A man in Chile contracted bird flu, but the threat to people from the virus remains low, US health officials said Friday.
Previous animal studies have suggested that these mutations may make the virus more deadly or easier to spread, health officials said. However, they also said there is no evidence that the mutation makes it easier to take root in the human upper lung.
Vivian Dugan of the Centers for Disease Control and Prevention said the mutation would not change public health officials’ assessment of the “remaining low” overall risk to people from the H5N1 virus.
CDC officials said the mutation only appeared in one hospitalized patient and may have occurred after the man became ill. There is no evidence that it has mixed with or developed the ability to repel current drugs or evade vaccines.
Such genetic alterations have been seen in past avian influenza infections.
“Nevertheless, it is important that we continue to monitor all cases of human infection closely,” Dugan said. “We need to remain vigilant for changes that make these viruses more dangerous to people.”
Threat first identified in 1997
This type of influenza, called type A H5N1, was first identified as a threat to people during an outbreak in Hong Kong in 1997, when visitors to a live poultry market became infected.
According to the World Health Organization, more than 450 people have died from bird flu infections in the past 20 years, with sporadic epidemics continuing. Most infected people were infected directly from birds.
But as bird flu hits other species, scientists fear the virus may have evolved to spread more easily among humans. I’m here.
millions of chickens died
In the United States, it has recently been detected not only in wild birds in every state, but also in commercial poultry and backyard flocks. was killed for
A new laboratory analysis focused on the virus found in the lungs of a 53-year-old man from the Antofagasta area of Chile. He may have been infected by contact with sick or dead birds, or infected sea lions, according to the WHO case summary.
The man was in good health and had not recently traveled. According to WHO, the cough, sore throat and hoarseness began on 13 March.
His symptoms worsened and he was eventually sent to an intensive care unit where he was treated with antivirals and antibiotics.He remains hospitalized and is being monitored, according to CDC officials. .
Gene sequencing this week revealed two things about the mutation. Health officials in Chile and the United States are cooperating with the investigation.
Andrew Pekoz, an influenza researcher at Johns Hopkins University, said he had not seen a preliminary analysis of the infection in Chilean patients.
“Once these viruses invade humans, they may begin to adapt to grow better within us,” he said.
He added that the H5N1 virus would need to see three or four mutations “before it really gives a warning signal that something is happening that is concerning.”
