Bird flu or avian influenza has been present in birds for years. However, in recent years, it has started to affect an increasing number of mammals. Since March 2024, after finding the virus affecting cows, 70 human cases have been reported in the US.
The Washington State Department of Health confirmed that the first case of a person with H5N5 bird flu was reported in the state. This strain, different from the ones traced before, has led to the person’s hospitalisation. The Centres for Disease Control (CDC) confirmed that this appears to be the first known human infection with the H5N5 bird flu virus.
This is the second reported case since early November in Washington. They were much older and due to the underlying health conditions, remained hospitalised. They developed high fever, confusion, and respiratory distress, as per state health official Scott Lindquist. They suspect high exposure to domestic poultry and wild birds while the investigation is underway.
What is H5N5 bird flu virus?
H5N5 bird flu virus is a kind of avian influenza which is highly similar to strains like H5N1 and has reported high-mortality rates in birds. It primarily spreads when someone comes in contact with infected birds, their droppings, secretions, or contaminated surfaces. Wild migratory birds are commonly attributed to its vast geographical effect. Humans can get infected due to prolonged close contact with infected birds, and communicability within humans remains extremely rare.
As per the CDC, the current public health risk for the H5N5 bird flu virus is low, as the current situation is being monitored closely. Even previous strains, which affected 70 people last year, reported non-severe effects and mild illness in dairy and poultry farm workers.
Common symptoms of the virus
In birds
Sudden death without signs
Respiratory distress, nasal discharge, coughing, sneezing
Swelling of the head, wattles, combs
Decreased egg production or soft-shelled eggs
Lethargy and loss of appetite
In Humans
Eye redness or conjunctivitis (pink eye)
Fever, cough, sore throat, runny or stuffy nose
Muscle aches, fatigue, headaches
Severe cases can develop pneumonia, respiratory failure, multi-organ failure, and even death
H5N5 vs H5N1: What’s the difference?
While they are both avian influenza, they differ significantly in genetic makeup and threat levels. The major difference is in the surface proteins that actually make up the virus. The H5N1 virus is considered highly pathogenic for poultry worldwide. Several outbreaks have resulted in major setbacks to the industry, and there have been documented cases of fatality in humans, too.
The H5N1 is said to be highly severe for humans, resulting in acute respiratory disease. While the transmission process remains the same, H5N1 has a nearly 60% higher mortality rate than H5N5.