The second recorded case ever of influenza A (H5N1) in the United States was reported last month in Texas, but officials say the threat to public health is low.
The case involved a dairy worker in an undisclosed location in Texas, according to Lara M. Anton, senior press officer for the Texas Department of State Health Services.
"The person was working directly with sick cows and had conjunctivitis (eye inflammation) as their only symptom. The person was treated with Tamiflu and has since recovered, and no other cases have been identified," Anton said.
Genetic testing of the virus found in the dairy worker indicates "the virus has not mutated in a way that would make it more likely to spread from person to person," Anton said.
No human cases of H5N1 have been reported in Arkansas, said Meg Mirivel, director of the Office of Health Communications for the Arkansas Department of Health.
The first human case of the illness was reported in 2022 in Colorado, according to the Centers for Disease Control and Prevention.
"Human infections with avian influenza A viruses, including A (H5N1) viruses, are uncommon but have occurred sporadically worldwide. CDC has been monitoring for illness among people exposed to H5 virus-infected birds since outbreaks were first detected in U.S. wild birds and poultry in late 2021," the agency said.
Symptoms of infection include mild illness (such as conjunctivitis or mild flu-like upper respiratory symptoms) to severe (such as pneumonia requiring hospitalization), according to a CDC informational flyer. An infected person may also experience a cough, sore throat, runny or stuff nose, muscle or body aches, headaches, fatigue, shortness of breath or difficulty breathing.
Less common symptoms include diarrhea, nausea, vomiting, or seizures.
A fever may not always be present, the CDC reports.
While seasonal flu vaccines reportedly provide no protection against the virus, FDA-approved flu antiviral medications are believed to be effective.
H5 bird flus are known to cause outbreaks in commercial and backyard poultry flocks and occasional infections in mammals.
The H5N1 strain in dairy cows in the U.S. was first reported in Texas and Kansas by the U.S. Department of Agriculture on March 25. Unpasteurized milk from sick cattle collected from two dairy farms in Kansas and one in Texas, as well as a throat swab from a cow in another dairy in Texas, tested positive for the virus, the CDC reported.
Colorado, Idaho, Ohio, New Mexico, North Carolina and South Dakota also have reported bird flu in dairy cows.
"Dairies are required to send only milk from healthy animals into processing for human consumption. Milk from affected animals is being diverted or destroyed so that it does not enter the food supply," the Texas Animal Health Commission said.
Pasteurization can make the virus inactive, according to the commission.
To avoid infection, people should not be near sick or dead animals or surfaces contaminated by with animal feces, litter and raw milk when not wearing respiratory or eye protection, Mirivel said.
"People should not prepare or eat uncooked or undercooked food or related uncooked food products, such as unpasteurized (raw) milk or raw cheeses, from animals with suspected or confirmed HPAI A(H5N1) virus infection," she said.
CDC is working with state and federal agencies to monitor the virus, including through close animal surveillance.