Seven students remained at Lansing’s Sparrow Hospital as of Tuesday afternoon.

“This particular type of E. coli – it’s actually a dangerous strain of E. coli, so we take this very seriously,” said Dean Sienko, director of the Ingham County Health Department.

Beginning Sept. 8, two students sought medical attention for the illness. Between Sept. 10 and 11, eight more students reported similar medical problems, bringing the total to 10.

Since then, Sienko said he’s only heard of one other case, with a student claiming similar symptoms Friday. It had not been confirmed if this person was infected with the same strain of E. coli.

Sienko said the strain is not a threat anymore.

“It certainly shows that it kind of peaked in the middle of last week and has come down precipitately,” he said.

Sienko said it’s still not clear how and where the bacteria was transmitted to the affected students — who all live on campus — and the investigation is ongoing. He said the county health department is interviewing the affected students about what they ate last week and analyzing their dining cards to determine a possible common eating location.

“We’re looking at all this likely being connected,” he said. “The time and onset of symptoms in such a tight time period indicates that there’s likely some connection. We’re still working on determining precisely what that is, but that’s certainly what our suspicions are.”

John Lux, a spokesperson for Sparrow, said the seven students still hospitalized are expected to make a full recovery.

“The indicators are favorable, they’re all expected to recover,” Lux said. “One or two of them may be released as early as tomorrow.”

MSU University Physician Beth Alexander said the dangerous strain of E. coli causes toxins to form in the body and cause diarrhea.

“It produces toxins that causes diarrhea which is true of many kinds of bacteria or things that cause gastrointestinal illness,” she said. “It’s not the bacteria itself, it’s the toxin.”

Sienko said this strain of E. coli is most commonly found in undercooked ground beef but also has been traced back to produce watered with contaminants.

According to the CDC, the same strain also sparked an E. coli outbreak in Michigan this past summer, affecting 20 people.

“We know the organism lives in intestines of animals so when animals defecate, they can leave this organism,” Sienko said.

He said anyone with infectious diarrhea should call the health department at (517) 887-4308 as soon as possible.

“The more people we capture, the better understanding we will likely have as to what caused things to go wrong,” Sienko said.