Five people who work at a poultry farm in northeastern Colorado have tested positive for the bird flu, the Colorado public health department reported July 14. This brings the known number of U.S. cases to nine.
It can be republished for free.The five people were likely infected by chickens, which they had been tasked with killing in response to a bird flu outbreak at the farm.
More than 99 million chickens and turkeys have been infected with a highly pathogenic strain of the bird flu that emerged at U.S. poultry farms in early 2022. Since then, the federal government has compensated poultry farmers more than $1 billion for destroying infected flocks and eggs to keep outbreaks from spreading.
The H5N1 bird flu virus has spread among poultry farms around the world for nearly 30 years. An estimated 900 people have been infected by birds, and roughly half have died from the disease.
The virus made an unprecedented shift this year to dairy cattle in the U.S. This poses a higher threat because it means the virus has adapted to replicate within cows’ cells, which are more like human cells. The four other people diagnosed with bird flu this year in the U.S. worked on dairy farms with outbreaks.
Scientists have warned that the virus could mutate to spread from person to person, like the seasonal flu, and spark a pandemic. There’s no sign of that, yet.
So far, all nine cases reported this year have been mild, consisting of eye irritation, a runny nose, and other respiratory symptoms. However, numbers remain too low to say anything certain about the disease because, in general, flu symptoms can vary among people with only a minority needing hospitalization.
The number of people who have gotten the virus from poultry or cattle may be higher than nine. The Centers for Disease Control and Prevention has tested only about 60 people over the past four months, and powerful diagnostic laboratories that typically detect diseases remain barred from testing. Testing of farmworkers and animals is needed to detect the H5N1 bird flu virus, study it, and stop it before it becomes a fixture on farms.
