Avian Flu Found in Seventh State as More Cattle Restrictions Imposed

Cows in New Mexico in a file photo. Rodrigo Abd/AP Photo

North Carolina authorities on April 10 reported that cows in the state tested positive for highly pathogenic avian influenza, as the state became the latest to impose restrictions on the movement of cows.

Testing of samples from North Carolina conducted by the U.S. Department of Agriculture (USDA) came back positive for the influenza, also known as the bird flu and HPAI, the North Carolina Department of Agriculture and Consumer Services said.

“We have spent years developing methods to handle HPAI in poultry, but this is new and we are working with our state and federal partners to develop protocols to handle this situation,” Steve Troxler, the state’s agriculture commissioner, said in a statement.

He noted that, according to the U.S. Food and Drug Administration, there is presently no concern regarding the safety or availability of pasteurized milk or milk products in the United States. Some experts, though, have warned there’s not enough evidence to support that position.

Avian influenza cases in cattle first appeared in the United States in March. USDA officials have since confirmed cases in 20 herds across six states, including Idaho, Kansas, and Texas, and a single case in a human. They have not yet commented on the North Carolina situation.

Stephanie Langel, Ph.D, an assistant professor at Case Western Reserve University’s School of Medicine, said on social media that because the influenza is not a reportable disease in cows, it’s likely the outbreak is larger than currently represented.

USDA officials do not require testing and only recommend testing if cows start exhibiting symptoms.

“Additionally, the majority of workers on dairy farms (especially large farms) are undocumented and are less likely to report symptoms,” Ms. Langel said, referring to illegal immigrants. “I worry we are underestimating human infections.”

The strain of HPAI that’s circulating, H5N1, originates from birds. Dead birds have been found on farms that have had cows with confirmed cases.

Bird flu is often fatal in birds and humans, but human cases are rare. The recent human case in Texas is only the second in history in the United States. Both patients recovered, officials say.

Worldwide, between 2003 and April 1 of this year, 889 human cases have been reported to the World Health Organization (WHO) from 23 countries. Of those patients, 463 died, the organization said.

Genomic sequencing of the virus in the Texas patient showed a mutation that makes the flu more likely to infect mammals, but the risk to people remains low, according to U.S. public health officials.

“Since the virus has not acquired mutations that facilitate transmission among humans and based on available information, WHO assesses the public health risk to the general population posed by this virus to be low and for occupationally exposed persons, the risk of infection is considered low-to-moderate,” WHO said in an April 9 brief. The agency noted that sustained human-to-human transmission of the strain and similar variants have never been detected.

No vaccines are currently available against H5N1.

Officials recommend people not get close to dead animals or animal droppings and not consume raw milk or raw cheese.

Restrictions

Due to the positive tests from cows in North Carolina, officials joined a growing number of states in restricting the movement of cows.

The movement of cattle from herds with confirmed cases in other states to North Carolina has been suspended, according to the North Carolina Department of Agriculture and Consumer Services.

Seventeen other states have also placed restrictions on cattle importations from the affected states, with Maryland joining the list on Wednesday.

Several states have said the sick cattle have come from Texas, where the first cases were detected.

Now that 21 herds have tested positive, it “stretches plausibility that it was all from one farm, but theoretically possible, given the amount cattle can move,” Gail Hansen, a doctor of veterinary medicine who used to be the state veterinarian for Kansas, wrote on the social media platform X.

The USDA has advised against moving sick or exposed animals and minimizing the movement of other cattle “as much as possible.”

“If cattle must be moved, we strongly encourage extreme diligence by producers, veterinarians, and animal health officials to ensure only healthy cattle are moving and to ensure the validity of interstate health certificates,” the agency said.