#18,956
Overnight the Washington State Department of Health published their first update in a week on the nation's first human H5N5 infection, originally reported on November 13th. Sadly, this patient has died.
While the subtype is different (H5N1 vs H5N5), this case shares similarities with the nation's only other HPAI H5-related fatality; an older Louisiana man who was also likely exposed via a backyard flock, who experienced severe illness and died in early January.
While all of the (n=41) confirmed human infections with the `bovine' B3.13 genotype have been mild, a substantial percentage of the 30+ other cases reported in the country have presented with more severe symptoms; including 2 fatalities.
First the statement from the WA DOH, which - while reassuring - disappointingly provides few details on the state's epidemiological investigation.
Grays Harbor County resident dies from complications of avian influenza
For immediate release: Nov. 21, 2025 (25-140)
Contact: DOH Communications
The person was infected with the H5N5 virus; the risk to the public remains low
OLYMPIA – A Grays Harbor County resident who was undergoing treatment for H5N5 avian influenza died today. The Washington State Department of Health offers its heartfelt condolences to the person’s family and friends.
The person was an older adult with underlying health conditions. Out of respect for the family’s privacy, we are not releasing their name, gender, or age. The person had been hospitalized in King County since early November.
Testing at the UW Medicine Clinical Virology Lab identified the virus as H5N5, making this the first recorded infection with this variant in a person globally. The result was confirmed by the Centers for Disease Control and Prevention (CDC).
The risk to the public remains low. No other people involved have tested positive for avian influenza. Public health officials will continue to monitor anyone who was in close contact with the patient for symptoms to ensure that human-to-human spread has not occurred. There is no evidence of transmission of this virus between people.
The person had a backyard flock of mixed domestic birds. DOH testing identified avian influenza virus in the environment of the flock, making exposure to the domestic poultry, their environment, or wild birds the most likely source of exposure for this patient. People who had exposure to the backyard flock and environment are also being monitored for symptoms.
Avian influenza is a disease caused by influenza type A viruses, which naturally occur in wild aquatic birds around the world. These viruses can infect other bird species, and occasionally mammals, and can be deadly to domestic birds such as chickens and turkeys. On rare occasions, avian influenza viruses can infect people and make them sick.
People with backyard poultry should avoid contact with sick or dead birds and report illness in poultry to the Washington State Department of Agriculture (WSDA) by calling 1-800-606-3056 or reporting online. Veterinarians should report sick or dead domestic animals or livestock suspected of having avian influenza to WSDA. Avoid contact with sick or dead wildlife and report sick or dead wild birds or other animals to the Washington State Department of Fish & Wildlife. Never handle or allow pets near dead birds or other wildlife.
Avoid eating raw or undercooked food products, such as unpasteurized (raw) milk or raw cheeses, and don’t feed these products to pets.
It is especially important that people who may have exposure to domestic or wild birds get a seasonal flu vaccine. While the seasonal flu vaccine will not prevent bird flu infection, it reduces the risk of becoming sick with both human and avian influenza viruses at the same time. Though unlikely, infection with both viruses could result in the emergence of an avian influenza virus that is more easily transmitted from person to person. Seasonal flu vaccine is recommended for everyone six months and older.
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As has become increasingly common, we've seen very little in the way of actual details on this HPAI case. While public health officials often redact patient information over `privacy concerns', statements like `DOH testing identified avian influenza virus in the environment of the flock' seem unnecessarily vague.
They don't specify what subtype was detected (was it H5N5, H5N1, etc.), and they aren't even clear on whether these birds were infected, or if any were symptomatic or had recently died.
Unfortunately, the USDA's Confirmations of Highly Pathogenic Avian Influenza in Commercial and Backyard Flocks dashboard doesn't help, as it doesn't identify the subtype of any of the 1,873 flocks infected in the U.S. since 2022.
While it is reassuring when the DOH states that `No other people involved have tested positive for avian influenza.', that leaves a lot of unanswered questions.
How many `contacts' have actually been tested? What criteria was used for determining a close contact? Have any `contacts' declined testing? How long after exposure were these tests conducted? How many tests are pending? Are there plans for serological follow-ups?
While I've little doubt that the local health department is being diligent in their epidemiological investigation - given the stakes - it would be nice to have more specifics.
Hopefully, we'll get a more detailed account in an MMWR field report down the road.
Stay tuned.
