A genetic analysis of the bird flu (H5N1)-infected patient who is severely ill has revealed mutations that were not there in the samples of the patient’s infected backyard poultry flock, said the Centers for Disease Control and Prevention (CDC).
The 65-year-old Louisiana patient, who has severe respiratory illness, showed a mutation in the hemagglutinin (HA) gene.
Similar mutations were seen in the sample from the H5N1-infected 13-year-old girl from British Columbia, Canada, who was hospitalised in November 2024. Researchers found she was infected with clade 2.3.4.4b, genotype D1.1 of the Highly Pathogenic Avian Influenza (HPAI) A or H5N1 virus, which is currently spreading among wild bird populations around the world.
However, the CDC asserted that the risk to general public is considerably low, and that there has not been any spread of the bird flu from the patients.
Mutations make it easier for the virus to attack the cell receptors found in the upper respiratory tract. There has been no instances of human-to-human transmission so far, but mutations can boost the spread.
Difference in genotype
By comparing the H5N1 genomes of the Louisiana patient and the dairy cows, CDC scientists state that “the changes observed were likely generated by replication of this virus in the patient with advanced disease rather than primarily transmitted at the time of infection.”
The virus genotype causing the outbreak in dairy cows and poultry is B3.13.
Though CDC highlights the risk of mutation, it would be more concerning if the mutation was detected in animals as it would lead to an epizootic disease.
CDC is closely monitoring the H5N1 cases, containment of outbreaks in dairy cattle and poultry, as well as finding prevention measures for people exposed to infected animals.
