Costco was forced to recall a brand of frozen berries on May 30 linked to a hepatitis A outbreak that’s infected 30 people in five Western states, according to San Jose Mercury News.

The product under investigation is Townsend Farm’s Organic Anti-Oxidant Blend and is a mix of cherries, blueberries, pomegranate seeds, raspberries and strawberries.

Among the states affected since illness was first reported at the end of April include Colorado, New Mexico, Nevada, Arizona and California.

Nine of the people sickened have been hospitalized, according to the Centers for Disease Control and Prevention (CDC), with perlimianry tests from two cases suggesting the strain originated from North African and Middle Eastern regions.

The U.S. agency is currently instructing retailers not to sell the product and suggests that consumers to discard the product, even if someone in consumed it without falling ill. Furthermore, the CDC suggests that individuals who have been exposed to the product to receive a hepatitis A vaccination within two weeks.

Hepatitis A is a viral liver disease that can cause mild to severe illness and is one of the most frequent causes of foodborne infection, according to the World Health Organization.

Symptoms of the disease include fever, loss of appetite, nausea, abdominal comfort, dark-colored urine and jaundice, though it warns not everyone infected will manifest symptoms. Furthermore, the incubation period for hepatitis A is anywhere from 14 to 28 days.

While there is no specific treatment, recovery can be slow and take several weeks or months. Therapy instead is aimed at maintaining comfort and adequate nutritional balance.

Fortunately, unlike hepatitis B and C, hepatitis A does not cause chronic liver disease and is rarely fatal, though it can cause acute liver failure, which is associated with high mortality.

Every year, an estimated 1.4 million people become infected with hepatitis A worldwide.