There now are 12 cases of Campylobacter infection among people who drank unpasteurized milk from a dairy in Chambersburg, PA, Pennsylvania health officials reported Monday.

State health and agriculture investigators are awaiting results of tests later this week to see if they can help determine whether milk from the Family Cow farm is the cause of the illnesses.

Last week, the Maryland Department of Health and Mental Hygiene issued a news release reporting 3 cases of Campylobacter Infection in Maryland, and 3 in Pennsylvania associated with raw milk from the Family Cow dairy, and recommended consumers discard any product purchased there since January 1. The health department alert said all of those sickened with campylobacteris “consumed raw milk from this farm.”

The retail sale of raw milk is legal in Pennsylvania but not allowed under Maryland state law.

The dairy agreed to temporarily halt its sale of unpasteurized milk. 

On Monday, Edwin and Dawn Shank, owners of The Family Cow farm, said results from “our last several month’s pathogen testing” were negative, and that preliminary results from an independent lab indicated no illness-causing bacteria in four samples from a more recent raw milk bottling.

The Shanks said they are skeptical “if this apparently powerful diarrhea bug we were hearing about is actually connected to our farm or if it was something going around in other communities not in any way connected to us.”

Symptoms of Campylobacter infection can occur within 2 and as many as 10 days after the bacteria are ingested, and stool cultures to isolate the bacteria, which are not fast growing organisms, can take up to a week. 

The shelf life for raw milk is about 10 days.

In many foodborne illness investigations, there is significant lag time between when a contaminated food is eaten, and when illnesses are diagnosed, confirmed and reported, and an outbreak is identified. By then, food that was the source of illnesses may no longer be available to be tested.

According to the Centers for Disease Control and Prevention, 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, and can result in paralysis. The CDC estimates that as many as 40 percent of Guillain-Barré syndrome cases in the U.S. may be triggered by campylobacteriosis.

To prevent Campylobacter infection, the CDC advises cooking poultry products thoroughly, washing hands with soap before preparing food, avoiding cross-contamination in the kitchen, and not drinking unpasteurized milk or untreated surface water.