Alerts:  Nov. 12, 2024: Pertussis (whooping cough) outbreak confirmed in Spokane County. SRHD urges parents and pregnant people to vaccinate. Read the press release.

Highly Pathogenic Avian Influenza Advisory for Health Care Providers

Assess patients with influenza-like illness for animal exposures this summer

Posted July 15, 2024. Past health advisories and alerts are archived for historical purposes and are not maintained or updated.

Current Situation

An ongoing global outbreak of highly pathogenic avian influenza (HPAI) in wild birds, with transmission to poultry and certain mammals, including dairy cattle, has resulted in four confirmed cases of HPAI in humans in the United States in 2024. To date, there have been no human cases of HPAI confirmed in Washington; however, clinicians should remain vigilant for patients presenting with potential symptoms of HPAI.

Clinicians in Washington are encouraged to consider HPAI infection in patients who present with influenza-like illness (ILI), and to assess patients presenting with ILI for animal exposures, including exposures to sick or dead wild birds or other wild animals, as well as exposure to cattle or pigs, or attendance at agricultural fairs this summer.

Actions Requested
  • Clinicians should consider highly pathogenic avian influenza (HPAI) H5N1 and other novel influenza virus infections in patients who present with influenza-like illness (ILI), including isolated conjunctivitis or symptoms of acute respiratory infection, and who have had recent close contact with animals known or suspected to have avian influenza A virus infection.
  • Specifically, ask patients seeking care for influenza-like illness about:
    • Exposure to cattle or pigs
    • Attendance at agricultural fairs or other livestock exhibitions
    • Consumption of unpasteurized dairy products
    • Exposure to sick or dead wildlife
    • Contact with birds or other animals with known or suspected avian influenza virus infection
  • Clinicians should consider testing for novel influenza for patients with ILI who endorse any of the above exposures in the past ten days and have no alternative diagnosis.
  • If novel influenza infection, including HPAI H5N1, is suspected, contact your local health jurisdiction immediately to help arrange sample collection and testing at the Washington State Public Health Laboratories (WA PHL). Your local health jurisdiction can provide guidance on collecting the below samples:
    • A nasopharyngeal swab collected in viral transport medium for testing at WA PHL
    • Patients with conjunctivitis should also have a conjunctival swab collected in viral transport medium for testing at WA PHL
  • Empiric antiviral treatment should be started as soon as possible for patients suspected to be infected with novel influenza A viruses as they have the potential to cause severe disease in humans. Your local health jurisdiction may be able to assist you in acquiring antiviral medications. For more information, see the Centers for Disease Control and Prevention‘s (CDC) interim guidance on the use of antiviral medications for treatment of human infections with novel influenza A viruses associated with severe human disease.
Background

This outbreak of highly pathogenic avian influenza (HPAI) is a strain of influenza A (H5N1) which has been circulating globally in wild birds for several years; as the name suggests, HPAI infection has been deadly for many species of birds. Cases of HPAI in wild birds and poultry were first identified in Washington state in the spring of 2022. Since 2022, Washington state agencies have detected infections in commercial and backyard poultry flocks, as well as sporadic infections of wild mammals such as skunks, raccoons, and harbor seals.

Avian influenza viruses had not previously been known to infect cattle, but in March 2024, HPAI H5N1 infection was reported in dairy cattle in Texas. As of July 8, the HPAI H5N1 outbreak in dairy cattle has continued to spread, with outbreaks in dairy cattle now identified in 12 U.S. states. While outbreaks of HPAI H5N1 have NOT been identified in dairy cattle in Washington, infections have been identified in neighboring states, including at least 21 dairy operations in Idaho.

Four avian influenza A(H5N1) infections in dairy workers exposed to dairy cattle have been detected since March 2024: one in Texas, two in Michigan, and one in Colorado. Three infected workers had conjunctivitis as a sole symptom, and one had mild respiratory symptoms. According to the U.S. Centers for Disease Control and Prevention, the current risk to the general public is low. However, it is important to understand and prepare for possible avian influenza and novel influenza infections in humans, as infections can range in severity and certain occupations are at increased risk of exposure to infected animals.

As the multistate outbreak of avian influenza A (H5N1) in dairy cattle, poultry and other animals continues and fair season begins, monitoring for novel influenza A virus infections in humans is critical to identify transmission of these viruses between animals and people. Rapid detection of, and treatment for, novel influenza A viruses and efforts to reduce transmission to other people remain important components of national efforts to prevent the emergence of new viruses that could have pandemic potential. To accomplish this, testing for influenza viruses and monitoring for novel influenza A virus infections should continue year-round.

Resources

To report suspected cases, or for any other questions, please contact:

Spokane Regional Health District
Reporting Line: 509.324.1449
General Questions: 509.324.1442
Secure email: CDEpi@srhd.org
Fax: 509.324.3623