Colorado’s New Bird Flu Testing Mandate

By Tom Polansek and Leah Douglas

CHICAGO (Reuters) – Colorado has implemented a weekly testing requirement for dairies to check milk supplies for bird flu, as a federal team assists in addressing a growing outbreak.

The state’s mandate aims to pinpoint additional farms that could spread the disease, following the largest cluster of human cases in the U.S., which occurred on a Colorado farm this month.

Bird flu infections tied to dairy cows have led to the culling of 3.1 million egg-laying chickens, with poultry workers also testing positive for the virus.

Since the outbreak began in late March, Colorado has confirmed infections in 47 dairy herds, with about 60% of cases occurring in the past month. Nationwide, 13 states have reported infections in about 168 herds since spring.

Due to the significant loss of chickens, licensed dairies with lactating cows are now mandated to test bulk milk weekly, according to state veterinarian Maggie Baldwin. Approximately 70% of Colorado’s laying hens have been lost.

“We really said what we’re doing right now is not effective and we need to change strategy,” Baldwin stated.

The U.S. Department of Agriculture (USDA) has required testing for lactating cows shipped interstate since late April and has initiated a voluntary bulk milk testing program.

A USDA epidemiological “strike team” is in Colorado this week to assess how the virus may be spreading among dairies since farm workers or vehicles could carry it.

If testing uncovers additional infections, Colorado can take further measures to control the outbreak, Baldwin added.

Recently, six farm workers tested positive for bird flu after culling infected chickens, with over 150 workers potentially exposed. Moreover, a presumptive positive human case was reported at another poultry farm.

The Colorado health department has indicated that testing is ongoing.