US: 2nd human bird flu case linked to cows reported
What's the story
The health authorities in the United States have confirmed a second case of bird flu in a human, following the first case reported less than two months ago.
Both infected individuals, who are dairy farm workers, contracted the H5N1 virus from dairy cows.
The first case was identified in Texas and the second one in Michigan.
Despite these incidents, the US Centers for Disease Control and Prevention (CDC) maintains that the risk to the general public remains "low."
Future cases
CDC anticipates more bird flu cases in future
The CDC has warned that more cases of bird flu in humans could be identified due to the high levels of the virus found in raw milk from infected cows.
"Given the high levels of the virus in raw milk from infected cows, and the extent of the spread of this virus in dairy cows, similar additional human cases could be identified," stated the CDC.
As it stands, 52 US herds across nine states have been infected with bird flu.
Transmission details
Bird flu transmission and symptoms in dairy workers
The most recent case in Michigan involved a dairy farm worker where the H5N1 virus was detected in cows.
Samples were taken from the worker's nose and eye, with only the eye sample testing positive for H5N1.
This mirrors the Texas case where symptoms were also reported only in the patient's eye.
The CDC has noted that individuals with close or prolonged unprotected contact with infected animals face higher infection risks.
Milk safety
Safety of milk and potential for human-to-human transmission
Despite the presence of virus fragments in pasteurised milk, health authorities assure that milk sold in US stores remains safe due to effective pasteurisation.
While there is currently no evidence of human-to-human transmission, officials remain concerned about the potential for the virus to mutate and become transmissible between humans.
This strain of H5N1 has caused widespread poultry deaths but affected cows have shown less severe illness.
Global spread
Global spread of bird flu and Australia's first case
Avian influenza A(H5N1) first emerged in 1996, but outbreaks in birds have significantly increased since 2020, along with a rise in infections among mammals.
In related news, Australia has reported its first confirmed case of human bird flu. The patient is a child who is suspected to have contracted the virus during a recent visit to India.
This marks another significant development in the global spread of the H5N1 virus.