Lab tests have confirmed the presence of Campylobacter bacteria in raw cream from Claravale Farm in California, according to state officials who have quarantined and issued a statewide recall notice for all the raw milk, raw nonfat milk and raw cream produced by the San Benito County dairy.

“Consumers are strongly urged to discard any raw milk products in their refrigerators with code dates of March 27 and earlier, and retailers are to to pull those products immediately from their shelves,” said California State Veterinarian Dr. Annette Whiteford.

In the announcement Friday, California Department of Food and Agriculture (CDFA) officials said the state Department of Public Health is continuing to conduct an epidemiological investigation into a cluster of Campylobacter infections, although no illnesses have yet been conclusively linked to Claravale raw milk.

Food Safety News reported earlier this week that authorities are investigating at least nine cases of campylobacteriosis associated with consumption of unpasteurized milk products from Claravale Farm. Many of those sickened are children.

Claravale Farm voluntarily stopped distributing its raw cow and goat milk products this week after the CDFA made a preliminary finding of Campylobacter in the dairy’s raw cream.

In February, Claravale also temporarily halted milk sales as CDPH began investigating the possibility that some of its products were contaminated with Campylobacter.

Claravale Farm is one of two state-licensed commercial raw milk dairies in California. Organic Pastures, the state’s other major raw milk dairy, is implicated in a 2011 outbreak of E. coli O157:H7 that sickened five children and a 2006 E. coli outbreak in which six children were infected.

All milk is susceptible to becoming contaminated, especially from manure, which can carry a wide variety of germs, including E. coli O157:H7, Salmonella, Listeria and Campylobacter. Heat treating milk — pasteurization — provides a significant measure of safety from these harmful bacteria.

Raw milk products account for about one percent of dairy production in the U.S., but raw milk dairies are linked to 60 percent of milk-related disease outbreaks. The Centers for Disease Control and Prevention recently reported that raw milk and raw milk products are 150 times more likely than their pasteurized counterparts to sicken those who consume them.

States that permit raw milk sales have more than twice as many illness outbreaks as states where raw milk sales are not legally allowed, the CDC said.

Since January 2007, the end of the CDC’s review, there have been at least 56 more foodborne illness outbreaks linked to raw milk. In 2010 ad 2011, unpasteurized dairy products were associated with 21 outbreaks and 201 illnesses, compared with two outbreaks and 39 illnesses caused by pasteurized dairy products.

Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain and fever that typically lasts one week. Some infected persons do not have any symptoms.

About one in every 1,000 reported Campylobacter illnesses leads to Guillain-Barré syndrome (GBS), which can result in paralysis. According to CDC estimates, as many as 40 percent of GBS cases in the U.S. may be triggered by campylobacteriosis.

A Campylobacter outbreak involving raw milk from a Pennsylvania dairy this year sickened at least 80 people.