An E. coli outbreak during a school trip to the Appalachian Fairgrounds is continuing to leave children in the hospital.

According to the Northeast Regional Health Office, eight children have been hospitalized and four others seriously ill. The kids who have contracted the bacteria were students in Washington County, Tennessee and Sullivan County.

According to a statement from Northeast Regional Health Office Medical Director Dr. David, Kirschke, the illnesses occurred after elementary school classes visited an animal exhibit at the fairgrounds.

Appalachian Fairgrounds Manager Phil Booher said during a phone call that he wasn’t sure what animals the guest came into contact with.

Less than three weeks ago, some Tennessee elementary school students took a field trip.
E. coli is bacteria, the CDC explains. Many strains are harmless, but there are some that can make you sick. Among those is Shiga toxin-producing E. coli, the strain health officials have determined the children were exposed to during their field trip. 

Though health officials have not identified an exact source for the infection, they did provide resources on staying healthy around animal exhibits – a common place for germs like E. coli, Cryptosporidium, and Salmonella, according to the CDC.