The World Health Organization expressed its fears this Thursday, April 18, about the growing spread of the H5N1 strain, with “extraordinarily high mortality rates,” to new species, including humans.
The World Health Organization (WHO) has announced its “huge concern” this Thursday, April 18 in the face of the increasing spread of the H5N1 strain of avian flu to new species, including humans. “It remains, I think, a huge concern,” Jeremy Farrar, chief scientist of the United Nations health agency, said at a press briefing in Geneva.
The fear is that the H5N1 virus which, in people contaminated by their contact with infected animals, has demonstrated “an extraordinarily high mortality rate”, adapts to become capable of transmission from human to human. There is currently no evidence of human-to-human transmission of H5N1.
Infection surveillance systems ‘are never enough’
Between the start of 2023 and April 1, 2024, the WHO said it recorded a total of 889 human cases of avian flu in 23 countries, including 463 deaths, bringing the case fatality rate to 52%.
Beyond the surveillance of humans infected by animals – cows in a recent case observed in the United States –, “It is even more important to understand how many human infections occur without your knowledge, because that is where adaptation will occur” of the virus, explained Jeremy Farrar.
“It’s tragic to say, but if I get infected with H5N1 and die, it’s over [la chaîne de transmission est rompue, ndlr]. If I go around the community and pass it on to someone else, then you start the cycle,” he explained.
He believes that infection surveillance and detection systems “are never enough” but note “that this is happening in the richest country in the world” where serological studies have been launched “to see if transmission between cow farmers and others is occurring.”
For the moment, cases of transmission to humans are very rare
In early April, American authorities indicated that a person had tested positive for bird flu after being infected by a dairy cow in Texas. Currently, cases of transmission to humans are very rare.
A 9-year-old child, carrying the H5N1 strain, died of avian flu in Cambodia in February, after three deaths in the same country in 2023. In the United States, the patient had shown “redness of the eyes (corresponding to conjunctivitis), as the only symptom”, authorities said, adding that he was isolated and treated with an antiviral drug used for the flu.
