Pennsylvania health officials say 38 people who drank unpasteurized milk from the Your Family Cow dairy became ill, and they expect additional cases to be confirmed.

Laboratory tests confirmed Campylobacter infections in 31 Pennsylvania residents; four Maryland residents; two West Virginia residents and one New Jersey resident. 

Nearly half of those sickened are under 18, Pennsylvania health officials said. The latest onset of illness was January 27.

The Maryland Department of Health and Mental Hygiene this week isolated the outbreak strain of Campylobacter jejuni in two unopened raw milk samples from the homes of customers of the Chambersburg farm. Pennsylvania Department of Agriculture officials are still waiting test results from samples they collected.

On Friday, Your Family Cow dairy owners Edwin and Dawn Shank posted an apologetic letter to their customers on the farm’s website.

“So now the wondering, suspense and uncertainty is over for our family and farm crew and is replaced by humiliation and embarrassment,” Edwin Shank wrote. “Dawn and I have shed a lot of tears over this. Now we know for sure what the growing list of emails and calls from you were pointing to. It was us. We are very sorry.”

He also thanked customers for their messages and calls. “…it never failed to bring healing to our souls and bring strength to our hearts to hear the forgiveness in your voices and emails,” he wrote.

Promising to resume raw milk sales as quickly as possible, Shank added, “If our family’s sustainable, local, know-your-farmer-shake-his-hand food production and distribution model cannot stand up to Honesty and Truth… then I guess Dawn and I are in the wrong business.”

Shank said the milk implicated in the outbreak was bottled on January 16 and carried a best-by date of January 31. Maryland health officials have advised consumers to discard products from the dairy purchased since January 1.

In a separate notice to customers, Shank reiterated that the results of tests he commissioned after January 16 were negative for pathogens and “prove that the ‘bad-milk’ incident two weeks ago that we suspected and MD and PA Health are just now verifying, was a once-and-past-happening.”

Shank wrote that “extremely hot water is needed for washing the milk tank, milking system and bottler” and that an older water heater, which had been making water “hot but not super hot,” likely “played a part in this.”

Since they stopped selling raw milk on January 27, the Shanks said they have made several small adjustments at the dairy, including replacing an older water heater with a tankless system that delivers hotter water, installing a computerized monitoring system, and outfitting their own laboratory to test every lot of milk produced, and then hold the milk until tests results are known.

They said they had been ready to resume selling milk on Thursday, and had sent notices announcing that, when the Pennsylvania Department of Agriculture contacted them and “instituted a whole new round of testing.”

Raw milk, which is milk not heated to kill many harmful bacteria, can become contaminated with a wide variety of germs, including E. coli O157:H7, Salmonella and Campylobacter, primarily from cow feces. Campylobacteriosis is most often associated with drinking unpasteurized milk or untreated surface water, or eating undercooked poultry, according to the Centers for Disease Control and Prevention.

Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain and fever within two to five days after exposure to the bacteria. 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.