WASHINGTON — The Centers for Disease Control and Prevention says an outbreak of hepatitis A linked to a frozen berry mix sold at Costco has grown to 87 people with illnesses in eight states.The CDC said Tuesday that illnesses have been reported in Arizona, California Colorado, Hawaii, Nevada, New Mexico, Utah and Washington.Townsend Farms of Fairview, Ore., last week recalled its frozen Organic Antioxidant Blend, packaged under the Townsend Farms label at Costco and under the Harris Teeter brand at those stores. So far the illnesses have only been linked to the berries sold at Costco.Craig Wilson, director of food safety at Costco, said the store is providing vaccinations for people who ate the berries within the last two weeks and is reimbursing others who have gotten the vaccine outside the store. The store has contacted about 240,000 people who purchased the berries at one of their stores, Wilson said. The company knows who bought the berries because purchases are linked to a membership card that customers present when they check out.The Food and Drug Administration is investigating the cause of the outbreak. The CDC said the strain of hepatitis is rarely seen in North or South America but is found in the North Africa and Middle East regions. Townsend Farms has said the frozen organic blend bag includes pomegranate seeds from Turkey.Hepatitis A is a contagious liver disease that can last from a few weeks to a several months. People often contract it when an infected food handler prepares food without appropriate hand hygiene. The CDC said that food already contaminated with the virus can also cause outbreaks, as is suspected in this case.