Multiple cases of infection are linked to raw, unpasteurized milk from Pennsylvania, according to the Maryland Department of Health and Mental Hygiene.
Three people from Maryland and three people from Pennsylvania came down with campylobacteriosis. All six drank milk from the Family Cow dairy store in Chambersburg, Pa., the Health Department said.
The Health Department suggested any product purchased at the farm since Jan. 1 be thrown away.
The Family Cow sells milk at the farm and at retail stores in Pennsylvania.
Maryland prohibits the sale of unpasteurized milk.
Campylobacter infection causes diarrhea, nausea and vomiting usually within two to five days of exposure. It can lead to more serious illness, like bloodstream infection.
Almost 600 Campylobacter infections were reported in Maryland in 2011.