USDA Bulk Milk Testing to Detect Bird Flu in the Nation’s Milk Supply

The United States Department of Agriculture (USDA) issued a press release of an upcoming rollout of bulk milk testing to detect bird flu in the nation’s milk supply.

If pasteurization kills bacteria, viruses, and other pathogens, why is this testing important?

The agency is not testing pasteurized milk for the presence of the virus. They are testing the raw milk before it undergoes a heat-kill step as a biosecurity measure to identify infected herds. It is a move meant to gather more data about the status of dairy cows.

Let’s talk about bulk milk testing and what it means for understanding the spread of bird flu.

Bird Flu in Humans Acquired by Dairy Cows

The threat of bird flu in cows has ebbed and flowed over the past year. The first reported case of bird flu in dairy cows was reported on March 25, 2024. This was the first time that virus was associated with cows.

Not long after, on April 1, 2024, the Centers for Disease Control and Prevention (CDC) confirmed a human case of bird flu from exposure to dairy cows in Texas. By May 2024, additional human cases of bird flu acquired by dairy cows began adding up.

As of November 20, 2024, there have been 31 cases of bird flu in humans acquired by dairy cows.

Bulk Milk Testing

The agency plans to enhance testing and monitoring for H5N1 (the virus associated with bird flu). A plan that builds on continued measures implemented by the USDA to detect and mitigate additional illnesses from this infection vector.

Cooperating with state partners, the USDA plans to test raw milk samples to identify herds that may be infected with the virus.

The idea is that bulk milk testing will take place at the regional level. As needed, additional testing at the farm level will take place. This tiered approach will continue until all herds in the area are determined to be free of the virus.

A New Application of an Old Idea

This not-so-new approach to keep an eye on diseases in cows is not all that different than what scientists and health agencies were doing by monitoring sewage for corona virus to identify infection hot spots.

In fact, bulk milk testing has been used as a biosecurity measure in cows before.

This same technique was employed to eradicate brucellosis (a bacterial infection that can spread from cows to humans). Efforts that were very successful.

What Does the Agency Plan to Do with Bulk Milk Testing Data

The goal of bulk milk testing is to implement containment and biosecurity measures as quickly as possible when bird flu is detected in milk from dairy cow herds.

Some States Are Already Bulk Testing Milk

Some states are already doing this. Colorado, for example, implemented bulk milk testing for bird flu after two counties were impacted. According to the most recent statewide test, no evidence of the virus in the milk supply in that state has been detected.

A sign that at least something these groups are doing is working.

More States Are Coming On Board

In the next month, the USDA plans to work with other regions and states to expand bulk milk testing. Eventually, all willing jurisdictions will participate. An effort that will help reduce the risk of spreading infection to other herds and reduce the human impact from bird flu in dairy cows.

Other Measures to Reduce Risk of Spreading Bird Flu to Other Dairy Cow Herds

To help reduce the risk of spreading bird flu to other dairy cow herds and across other states, the USDA is using certain tools at its disposal. This includes testing cattle moving across state lines, working on a bird flu vaccine, and monitoring other animals for bird flu.

Testing Cows During Interstate Travel

In addition to bulk milk testing to understand what herds are impacted, the Federal Order made in May 2024 requiring cattle to be tested before moving into another state. This interstate movement monitoring has reduced the number of states with known avian influenza detections in dairy herds from 14 to two.

Supporting Rapid Development of Bird Flu Vaccine

The USDA is supporting the rapid development of a bird flu vaccine intended for cows. However, other species are on the list for this preventative approach. Field trials are currently taking place for two vaccine candidates intended for use in dairy cows.

Monitoring Other Animals for Bird Flu

The USDA, along with other state and local agencies continue to monitor other animals for bird flu. Several barn cats from dairy farms have become seriously ill since the onset of bird flu in dairy cows. Dogs have also tested positive, in addition to mice and other small animals.

Recently, the Oregon Department of Agriculture announced the first detection of bird flu in pigs in the United States. This result came from a non-commercial farm located in the state.

Is the Milk Supply Safe?

Despite the USDA purposefully looking for bird flu in the nation’s milk supply, pasteurized milk is safe to drink.

The process of pasteurization includes a heat kill step and rapid cooling designed to kill any bacteria, virus, or parasite lurking within.

Most of the milk sold in the United States is pasteurized. But not all of it.

While anyone can become sick from consuming “raw” or unpasteurized milk, certain people are more susceptible. This includes the very young, the very old, and those with a compromised immune system are most susceptible to illness. While most people relate this to Listeria, Campylobacter, E. coli, and other typical foodborne illnesses. States with bird flu now have that risk added to an already risky product.

Want to Learn More?

If you’d like to know more about food safety topics in the news, like “USDA Bulk Milk Testing to Detect Bird Flu in the Nation’s Milk Supply,” check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!

By: Heather Van Tassell (contributing writer, non-lawyer)