That Bloomington, Illinois, McDonald’s restaurant that closed because of possible links to a Salmonella outbreak has reopened after tests cleared employees to return to work.

The McLean County Health Department (MCHD) and the Illinois Department of Public Health are still investigating the source of the salmonella cluster, which originated from individuals who reported eating at a variety of different restaurants in Central Illinois from Oct. 18 to Nov. 11. Not all cases in the investigation have a relationship to the McDonald’s restaurant on South Main Street in Bloomington, and the investigation at this time is focused on preventing further spread of illness.

The suspected transmission of salmonella related to this cluster does not seem to be a certain food, but rather human transmission. As a result, MCHD collected samples from all employees of the establishment to test for infection out of an abundance of caution. All samples collected from surface-testing in the establishment were free of salmonella bacteria.

At this time, 12 reported Salmonella Stanley cases have been confirmed through laboratory testing in McLean County.