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 CDC. However, specialists put the danger into perspective.
The American Centers for Disease Prevention and Control (CDC) announced on December 18 that an elderly patient was hospitalized in Louisiana in “critical condition” after being contaminated by H5N1. A small portion of the virus found in his throat has genetic changes that may result in “increased binding of the virus” to certain “cellular receptors in the human upper respiratory tract,” the CDC revealed Thursday.
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.
One more step
Experts contacted by AFP said it was 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”, Angela Rasmussen, virologist at the University of Saskatchewan, in Canada, explained to AFP. “But I insist that it is not the only one” necessary, she added.
Angela Rasmussen said 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.
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.
ats/miro
Swiss
