The first U.S. death from H5N1, or bird flu, has raised concerns among health experts, though they stress that the risk to the general public remains low. A Louisiana man, aged over 65 with underlying health conditions, passed away on January 6 after contracting the virus. This marks the first death in the United States linked to H5N1, which has infected 66 people in the country to date, mostly farmworkers exposed to infected poultry and cattle. All other cases so far have resulted in mild illness and recovery.
Health officials closely monitor any human infection with H5N1, as each case presents an opportunity for the virus to mutate and possibly become more transmissible among people or cause more severe disease. Although mutations were found in the virus isolated from the Louisiana patient, the Centers for Disease Control and Prevention (CDC) reassured the public that these changes do not suggest the virus is becoming better at human-to-human transmission.
The CDC analyzed samples from both the deceased man and infected chickens at his home. Genetic sequences showed some mutations in the virus after infecting the patient, but these changes were not enough to make the virus spread more easily between people. The virus was also found in wild birds and chickens across the U.S. and Canada, but it differed from the strain causing widespread outbreaks in poultry.
While the genetic changes were concerning, they were less alarming than if they had been found in wild birds or early in the infection’s course, when changes are more likely to enable the virus to spread to close contacts. The CDC also noted that the mutations did not affect the part of the viral genome that helps the virus resist antiviral drugs, meaning current treatments remain effective.
Although the Louisiana man’s death is tragic, experts point out that his age and underlying health conditions likely contributed to the severity of his illness. There is no evidence that the virus has evolved into a more dangerous or transmissible form. “The risk to the public has not changed and remains low,” the CDC concluded. The highest risk remains for individuals who work closely with infected animals, such as those in the poultry industry or those who keep backyard flocks.
For now, U.S. health officials have not recommended widespread vaccination, though new vaccines based on mRNA technology are being developed and tested in case of future human outbreaks. While mutations in the H5N1 virus are being closely watched, experts continue to emphasize that the risk of a major public health threat remains low for the time being.