A tragic first has emerged from Washington state, as an older adult has died following infection with the H5N5 subtype of avian influenza. This case marks what is believed to be the world’s first confirmed human fatality attributed to this specific H5N5 variant. While the news is sobering, health officials are emphasizing that the overall risk to the general public remains exceptionally low. Authorities are actively monitoring close contacts and reassuring the community that there is no evidence of human-to-human transmission.
Unprecedented Human Case: A Global First for H5N5
The deceased individual, a resident of Grays Harbor County, was an older adult who also had underlying health conditions. They had been hospitalized in King County since early November before their death. Out of respect for the family’s privacy, specific details regarding their name, gender, or precise age have not been publicly released. The H5N5 virus was initially identified by the University of Washington Medicine Clinical Virology Lab and subsequently confirmed by the Centers for Disease Control and Prevention (CDC). This official validation underscores the rare and significant nature of this case.
This incident is particularly notable because it represents the first recorded human infection with this specific H5N5 variant anywhere in the world. While other avian influenza strains, like H5N1, have caused human infections, this particular subtype’s emergence in a human is unprecedented. The discovery has prompted renewed vigilance among public health and agricultural agencies across the nation.
Understanding the H5N5 Threat: Why Public Risk Remains Low
Despite the severe outcome in this singular case, public health officials are steadfast in their assessment that the risk to the general population remains low. The Washington State Department of Health (DOH) has confirmed that no other individuals involved have tested positive for avian influenza following this incident. Public health teams are continuing to monitor anyone who had close contact with the patient for symptoms. This proactive surveillance ensures that any potential spread would be quickly identified and contained.
Crucially, there is currently no evidence of human-to-human transmission of this H5N5 virus. This observation aligns with previous findings from the Washington State Department of Health. The DOH noted that while H5 avian influenza cases were first reported in the state in October 2024, there has been no documented person-to-person spread of avian influenza in Washington state to date. The primary distinction between H5N5 and H5N1 lies in a specific protein. This protein is involved in the virus’s release from an infected cell and its subsequent spread to surrounding cells. However, H5N5 is not believed to pose a greater threat to human health than the H5N1 virus, which has been responsible for approximately 70 reported human infections in the U.S. during 2024 and 2025. Most of these H5N1 cases resulted in mild illnesses among dairy and poultry farm workers.
How Bird Flu Spreads: Protecting Yourself and Your Flock
Investigations into the likely source of the H5N5 infection revealed that the deceased individual maintained a backyard flock of mixed domestic birds. The Department of Health conducted environmental sampling of the flock’s habitat, confirming the presence of the avian influenza virus. This finding strongly suggests that direct exposure to these domestic poultry, their contaminated environment, or potentially wild birds, was the most probable pathway for the human infection. Avian influenza, caused by influenza type A viruses, naturally circulates among wild aquatic birds. It can infect other bird species and various mammals. Birds and other animals infected with avian influenza shed the virus in their saliva, mucous, and feces, making these common routes of environmental transmission. While the virus can be lethal to domestic birds, human infections are rare.
Essential Public Health Guidelines and Prevention
In light of this significant case, public health and agriculture agencies have issued several important recommendations to minimize risk and ensure public safety:
For Backyard Poultry Owners in Washington: The State Department of Agriculture advises avoiding contact with sick or dead birds. Owners should promptly report any illnesses or unexplained deaths in their flocks.
For Veterinarians: All veterinarians are urged to report any suspected cases of avian influenza in domestic animals or livestock.
For the General Public: Avoid handling sick or dead wildlife. Report such sightings to the Washington State Department of Fish & Wildlife. Oregon residents should contact the Oregon Health Authority Influenza Team or email them to report potential cases.
Food Safety Practices: Always avoid the consumption of raw or undercooked food products, especially poultry and eggs. Ensure all food is cooked to safe internal temperatures. Pet owners should also prevent their pets from coming into contact with dead wildlife.
Seasonal Flu Vaccine Recommendation: Health officials recommend that individuals with potential exposure to domestic or wild birds receive a seasonal flu vaccine. While the seasonal vaccine does not directly prevent bird flu, it significantly reduces the risk of simultaneous infection with both human and avian influenza viruses. Such a co-infection could potentially lead to the emergence of a more transmissible hybrid virus. The seasonal flu vaccine is broadly recommended for everyone aged six months and older.
Broader Context: Ongoing Avian Influenza Surveillance
The emergence of H5N5 in a human is part of a larger, ongoing concern regarding avian influenza. Bird flu has been detected in various bird populations since January 2022. Its reach expanded in March of the previous year when it was first identified in dairy cows. The virus is known to infect a wide range of animals, including birds, pigs, cattle, and cats. Human infection typically occurs through close, direct contact with infected animals, which explains why farm workers and backyard poultry owners are identified as higher-risk groups for contracting the virus. This tragic case underscores the critical importance of continuous surveillance, rapid response, and public education efforts in managing avian influenza threats globally.
Frequently Asked Questions
What makes the Washington H5N5 case unique, and how does this variant compare to H5N1?
The Washington state case is unique because it represents the first recorded human infection with this specific H5N5 variant* globally, leading to a fatality. While H5N1 has caused more human infections (over 70 in the U.S. in 2024-2025, mostly mild), H5N5 is generally not considered a greater threat to human health. The primary biological distinction between H5N5 and H5N1 lies in a specific protein that aids the virus’s release and spread within cells. Public health officials emphasize that despite the unique H5N5 case, the risk of human-to-human transmission remains low.
What specific precautions should backyard poultry owners and the public take to avoid H5N5 bird flu?
Backyard poultry owners in Washington should avoid contact with sick or dead birds and report any illnesses in their flocks to the State Department of Agriculture. The general public should avoid handling sick or dead wildlife and report sightings to the Washington State Department of Fish & Wildlife. It is also crucial to practice strict food safety, ensuring all poultry and eggs are thoroughly cooked. Additionally, consider getting a seasonal flu vaccine, which helps prevent co-infection with human and avian flu viruses, reducing the risk of a new hybrid strain.
Is it safe to consume poultry or dairy products, and should I get a seasonal flu shot to protect against bird flu?
Yes, it is generally safe to consume poultry and dairy products as long as they are properly handled and cooked. Health officials recommend avoiding raw or undercooked food products. The risk of contracting bird flu from thoroughly cooked food is negligible. Regarding the flu shot, health officials highly recommend getting a seasonal flu vaccine for individuals with potential bird exposure and the general public. While it doesn’t directly prevent bird flu, it helps prevent co-infection with human and avian flu, which could otherwise lead to the emergence of a more dangerous, transmissible hybrid virus.
Conclusion
The first human death from an H5N5 avian influenza variant in Washington state serves as a stark reminder of the ongoing threat posed by zoonotic diseases. While this event is unprecedented, health authorities are working diligently to contain any potential spread and reassure the public. The consistent message is clear: the overall risk to the general public remains low, and there is no evidence of human-to-human transmission. By staying informed, following public health guidelines, practicing good hygiene, and taking recommended precautions—especially for those in contact with poultry or wildlife—we can collectively mitigate risks and protect our communities. Your vigilance and adherence to health advice are crucial in these evolving circumstances.
