California officials have confirmed three new cases of H5N1 avian influenza at dairy farms in the Central Valley, bringing the total number of infected farms to six.
Wednesday’s announcement came as Missouri health officials try to determine how people with no ties to dairy or poultry farming became infected.
“While other cases of novel influenza have been detected through the country’s national influenza surveillance system, this is the first time the system has detected a case of H5,” according to a statement from the Centers for Disease Control and Prevention.
The California Department of Food and Agriculture said the newly reported cluster was “a group that was targeted for testing due to heightened risk from recent contact.”
Nationwide, 201 herds have been infected in 14 states, with a new infected herd identified in Michigan earlier this week.
In a statement, the state Agriculture Department said the discovery of the three new herds was not unexpected, but was the result of its surveillance methods aimed at “locating affected farms as quickly as possible.”
The affected dairy farms have been quarantined and “enhanced biosecurity measures are being implemented to prevent the spread of the virus,” officials said.
The risk of H5N1 to the general population remains low, and milk and dairy products in the state are safe and “unaffected by these events,” the statement said. Health officials said consumers of pasteurized milk and dairy products need not be concerned because pasteurization inactivates the virus.
Steve Lyle, a spokesman for the state’s Agriculture Department, said none of the affected farms are raw milk farms.
There are at least four raw milk dairies in California: three in the Central Valley and a fourth in Grenada, north of Mount Shasta.
Mark McAfee, owner of Raw Milk Farms, which operates farms in Fresno and Hanford, said he tests his milk regularly and so far his cows have tested negative for the virus.
