviruses, I wouldn’t have predicted it,” Lipkin, professor of epidemiology at the Columbia University Mailman School of Public Health, told TODAY.com.

“So no one knows what’s going to happen with this particular flu.”

Human infection with bird flu can happen when the virus gets into a person’s eyes, nose or mouth or is inhaled, the CDC said. The disease can range from mild to severe and can be fatal.

Human H5N1 cases in the US have been relatively mild, perhaps because people usually become infected through their eyes, Adalja notes.

It can happen, for example, when a dairy worker milks an infected cow and is sprayed in the face with the milk.

“You are more likely to become infected through the eyes than through the respiratory tract,” Adalja tells TODAY.com. That may be “less risky than respiratory inhalation” of the virus, he adds, while it can travel to the lungs.

Is bird flu a global public health emergency?

No, the World Health Organization does not currently categorize the bird flu outbreak as a global public health emergency. Outbreaks that do fall into this category include COVID-19, cholera, dengue, Marburg virus and MPox.

Can bird flu turn into a pandemic?

Experts say this is unlikely this a certain strain of bird flu would lead to a pandemic because it cannot spread efficiently among humans.

H5N1 has been infecting people since 1997, so it has had time to evolve, but still doesn’t jump easily from person to person, Adalja points out.

“I don’t think this is the highest risk strain of bird flu,” he says. “You can’t say the risk is zero. But the risk is lower with bird flu viruses.”

Lipkin had a similar opinion.

“No one ever wants to say ‘never’ because you could be wrong,” he warns. “Could this virus evolve to become more transmissible? Yes. Has that happened so far? No. Do I personally think this will be responsible for the next pandemic? No. Could that be so? Yes.”

In a worrying development, a pig in Oregon tested positive for H5N1 in October – the first time the virus has been detected in pigs in the US, NBC News reported.

It is worrying because pigs can become infected with both avian and human viruses at the same time, creating mutated strains.

“Pigs are considered a mixing vessel for flu viruses, so we are always concerned when a pig becomes infected with a strain of bird flu, because pigs can also be infected with other strains,” says Adalja.

“Those strains can all recombine in the pig like a mixing vessel and then something different comes out.”

Because there are many different types of bird flu, one of them could cause a pandemic at some point in the future, Adalja added.

The bird flu variant he is more concerned about as a pandemic risk is H7N9, which was first reported in people in China in 2013 and had expanded to more than 1,500 people by 2017. This virus also does not spread easily from person to person, but when people become infected, most become seriously ill, the World Health Organization warns.

According to the CDC, the most recent human H7N9 virus infection was reported in China in 2019.

Could there be a lockdown due to bird flu?

Again, this isn’t likely for this species, as H5N1 poses no threat to the general public, both experts say.

If that were to change, people would have to realize that lockdowns, like those during COVID-19, are not the “go-to measure” for an infectious disease emergency, Adalja says, calling them “very blunt instruments.”

Instead, proactive measures — such as more aggressive testing of farm animals — will allow health officials to be much more accurate when it comes to stopping the spread of infections, he notes.

When it comes to lockdowns, the question is also how far the authorities are willing to go.

“If H5N1 became a major health problem, we would have to talk about (containment),” Lipkin said.

“But I don’t think this new government will be amenable to that.”

What is the treatment for bird flu?

It is oseltamivir, also known as Tamiflu, the same antiviral drug used for common flu cases.

It’s important to start that drug as soon as possible after symptoms start so that it takes effect, Lipkin says. Some close contacts of people infected with H5N1 have also been given the drug as a precaution to prevent infection.

Is there a bird flu vaccine?

Four candidate vaccines for dairy cows have been approved for field trials, according to the U.S. Department of Agriculture.

Four potential bird flu vaccines were tested in poultry in 2023, Reuters reported.

When it comes to humans, the CDC says the U.S. government is developing vaccines against H5N1 viruses “just in case they are needed.”

The agency adds that it has H5 candidate vaccine viruses that could be used to produce a vaccine for humans, and preliminary analyzes show that “they are expected to provide good protection” against H5N1.

There are also some vaccines in the strategic national stockpile that closely – if not exactly – match this specific form of bird flu, Adalja says.

“There are efforts to create more updated vaccines. But there is currently no widespread vaccination program against H5N1 underway in the US,” he noted.

In the summer of 2024, Finland became the first country in the world to offer bird flu vaccinations to people at risk of exposure, including workers on fur and poultry farms.

Finland bought vaccines for 10,000 people, each requiring two shots, Reuters reported.

Symptoms and prevention of bird flu

The CDC lists the following bird flu symptoms:

• Redness of the eyes
• Mild flu-like symptoms of the upper respiratory tract
• Fever or feverish feeling
• Cough
• A sore throat
• Runny or stuffy nose
• Muscle or body pain
• Headache
• Fatigue
• Shortness of breath or difficulty breathing
• Pneumonia requiring hospitalization
• Diarrhoea, nausea, vomiting or seizures (these are less common symptoms).

The people most at risk from H5N1 bird flu are dairy and poultry workers who may be around infected animals, Adalja says. They should wear personal protective equipment while working on farms affected by the virus, the CDC advises.

When it comes to the general public, “absolutely do not consume raw milk,” as H5N1 is viable in it, Lipkin says. Pasteurized milk can eliminate the risk of infection, he notes.

Properly cooked chicken is safe to eat, but wash your hands with soap and water after handling raw chicken, he adds.

It may be wise to skip petting zoos or events where you can learn how to milk a cow, Adalja adds.

Avoid direct contact with sick or dead wild birds, poultry and other animals, the CDC advises.