Wisconsin has not detected bird flu in its dairy cattle, but is it looking hard enough?
Wisconsin officials are preparing for the possibility of bird flu spreading from dairy cattle in Wisconsin to people, as the virus continues to infect dairy herds in surrounding states, part of an evolving situation that scientists and public health officials are keeping a close eye on.
Bird flu has not been detected in any dairy herds in Wisconsin, but most surrounding states have reported infections in dairy cattle since March, when bird flu, specifically the H5N1 strain, was identified for the first time in U.S. dairy cattle, according to the U.S. Department of Agriculture. Though state officials say there is no indication that bird flu is in Wisconsin dairy herds, others suggest state officials may not be looking hard enough.
The virus has been reported in 115 dairy herds across 12 states since late March, including in Michigan, Iowa and Minnesota, according to the U.S. Department of Agriculture. The outbreaks among dairy cattle have led to three known cases in dairy farm workers in the U.S. All three people had mild illnesses, according to the Centers for Disease Control and Prevention.
"We are preparing ourselves as if we're going to have cases, and we're going to be working with the local public health departments and providers to be sure that we're testing people who need to be tested," said Tom Haupt, research scientist and epidemiologist with the Wisconsin Department of Health Services, during a briefing with reporters on Tuesday.
The risk posed by bird flu to the general public is currently low, according to the Centers for Disease Control and Prevention. But scientists and health officials are keeping a close eye on the virus, which could become more of a health risk to people if the virus adapts to spread more easily among humans.
In Wisconsin, more than 600 dairy cattle have been tested for H5N1 since late April, when a federal order went into effect requiring that lactating dairy cattle be tested for H5N1 before being moved across state lines, according to Wisconsin State Veterinarian Darlene Konkle.
State officials are trying to emphasize the importance of reporting signs of possible H5N1 infection in dairy cattle and getting sick cattle tested.
"If we do detect anything in Wisconsin cattle, we want to detect it early," Konkle said. "We're trying to encourage people to get testing done through us and the lab in Madison, the Veterinary Diagnostic Lab, if they have any suspicions and trying to also walk through the what-ifs of what would happen with a positive case."
However, Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory, said dairy farmers are not incentivized to report if their dairy cattle are sick. It's very possible, he said, that infected herds in Wisconsin are going undetected.
"It would not surprise me that we could have people that aren't reporting" possible cases, he said. "It is hard to say it is zero (cases) if we’re not really looking."
Poulsen said the existing testing strategy is not working and that too few dairy farms are reporting cattle with signs of the flu. He believes there needs to be more collaboration between dairy farmers, regulators and others involved in the response.
"The risk of human disease and zoonotic disease is going to go up," he said. "They need to buy in and collaborate and work together soon. … Something needs to happen quickly."
Michigan has been among the most aggressive in testing for H5N1 in its dairy cattle herds and so far, has identified bird flu in 25 dairy herds and two cases in dairy workers, according to the U.S. Department of Agriculture.
This article originally appeared on Milwaukee Journal Sentinel: Wisconsin has not detected bird flu in dairy cattle, but is preparing for it
