COLUMBIA — A suspected case of E. coli in Boone County tested negative for the bacteria over the weekend, leaving four confirmed cases in the area.
The county outbreak coincides with 30 confirmed cases of the bacteria in St. Louis. Geni Alexander, spokeswoman for Columbia/Boone County Department of Health and Human Services, said two of the local cases share genetic material with the cases confirmed in St. Louis.
Although only one of the patients from these cases had recently traveled to St. Louis, both are part of the St. Louis outbreak, Alexander said.
The health department investigates cases by interviewing people who have been affected and looking for any commonalities among them. The process is difficult because it is usually weeks before patients can be interviewed. It can take up to 10 days for people to start showing symptoms, Alexander said, and often they aren't feeling well enough to be interviewed for a few days after that.
"We're sometimes asking people to think back three weeks to where they shopped, where they ate and what they had at a friend's house," Alexander said.
Public health officials have not found any commonalities among the Boone County cases and have not sent any food samples for testing, according to a health department news release.
Alexander said it's important for food to be safe, but because it's often difficult to pinpoint what causes an outbreak of E. coli, it's important for people to take precautions themselves, such as washing their produce, handling and cooking meat properly and washing their hands before they prepare food.