12/18/25 Health Update: Guidance for Clinical Consideration of Avian Influenza

This is a Provider Update from the Washington State Department of Health (WA DOH) with
updated guidance about clinical consideration of, and testing for, avian influenza.

Current Situation

In November of this year, WA DOH confirmed the first known human case of H5N5 influenza.
The patient was hospitalized with severe disease that unfortunately resulted in death. This
Provider Update is a follow-up to our November 18, 2025 Provider Alert about the H5N5 case;
With this message, WA DOH is providing updated exposure screening questions, testing
strategies, and clarification about our influenza subtyping guidance.


The Centers for Disease Control and Prevention (CDC) and WA DOH currently consider the
risk from highly pathogenic avian influenza (HPAI) to be low for the general public. As
seasonal influenza activity increases in Washington and across the United States, the greatest
risk to the general public is seasonal influenza, and the best protection remains seasonal
influenza vaccination.

Actions Requested

IDENTIFY

  • Be alert for patients with influenza-like-illness (ILI).
    • Symptoms of avian influenza in humans can range from mild to severe and can be
      similar to seasonal influenza viruses.
    • Getting an accurate exposure history from symptomatic patients is important to
      rapidly identify patients with suspected avian influenza.
  • Assess ALL patients with ILI for epidemiologic risk factors for avian influenza. Ask
    patients if they have had exposure to any of the following in the 10 days before symptom onset:
    • Close contact with sick or dead animals or their environments, especially birds, wildlife,
      livestock, or domestic cats, OR
    • Consumption or handling of raw animal products or animal parts from potentially infected
      animals (e.g., raw cow milk, products made with raw cow milk, and raw meat-based pet
      food), OR
    • Close contact (within six feet) of a person who is suspected or confirmed to have avian
      influenza.
  • WA DOH suggests that healthcare systems add the following screening questions for
    patients with ILI (at minimum, for Emergency Departments and hospital inpatient settings):
    • In the 10 days before symptom onset, have you had
      • Close contact with sick or dead animals, or their environments, including
        birds, wildlife, livestock (e.g., cows, pigs, or poultry), or domestic cats
      • Contact (within 6 feet) with a person who is suspected or confirmed to
        have avian influenza, also called bird flu.
    • “Yes” response to either of these questions should trigger patient isolation and
      notification to the Local Health Jurisdiction (see below).

ISOLATE

  • Isolate patients with suspected or confirmed avian influenza in ALL healthcare settings:
    • Use contact, droplet, and airborne precautions with eye protection (goggles or face
      shield).
    • If possible, isolate the patient in an airborne infection isolation room (AIIR; negative
      pressure room).
    • If the patient is intubated, ensure a closed system and HEPA filter.

INFORM

  • As soon as a provider suspects that a patient could have avian influenza, IMMEDIATELY
    contact
    the Local Health Jurisdiction (LHJ) or Tribal Health Jurisdiction. The following are
    notifiable to public health:
    • All influenza A specimens that result as “unsubtypeable” (when the subtype of
      influenza cannot be determined by available tests).
    • All suspected or confirmed cases of novel influenza, including avian influenza
      (influenza A H5 or others), regardless of influenza test results.

