Washington State Confirms Human Avian Flu Infection - Flu Screening Guidance

[Michael Coston]

Washington State Confirms Human Avian Flu Infection​

#19,376


A week ago Washington state confirmed their first detection of avian influenza in dairy cattle, and overnight it was announced by the Yakima County Health District that a local resident who was exposed to infected dairy cows has tested positive for the virus.

There is still a lot we don't know about this case, hopefully the CDC will provide more details later today in their weekly FluView.

The full press release follows. I'll update this report as more information becomes available.

Yakima County Resident Tests Positive for Avian Influenza

We Are Public Health

Media Release

For immediate release: October 15, 2026

Contact: Stephanie Ruiz, Communications Specialist (509) 941-7364

Yakima County Resident Tests Positive for Avian Influenza

Yakima, WA- The Yakima Health District (YHD), in coordination with the Washington State Department of Health (DOH), is reporting a confirmed case of avian influenza in a Yakima County resident who was exposed to infected dairy cattle at a Yakima County dairy. The resident has not experienced severe illness or been hospitalized. The individual is isolating at home.

The risk of avian influenza infection to the general public remains low. People at greater risk include dairy workers and others who have close or prolonged contact with infected animals or environments contaminated with the virus. Transmission of avian influenza between humans is extremely rare and has never been documented in the United States. To ensure that human-to-human spread is not occurring, public health officials are contacting anyone who has been in close contact with the patient to monitor for symptoms.

Since the initial detection of Highly Pathogenic Avian Influenza (HPAI) H5N1 in Yakima County, YHD has been in contact with the impacted dairies to protect the health of people who may be exposed to infected cattle.

YHD continues to coordinate with state and federal public health partners to provide guidance and resources to help protect exposed individuals. This includes providing tests for exposed individuals who develop symptoms to support prompt diagnosis and appropriate medical care. YHD is working with partners to connect affected dairies with appropriate personal protective equipment (PPE) for their workers.
About Avian Influenza

Avian influenza, commonly called bird flu, is caused by influenza viruses that primarily circulate among wild birds but can also infect other animals, including poultry and dairy cattle. On rare occasions, these viruses infect people and cause illness.

Most human infections with avian influenza have occurred following close or prolonged contact with infected animals or environments contaminated with the virus. People can become infected when virus enters their eyes, nose, or mouth. The severity of illness can range from mild to serious and potentially life-threatening.

Public Health Recommendations

The risk of avian influenza infection to the general public is low. However, people who work with or have contact with potentially infected animals are at higher risk and should follow workplace safety guidance and use recommended personal protective equipment. Residents should avoid touching sick or dead animals, animal waste, and surfaces that may be contaminated.

Pasteurized milk and dairy products remain safe to consume. Pasteurization inactivates avian influenza virus and other harmful pathogens. People should avoid raw milk and unpasteurized dairy products because they may contain harmful germs, including avian influenza. Do not feed pets raw milk, unpasteurized dairy products, or raw meat, including raw pet foods.

It is especially important that people who may have exposure to sick animals 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. Seasonal flu vaccine is recommended for everyone six months and older.

Symptoms of avian influenza in people can include eye redness or irritation, fever or feeling feverish, cough, sore throat, runny or stuffy nose, muscle or body aches, headache, and fatigue. More severe illness can occur.

If you work on a dairy farm and develop symptoms after potential exposure to infected cattle, contact your healthcare provider or the Yakima Health District at (509) 249-6541.
Reporting Sick or Dead Animals

Domestic Birds:Report sick/dead domestic birds using the online form, or call the Washington State Department of Agriculture’s Avian Health Program: 1-800-606-3056. Visit Avian Influenza | Washington State Department of Agriculture for more information about how to protect backyard flocks.

Wild Birds:Use an online form to report sick/dead wild birds suspected of avian influenza to the Washington Department of Fish & Wildlife.

Livestock: To report sick livestock, isolate affected animals and contact your veterinarian and WSDA at 360-902-1878 or email ahealth@agr.wa.gov.

Quote

“We are working closely with our public health partners to follow up with people who have been in close contact with this individual. We want to make sure they know what symptoms to watch for and can access testing and treatment if needed.” -Dr. Dave Atteberry, Health Officer, Yakima Health District

https://afludiary.blogspot.com/2026/10/washington-state-confirms-human-avian.html

 

[sharon sanders]

Please see:

US - Humans with full or partial test positive H5N1/H5N5 results list (CDC + states + seropositive + assay positive)

 

[Michael Coston]

Washington State Confirms 3rd Dairy Herd Infected With H5N1​

#19,377

Since 2024 Washington State has seen scores of HPAI outbreaks in poultry, and more than a dozen confirmed and probable human infections related to exposure to poultry and/or wild birds.

