The first serious human case of avian flu in the United States carries a virus that may have mutated inside its body to adapt to human respiratory tract, according to the American Centers for Disease Control and Prevention ( CDC). However, specialists put the danger into perspective.
The CDC announced on December 18 that an elderly patient was hospitalized in Louisiana in “critical condition” after being contaminated by H5N1. A small part of the virus found in his throat has genetic modifications that could result in “increased binding of the virus” with certain “cellular receptors in the human upper respiratory tract,” the CDC revealed Thursday, in an announcement released Friday evening.
They were “probably generated during the replication of the virus in the patient,” indicated the CDC, specifying that no transmission of this mutated virus has been identified. These changes have not been observed in contaminated birds, including those with which the patient may have been in contact in a farmyard.
On December 19, 2024: First serious case of bird flu in humans detected in the United States
One more step, but not decisive, say the experts
Experts contacted by the AFP agency say it is too early to determine whether these changes could allow the virus to spread more easily or cause more serious cases in humans.
The mutation in question constitutes “a necessary step for a virus to become more contagious,” explains Angela Rasmussen, virologist at the University of Saskatchewan, in Canada. “But I insist on the fact that it is not the only one” necessary, she added. Angela Rasmussen says the mutation could make it easier for the virus to enter cells, but further testing will need to be done in animals to confirm this.
Our details: The avian flu epidemic continues in the United States and warning signs worry experts
There have already been genetic modifications
Genetic modifications have already been observed in the past in patients infected with avian flu and seriously ill, but have not yet resulted in an increase in the transmissibility of the virus to humans.
Avian influenza A (H5N1) first appeared in 1996, but since 2020 the number of outbreaks in birds has exploded and an increasing number of mammal species have been affected.
