Iowa State University Associate Professor Dr. Rahul Nelli works in the diagnostic veterinary lab on campus. Since March of this year, he's been working with fellow scientists to study possible transmission methods of avian flu in dairy cows.
The research question was prompted by reports of infected cattle in Texas earlier this year. The Texas Animal Health Commission announced its first cases of avian influenza in dairy cattle in late March, and soon after, the Texas Department of State Health Services made public the second national case of avian influenza in people in April. That individual experienced eye inflammation.
Nelli says the team focused on one question: Why is influenza affecting cattle, especially the mammary glands? Before this, most avian influenza cases were upper respiratory infections.
The team focused on sialic acid (SA) receptors and how the virus could bind itself to them using plant lectin, a protein that is often used as a marker in animal research. Nelli says they differentiated between avian receptors and mammalian receptors in dairy cattle.
"We found out both avian and mammalian receptors are present in the dairy cattle. More so, the avian receptors are more abundant compared to mammalian receptors and that even more higher in the mammary gland, which got infected," Nelli said in a phone interview with WVIK. "We came to a conclusion because of the abundant receptor distribution in the mammary gland this is why the virus is probably affecting the tissue."
Nelli points out this is only one factor in the ongoing spread of avian influenza in cattle and poultry nationwide.
"Yes. there is evidence that milk can be one of the transmission contributions, but there are also other factors...the movement of people, the movement of trucks, material, there can be other several factors too," Nelli said.
The American Veterinary Medical Association says that as of Wednesday, July 24, "Avian influenza virus type A (H5N1) has been confirmed in dairy cattle in 13 states: 48 herds in Colorado, 29 in Idaho, 26 in Michigan, 22 in Texas, 13 in Iowa, nine in Minnesota, eight in New Mexico, five in South Dakota, four in Kansas, two in Oklahoma, and one each in North Carolina, Ohio, and Wyoming," according to the group's website.
The American Veterinary Medical Association also collects data on the number of infected cats with H5N1, which stands at 32. The virus has been severe and causing neurological issues before death in many of these cats. The association says to keep domestic cats indoors and avoid dead birds, rodents and raw milk.
Nelli says the most common evidence of human infection with H5N1 is conjunctivitis, the reddening of the eyes. According to the Centers for Disease Control, 13 people in the U.S. have tested positive for the virus so far.
Nelli says to avoid human mutations in the virus, those working with cattle and poultry should wear goggles, masks, gloves, and other personal protective equipment.
"You know those are simple steps which we were doing during COVID. I think we should contain the virus and limit it to animals and not go beyond that," Nelli said. "This virus is always trying to come up with innovative ways and approaches to infect a human, and they do adapt. It's a constant process."
Nelli and his fellow team members were asked about other species and their receptors, so they're currently working on expanding their research. He says working with the live H5N1 virus would streamline the process but understands with health risks, the necessary regulations in place prohibit working with live viruses without full containment procedures.
Nelli says Iowa is an ideal spot for migratory birds, and with cattle and poultry farms within the state, the birds could pass the virus to herds.
"Some birds can die, too, and farmers and local communities should be aware of that. Make sure that you approach your local veterinarian and see if that bird got infected with any of these pathogens, including the highly pathogenic H5N1. So those are things we need to be mindful as a community and be collective in handling these kinds of situations."
You can access their research here.
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