Eight days ago (Oct 9th), however, their WSDA confirmed their first detection of avian influenza in dairy cattle (herds=2).

Yesterday, Washington State reported their first (reportedly mild) human infection with H5N1 derived from an (unspecified) dairy exposure.


Details on this latest case remain scant, and yesterday's CDC FluView Report (wk 40) did not include this case, reporting:

Novel Influenza A Virus Infections

No new confirmed human infections with a novel influenza virus were reported to CDC as of October 14, 2026.

The CDC's A(H5) Bird Flu: Current Situation webpage was updated on the 15th, showing the latest dairy-associated case (see below). Presumably we'll get an update in next week's FluView.




In the meantime, the USDA has added a 3rd dairy herd from Washington State to their HPAI positive list. Other than the one-line entry (below), I've seen no other information on this outbreak.





Thus far, the genotype of the virus infecting Washington Cattle (likely either B3.13 or D1.1) - and the recent human case - have not been announced, nor do we know exactly what kind of exposure the recent human case had.


For more than 2 years the CDC, the USDA, and state agricultural agencies have urged the use of PPEs for farm workers, and anyone else who might be exposed to infected livestock or birds.




While recommended, the use of PPEs has been suboptimal, particularly on farms and ranches. They can be hot, cumbersome to wear, and difficult to don and doff properly. (see MMWR: PPE Use by Dairy Farmworkers Exposed to Cows Infected with HPAI A(H5N1) Viruses — Colorado, 2024).

Over the past 30 days the number of infected backyard flocks vs. commercial flocks has run nearly 2 to 1, and over the course of the past 4+ years the number of backyard flock (n=1227) outbreaks have exceeded commercial outbreaks (n=1048).

Although the risks of infection are believed low, we've already seen at least two fatalities (here, and here) in the United States from H5Nx following `. . . exposure to a combination of a non-commercial backyard flock and wild birds.'

The APPA estimates `Eleven (11) million U.S. households own backyard chickens (a 28% increase from 2023)', yet a recent survey (see MMWR: Knowledge, Attitudes, and Practices Regarding Avian Influenza Among Owners of Backyard Flocks) found significant gaps in their knowledge of dealing with avian flu.

Although it is too early to predict what kind of avian flu season we will see this fall and winter - or whether any new genotypes will be added to the mix - we are already seeing signs of increased activity.

Which means, if you raise backyard birds, frequent live markets, or have outdoor pets, now would be a good time to familiarize yourselves with the risks of avian flu, and the things you can do to reduce those risks to you and your families.

UF/IFAS Extension: What Backyard Flock Owners Need to Know about Bird Flu (Influenza H5N1)

CDC Guidance on Bird Flu in Pets and Other Animals

https://afludiary.blogspot.com/2026/10/washington-state-confirms-3rd-dairy.html

 

[Michael Coston]

Washington State: Updated guidance for novel influenza screening and influenza subtyping​

MMWR: Fatal Human Case of HPAI A(H5N5) in a Backyard Flock Owner
— Washington, November 2025
#19,381

In November of 2025, Washington State reported the first known human infection with avian H5N5; a diagnosis that was delayed - according to an MMWR report - by repeated `early and repeated negative influenza test results from upper respiratory swab specimens'.

As we've previously discussed, it takes a certain amount of luck for novel flu infections to be detected, properly treated, and then reported to the CDC.

The problem being that standard rapid influenza tests don't distinguish between seasonal and novel flu strains, and sometimes, repeated swabs of the upper airway can fail to `capture' a deep lung infection for RT-PCR testing.

In the H5N5 case above, the patient died. In 2024, a Missouri patient was hospitalized with influenza A, and released, before being notified they had H5N1 (see Missouri DHSS: Human H5 bird flu case confirmed in Missouri). In both cases, numerous hospital workers (and others) were unknowingly exposed.

How many novel flu infections go undetected is unknown, although numerous studies suggest it happens more than we think (see JAMA Open: Asymptomatic Human Infections With Avian Influenza A(H5N1) Virus Confirmed by Molecular and Serologic Testing and MMWR: Serologic Evidence of Recent Infection with HPAI A(H5) Virus Among Dairy Workers).

No screening system can be expected to catch every case (and many mild cases simply won't seek medical care), but a standardized screening procedure can improve the chances.

Yesterday King County, Washington published updated guidance for screening for novel influenza, following last week's report of a dairy-exposure infection in Yakima county. This appears to be a condensed version of guidance published by the WA State Dept. of Health (Provider Alert: Testing and Subtyping for Avian Influenza) published on Oct 9th.

