The Centers for Disease Control (CDC) has announced that a genetic analysis of the two avian influenza viruses wreaking havoc on the U.S. poultry industry reveals that they are different from the H5NI virus. The highly pathogenic H5N1 strain has spread from birds to humans in earlier outbreaks.
The CDC indicates that the two avian viruses (H5N2 and H5N8) circulating in the U.S. “do not contain genetic markers which have been linked in the past to more severe outbreaks in birds and transmission to humans.” The current epidemic has led to the culling of more than 7 million birds in recent weeks.
Julie Steenhuysen and Meredith Davis report for Reuters. (This piece also appeared in Scientific American):
A principal concern with any new flu virus in birds, however, is that it will mutate to become easily transmissible from human to human. “At this point we don’t know very much about these viruses,” said the CDC’s [Alicia] Fry. “They have only recently been identified.”
At present, she said, “it seems the risk for human infection is very low.” But she added: “This is a rapidly evolving situation.”
Fry said the CDC will monitor any person who has been exposed to the virus in the United States. At least 100 people have been monitored so far.
No end to the outbreak is in sight, although officials hope that warmer weather and sunlight will help.