Flu virus that killed millions of poultry found in dairy cows. Is it in California?

A highly pathogenic flu virus that has jumped from poultry to dairy cows is spreading its way across the United States and raising concerns among California dairy operators, the nation’s top milk producers.

The virus, known as Avian influenza, bird flu, or H5N1 , is fatal to poultry and is responsible for wiping out 50.5 million birds during a major outbreak in 2015.

But the insidious virus hasn’t stopped there.

In March, scientists discovered dairy cows in Texas, Kansas and New Mexico had become sick from the contagious virus. Within six months, 189 dairy herds in 13 states were infected, according to the Centers for Disease Control and Prevention.

This jump to dairy cows from birds surprised scientists, prompting California dairy operators and industry officials to be on edge ever since.

“It is alarming,” said Anja Raudabaugh, chief executive officer of Western United Dairies in Modesto.

For now, California remains free of avian flu. Industry officials credit the coordinated mitigation efforts of dairy operators, scientists and health officials for holding the line and keeping the virus out of the state.

Any cow, beef or dairy, is forbidden from entering the state without a Certificate of Veterinary Inspection for cattle. There are few exemptions, including cattle being transported directly for slaughter.

There is much at stake in California where milk and dairy products were valued at $10.4 billion in 2022.

California, lead by the San Joaquin Valley, dominates U.S. milk production, pumping out more than 4 billion pounds annually. In the Valley, Tulare County reigns as the number one milk producer in the nation, supplying about one-fourth of the state’s production.

Extra vigilant

Tulare County dairy farmer Tom Barcellos has remained extra vigilant since news broke of the avian flu. Dairy operators in California are no strangers to protecting against diseases. In 2012 a dairy cow in Tulare County was discovered to have Mad cow disease, or bovine spongiform encephalopathy.

The cow was euthanized and was not slated for the ground beef market. Nationwide, about 20% of the U.S. ground beef supply comes from dairy cows.

Barcellos keeps a close watch over his cow’s health and maintains strict guidelines for who is allowed on his dairy. His dairy workers also regularly use hand washes and sanitizing products when working around the cows.

Recently, Barcellos sold some of his bulls and when the buyer came to pick them up, the driver sprayed his trailer, including tires, with a disinfectant before entering the dairy.

“The folks who come onto our dairy are taking precautions, and we are as well,” Barcellos said. “If that virus comes into California, it is not going to happen without the industry having taken precautions.”

Scientists believe the avian flu virus was transmitted to cows from an infected wild bird or from direct contact from a dairy worker or unwashed livestock trailer.

Michael Payne, a food animal veterinarian with the UC Davis Western Institute for Food Safety and Security, said it is likely that the virus was spread from cow to cow by milking or by dairy workers coming in contact with an infected cow.

Payne said the virus can be contained in a cow’s droplets of saliva or in the unpasteurized milk. Researchers noted that several cats on dairies with infected cows died after drinking raw milk.

As a precaution, Payne and other food safety experts strongly recommend to not drink raw milk, ever.

Pasteurization of milk is designed to kill harmful bacteria and viruses, including the avian flu.

“Drinking raw milk is like playing Russian roulette with your health,” he said. “And with the avian flu it is like putting another bullet in the chamber.”

Humans at risk

Although not deadly to cows, the virus causes the animals to become lethargic and to produce less milk, resulting in a loss of revenue for the dairy operator. Sick cows must also must be taken out of milking rotation and isolated from the rest of the cows until they recover, a process that could take several weeks.

“Some dairies with infected cows lost 30% to 40% of their milk production for several months,” said Anja Raudabaugh, chief executive officer of Western Unitied Dairies in Modesto.

Dairy workers are also at risk of becoming infected with flu-like symptoms. The CDC recommends workers should wear personal protective equipment, including fluid-resistant coveralls, gloves, boots and safety googles.

Since March, four dairy workers have become sick with the avian flu with mild-to-moderate symptoms, according to the CDC.

According to the CDC, human infections can happen when the virus gets into a person’s eyes, nose or mouth, or is inhaled.

Although California has been successful in preventing the virus from crossing it’s borders, Payne believes it may not be able to keep it out forever.

It’s possible the virus could run its course and burn itself out without mutating into something more devastating. The worst case scenario is that the virus mutates, much like the coronavirus did during the pandemic, and becomes easily transmissible to humans.

“The risk of that happening has not changed,” Payne said. “But we are also better prepared because of the Covid outbreak and the immunization tools and vaccination technologies that we developed.”