Americans may have had bird flu and not even know it, new study suggests
A new report suggests that more Americans may be walking around with bird flu − and not even know it.
Researchers from the Centers for Disease Control and Prevention randomly tested 150 veterinarians for H5N1, or bird flu, antibodies, which would indicate if they had a recent infection.
Three veterinarians specializing in cattle tested positive, according to the study published in the Morbidity and Mortality Weekly Report Thursday. The vets said they never experienced any flu-like symptoms.
Two vets said they had no known exposures to animals with known or suspected bird flu, and one said they didn’t practice in a state where there were known bird flu infections among cattle.
The report adds to a growing body of evidence that suggests people may have asymptomatic bird flu infections, or infections showing no obvious symptoms. In November, the CDC posted a study that found dairy workers may have gotten sick without showing symptoms after being exposed to infected cows.
Asymptomatic disease played a role in how COVID-19 spread in 2020. People who were sick with no symptoms mingled with others in public, unknowingly transmitting the virus.
It allowed the virus to spread undetected.
Although it’s still unclear if bird flu can be transmitted asymptomatically, experts have told Paste BN the number of bird flu cases is likely much higher than reported.
“Not quite knowing the full picture of things right now is concerning,” Dr. Ben Bradely, assistant professor at the University of Utah School of Medicine’s pathology department, said during a briefing in December.
Unlike the start of the COVID-19 pandemic, there is already a test that detects H5N1, which is a subtype of influenza A. But a person infected with bird flu who isn't experiencing any symptoms is unlikely to get tested.
Most people with bird flu infections typically experience mild symptoms: Pink eye, fever, fatigue, cough, muscle aches, sore throat, nausea and vomiting, diarrhea, stuffy or runny nose, and shortness of breath, according to the Cleveland Clinic.
But the more the virus spreads undetected, the more opportunities it has to mutate into something more dangerous to humans.
“Public health officials are very concerned about this possibility,” said Dr. Elizabeth Jacobs, internal medicine physician and chair of the internal medicine department at the University of California, Riverside Health. “The virus that causes bird flu, H5N1, is following the same path that other viruses have taken to become one that spreads efficiently in humans.”
Since April, the CDC says nearly 70 people have been infected with bird flu and one person died. This includes new cases that were recently reported in Nevada and Ohio.
The H5N1 virus has reduced milk output in cattle and pushed up egg prices by wiping out millions of hens.
“We’re seeing the H5N1 virus itself be smarter than all of us,” said Dr. Beth Thompson, South Dakota’s state veterinarian.
Contributing: Reuters.
Adrianna Rodriguez can be reached at adrodriguez@usatoday.com.