The emphasis here is on testing patients with ARI (Acute Respiratory Illness) with recent (past 10 days) epidemiologic risk factors (poultry/livestock exposure, raw dairy or animal products, known contact with a human case, etc.).

It should be noted that this criteria would not have targeted the BC teenager with H5N1, the Missouri case mentioned above, and several others whose source of exposure remains unknown.


Credit CDC
In early 2025, the CDC issued a HAN: Accelerated Subtyping of Influenza A in Hospitalized Patients, requesting that all hospitalized patients with suspected influenza be subtyped within 24 hours.

Today's guidance appears to back away from that, although the reason behind that isn't stated.

Based on the CDC's analysis of 72 human cases since 2024, however, it does appear that the vast majority of known cases had some kind of animal exposure.

I've reproduced the King County Guidance below, followed by a link to the WA State provider update. I'll have a postscript after the break.

October 20, 2026

Updated guidance for novel influenza screening and influenza subtyping

➜ This health advisory is also available in PDF format (223 KB)

Current situation

Highly pathogenic avian influenza (HPAI or bird flu) continues to circulate among wild birds and other animals in Washington. Although the risk to the general public remains low, clinicians should remain vigilant for possible avian influenza infections in patients with acute respiratory illness (ARI) and epidemiologic risk factors.

Guidance has changed for the 2026-27 influenza season, summarized below.

Actions requested

Identify

• Test all patients with ARI AND epidemiologic risk factors for influenza and obtain seasonal influenza subtyping for influenza A-positive specimens. Epidemiologic risk factors include the following within 10 days before symptom onset:

• • Close contact with sick or dead animals or their environments, especially birds, wildlife, livestock (including poultry), or domestic animals suspected of HPAI
  • Consumption or handling of raw animal products or parts from potentially infected animals (e.g., raw cow milk or products made with it, raw meat-based pet food)
  • Close contact (within 6 feet) to someone suspected or confirmed to have avian influenza
• Influenza A subtyping is NOT requested for patients without epidemiologic risk factors, including hospitalized patients. Note this is a change from previous recommendations.

Test

• Avian influenza testing is available at WA DOH Public Health Laboratories (PHL) with prior approval from Public Health.
• If seasonal influenza A subtyping is not available through a clinical or commercial lab, the following specimens may be submitted directly to PHL without pre-approval:

• All influenza A specimens that result as "unsubtypeable" (influenza A positive test but seasonal influenza A subtype was negative or not identifiable)
• Specimens from hospitalized patients with risk factors for avian influenza, when seasonal influenza subtyping is not available

Notify

• Immediately report suspected and confirmed cases of novel influenza to Public Health at 206-296-4774, including patients with ARI and identified epidemiologic risk factors. Do not wait for lab confirmation before notifying us. The following are immediately notifiable:

• All suspected novel influenza, including avian influenza (influenza A H5 or others); a negative influenza PCR does not rule out avian influenza
• All influenza A specimens that result as "unsubtypeable"

CONTACT

Communicable Diseases Epidemiology and Immunization Section

401 5th Ave, Suite 1250
Seattle, WA 98104

Phone: 206-296-4774
TTY Relay: 711

Fax: 206-296-4803

• Provider Alert: Testing and Subtyping for Avian Influenza, WA State Dept. of Health
• Influenza Virus Testing at the Washington State Public Health Laboratories (PHL) including Novel Influenza and Fatal Influenza
• Influenza Specimen Collection and submission Instructions, WA State Dept. of Health
• Influenza Specimen Collection, CDC
• A(H5) Bird Flu: Current Situation | Bird Flu, CDC

Three years ago, in UK Novel Flu Surveillance: Quantifying TTD, we looked at a UKHSA report that it would likely take between 3 and 10 weeks before community spread of a novel flu virus would become apparent to authorities, after anywhere between a few dozen to a few thousand community infections
In 2024 the ECDC issued guidance for member nations on Enhanced Influenza Surveillance to Detect Avian Influenza Virus Infections in the EU/EEA During the Inter-Seasonal Period., which cautioned:

Sentinel surveillance systems are important for the monitoring of respiratory viruses in the EU/EEA, but these systems are not designed and are not sufficiently sensitive to identify a newly emerging virus such as avian influenza in the general population early enough for the purpose of implementing control measures in a timely way.

A sobering reminder that, while we comfort ourselves with our current low number of human novel flu detections, we are probably missing some cases.


https://afludiary.blogspot.com/2026/10/washington-state-updated-guidance-for.html