Advice reaffirmed

Avian flu: WHO warns against consumption of raw milk

The WHO warns against the consumption of raw milk and recommends consuming only pasteurized dairy products.

(Bild: Philipp - stock.adobe.com)

Following the discovery of the dangerous avian influenza virus A(H5N1) in dairy cows in the USA, the World Health Organization (WHO) has reiterated existing recommendations to consume only pasteurized dairy products.

The background: In the US state of Texas, a man who worked on a cattle farm tested positive for the A(H5N1) virus - krone.at reported. Exactly how the transmission took place is still being investigated, said the head of the WHO influenza program, Wenqing Zhang, in Geneva on Friday.

It is the first known case of transmission from a cow to a human. "Human infections with A(H5N1) remain rare and are related to contact with infected animals and the environment," she emphasized.

Man infected on US cattle farm
The US authorities had informed the WHO about the man's infection at the beginning of April and also reported that the virus (pictured below) had been found in unpasteurized milk. According to the US, the man only had mild symptoms, such as red eyes that resembled conjunctivitis.

Elektronenmikroskopische Aufnahme eines H5N1-Virus

(Bild: CDC/Dr. Erskine Palmer (gemeinfrei))

According to the US, cows are probably infected by wild birds. So far, the virus has only been found in dairy cows in the USA. According to the WHO, 29 herds in eight states are affected. Wenqing said that analyses of the virus had shown that it had no changes that would make it more adaptable to mammals.

"In the current outbreaks, transmissions from birds to cows, from cows to cows and from cows to birds have also been recorded, suggesting that the virus may have found different transmission routes than we previously thought," Wenqing said.

Virus A(H5N1) first appeared in 1996
The highly pathogenic avian influenza virus A(H5N1) first appeared in 1996, but since 2020, infections among birds have been rising rapidly and more and more mammals have been affected, including minks, seals, sea lions and foxes. The largest wave of bird flu ever documented is currently spreading across almost the entire world and also affecting Europe. The WHO is currently working with partners on a new risk assessment in connection with (A)H5N1.

According to the WHO, almost 900 cases of A(H5N1) infections in humans have been reported since 2003. Half of them have died. However, according to the WHO, it cannot be ruled out that many more people were infected but showed no symptoms and the cases were therefore not detected.