In early April, a dairy worker in Texas was diagnosed with avian influenza, or bird flu, during a multi-state outbreak among cows.
While the virus was also found in raw milk, authorities reassured the public that the current risk was low.
This marked the first instance of this strain of bird flu, known as highly pathogenic avian influenza A (H5N1), being detected in cattle and the first documented case of cow-to-human transmission of an avian influenza virus in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC).
The individual in Texas is only the second case of bird flu in a human ever reported in the country.
Despite no evidence of human-to-human transmission of the highly pathogenic H5N1 virus, health officials remained vigilant.
In a recent press conference, a leading expert at the World Health Organization expressed concern about the potential for the virus to spread to humans, highlighting the evolving nature of bird flu viruses and their increasing infectivity in mammals.
While the current outbreak primarily affected cows in over a dozen dairy farms across the country, health officials emphasized that the risk to humans was low.
They called for increased monitoring of infected animals and individuals exposed to them.
Dr. William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center, explained that while the term "bird flu" may evoke alarm and memories of the Covid-19 pandemic, influenza among birds is not new.
The current strain of bird flu, H5N1, has been circulating globally for some time and is widespread among wild birds, causing an ongoing outbreak among poultry in the U.S.
Avian influenza type A viruses, which cause bird flu, naturally occur among wild aquatic birds such as geese, ducks, and swans, but can also circulate among domestic poultry.
These viruses can occasionally infect other mammalian species, including pigs, horses, bats, and dogs, though transmission to humans is rare.
The current outbreak of highly pathogenic H5N1 has been detected in wild aquatic birds, commercial poultry, and backyard bird flocks in the U.S. since January 2022.
While 48 states have reported cases of highly pathogenic H5N1, the outbreak affecting cows has spread to eight states so far, according to the U.S. Department of Agriculture.
Experts emphasize that the risk to the general public in the U.S. is low, with the World Health Organization describing the risk for those exposed due to their line of work as "low-to-moderate."
Transmission of avian influenza viruses to humans typically occurs through close contact with infected birds without protective gear, or through contact with environments contaminated with the virus.
While rare, cases of human-to-human transmission have occurred, often in rural areas where people live closely with poultry or other birds.
Properly prepared and cooked food, including eggs, chicken, beef, and pasteurized milk, is considered safe.
The pasteurization process in the U.S. ensures that milk products are safe for consumption.
However, experts discourage the consumption of raw milk due to associated infectious disease hazards.
While bird flu infections in humans can range from mild to severe, recovery is possible with appropriate treatment. Symptoms of avian influenza in humans may include fever, cough, runny nose, muscle or body aches, headache, fatigue, shortness of breath, eye redness or inflammation, diarrhea, and nausea.
Preventive measures recommended by the CDC include avoiding visiting poultry farms if possible, wearing a mask and avoiding touching birds when visiting such farms, avoiding sick or dead birds, maintaining good hand hygiene, not eating raw or undercooked poultry, and seeking medical attention if you become sick after contact with birds.