A hepatitis A outbreak linked to frozen berries has sickened as many as 56 people in 4 of Europe’s Nordic countries, according to health officials. The European Centre for Disease Control and Prevention announced Tuesday that 16 hepatitis A infections arising from the same strain of the virus have been reported in Denmark, Finland, Norway and Sweden. A further 40 cases are suspected to be part of the outbreak, but have not been confirmed by testing. The first illnesses began in October of last year, and the most recent reported illnesses occurred this month, according to the ECDC report. Since none of the victims traveled outside the European Union during the time they would have been exposed to the virus, the source of the outbreak is thought to be within the EU, say authorities. Local investigations within the affected countries “strongly point towards frozen berries as the vehicle of infection,” said ECDC in a press release Tuesday. So far, no samples of frozen berries collected from the four affected countries have tested positive for hepatitis A. Among the confirmed cases, 75 percent are female and 25 percent are male. Victims range in age from 4 to 62 years old, with a median age of 30.5. Health authorities in the affected countries are advising that consumers boil all frozen or imported berries before consumption. As Food Safety News reported last week, the hepatitis A virus is relatively stable and can survive for several hours on fingertips and hands, and for up to two months on dry surfaces. And although high temperatures will kill the virus, freezing temperatures do not. ECDC reports that the strain causing this outbreak is a 99 percent match to strains isolated from people in Canada, France and the Netherlands who had recently traveled to Egypt. In 2012, an outbreak of hepatitis A that in Canada was also linked to frozen berries. Two health alerts regarding hepatitis A in frozen strawberries were issued in the European Union last year. The virus was was isolated from strawberry yogurt cake and in frozen strawberry cubes imported from China.