First Human Case of Bird Flu in Texas Confirmed, Following Infections in Cattle—Here’s What to Know

This marks only the second time in U.S. history that a human has contracted the H5N1 strain of avian influenza

A brown and white dairy cow, an orange tag dangling from its ear, bends down and eats from the ground.
A person has tested positive for the H5N1 strain of bird flu just days after livestock across four states were reported to be infected. Edwin Remsberg via Getty Images

Last week, officials announced that a number of dairy cows across 11 total herds in Texas, Kansas, Michigan and New Mexico have tested positive for the H5N1 strain of avian influenza, also known as bird flu. Now, the first human case of bird flu has been confirmed in Texas.

Whereas the livestock are likely to have contracted the virus through contact with birds carrying the strain, the infected person became ill after exposure to sick cows—marking just the second human case of H5N1 in United States history and the first in the Lone Star state.

The patient is reportedly doing well and being treated with an antiviral drug, according to a statement from the Texas Department of State Health Services (DSHS). Eye inflammation—or pink eye—is their only current symptom, and they have been instructed to isolate to prevent further spread. The Centers for Disease Control and Prevention (CDC), which conducted testing to confirm the single case, is not currently pursuing any further tests of humans who may have also been exposed, reports STAT News’ Helen Branswell.

“We are not aware of reports that any of this individual’s close contacts have developed any symptoms,” Nirav Shah, principal deputy director of the CDC, tells the publication. “The fact that there are not other samples cooking right now is reassuring, insofar as that we’re not aware of other individuals who are symptomatic following an exposure to livestock.”

The CDC remains vigilant in looking for others who report H5N1-like symptoms, though the virus presents no known risk to the public at large. Meanwhile, officials continue to stress that the milk supply is safe.

“The cattle infections do not present a concern for the commercial milk supply,” per the statement. “Dairies are required to destroy or divert milk from any sick cows, plus pasteurization kills avian flu viruses.”

Black and white dairy cows stand side-by-side, poking their heads through a metal fence
The person in Texas tested positive for the H5N1 strain after having contact with infected cattle, which are not pictured here. Iain Farrell via Flickr, under CC BY-ND 2.0 DEED

Since avian flu spilled over into mammals, its potential to evolve and infect humans has remained a concerning unknown for scientists. Foxes, raccoonssea lions, bears, minks and other mammals across the globe have contracted H5N1 and died. But up until last month, many scientists thought that livestock, such as dairy cows and goats, would not be susceptible to the strain. Now, it appears that mammal-to-mammal spread—from cow to cow, and potentially from cow to human—may be more probable than previously assumed.

“How else could it move so rapidly?” Gregory Gray, an infectious disease epidemiologist at the University of Texas Medical Branch, tells the New York Times’ Emily Anthes and Apoorva Mandavilli. However, it remains possible that each cow independently contracted the virus from a bird, perhaps through contaminated food or water.

Officials say the virus has shown no signs of evolving in a way that would make it spread easily among humans, per the New York Times.

In the past 20 years, approximately 900 human cases of avian flu have been reported across 23 countries. Older strains were more aggressive in humans, but recent iterations have generally yielded milder symptoms and less frequent infections. In 2022, the first U.S. human case of the H5N1 strain was confirmed in a Colorado man working on a poultry farm. He reported feeling fatigued and later recovered.

With the new case, health officials maintain that it is “extremely rare” for the virus to transmit between people, though they continue to approach the situation with caution.

“On the positive side, it seems like this was a very mild case, and it’s the only case that’s been identified so far,” Lauren Ancel Meyers, director of the Center for Pandemic Decision Science at the University of Texas at Austin, tells the Texas Tribune’s Neelam Bohra. “But at the same time, it seems like there’s quite a bit of this virus that has been detected in cattle populations. Anytime a virus jumps into a new species, especially a rapidly evolving virus like influenza—we need to be approaching it with the utmost caution and vigilance to make sure we really understand the situation.”

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