The public is being advised to throw out packages of frozen berries sold by Costco under the label Townsend Farms Organic Antioxidant Blend.
An outbreak of hepatitis A in five states -- including California -- has been linked to the berries.
The Kern County Public Health Services Department, in a public statement, is urging people to check their freezers for packages of the berries -- which includes strawberries, cherries pomegranate seeds, blueberries and raspberries -- and dispose of them.
People who have eaten the berries in the last 14 days are being asked to contact their medical provider or the Health Department to get medical advice or treatment.
As of Friday there had not been any cases of hepatitis A linked to the berries in Kern County.
Costco is removing the product from its shelves voluntarily.
Hepatitis A is caused by eating uncooked food that has been exposed to fecal matter. It can, according to the Kern County Health Department press release, cause "fever, fatigue, body ache, nausea, abdominal discomfort, dark colored urine and pale stools" followed by jaundice.
The illness can last one or two weeks, during which the infected person is highly contagious.
Vigorous handwashing with soap and warm water after using the restroom, and before eating, are the best ways to prevent the disease from spreading, according to health department officials.
More information is available at http://www.kernpublichealth.com/