Correction appended: May 23.
Up to 5,000 people may have eaten at a fast food restaurant in Springfield, Missouri, where an employee had hepatitis A and was possibly contagious.
Food chain Red Robin told people who visited their Springfield location in mid-May to contact the health department for more information about the situation, CNN reports.
The restaurant chain said the employee in question last worked on May 16 and that the restaurant had been deemed safe after a county health department check. However, county health officials said customers should watch out for symptoms including fever, nausea, abdominal pain, dark urine and clay-colored bowel movements.
"It scared me because my husband has been sick," Andrea Hall, a Red Robin customer, told CNN. "And a lot of his symptoms of his matched. A red flag just went off and I was like what do I do from here."
Every worker at Springfield's Red Robin location has been treated for the illness. The county health department will also run a two-day vaccination clinic nearby for concerned customers.
Hepatitis A is an illness which inflames the liver and limits its ability to function. The disease can be transmitted by food, water or by contact with someone who's infected. Mild cases do not require treatment. Most people recover completely from the sickness, although severe cases can be fatal.
Correction: The original version of this story misstated the location of the restaurant tied to the potential hepatitis A exposure. It is in Springfield, Missouri.