“No Animal Contact”… First Case of ‘Bird Flu’ Appears in the U.S.

The first case of highly pathogenic avian influenza without contact with animals such as birds or cows has appeared in the United States. This has raised concerns that avian influenza can spread undetected among people. This is what CNN and the New York Times (NYT) reported on the 6th (local time) based on an announcement from the U.S. Centers for Disease Control and Prevention (CDC).

“Routine seasonal flu testing in Missouri has identified a case of avian influenza without animal contact,” the CDC said in a statement. “This is the 14th human case of H5 infection reported in the United States in 2024 and the first case of H5 without a known occupational exposure to a sick or infected animal.” All previous human cases had involved contact with infected cattle or poultry. There have been no reported cases of avian influenza in Missouri in cattle, but there have been cases of avian influenza in poultry.

It is not known how the patient became infected, but Missouri health officials said they are working to determine the exact source of the infection. The patient had underlying health conditions and was hospitalized on August 22. After testing positive for influenza A, he was treated with the antiviral drug Tamiflu and is now recovering and staying at home.

The patient’s sample was analyzed by the CDC and confirmed to be a type of avian influenza. Influenza viruses are classified based on the type of two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). Highly pathogenic avian influenza is classified as H5N1, meaning it consists of H5 and N1 types. A CDC spokesperson said that the H type has been confirmed as H5, but the N type has not been confirmed yet.

CDC scientists have isolated the virus and are sequencing its genome, and they hope to have more genetic information about it in the coming days, a CDC spokesperson said.

The genetic sequence, if known, will tell us how closely related the virus that infected the patient is to the viruses currently causing outbreaks in chickens, cattle and other mammals in the United States. Since March, avian flu viruses have been found in about 200 dairy herds in 14 of the 50 states. In California, the largest milk producer in the United States, avian flu was found in three dairy herds last week.