Colorado's outbreak of avian flu in poultry and dairy cattle seems to have died down, though the state continues to monitor farms for signs of the virus. That doesn't include regularly testing farms' workers though—unless they have symptoms and their employers have a known outbreak. Dairies have to bulk-test their milk at least once a week for H5N1, a flu virus that is particularly lethal to poultry and spilled over to cattle earlier this year.
Poultry farms that had to cull their animals because of infections also must test as they introduce new birds, in case they missed something while disinfecting. Surveillance of people is far less regular, though. The Colorado Department of Public Health and Environment only monitors workers on farms with known outbreaks, and only tests those who show symptoms, which is in line with guidance from the Centers for Disease Control and Prevention.
The department hasn't reported any new human testing since at least the start of September. At that point, 137 people had taken tests and 10 came back positive since 2022. The health department also routinely tests wastewater for unusual spikes in flu, and asks local labs to send samples of the influenza family that includes H5N1, so it can find out if that particular strain is spreading, spokeswoman Kristin Richmann said.
"Since there is a substantial decrease in newly affected farms in Colorado, no active outbreaks among birds at poultry facilities and no affected dairies with symptomatic work.