Bird Flu Spreads to Dairy Cows

A type of avian influenza that’s extremely deadly in birds has been confirmed in U.S. dairy cattle in Texas and Kansas, the Division of Agriculture introduced on Monday.

It’s the first time that cows contaminated with the virus have been recognized.

The cows seem to have been contaminated by wild birds, and lifeless birds had been reported on some farms, the company mentioned. The Texas Animal Well being Fee confirmed that the influenza subtype generally known as H5N1 has been recognized and mentioned that the virus resembled the model that has been spreading in birds throughout the nation.

The outcomes had been introduced after a number of federal and state companies started investigating reviews of sick cows in Texas, Kansas and New Mexico. The sickness has primarily affected older cows, inflicting signs that embrace diminished urge for food, fever and a sudden drop in milk manufacturing. Up to now, the usD.A. mentioned, there had been few or no reviews of deaths within the affected herds.

In a number of instances, the virus was detected in unpasteurized samples of milk collected from sick cows. Pasteurization ought to inactivate the flu virus, consultants mentioned, and officers pressured that the milk provide was protected.

“At this stage, there is no such thing as a concern concerning the security of the business milk provide or that this circumstance poses a threat to shopper well being,” the company mentioned in a press release.

Outdoors consultants agreed. “It has solely been present in milk that’s grossly irregular,” mentioned Dr. Jim Lowe, a veterinarian and influenza researcher on the School of Veterinary Medication on the College of Illinois at Urbana-Champaign.

In these instances, the milk was described as thick and syrupy, he mentioned, and was discarded. The company mentioned that dairies are required to divert or destroy milk from sick animals.

The cattle infections come on the heels of the nation’s first detection of extremely pathogenic chook flu in goats, which was introduced by Minnesota officers final week.

Up to now, the flu samples from sick cows haven’t contained genetic mutations which are identified to make the virus extra prone to infect people, the agriculture company mentioned, including that the chance to most of the people remained low.

“There’s nonetheless no trigger to panic,” mentioned Stacey L. Schultz-Cherry, a virologist and influenza professional at St. Jude Kids’s Analysis Hospital. “It simply seems prefer it’s one other spillover occasion as a result of contact with diseased wild birds.”

Nonetheless, she famous, cows weren’t considered among the many species that had been notably prone to avian influenza, and the instances had been one other worrisome flip in a world chook flu outbreak that has devastated wild chook populations over the previous couple of years.

The outbreak has been brought on by a brand new type of chook flu virus, generally known as H5N1, that emerged in Europe in 2020. Wild birds can unfold the virus, by their feces and oral secretions, to farmed poultry and different animals. Outbreaks typically flare up within the spring and summer season, when migrating birds are on the transfer.

Though avian influenza viruses are tailored to unfold primarily amongst birds, the brand new model of H5N1 has grow to be so widespread in wild birds that it has additionally repeatedly unfold to mammals, particularly scavenging species, equivalent to foxes, which may feed on contaminated birds.

Contaminated wild birds might transmit the virus to cows by contaminating their meals or water, mentioned Dr. Joe Armstrong, a veterinarian and cattle manufacturing professional on the College of Minnesota Extension. “You get onto a farm, particularly throughout the migratory season, and also you’ve bought geese and geese searching for feed identical to everybody else,” he mentioned. “To me that’s the most probably route.”

However it’s also attainable that free-ranging cats, which aren’t unusual on farms and are identified to be prone to the virus, could possibly be concerned in spreading the pathogen, he mentioned.

Dr. Armstrong additionally cautioned that it was too quickly to conclude that avian influenza was the first reason for illness in all the sick cows which have been reported.

Infections of mammals, which give chook flu viruses new alternatives to evolve, are at all times a supply of some concern, Andrew Bowman, a molecular epidemiologist and influenza professional at Ohio State College, mentioned. Scientists have lengthy been involved {that a} chook flu virus that advanced to unfold extra effectively amongst mammals, together with people, might set off the following pandemic.

At this level, Dr. Bowman mentioned, it stays unclear whether or not the contaminated cows have all picked up the virus straight from birds or whether or not the virus can also be spreading from cow to cow.

“That’s a query that’s going to should get resolved rapidly,” he mentioned. “If we’ve transmission cattle to cattle, that’s a distinct story. That actually makes me slightly extra nervous.”

A better have a look at the viral genomes ought to assist scientists study extra about how the virus is spreading and whether or not it’s evolving in ways in which would enhance the general public well being threat, scientists mentioned.

These first instances additionally imply that flu surveillance in cattle ought to be ramped up, mentioned Richard Webby, a virologist and influenza professional at St. Jude Kids’s Analysis Hospital.

“It’s fairly clear that we’ve to now get a greater really feel for a way widespread that is in cows,” he mentioned. “Flu most likely wasn’t a significant a part of a diagnostic work-up for a sick cow earlier than this, but it surely’s actually going to be shifting ahead.”