TEST

  • Collect specimens from suspect avian influenza patients within 24 hours of presentation to the
    healthcare facility, and ideally within 7 days of symptom onset.
    • Notify the LHJ before testing.
  • Testing is available at the WA DOH Public Health Laboratories (PHL).
    • Avian influenza testing is available at PHL with prior arrangement from the LHJ.
    • Requests for influenza subtyping can be sent directly to PHL (no prior arrangement
      needed) for the following specimen types:
      • All unsubtypeable influenza specimens
      • Specimens from hospitalized patients when subtyping is not available
    • When submitting to PHL, follow PHL influenza specimen submission guidelines.
  • ED/INPATIENT SETTINGS: Test ALL patients with ILI AND epidemiologic risk factors for
    influenza
    .
    • A negative influenza result should not rule out avian influenza in hospitalized
      patients with ILI and epidemiologic risk factors
      .
      • Avian influenza should remain on the differential for hospitalized patients with
        epidemiologic risk factors.
      • Maintain isolation until consultation with public health has determined avian
        influenza to be an unlikely cause of illness or further testing has ruled out avian
        influenza.
      • Repeat influenza testing on at least two consecutive days for hospitalized
        patients unless an alternative diagnosis (e.g., COVID, RSV) is laboratory
        confirmed.
      • If the patient has severe respiratory disease, consider collecting lower
        respiratory tract specimens
        ; lower respiratory tract specimens may have a
        higher yield for detecting avian influenza.
    • Positive influenza A specimens from hospitalized patients with ILI AND
      epidemiologic risk factors should be subtyped
      (e.g., H1, H3, etc.).
      • Option 1: Subtyping at hospital’s clinical lab or a commercial lab:
        • If H1 or H3 subtyping has resulted no further subtyping is necessary.
        • Submit specimen to PHL if identified as H5 or unsubtypeable.
      • Option 2: Subtyping request sent to PHL:
        • Facilities who do not have subtyping capability should submit specimens
          to PHL after communication with the LHJ.
      • Subtyping is NOT being requested for ALL hospitalized patients.
      • Hospitals and labs participating in voluntary influenza subtyping surveillance
        should NOT deviate from established agreements, sentinel influenza surveillance
        network and RESP-NET (Benton, Clark, Franklin, King, Pierce, Snohomish,
        Spokane, and Yakima).
  • OUTPATIENT SETTINGS: Test ALL patients with ILI AND epidemiologic risk factors for
    influenza.
    • Positive influenza A specimens should be subtyped.
      • If subtyping is not available through your facility, specimens can be sent to PHL
        for subtyping after discussion with the LHJ.
    • A negative influenza A PCR in an outpatient setting may not rule out avian influenza.
      • Notify the LHJ to determine if additional testing should be conducted at PHL.
      • If the patient returns with increased severity, influenza testing should be
        repeated.

MANAGE

  • Treat suspected avian influenza patients immediately with oseltamivir, do not wait for
    influenza confirmation
    .
    • Consider combination antiviral treatment (e.g., oseltamivir and baloxavir) for hospitalized
      patients with suspected or confirmed avian influenza.
    • Refer to CDC’s Interim Guidance on the Use of Antiviral Medications for additional
      information about treating patients with suspected or confirmed avian influenza.

ADVISE

  • Advise patients not to handle sick or dead birds or other wildlife. Instead:
  • WA DOH continues to recommend seasonal influenza vaccine for patients 6 months of
    age and older.
    • Yearly flu vaccination is the best way to reduce severe disease and hospitalization.
    • While the seasonal influenza vaccine may not protect against avian influenza, it may
      prevent patients from getting infected with both strains of influenza at the same time.

Background

Avian influenza is a disease caused by influenza type A viruses, which naturally occur in wild aquatic
birds around the world. On rare occasions, avian influenza can infect people and make them sick. Most
cases have occurred among people who have been exposed to sick or infected animals. The risk of
avian influenza increases in the fall and winter because migratory birds can carry the virus and spread
it to domestic animals including commercial poultry, dairy farms, and backyard flocks.

Transmission of avian influenza between humans is extremely rare and has not 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 and provide
testing and treatment as needed.

CDC has routinely recommended influenza testing for hospitalized patients with suspected influenza. In
light of the continued circulation of HPAI (highly pathogenic avian influenza) A(H5) virus among wild
and domestic animals in Washington state, CDC and WA DOH recommend subtyping of all influenza A
virus-positive specimens from hospitalized patients with ILI and epidemiologic risk factors.

The CDC considers the risk of avian influenza infections to be low for the general public but is closely
monitoring the situation. As seasonal influenza activity increases in Washington and across the United
States, the greatest risk to the general public is seasonal influenza. WA DOH publishes a Weekly
Influenza Update for seasonal influenza on our Influenza Surveillance Data webpage.

Resources

Contact

Contact Whatcom County Health and Community Services at 360-778-6100
  • 360-778-6100 Main Call Line – available M-F 8:30am to 4:30pm.
    • Afterhours Answering Service – available after 4:30pm and weekends, call 360-778-6100 and press 2 to be connected to the on-call manager or health officer.
  • 360-778-6150 Communicable Disease Report Line – 24 hours a day 7 days a week
  • 360-778-6103 Confidential Communicable Disease Fax – 24 hours a day 7 days a week
  • 509 Girard Street, Bellingham WA 98225