Person Infected With Bird Flu in Texas After Contact With Cattle

At least one particular person in Texas has been recognized with hen flu after having contact with dairy cows presumed to be contaminated, state officers stated on Monday.

The announcement provides a worrying dimension to an outbreak that has affected tens of millions of birds and sea mammals worldwide and, most not too long ago, cows within the United States.

So far, there are not any indicators that the virus has advanced in ways in which would assist it unfold extra simply amongst folks, federal officers have stated.

The affected person labored immediately with sick dairy cows, stated Lara M. Anton, a spokeswoman for the Texas Department of State Health Services. “We have tested around a dozen symptomatic people who work at dairies, and only the one person has tested positive” for the virus, she stated in an electronic mail.

The affected person’s main symptom was conjunctivitis; the person is being handled with an antiviral drug and is recovering, in accordance with the Centers for Disease Control and Prevention.

The Department of Agriculture introduced the primary instances in dairy cows final week. As of Monday evening, the virus had been confirmed in 11 herds throughout 4 states: Texas, Kansas, Michigan and New Mexico, the company stated. Cows in Idaho might also be contaminated.

The virus has been recognized as the identical model of H5N1, an influenza subtype, that’s circulating in North American birds.

The C.D.C. is working with state well being departments to watch different individuals who might have been involved with contaminated birds and animals, the company stated on Monday. It additionally urged folks to keep away from publicity to sick or useless birds and animals, and to uncooked milk, feces or different doubtlessly contaminated supplies.

This is just the second case of H5N1 hen flu in folks within the United States; the first was in 2022. The danger to most people stays low, specialists stated. But testing and evaluation is ongoing, and there are numerous unanswered questions.

“This is a rapidly evolving situation,” the usD.A. stated in its announcement final week.

Here’s what to know:

What is hen flu?

Bird flu, or avian influenza, is a gaggle of flu viruses which might be primarily tailored to birds. The explicit virus in these new instances, referred to as H5N1, was first recognized in 1996 in geese in China, and in folks in Hong Kong in 1997.

In 2020, a brand new, extremely pathogenic type of H5N1 emerged in Europe and unfold rapidly around the globe. In the United States, it has affected greater than 82 million farmed birds, the worst hen flu outbreak in U.S. historical past.

Since the virus was first recognized, sporadic instances have been present in folks in different international locations. But a overwhelming majority resulted from extended, direct contact with birds.

H5N1 doesn’t but appear to have tailored to unfold effectively amongst folks, specialists say.

How did cows get hen flu?

Cows weren’t regarded as a species at excessive danger.

“The fact that they are susceptible — the virus can replicate, can make them sick — that is something I wouldn’t have predicted,” stated Richard Webby, an influenza virologist at St. Jude Children’s Research Hospital.

But this 12 months, reviews of sick cows started to emerge in Texas and New Mexico. Dead birds have been additionally discovered on a few of these farms, and laboratory testing confirmed that some cows have been contaminated with hen flu.

There are quite a lot of ways in which the virus may need discovered its means into cattle. The probably route, a number of specialists stated, is that contaminated wild birds, which shed the virus of their feces, saliva and different secretions, contaminated the cows’ meals or water.

But different free-ranging animals recognized to be vulnerable to the virus, comparable to cats and raccoons, may even have introduced the virus onto dairy farms.

How have cows been affected?

Although the virus is usually deadly in birds, it seems to be inflicting comparatively delicate sickness in cows.

“It’s not killing animals, and they seem to be recovering,” stated Dr. Joe Armstrong, a veterinarian and cattle manufacturing professional on the University of Minnesota Extension. Last week, the usD.A. stated that there have been no plans to “depopulate,” or kill, affected herds, which is the usual process when poultry flocks are contaminated with the virus.

The illness is primarily affecting older cows, which have developed signs that embrace a lack of urge for food, a low-grade fever and a big drop in milk manufacturing. The milk that the cows do produce is usually “thick and discolored,” in accordance with Texas officers. The virus has additionally been present in unpasteurized milk samples collected from sick cows.

