A Grays Harbor County resident undergoing treatment for H5N5 avian influenza died Thursday, marking the first recorded human death from this particular variant of bird flu globally, the Washington State Department of Health announced.
The Washington State Department of Health expressed heartfelt condolences to the person’s family and friends following the death of the individual who had been hospitalized in King County since early November.
The deceased was an older adult with underlying health conditions that likely complicated their ability to fight the infection. Out of respect for the family’s privacy, health officials are not releasing the person’s name, gender, or specific age beyond characterising them as an older adult.
Testing conducted at the UW Medicine Clinical Virology Lab identified the virus as H5N5, making this the first recorded infection with this particular avian influenza variant in a human globally, a significant epidemiological development that health authorities are monitoring closely. The laboratory result was subsequently confirmed by the Centers for Disease Control and Prevention, providing verification of this unprecedented case.
Despite the death, the risk to the general public remains low, health officials emphasised. No other individuals who had contact with the deceased patient have tested positive for avian influenza during monitoring efforts. Public health officials will continue monitoring anyone who was in close contact with the patient for symptoms to ensure that human-to-human transmission has not occurred, the primary concern when avian influenza infects humans. There is no evidence of transmission of this virus between people, officials stated.
The deceased individual maintained a backyard flock of mixed domestic birds at their Grays Harbor County residence. Washington State Department of Health sampling identified avian influenza virus in the environment surrounding the flock, making exposure to the domestic poultry, their living environment, or wild birds the most likely source of infection for the patient. People who had exposure to the backyard flock and its environment are also being monitored for symptoms as a precautionary measure.
Avian influenza is a disease caused by influenza type A viruses that naturally occur in wild aquatic birds throughout the world. These viruses can infect other bird species and occasionally mammals, and can prove deadly to domestic birds including chickens and turkeys that lack natural immunity to these pathogens. On rare occasions, avian influenza viruses can infect humans and cause illness, though such spillover events remain uncommon and typically occur only with direct exposure to infected birds.
Health officials provided guidance for people who maintain backyard poultry flocks, emphasising they should avoid contact with sick or dead birds and report illness in poultry to the Washington State Department of Agriculture by calling 1-800-606-3056 or reporting online through the agency’s website. Veterinarians should report sick or dead domestic animals or livestock suspected of having avian influenza to WSDA to enable rapid response and prevent spread.
The public should 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, which monitors wildlife disease outbreaks. People should never handle dead birds or other wildlife themselves, and should not allow pets to approach or interact with dead birds or wildlife, as pets can potentially contract infections or carry contaminated material into homes.
Health officials warned against consuming raw or undercooked food products including unpasteurised (raw) milk or raw cheeses, as these products can harbour pathogens including avian influenza if produced from infected animals. Pet owners should similarly avoid feeding these products to pets, which can become ill from contaminated raw dairy or meat products.
Officials emphasised it is especially important that people who may have exposure to domestic or wild birds receive seasonal influenza vaccine. Whilst the seasonal flu vaccine will not prevent bird flu infection, it reduces the risk of simultaneously becoming infected with both human seasonal influenza and avian influenza viruses. Though unlikely, co-infection with both viruses could theoretically result in genetic reassortment creating an avian influenza virus more easily transmitted between humans, the nightmare scenario that public health authorities work to prevent. Seasonal flu vaccine is recommended for everyone six months of age and older.
