Bird flu infections in dairy cows are more widespread than we thought, according to a new CDC study

A caller survey published by the U.S. Centers for Disease Control and Prevention shows that the H5N1 vertebrate flu microorganism is astir apt circulating undetected successful livestock successful galore parts of the state and whitethorn beryllium infecting unaware veterinarians.

In the wellness agency’s Morbidity and Mortality Weekly Report, a radical of researchers from the CDC, the Ohio Department of Health and the American Assn. of Bovine Practitioners, reported the results of an investigation they conducted connected 150 bovine, oregon cow, veterinarians from 46 states and Canada.

They recovered that 3 of them had antibodies for the H5N1 vertebrate flu microorganism successful their blood. However, nary of the infected vets recalled having immoderate symptoms — including conjunctivitis, oregon pinkish eye, the astir commonly reported grounds successful quality cases.

The 3 vets besides reported to investigators that they had not worked with cattle oregon poultry known to beryllium infected with the virus. In 1 case, a vet reported having practiced lone successful Georgia (on dairy cows) and South Carolina (on poultry) — 2 states that person not reported H5N1 infections successful dairy cows.

Seema Lakdawala, a microbiologist astatine Emory University successful Atlanta — who was not progressive successful the probe — said she was amazed that lone 2% of the veterinarians surveyed tested affirmative for the antibodies, considering another CDC survey showed that 17% of dairy workers sampled had been infected. But she said she was adjacent much amazed that nary of them had known they were infected oregon that they had worked with infected animals.

“These astonishing results bespeak that serum surveillance studies are important to pass hazard of infections that are going undiagnosed,” she said. “Veterinarians are connected the beforehand enactment of the outbreak, and accrued biosafety practices similar respiratory and oculus extortion should trim their vulnerability risk.”

Jennifer Nuzzo, manager of the Pandemic Center astatine Brown University, described the survey arsenic a “good and atrocious quality story.”

“On 1 hand, we spot concerning grounds that determination whitethorn beryllium much H5N1 outbreaks connected farms than are being reported,” she said. “On the different hand, I’m reassured that determination isn’t grounds that infections among vets person been widespread. This means there’s much enactment that tin and should beryllium done to forestall the microorganism from spreading to much farms and sickening workers.”

The investigation was conducted successful September 2024. At that time, determination had been lone 4 quality cases reported, and the corruption was believed to beryllium restricted to dairy cattle successful 14 states. Since then, 68 radical person been infected — 40 moving with infected dairy cows — and the microorganism is reported person infected herds successful 16 states.

John Korslund, a retired U.S. Department of Agriculture scientist, said successful an email that uncovering H5N1 antibodies successful the humor of veterinarians was an absorbing “but precise imprecise mode to measurement authorities cattle incidence.” But it underscored “that humans ARE susceptible to subclinical infections and imaginable reassortment risks, which we already knew, I guess.”

Reassortment occurs erstwhile a idiosyncratic oregon carnal is infected with much than 1 influenza virus, allowing the 2 to mingle and speech “hardware,” perchance creating a new, much virulent strain.

More important, helium said, the D1.1 mentation of the strain — which has been detected successful Nevada dairy cattle and 1 idiosyncratic surviving successful the state — is “changing the landscape. ... [P]eople whitethorn beryllium much more susceptible (or not) with a greater imaginable for severeness (or not).”

“I’m assured that we’ll find it successful different states. Its behaviour and transmissibility wrong and betwixt cattle herds is inactive beauteous overmuch a achromatic box,” helium said.