Ledes from the Land of Enchantment

Avian flu confirmed in NM dairy cows in two Curry County herds • Source New Mexico

For days, federal officials have said some New Mexico dairy cows were sick with bird flu. 

On Tuesday, the state’s top veterinarian said that cows from two separate herds have been confirmed positive for highly pathogenic avian influenza and another herd has “presumptive positives,” meaning suspected positive cases. 

All of the known cases are in Curry County.

“We don’t have an actual count of the cows individually,” said New Mexico State Veterinarian Samantha Uhrig. “We have a number of herds that have been confirmed.”

The U.S. Department of Agriculture announced Monday that one New Mexican dairy had confirmed cases of avian influenza, along with five more dairies in Texas.

Also, a Texas dairy worker tested positive Monday for avian influenza A(H5N1) after being in contact with infected cows. The symptom he showed was conjunctivitis or reddened eyes. It’s the second case recorded in the U.S., according to health officials.

First human case of bird flu in Texas detected after contact with infected dairy cattle

The Texas Health Department issued an update Tuesday, finding that three cats on the dairy farms in Texas also tested positive for HPAI.

In statements, federal health officials have emphasized that most of the public is at low risk for contracting avian influenza, but people in contact with birds and livestock are at higher risk.

In a statement, officials said the New Mexico Department of Health is managing the diagnosis, treatment and prevention efforts.

The department is using local public health offices to test dairy workers who are showing symptoms, said spokesperson David Barre. Any confirmed or probable cases will be monitored, and treated with a generic antiviral Oseltamivir, an alternative to Tamiflu.

“To date, there are no laboratory-confirmed human cases of avian influenza A (H5N1) in New Mexico,” the statement stated.

The department is providing personal protective equipment, such as N-95 masks and face shields to dairies, Barre said.

Uhrig said workers in contact with infected cows should use gloves, eye protection and masks.

Several other New Mexico dairy herds are undergoing tests after some cows appeared sick, Uhrig said Tuesday. This includes collecting nose swabs, and samples of blood, fecal matter and milk.

First, those are tested at state laboratories. Any positive samples are sent to the National Veterinary Services Laboratories in Ames, Iowa, operated by the Animal and Plant Health Inspection Service at the USDA.

The federal labs can issue a “presumptive positive generally in a day or two,” Uhrig said, but the confirmed positive results will be delayed for several days up to a week.

“At this point, because it’s an emerging disease, they are doing whole-genome sequencing to actually confirm any positive, and that does take a longer period of time,” she said.

A USDA spokesperson declined to make anyone from the agency available for an interview, and referred Source NM to news releases.

What is avian influenza?

This family of viruses usually only affects wild and domestic birds. Normally, these diseases do not spread to people or other animals, except when they come into direct contact with sick birds and carcasses.

The virus is shed through bird’s mucus, feces and saliva, so coming into direct contact, or touching a contaminated item, could pass the virus to people, according to the Centers for Disease Control and Prevention.

The viruses can “spill” from domestic birds, into wild bird populations, and then into other animal species. Infectious disease researchers said the viruses’ ability to adapt to different hosts and change its genetic code increases its pandemic potential.

In 2009, the H1N1 variant (nicknamed the “swine flu”) was a new combination of genes from influenza viruses that infected pigs, people and birds. It infected 20% of the global population.

Since early 2022, an outbreak of the (H5N1) variant of avian influenza has killed more than 50 million birds across the U.S. Their deaths drove up egg and poultry prices. Only two people were recorded with infections, one person in the U.S. and the other in the United Kingdom.

Last November, a backyard flock in New Mexico’s San Juan County was confirmed to have contracted avian flu, killing 13 of 14 birds. Uhrig said that incident remained isolated.

“At this time, we have not had any other detections,” she said.

An infographic demonstrating how avian influenza from backyard chickens can infect people. (Courtesy of the Centers for Disease Control and Prevention).

What caused the outbreak in NM?

There’s no answers yet, Uhrig said, but investigators are looking to water and feed sources that could have been contaminated by migratory birds.

“We suspect that there may have been multiple introductions at different locations from wild birds,” Uhrig said. “We’re not really sure why it is now affecting cattle the way that it is. That’s the big question.”

Uhrig said the method of transmission is still unclear. The transmission may be manually spreading by cows sharing the same feed bucket or touching infected objects.

“We don’t have an indication that it is directly spreading from one cow to another, but that there may be some sort of mechanical transmission that’s a lateral transmission as well,” Uhrig said. “We can’t rule any of those things out.”

She said symptoms are not respiratory. 

“In people, that’s what we look at: our nasal swabs, because that’s the route of transmission,” she said. “In cattle, the nasal swabs are not as hot, per se, with the viral load, but the milk does have a pretty heavy viral load.”

Uhrig said the milk supply for humans is not at risk.

Any milk from symptomatic cows is diverted and destroyed, she said, and most commercial milk is pasteurized — heated to kill viruses and bacteria.

The New Mexico Department of Health urged residents against consuming unpasteurized or “raw” milk due to the potential for viral transmission. 

“The pasteurized dairy supply in New Mexico is safe because the pasteurization process effectively eliminates influenza viruses,” according to the statement.

When reached for comment on Tuesday, a staff member at the New Mexico Cattle Growers Association referred all questions to Uhrig.

Requests for comment sent to the Dairy Producers of New Mexico and popular Creamland Dairy went unreturned. 



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