A farmworker on an egg farm in northeastern Colorado is the ninth person in the state, and the 12th in the nation, to be diagnosed with the H5N1 avian flu virus, said state public health officials. The new case was confirmed at a different farm in Weld County than the location where six laborers were infected in the past week.
“Testing of other workers, who are culling infected poultry at the commercial egg layer operation, is ongoing,” said the Colorado Department of Public Health and Environment.
Besides the seven infections at the egg farms, a dairy worker in Colorado was infected in early July and in 2022, a correctional inmate was infected while culling chickens in western Colorado. Three other farmworkers, two in Michigan and one in Texas, have contracted bird flu since April while employed on dairy farms. In all of the cases, symptoms were mild.
Highly pathogenic aviation influenza (HPAI) was reported at two egg farms with a total of 3.1 million hens in Weld County this month. More than a quarter of U.S. dairy herds infected with the avian flu virus, 46 of 168, are in Colorado.
The risk of bird flu to the general population remains low, said the Centers for Disease Control.
For weeks, public health officials have encouraged people to wear protective gear, such as goggles, masks, and gloves, if they work around infected or possibly infected animals. But they acknowledge the difficulty of wearing a full set of protective equipment — water-resistant coveralls, boots, gloves, masks, and goggles — while killing and disposing of infected chickens during hot weather.
Analysis of blood samples from Michigan dairy farmworkers suggest “asymptomatic infections in people are not occurring” — an important result that buttresses the current protocol to test people for bird flu if they have been exposed to sick animals and develop symptoms, said the CDC. The Michigan Department of Health and Human Services led the seroprevalence study, which examined blood samples from 35 people who worked on two dairy farms with infected herds. The employees worked directly with sick cows. Fewer than half of them reported using masks or goggles, said the CDC.
Fifteen dairy herds in eight states have enrolled in a herd status program that calls for weekly testing of milk from bulk coolers for presence of the avian flu virus, said the USDA. In exchange, farmers are not required to test lactating cows for bird flu before transporting them across state lines if they have tested negative for three weeks. Two of the states in the program, Nebraska and Pennsylvania, are free of bird flu in cattle.