An outbreak of hepatitis A linked to frozen berries has sickened nearly 60 people in Germany over two years.
According to data from the Robert Koch Institute (RKI), a total of 55 confirmed cases of the sequence and 4 suspected cases of infection have been detected in 10 federal states.
In January 2022, the RKI became aware of eight cases of hepatitis A virus (HAV) with the same genotype IB sequence from the two federal states of Hesse and Bavaria. Due to the lack of travel history and disease distribution, transmission via contaminated food is suspected.
Based on initial investigations by health authorities and experience with past outbreaks, it is hypothesized that the cases may be related to the consumption of contaminated frozen berries. Due to the long shelf life and high stability of the hepatitis A virus, frozen products can still cause illness to consumers months after purchase.
Frozen Strawberry Product Links
There were 43 primary cases and 16 secondary cases, all of which were caused by human-to-human transmission. The first onset date was late October 2021, and the latest onset date was July 2023. A total of 42 people have become ill since the beginning of 2023. In 2021, 8 people became ill and in 2022, 9 people became ill.
Among the 42 sequence-confirmed primary cases, 15 were male, with a median age of 30 and a half years and an age range of 8 to 73 years. Thirty-eight of the 55 patients were reportedly hospitalized, but no deaths were recorded.
Patients most commonly report having frozen strawberries or products made from them. Twenty-five of the 39 people were likely to have tuberculosis, and an additional seven patients were also likely to have tuberculosis.
Different retailers were mentioned as places to purchase frozen strawberry products, but ten people mentioned one supermarket.
“The results provide clear epidemiological evidence that frozen strawberries marketed in Germany may be an important vector of infection in this outbreak. Based on the results of the survey of affected persons, it can be speculated that contaminated frozen strawberries are sold in different markets across the country Sold under different brands and product names,” the scientist said.
The Federal Office for Consumer Protection and Food Safety (BVL) has also shared HAV sequences in the European disease surveillance system EpiPulse.
About hepatitis A
Hepatitis A is a viral infection of the liver. Symptoms include loss of appetite, nausea, fever, stomach pain, dark urine, pale stools, and jaundice. Hand washing and good hygiene are important to prevent transmission and to get vaccinated.
The incubation period ranges from 15 to 50 days, with an average of 28 days. The virus is spread by the fecal-oral route, usually by consuming contaminated food or water or through contaminated hands or objects. People are contagious from two weeks before symptoms appear until a week after jaundice or dark urine appears. This means they may be spreading the infection before they know they are infected.
The illness is usually mild and lasts one to three weeks. Most people recover, but hepatitis A can lead to hospitalization and serious illness, especially in people with chronic liver disease. Infected young children often have few or no symptoms but can still spread the infection to others. Officials are also telling people not to go to work if they have symptoms consistent with hepatitis A infection, especially food handlers, child care workers or health care workers.
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