Raw milk from Foundation Farm near Wilsonville, Oregon, has been identified as the link in an outbreak of E. coli infections that has put four children in the hospital and may have sickened as many as 18 people.

According to a news release Tuesday from the Oregon Department of Public Health, test results of samples taken from Foundation Farm’s cows, manure and surfaces at the farm, as well as raw milk from a farm customer, are positive for E. coli O157:H7.

milk-cartons-on-black-406.jpgThe samples were gathered from leftover milk recovered from one household, rectal swabs from two to four cows, and multiple manure and other environment samples collected at the farm.

“We continue to warn people to not drink the raw milk or any products made from this farm or any other source,”  Public Health Epidemiologist Dr. Katrina Hedberg said in the news release.

Of the four children hospitalized, all have developed hemolytic uremic syndrome (HUS), a type of kidney failure.

As of Tuesday, a total of five people, ages 1 to 14, have lab-confirmed cases of E. coli infection. Thirteen others have reported having diarrhea, but their cases have not been lab-confimed.

All of the ill people drank milk from Foundation Farm, according to the state’s Public Health Department.

Health officials in Clackamas, Washington and Multnomah counties and the Oregon Department of Agriculture are investigating these cases, which includes interviewing customers and family members of those infected.

E. coli can be transmitted by someone who has been infected with the potentially fatal pathogen.

Bruce Pokarney, spokesman for the Oregon Agriculture Department, said the farm’s owner, Brad Salyers, has been forthcoming with information and very cooperative.

“He told  his customers about it as soon as he knew there was a problem,” Pokarney said.  Foundation Farm, which distributes raw milk to 48 families, operates as a herdshare, a type of enterprise that allows people to buy shares in the herd or even an individual animal. Under that sort of arrangement, they are not considered customers. Pokarney said herdshares are legal in Oregon because there are no laws prohibiting them.

Oregon permits on-farm sales of raw milk from farms with no more than two producing cows, nine producing sheep, and/or nine producing goats. No advertising is allowed.

Farmers producing raw goat or sheep milk can sell in retail stores if they obtain a producer-distributor license and have their own bottling plant on site.

Food Safety New’s efforts to contact the Foundation Farm owner were not successful.

E. coli O157 infections are characterized by diarrhea — sometimes bloody — and abdominal pain. Kidney failure and related complications may occur, especially among young children and the elderly. Symptoms usually develop within two to eight days of eating contaminated food. Antibiotics have not been shown to reduce the duration or severity of symptoms, and may increase the risk of kidney failure.

Anyone who has consumed raw milk and is experiencing these symptoms is urged to contact his or her doctor or health-care provider.

Food safety attorney, Bill Marler, and publisher of Food Safety News, said he has been tracking raw milk outbreaks for the past several years and that as raw milk consumption has increased, so too has the number of people who have become ill from drinking it.

“We are seeing more E. coli and Campylobacter illnesses — especially in children,” he said. ” The bottom line is that raw milk is a risky elixir.”

Oregon Public Health epidemiologist Dr. Katrina Hedberg warns that pasteurized milk is the only safe milk “because it kills harmful bacteria such as E. coli.

Go here for more information about E. coli.