As questions arise about the spread of bird flu among livestock and people, one US state (Michigan) has taken the lead in tracking and studying the outbreak.
Other states appear cautious about tracing cases among animals and people, but Michigan has taken a proactive approach, with daily text messages and phone calls to check on farmworkers who work with cows who have tested positive for H5N1. They have also offered free testing if symptoms develop.
Officials were not surprised when a third person tested positive for highly pathogenic avian flu, and they were not surprised that this happened in Michigan. Nearly two-thirds of the people being monitored for H5N1 symptoms are in Michigan, Nirav Shah, principal deputy director of the U.S. Centers for Disease Control and Prevention (CDC), said recently.
As of May 22, 35 of the 40 tests on people had been conducted in Michigan. That means only five other bird flu tests have been conducted in other states, including Texas, the only other state to report a human case in this outbreak.
Michigan is the state with the highest concentration of influenza A in its wastewater, according to WastewaterScan. H5N1 belongs to the influenza A family, and relatively high levels of influenza A indicate possible outbreaks of H5N1, most likely among animals.
But that’s not the only reason Michigan continues to be in the news about bird flu.
“I don’t think we are the only state that has cases. “I think we’re the only state that’s detecting our cases,” other than Texas, said Dr. Natasha Bagdasarian, Michigan State’s chief medical executive. “It gives me hope that the system is working here.”
It’s not just about testing and tracing. Michigan also invited epidemiologists from the U.S. Department of Agriculture (USDA) to study the transmission of the virus. The authors of a recent USDA report thanked Michigan dairy producers for their openness and transparency. “This report could not have been completed without them,” the researchers wrote.
Michigan officials announced new biosecurity rules for farms after the first detection of bird flu in cows, and soon began promoting seasonal flu vaccines among dairy and poultry workers to prevent the possibility of flu variants mixing and causing more severe illness.
Michigan also announced additional funding for farms affected by the flu, in addition to available federal assistance. Up to 20 farms affected by H5N1 can receive up to $28,000 for participating in studies and working with health officials.
“Michigan has been working hard to really understand what’s going on with H5N1,” said Marisa Eisenberg, associate professor of epidemiology and co-director of the Michigan Public Health Integrated Outbreak Analysis and Modeling Center at the University of Michigan.
“Part of what we’re seeing is that when you search for something, that’s how you find it.”
It’s important for state and local officials to work closely with agricultural industries — which encompass cows, chickens, pigs and other potentially affected animals — to understand how transmission occurs and how to stop it, experts said.
“It’s a win-win for everyone to try to be as proactive as possible,” Eisenberg said. “Because if you bury your head in the sand, ostrich-style, it will continue to spread and cause a wider range of problems, from a public health perspective, from an economic perspective and from a milk production perspective.”
In Michigan, that approach has involved regularly monitoring farmworkers for symptoms and working closely with officials from state and local health and agriculture departments.
“We are seeing how human health and animal health are inextricably linked and we are making sure that we address these issues together,” Bagdasarian said.
Farm owners and workers who come into contact with sick cows receive daily text messages or phone calls to check for even mild or unusual symptoms.
Those who report any symptoms are tested for H5N1 and, in the case of two people who tested positive, are offered antivirals.
That program, Eisenberg said, “has been really helpful in terms of finding the two cases we’ve seen so far, and also encouraging testing on farms and dairies in particular.”
A Michigan worker who tested positive developed conjunctivitis after milk from a sick cow splashed into his eyes.
The other worker developed more typical flu symptoms, including cough, congestion, sore throat and watery eyes, after working in a confined space with a sick cow.
The risk of contracting bird flu for most people remains low, but anyone who is in close contact with potentially sick animals should take precautions, officials say.
“This really highlights how helpful personal protective equipment can be for people who have prolonged exposure to sick animals,” Bagdasarian said.
But that protective gear can be difficult to wear while working on a farm, amid conditions like summer heat and splashes of water and milk.
“One of the big concerns has been visibility,” Bagdasarian said. “When you’re working with a large animal and there’s a risk of injury, anything that blocks your vision can also be difficult to use.”
Michigan officials are being careful not to reveal details that could identify affected farms or individuals while announcing new cases.
“Michigan, as a state, has been very good at managing privacy concerns and not wanting to single out specific farms, but also wanting to share data in a transparent way,” Eisenberg said.
Throughout this bird flu outbreak, officials have emphasized the importance of trust.
“One of the things we learned from the pandemic is that you need to build relationships before any kind of public health emergency occurs,” Bagdasarian said.
“We have many health centers and outreach staff who work directly with farmworkers, and local health departments are familiar with the farms in their jurisdictions.”
If an H5N1 vaccine does become widely available, it could fall prey to the same politicization and misinformation around vaccines that accelerated during the pandemic, he said, including lower uptake of the seasonal flu vaccine.
“We’re still working to restore that public trust,” Bagdasarian said.
The bird flu outbreak is “worrisome, but we can’t yet say whether it will really become a major problem that the general public needs to worry about,” Eisenberg said.
“It’s such a big concern that we should do everything we can to make sure it doesn’t become a bigger problem.”