Concern grows as bird flu outbreaks continue to rise among California dairy herds

Reports of H5N1 bird flu outbreaks at California dairy herds are continuing to rise as the nation’s largest milk producer scrambles to contain the spread.

On Monday, officials reported that the number of infected dairy herds in the Central Valley had doubled over the weekend, rising from 17 to 34.

A spokesman for the California Department of Food and Agriculture said they expect more cases to be announced in the coming days and weeks, as testing continues.

With roughly 1,100 dairy herds in California — and 90% located in the San Joaquin Valley — concern is palpable, say industry insiders. Outbreaks interrupt milk production at affected dairies. Not only are the infected herds quarantined, but special testing must be conducted at nearby dairy farms as well.

“Farmers are genuinely worried about the virus and do not feel it’s under control,” said Anja Raudabaugh, CEO of Western United Dairies, the trade association of California dairy farmers. She added the industry is hoping a vaccine for cows will be developed “that would protect our animals” and be compliant under trade agreements.

The threat to humans is considered low. However, infectious disease experts worry that the longer the the virus remains present in dairy farms, the greater the likelihood it could mix with a human virus and pose a greater risk to people.

Both state and federal health officials say milk is safe to drink, as long as it has been pasteurized.

Steve Lyle, an agriculture department spokesman, said the agency’s call to to test dairies within six miles of infected herds, as well dairies that share share personnel or equipment with infected herds, has allowed officials to detect infected dairies “at about the time or just before they are showing clinical signs –- during their incubation period.”

The U.S. Department of Agriculture is working on a bovine vaccination for bird flu, but noted in a statement that this does not mean efforts to control the virus have failed.

“The pursuit of bovine vaccine development does not mean that biosecurity measures have failed,” the agency said in a prepared statement. “Nor does it mean that USDA believes the virus is here to stay. Vaccine development is one part of an overall strategy that includes enhanced and strengthened biosecurity efforts to contain the virus and help mitigate spread.”

The statement went on to say that a vaccine could prove helpful in eliminating the virus from the nation’s dairy cattle, but it’s just one tool.

“We continue to deploy all available efforts, including biosecurity and mandating the testing of lactating dairy cattle moving across state lines,” the statement said.

It is still unclear how the virus got into the state, but genetic sequencing suggests the virus is similar to that found in infected cattle in other states — and that it did not come from wild birds.

It is also unclear what impact the disease will have on milk production in the state, although Raudabaugh said it will not affect milk prices.

“Dairy is a ‘loss leader’ at the grocery store,” she said, and is often the major incentive for other items in the store.