Bird Flu Found in California Rats as USDA Scrambles to Rehire Scientists

The U.S. Department of Agriculture (USDA) confirmed H5N1 bird flu in four black rats in Riverside County, California this week. The rats were discovered in late January near two recently affected poultry farms, marking the first detection in rats since 2021.

Newsweek reached out to the USDA via email on Saturday for comment.

Why It Matters

Black rats, typically found in urban environments, represent a new transmission risk because they can spread the virus through multiple pathways: droppings, urine, blood, and saliva. Their mobility between farms and residential areas could accelerate the virus’s spread to both humans and their pets.

Additionally, the USDA said last week that it mistakenly fired officials involved in the federal response to the H5N1 avian flu outbreak. In a statement sent to Newsweek, the agency said it is working “swiftly” to reverse the dismissals.

What To Know

This recent discovery adds rats to more than 50 North American mammal species infected with H5N1, including skunks, domestic cats, bottlenose dolphins, harbor seals, foxes, mountain lions, and coyotes.

The virus has significantly impacted U.S. agriculture, with approximately 148 million poultry birds euthanized since 2022.

The outbreak has spread to dairy cattle, with cases confirmed in 973 herds across 17 states. Nearly 70 human cases have been reported, primarily among dairy and poultry workers, with one death recorded in Louisiana.

USDA’s Fight Against the Bird Flu

The USDA combats bird flu through a combination of surveillance, containment, and prevention measures to protect poultry, livestock and public health. It monitors commercial poultry flocks, backyard birds, wild birds, and now dairy cattle, working with state agencies and private labs to detect outbreaks.

When infections are confirmed, the USDA enforces strict quarantine measures and mandates culling of affected flocks to prevent further spread, offering financial compensation to farmers. It also promotes biosecurity practices such as limiting farm visitors, disinfecting equipment and controlling bird movement to minimize risks. While the U.S. has historically avoided poultry vaccination due to trade concerns, the agency is now testing new vaccines as the virus continues to spread.

The USDA also collaborates with the Center for Disease Control (CDC) and the Food and Drug Administration (FDA) to ensure food safety and track mutations that could pose risks to humans. Additionally, it works with international partners to maintain trade stability and prevent supply chain disruptions.

What People Are Saying

A USDA spokesperson said in a statement: “Although several positions supporting [avian flu] were notified of their terminations over the weekend, we are working to swiftly rectify the situation and rescind those letters.”

The spokesperson added: “USDA’s Food Safety and Inspection Service frontline positions are considered public safety positions, and we are continuing to hire the workforce necessary to ensure the safety and adequate supply of food to fulfill our statutory mission.”

What Happens Next

The USDA says it is actively working to rehire bird flu scientists recently terminated due to cost-cutting recommendations from the Department of Government Efficiency (DOGE).

The agency has already exempted veterinarians and emergency response personnel from these cuts to maintain its bird flu monitoring and control efforts.