More than 100 poultry workers likely exposed to avian flu, Colorado health officials say

State health workers distributed antiviral medication earlier this week to more than 150 workers who were potentially exposed to poultry infected with avian flu at a commercial egg facility in Weld County.

Last week, state officials tested more than 50 symptomatic workers, Annemarie Harper, a Colorado Department of Public Health and Environment spokesperson, said in an email to The Denver Gazette.

At least four poultry workers have tested positive for avian flu. A fifth is case is presumed positive, pending confirmation.

“All of the workers who had been exposed to infected poultry and were symptomatic reported mild symptoms,” Harper said. “They were instructed to isolate and offered Tamiflu.”

None of the poultry workers were hospitalized, according to state officials.

The risk to the public continues to remain low, according to the Centers for Disease Control and Prevention (CDC).

“So far, we have not seen evidence of person-to-person transmission,” Harper said. “However, as our response is ongoing, we continue to monitor for genetic variations in the virus and changes in transmission patterns.”

The new infections doubles the number of cases found in humans in the United States since 2022.

State epidemiologists suspect the workers were exposed by working directly with infected poultry.

Earlier this month, officials reported a dairy farm employee in northeast Colorado had tested positive for a human case of avian flu associated with a multi-state virus outbreak among dairy cattle.

H5N1 — or colloquially known as “bird flu” or “avian flu” — is widely found in wild birds, causing outbreaks in poultry and U.S. dairy cows.

Risk depends on exposure, specifically to infected animals.

Coloradans should avoid touching sick or dead animals.

Individuals who must handle sick or dead animals should wear personal protective equipment — which includes an N95 respirator, eye protection and gloves — and should wash their hands with soap and water afterward handling.

The first case in the U.S. of bird flu in humans this year was identified in March.

Since 2022, more than 99 million birds in 48 states have been affected by bird flu, according to the CDC. That number in Colorado is 1.8 million, in five counties — Arapahoe, Delta, Larimer, Morgan and Weld.

H5N1 bird flu has a fatality rate of up to 90% in chickens, often within 48 hours, according to the CDC.

The last case of bird flu detected in humans in Colorado was two years ago.

At the time, the state health department reported the case was in an adult male poultry worker in Montrose County, who was largely asymptomatic.