(NewsNation) — A dairy farmworker who is the first reported human case of avian influenza, or “bird flu,” recorded in the state of Texas did not experience fever, feverishness or respiratory symptoms last month, according to scientists.

A new report published by the The New England Journal of Medicine Friday said while the farmer had an “onset of redness and discomfort in the right eye” consistent with conjunctivitis, his vital signs were “unremarkable.” They showed normal respiratory effort and oxygen saturation of 97% while the patient was breathing regular air, scientists from the Centers for Disease Control and Prevention, Texas Department of State Health Services and Texas Tech University Bioterrorism Response Laboratory said. 

The worker did not have any contact with sick or dead wild birds, poultry, or other animals except for “direct and close exposure” to cows, some of which showed signs of illness similar to those of animals at different farms in the area. These included decreased milk production, reduced appetite, lethargy, fever and dehydration. The dairy farmworker wore gloves but did not use any respiratory or eye protection, the report said. 

The farmworker, who had only the second recorded human case of bird flu in the United States, was diagnosed after conjunctival and nasopharyngeal swab specimens were obtained from his right eye for influenza testing. Test swabs showed he had the same strain of bird flu being reported in dairy cows around the same time.

A day after being tested, the farmworker said they had no symptoms except for feeling discomfort in both eyes. In the following days, the worker said his conjunctivitis, commonly known as “pink eye,” had cleared, and those in his household were OK as well.

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The Texas Department of State Health Services said in a news release at the time that even with this case, the bird flu risk to the general public remains low. 

Still, the CDC said Friday it is continuing to respond to the “public health challenge posed” by the multistate outbreak of bird flu in animals.

U.S. officials had previously announced that milk from dairy cows in Texas and Kansas tested positive for bird flu, with cattle in other states affected as well. 

Wild birds, the United States Department of Agriculture had said, were likely the source of the infection.

“CDC is working in collaboration with the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), state public health and animal health officials, and other partners using a One Health approach,” the agency said on its website. 

As of last Friday, at least 220 people have been monitored, with at least 30 people tested for novel influenza A, since March 2024, per CDC data. Still, there has been only one case, the Texas man, in that time period. 

“Although avian (bird) influenza (flu) A viruses (sic) usually do not infect people, there have been some rare cases of human infection with these viruses,” the Centers for Disease Control and Prevention wrote on its website.

Infected birds shed the virus through saliva, mucus and feces, while humans get it through their eyes, nose or mouth. 

People who get the bird flu can develop illnesses with a range of symptoms, from virtually none to severe diseases resulting in death. According to the CDC, less common symptoms include diarrhea, nausea, vomiting or seizures.

To diagnose bird flu virus infection, the CDC says laboratory testing is required. 

First identified as a potential threat during a 1997 outbreak in Hong Kong, the first time a human was diagnosed with bird flu in America was in 2022. That man, who had picked up the virus while killing infected birds at a poultry farm as part of a prison work program, said his only symptom was fatigue. He ultimately recovered.

More than 460 people have died in the past twenty years from bird flu infections, the World Health Organization says.