(Jim Vondruska, Reuters/Contrasto)
On April 18, the World Health Organization (WHO) expressed concern about the increase in cases of transmission of the H5N1 strain of avian influenza to other species, including humans.
“The hypothesis raises enormous concern,” Jeremy Farrar, chief scientist of the United Nations health agency, said at a news conference in Geneva.
The fear is that the H5N1 virus, which has shown “an extraordinarily high mortality rate” in people infected by animals, could mutate and acquire the ability to transmit from one human to another.
There is currently no evidence of human-to-human transmission of the H5N1 virus.
Between January 1, 2003 and April 1, 2024, WHO recorded 889 cases of avian influenza among humans in twenty-three countries. There were 463 deaths, with a mortality rate of 52 percent.
“More than monitoring people infected by animals, it is important to understand how many human infections occur without our knowledge, because that is where the adaptation of the virus will take place,” Farrar explained.
“If I get infected with H5N1 and die, the chain of transmission is broken, but if I go around transmitting it to others, a cycle starts,” he added.
Infected by a cow in Texas
At the moment, however, cases of transmission to humans remain very rare.
In February, a nine-year-old boy died of bird flu in Cambodia. The Asian country had already recorded three victims in 2023.
In early April, US authorities revealed that a man in Texas tested positive for bird flu after being infected by a cow.
The patient had “redness of the eyes” as his only symptom, authorities said, adding that he was isolated and treated with an antiviral drug used for influenza.
