Health officials confirmed Sunday that four poultry workers in Colorado have been diagnosed with bird flu.
The U.S. total is now nine cases since the first human case of the current outbreak was detected in 2022, with eight cases reported this year.
The symptoms experienced by the affected workers were relatively mild, including reddened and irritated eyes, fever, chills, coughing, sore throat, and runny nose. None of them required hospitalization. Similarly, the other cases in the U.S. have also been mild.
One additional person showing symptoms is currently undergoing testing, awaiting the results. These workers had direct contact with infected birds while culling poultry at a farm in northeast Colorado, according to state health officials.
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The bird flu virus has been spreading among mammals in numerous countries since 2020, affecting various animals such as dogs, cats, skunks, bears, seals, and porpoises. Earlier this year, the H5N1 virus was also detected in U.S. livestock and is now circulating among cattle in several states.
Although health officials assess the threat to the general public as low, they are closely monitoring the situation due to the potential lethality of previous versions of the virus. The virus has not yet been transmitted between people.
A team of nine personnel from the Centers for Disease Control and Prevention has been dispatched to Colorado at the state’s request to assist in the investigation.
Prior cases earlier this year involved dairy farm workers in Michigan, Texas, and Colorado. The virus strain identified in the four most recent cases is partially similar to the type found in previous U.S. cases, with ongoing genetic analysis to confirm the exact match.
As of Friday, the H5N1 virus has been detected in 152 dairy herds across 12 states, and numerous commercial poultry flocks in over 30 states have reported H5N1 or other bird flu strains.
