Now the hunt is on. Health officials want to know how the patients got sick and if the problem is larger than they now know.
Investigators met on Monday afternoon to compare notes.
Their goal is to trace the dangerous bacteria back to its source to stop it from spreading.
It's not the number of people who became infected with E.Coli bacteria that's alarming to Livingston County's Public Health Director.
It's the time period in which they got sick.
Since August 6, seven people tested positive for contamination. Two were hospitalized. Just how they're all connected remains a mystery.
Public Health Director Joan Ellison said "There are some commonalities among cases but not enough to say there is a cluster in one geographic area."
Ellison says its all about putting the proverbial "puzzle" back together.
First, investigators interviewed the patients on what and where they ate, and then cross checked their lists.
"We have ID'ed that there may be several food establishments where they have indicated they may have purchased food, so we are interviewing the food handlers there to determine if they wore gloves, what their process was in preparing the food, etc."
Undercooked meat and unpasteurized milk or juice are common sources of E. Coli contamination.
Symptoms include severe diarrhea and abdominal cramps, and could lead to kidney damage if not treated.
Those serious complications can be dangerous for the very young, and the elderly.
Ellison added "Generally speaking we talk about the importance of washing hands before and after preparing food, after going to the bathroom, after changing diapers, anywhere that there's other contamintion or any other possibilities of contact."
The seven patients range in age from 22 to 67.
Ellison hopes her department can find the source of the contamination, or that in one way or another, the outbreak will work itself out.
"Most often in foodbourne outbreaks we never know what the real cause is, it just happens," said Ellison. "Sometimes you can put it all together and it turns out, but not always."
Right now there's no concern that the bacteria could spread among children heading back to class.
At this point, none of the patients are of school age.
If you think you or someone in your family may be infected you're asked to call the Livingston County Health Department right away, at (585) 243-7299.
For more information on the county's health alert, click here.