Washington state health officials have confirmed the first human case of H5N5 avian influenza, a rare strain of bird flu that has previously only been documented in animals. The infected individual, an older adult with underlying health conditions, is currently hospitalized after showing flu-like symptoms in early November. The Washington State Department of Health (DOH) stated that the patient had a mixed backyard flock of domestic poultry that had exposure to wild birds, potentially leading to the infection. While no significant public risk has been identified, experts are investigating the source of the virus and its potential impact on human health.
The confirmation of this case marks a rare and concerning development in the United States, as the H5N5 strain has never been found in humans before. Public health officials at the Department of Health emphasized that the risk of transmission between humans remains extremely low, and no widespread cases have been reported. However, the case raises concerns about the potential for zoonotic transmission, where diseases move from animals to humans, and highlights the importance of monitoring and controlling outbreaks in both domestic and wild bird populations. While the U.S. has recently declared the bird flu emergency over due to declining animal infections and the absence of human cases since February, this case serves as a reminder of the need for vigilance.
In addition to this development, the DOH is advising poultry owners and individuals who interact with wildlife to take appropriate precautions. These include avoiding contact with sick or dead birds, using protective equipment, and reporting any signs of illness in domestic or wild animals to the Washington State Department of Agriculture (WSDA). While the seasonal flu vaccine does not prevent bird flu infections, it is still recommended as it can reduce the risk of co-infection with both influenza viruses, which could potentially lead to the emergence of a more transmissible strain of avian influenza.
Health experts are also monitoring the H5N5 virus closely, as it is a close relative of H5N1, a strain that has previously caused human illness and deaths. While H5N5 has primarily affected birds, the new case suggests that it may pose a risk to humans in certain circumstances. Public health authorities are continuing to assess the situation and have not yet raised any alerts about the broader implications for public health. Nonetheless, the confirmation of the first human case of H5N5 in the U.S. underscores the importance of ongoing surveillance and preparedness for emerging infectious diseases.