People in five Western states infected with hepatitis A -- possibly from bags of Costco frozen berry blend -- may have to wait 30 days before the virus can be detected.

The frozen berries are being investigated as the cause of a hepatitis A outbreak in in Colorado, New Mexico, Nevada, Arizona and California, according to a joint statement released by the Centers for Disease Control and Prevention and the Food and Drug Administration. At least 30 cases have been reported as of May 31, with 11 of 17 cases being confirmed to be people who consumed the frozen fruit. The fruit blend associated with the outbreak is Townsend Farms Organic Anti-Oxidant Blend. People who purchased the product are being asked to throw it away immediately. Costco is believed to be the only store that sold it.

Health officials are currently looking into pomegranate seeds from Turkey in the product, said Townsend Farms attorney Bill Gaar.   "We do have very good records, we know where the (pomegranate seeds) came from, we're looking into who the broker is and we're sourcing it back up the food chain to get to it," Gaar said.

Hepatitis A is a highly contagious liver disease that can lead to hospitalization and severe illness, says the California Department of Public Health. Most people do recover fully, however.

Symptoms can include fever, nausea vomiting, abdominal pain or discomfort, loss of appetite and fatigue. The FDA says it takes 15 to 50 days to become ill with hepatitis A after exposure. Those who have already received the hepatitis A vaccination will likely not become sick from the illness.

If you've consumed the contaminated fruit blend in the past two weeks, the CDC recommends you contact your health care provider to see if you should be vaccinated.