This story by Coral Beach first appeared in Food Safety News and is reposted here with permission.

Unpasteurized, raw milk and a visit to an unrelated agricultural animal operation are most likely the causes of an outbreak of E. coli infections among children in Knox County, TN. At least four of the victims are in kidney failure.

Health department spokeswoman Katharine Killen told Food Safety News this afternoon that all of the confirmed illnesses have been caused by the same serotype of E. coli bacteria. During a press conference with local media today, Dr. Joe Childs of East Tennessee Children’s Hospital also reported that all of the cases at that hospital are from one serotype.

Knox County Health Department epidemiologists are working with investigators from the state’s health department and other local and state agencies, including agriculture officials to pinpoint the source of the bacteria.

Childs said the ongoing E. coli outbreak is the largest he has seen in his 30 years at the hospital. Killen said the county averages only about 19 cases on an annual basis. Both said some of the sick children had consumed unpasteurized milk in the days before their symptoms began.

Other victims visited a farm unrelated to the raw milk dairy before becoming ill. Cows and other animals carry E. coli that can cause serious infections in humans. Swimming pools, however — especially public pools — are not a likely source because chemicals used to treat the water are very effective at killing E. coli bacteria, Childs said.

Neither the doctor nor the county spokeswoman would identify the dairy or animal farm. Killen said she wasn’t sure if the dairy was still selling its unpasteurized milk as of this afternoon. A conference call set today could provide more details.

The county started receiving reports about a cluster of E. coli infections among children last week, Killen said. She did not provide the total number of cases or the age range of the patients. However, there are “several” cases and all are children, according to county information.

The East Tennessee Children’s Hospital started hearing about the cluster of E. coli illnesses about 10 days ago, Childs said. He said the hospital is “approaching” 10 cases. Some children who were admitted have recovered enough to go home. Other’s are more seriously ill. Children started being admitted to intensive care units at the hospital about four days ago. Four of the children have developed a life-threatening form of kidney failure called hemolytic uremic syndrome (HUS).

Tennessee is one of the states that allows sales of unpasteurized raw milk. Federal law prohibits the interstate sale of raw milk because of its high risk for causing foodborne illnesses. Young children, elderly people, pregnant women and people with depleted immune systems are at the highest risk of developing life-threatening complications, according to a wide variety of health care providers and other entities.

Among those recommending against consumption of unpasteurized, raw milk are the American Academy of Pediatrics, state health departments, the federal Centers for Disease Control and Prevention, the Food and Drug Administration, and the U.S. Department of Agriculture.

Pasteurization is the process of heating milk to 161 degrees F for 15 seconds. It kills bacteria, viruses and parasites commonly carried by dairy cows. Those pathogens include E. coli, Listeria monocytogenes and Brucella.

Advice to consumers
Anyone in the Knox County area — including people who consumed raw milk from the area or visited an animal operation — who develops symptoms of E. coli infection should immediately seek medical attention. 

People should make sure their doctors know about their possible exposure to the pathogen so the proper diagnostic testing and treatment can be provided, Childs said. 

Antibiotics generally should not be used for E. coli infections because the bacteria die off and release even more toxins into the body. This complicates diagnosis because the symptoms of E. coli infections are similar to other illnesses that should be treated with antibiotics.

Symptoms usually begin one to eight days after ingesting the bacteria, according to the U.S. Centers for Disease and Prevention. Symptoms can include diarrhea that can range from mild and watery to severe and bloody; abdominal cramping, pain or tenderness; nausea; and vomiting in some people.

Healthy adults usually recover from E. coli O157:H7 infections within a week. Young children, older adults, pregnant women and people with compromised immune systems have a greater risk of developing a life-threatening form of kidney failure called hemolytic uremic syndrome (HUS).