Health officials say a person in Washington state has tested positive for a new form of the avian influenza virus.
The H5N5 virus has never been observed in humans before. It first appeared in 2023 in birds and mammals in eastern Canada. The strain was confirmed by the Washington State Department of Health on Friday.
“Given the rarity of such infections in humans and the fact that this person was hospitalized, there is an urgent need to understand how this person may have come into contact with the virus and whether anyone else was infected,” said Jennifer Nuzzo, director of the Brown University Pandemic Center in Providence, Rhode Island.
Epidemiologists and virologists are concerned that bird flu could cause a pandemic if allowed to spread and mutate. For example, the H5N1 virus circulating among dairy cattle in North America. one mutation left from the ability to easily spread between people.
“Whenever someone becomes infected with a new influenza virus, we want to gather as much information as possible to make sure that the virus has not acquired the ability to become more easily infected and spread between people, which could cause a pandemic,” Nuzzo said.
The case involves a man who lives in Grays Harbor County on the Olympic Peninsula. Their illness became so severe that they were transferred to a hospital in more populous Thurston County and then to King County, where Seattle is located.
Melissa Dibble, a spokeswoman for the US Centers for Disease Control and Prevention, confirmed the Washington Department of Health's findings and said the patient had a flock of “mixed poultry” in his backyard.
“The most likely source of the virus is poultry or wild birds,” she said in an email.
According to press release The person is “older” and has underlying health conditions, according to county health officials. Their symptoms included high fever, confusion and difficulty breathing. The man has been in the hospital since early November.
“The fact that the patient suffered severe illness due to this infection only reinforces the need to learn more about this particular case,” Nuzzo said.
Henry Nieman, an evolutionary molecular biologist and founder of Recombinomics Inc., a virus and vaccine research company in Pittsburgh, said other animals and birds in Canada have also been infected, including a red fox, a cat and a raccoon.
According to study published last year As for the new strain, some infected animals had a key mutation in the virus that allows it to be more easily transmitted from one mammal to another.
Every time a bird flu virus infects a person, fears grow that it could change, become more contagious or more deadly. For example, if a sick person has another influenza virus replicating in their body, there is concern that the viruses may be exchanging genetic material. Simply by being able to reproduce and evolve millions of times in the human body, it can acquire deadly mutations.
Virus samples taken from seriously ill teenager in CanadaFor example, they showed that the virus acquired genes that allowed it to more easily infect human cells and cause severe diseases.
Richard Webby, a flu expert at St. Jude Children's Research Hospital in Memphis, Tennessee, said the new virus is “interesting” but he's not too worried about it yet.
“There is no reason to expect an increased risk,” he said.
But Niemann, the molecular biologist, said the fact that the disease is a severe clinical event in the first person infected with it should be cause for concern.
“I think it’s a big deal,” he said.
Dibble, the CDC spokeswoman, said they are investigating the case with the Washington Department of Health and say the risk of bird flu to the public remains low. However, the CDC urges caution among people who work or have recreational contact with infected birds, cattle, or other potentially infected domestic or wild animals. They should wear gloves, masks and eye protection.
They also recommend that people (and their pets) avoid raw or undercooked meats and eggs, as well as raw milk and cheeses.
