A Bloomington, Illinois McDonald’s restaurant that voluntarily closed down while being investigated as a possible link to a 12-person Salmonella outbreak, has been cleared to reopen, the McLean County Health Department (MCHD) announced on Sunday.

According to MCHD, the restaurant was closed for Thanksgiving on Nov. 22 and then the owners chose to keep the establishment closed while MCHD investigated the cause of the Salmonella Stanley. After employees were cleared by lab results, the restaurant was approved to reopen Sunday morning, with condensed hours.

Local health officials have not yet determined the source of the cluster of illnesses, which includes 12 individuals who ate a variety of different restaurants in Central Illinois from Oct. 18 to Nov. 11, according to MCHD. The county and the Illinois Department of Public Health are still investigating.

“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,” said a press release by MCHD. “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.”

“This scenario could occur at any place of business, restaurant or home,” McLean County Health Department Director Walt Howe said. “As we enter the holiday season, it’s important to remind people that if you’re sick, stay home to protect family, friends or co-workers from becoming sick. Healthy individuals should wash their hands diligently and use a barrier, such as a napkin or a paper towel, to turn off faucets or open doors in public facilities.”

MCHD also reminded consumers that symptoms of Salmonellosis include fever, vomiting, abdominal cramps and diarrhea. This specific strain of salmonella—Salmonella Stanley— can produce bloody diarrhea. Those who think they may have been sickened are encouraged to contact the MCHD Communicable Disease division at 309-888-5435.