It is just not but clear whether or not the hen flu virus is the only reason for all of the signs and diseases which were reported, specialists cautioned.

How widespread is the issue?

It’s unclear. As of Monday, the usD.A.’s National Veterinary Services Laboratory had confirmed hen flu infections in seven herds in Texas, two in Kansas, one in Michigan and one in New Mexico, the company stated.

Initial testing has advised that an extra herd in Idaho might also have the virus, however that has not but been confirmed by the nationwide laboratory. So far, the virus has been discovered solely in dairy cows and never in beef cattle.

But as a result of cows will not be routinely examined for hen flu, and the sickness has been comparatively delicate, there could possibly be different contaminated herds which have escaped detection, specialists stated.

And the motion of cattle between states may transport the virus to new places. The affected dairy in Michigan had not too long ago imported cows from an contaminated herd in Texas. When the cows have been transported, the animals weren’t displaying any signs. The farm in Idaho had additionally not too long ago imported cows from an affected state, Idaho officers stated.

How is it spreading?

That is a key, and nonetheless unanswered, query. It is feasible that the contaminated cows are choosing up the virus independently, particularly if shared meals or water sources have been contaminated.

A extra worrisome chance, nevertheless, is that the virus is spreading from cow to cow. On Friday, the usD.A. famous that “transmission between cattle cannot be ruled out.”

Several scientists stated that they’d be shocked if there weren’t some extent of cow-to-cow transmission. “How else could it move so rapidly?” stated Dr. Gregory Gray, an infectious illness epidemiologist on the University of Texas Medical Branch.

If the virus can unfold simply between cows, that would result in bigger, extra sustained outbreaks. It would additionally give the virus extra alternatives to adapt to its new mammalian hosts, rising the danger that it acquires mutations that make it extra harmful to folks.

How will officers know if hen flu adapts to unfold between folks?

Analyzing the genetic sequence of the virus from contaminated birds, cows and other people can reveal whether or not H5N1 has acquired mutations that assist it unfold amongst folks.

Scientists have been carefully monitoring infections in birds and sea mammals and, now, cows. So far, the virus doesn’t appear to have the flexibility to unfold effectively between folks.

In 2012, scientists confirmed that H5N1 was capable of unfold by means of air between ferrets — a preferred mannequin for finding out transmission of respiratory viruses amongst folks — after buying 5 mutations.

A pattern of hen flu remoted from a Chilean man final 12 months had two mutations that point out adaptation to infecting mammals. But these mutations have beforehand been seen with out the virus evolving additional to unfold between folks, specialists stated.

Is it protected to eat dairy merchandise?

Federal officers have burdened that commercially processed milk stays protected to drink. Dairies are required to maintain milk from sick animals out of the human meals provide, and milk offered throughout state strains should be pasteurized, a course of during which the milk is heated to kill potential pathogens. Pasteurization “has continually proven to inactivate bacteria and viruses, like influenza, in milk,” the Food and Drug Administration stated in a new on-line information to take advantage of security.

Dr. Gail Hansen, a veterinary public well being professional and unbiased guide, agreed that the danger of being contaminated by pasteurized milk was most likely “very low.” She added, “I would not want people to stop drinking milk because of it.”

But the likelihood couldn’t be completely dominated out, she stated, expressing some concern that federal officers had been “overconfident in the face of so many unknowns.” If cows are shedding virus into their milk earlier than they present indicators of sickness, that milk may doubtlessly discover its means into the industrial milk provide, she stated. And completely different pathogens might require completely different pasteurization temperatures and durations; the precise circumstances required to inactivate this explicit virus remained unclear, Dr. Hansen stated.

The danger of being contaminated by the virus by consuming unpasteurized, or uncooked, dairy merchandise stays unknown, the F.D.A. stated. Raw milk is understood to pose quite a lot of potential illness dangers past avian influenza.