THINK GLOBAL HEALTH – When U.S. officials first announced in late March 2024 that the H5N1 avian influenza had been detected in Texas dairy herds, Beth Thompson knew it was only a matter of time before the virus reached cows in South Dakota, where she serves as the state veterinarian.
Her prediction came true days later on April 8, when she received an email reporting likely cases of H5N1 in approximately 50 cows at a dairy in an unidentified part of the state.
Thompson says that her immediate reaction was to contact the farm owner and manager to see how she and her colleagues could assist and to ensure that they could work together to gather valuable data along the way.
She knew, though, that she would have to navigate the challenges with more questions than answers.
“This is not a previously reported disease in dairy cows, so there isn’t nearly enough data available on how [it] is affecting animals,” Thompson says.
“How is it moving through dairies? How quickly do animals recover? What does it look like when they do recover? All these questions and more need to be answered.”
Many of those questions remain unaddressed a month after the initial federal announcement, even as more herds come down with the virus.
As of April 24, H5N1 has been confirmed in 33 dairy herds across eight states.
Veterinarians who spoke to Think Global Health say they recognize that it takes time to implement new protocols, but without basic information such as how cows contract the virus and how long they shed it once infected, it’s difficult to issue precise instructions for things like quarantine.
The efforts to gather the data to fill in these unknowns have also been piecemeal and slow, says Keith Poulsen, a clinical associate professor at the University of Wisconsin–Madison School of Veterinary Medicine, and the director of the Wisconsin Veterinary Diagnostic Laboratory.
He says each state is acting differently rather than following a unified approach …
