The US Centres for Disease Control and Prevention (CDC) announced on Thursday.
That tests on the first severe human case of bird flu in the United States revealed unusual genetic changes in the virus. These mutations were not found in samples from infected poultry on the patient’s property.
The CDC explained that the changes occurred in the hemagglutinin (HA) gene, which helps the virus attach to host cells. Despite the findings, the agency reassured the public, saying the overall risk to the general population remains low.
Last week, the case was confirmed in a Louisiana resident over the age of 65, who was experiencing serious respiratory issues. The individual was infected with the D1.1 strain of the virus, recently found in wild birds and poultry in the US. This differs from the B3.13 strain seen in dairy cows, some poultry, and human cases in various states.
The CDC noted that while these mutations are uncommon, they have been observed in severe cases in other countries. A similar change was detected in a severe infection in British Columbia, Canada.
No evidence of the virus spreading from the Louisiana patient to others has been identified, the CDC added.