Health officials are warning people not to drink unpasteurized milk from Tucker Adkins Dairy of York, South Carolina, because as many as eight cases of Campylobacter infection in neighboring North Carolina have been linked to the farm’s raw milk.

The U.S. Food and Drug Administration said on Saturday that the outbreak includes three confirmed cases and five probable cases of campylobacteriosis, a diarrheal illness caused by ingesting fecal bacteria.

The eight North Carolina residents sickened are from three different households. All said they drank raw milk delivered from Tucker Adkins Dairy on June 14, and the onset of their illnesses was in “mid June,” according to the FDA.  One person was admitted to the hospital with severe symptoms.

Dairy owner Carolyn Adkins told the Associated Press that South Carolina health officials have not detected the bacteria in milk samples. A spokesman for the state health department said lab test results are still pending.  It’s not clear from press reports when the milk samples were collected or if there was any milk available from the implicated June 14 batch to test.

Although the retail sale of raw milk is legal within South Carolina, it is prohibited in North Carolina, where unpasteurized milk is sometimes distributed through informal “milk clubs.”  Under federal law, milk sold across states lines must first be pasteurized to protect the public health. There is no law against drinking raw milk.

The North Carolina customers who became ill told public health investigators they were getting raw milk deliveries twice a month via a courier from South Carolina; the FDA said the raw milk could have been distributed in other states as well. “While it is believed the full distribution of this courier is limited, this information is not fully understood at this time,” the FDA said in a news release. The agency said the milk was being transported in one-gallon containers.

The North Carolina Division of Public Health and the state’s Department of Agriculture and Consumer Services, together with the South Carolina Department of Health and Environmental Control and the FDA, are working to investigate the outbreak and “to take appropriate action to address any product that may be remaining on the market,” the FDA said in its warning statement.

Advocates extol raw milk as natural, and fecal and other microorganisms are a natural part of dairy milk. The FDA says the claim that fresh milk is antimicrobial is false: “raw milk does not contain compounds that will kill harmful bacteria.”

Raw milk has long been and continues to be a common vehicle for Campylobacter as well as Salmonella, E. coli and other pathogens. Healthy cows, goats and other animals, grass-fed or grain-fed, from small farms or large-scale operations, shed germs in their feces, and excrement can contaminate milk, usually during milking. Pasteurization — heating milk briefly, to 161 degrees for about 20 seconds — is an effective way to eliminate harmful bacteria, and public health experts stress that pasteurization does not make milk less nutritious. 

Campylobacter causes two to five days of abdominal cramps, pain, fever, vomiting and diarrhea. Most people recover after about 10 days, although there can be long-term effects such as arthritis.  About one out of every 1,000 reported Campylobacter cases leads to Guillain-Barre syndrome (GBS), a serious complication that can include paralysis. An estimated 40 percent of GBS cases in the U.S. are triggered by campylobacteriosis.

The Centers for Disease Control and Prevention says that from 1998 to 2008 it recorded 85 outbreaks of disease with a total of 1,614 reported illnesses, 187 hospitalizations and two deaths related to raw milk. The actual number of illnesses is likely much higher, because not all cases of foodborne illness are lab-confirmed and reported.