The FDA warns people to throw out the berries bought from Sept. 9 through Sept. 30 at the Fresh Thyme stores in any of those states. If you froze the berries to eat them later, you should still discard them. Or Fresh Thyme says you can return them for a refund.

If you’ve eaten these berries in the last two weeks and haven’t been vaccinated against the hepatitis A virus, you should contact your healthcare provider or your local health department. The virus can cause liver disease, and there’s a possible method to prevent illness after exposure.

The illnesses started Oct. 15, with the last reported case beginning Nov. 5. The outbreak appears to be ongoing as of Nov. 20, the Centers for Disease Control and Prevention says.

Investigators continue to try to identify suppliers or a specific brand.

Fresh Thyme is working with investigators to isolate the source and says in a statement that there’s no indication that the contamination happened during handling in the stores.

“Fresh Thyme takes the health and safety of our customers and our team members very seriously. Fresh Thyme Farmers Market has a stringent process for ensuring compliance to all local, state and federal health and hygiene regulations.”