A traceback investigation by the FDA did not find a single, common source of blackberries linked to a hepatitis A outbreak.

People who became ill said they bought the fresh, conventional blackberries at either Fresh Thyme Farmers Market or Woodman’s Market grocery stores.

The FDA says 20 illnesses were reported from seven states: Indiana, Michigan, Minnesota, Missouri, Nebraska, Pennsylvania and Wisconsin. The most recent illness started Nov. 15.

The Centers for Disease Control and Prevention says the outbreak investigation is over.

The FDA warns people who froze blackberries not to eat them if they were fresh, conventional blackberries bought Sept. 9-30, 2019, from Fresh Thyme Farmers Market in these 11 states: IA, IL, IN, KY, MI, MO, MN, NE, OH, PA and WI, or from Woodman's Market in Wisconsin or Illinois.

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.