Bird Flu Is Now Transmitting Mammal-to-Mammal: Study

Medically reviewed by Carmen Pope, BPharm. Last updated on July 25, 2024.

THURSDAY, July 25, 2024 -- The bird flu is now jumping between species of mammals, a step that draws the virus closer to hopping into human beings, a new study warns.

Researchers have tracked transmission of avian influenza between dairy cows in herds, as well as from cows to cats and a raccoon.

“This is one of the first times that we are seeing evidence of efficient and sustained mammalian-to-mammalian transmission of highly pathogenic avian influenza H5N1,” said senior researcher Dr. Diego Diel, director of the Virology Laboratory at the Animal Health Diagnostic Center in the Cornell University College of Veterinary Medicine.

Still, genetic analysis of the virus did not reveal any mutations that would lead to enhanced transmissibility of H5N1 in humans, Diel said. The findings were published July 25 in the journal Nature.

However, mammal-to-mammal transmission does raise concerns that the virus might eventually adapt to spreading in humans, Diel said.

So far, 11 human cases have been reported in the United States, with the first dating back to April 2022, researchers said.

Four human cases are linked to cattle farms and seven to poultry farms, including an outbreak of six cases over the last few weeks in Colorado, researchers said.

These recent human cases contracted the same bird flu strain identified in the study as the one circulating in dairy cows, researchers said.

Luckily, all human cases to date have had mild symptoms, and the virus has not developed an ability to pass easily between humans.

“The concern is that potential mutations could arise that could lead adaptation to mammals, spillover into humans and potential efficient transmission in humans in the future,” Diel said in a Cornell news release.

For the study, researchers used genetic sequencing to track the viral strains that transmitted between cows when infected animals from Texas were moved to a farm with healthy cows in Ohio.

They also found that the virus was transmitted to cats, a raccoon and wild birds found dead on affected farms.

The cats and raccoon likely became infected from drinking raw milk from infected cows, researchers said.

More than 100 million cases of avian flu in poultry have been reported in the United States, and 168 dairy herds have been affected, the U.S. Centers for Disease Control and Prevention says.

Outbreaks in poultry have been reported in 48 states, and 13 states have had outbreaks in dairy cows.

Sources

  • Cornell University, news release, July 24, 2024
  • Disclaimer: Statistical data in medical articles provide general trends and do not pertain to individuals. Individual factors can vary greatly. Always seek personalized medical advice for individual healthcare decisions.

    Source: HealthDay

    Read more

    Disclaimer

    Every effort has been made to ensure that the information provided by Drugslib.com is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Drugslib.com information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Drugslib.com does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Drugslib.com's drug information does not endorse drugs, diagnose patients or recommend therapy. Drugslib.com's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners.

    The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Drugslib.com does not assume any responsibility for any aspect of healthcare administered with the aid of information Drugslib.com provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

    Popular Keywords