A hepatitis E-positive meat product appears to be behind most of the infections that occurred earlier this year in Finland.

The hepatitis E virus previously detected in sausages from a domestic manufacturer is similar to samples from most people affected by the outbreak at the start of 2024.

This was found during a strain comparison of viruses by the Finnish Food Authority (Ruokavirasto) and the National Institute of Health and Welfare (THL).

More than 120 people from different parts of Finland have fallen ill in the outbreak between January and March.

At least 42 people have needed hospital treatment. Of the 44 patients, the median age of those affected is 64, and 70 percent are men. One infected person died, but it is not clear what role hepatitis E played in the death.

Product recalls
In March, Kotivara withdrew six products sold since early November 2023 in retail stores and wholesalers. This recall was later expanded to other products and dates.

“We are investigating the origin of the meat raw material containing the hepatitis E virus in close cooperation with Ruokavirasto and local authorities, so that corrective measures can be taken as quickly as possible,” said a company statement.

A THL survey found people infected with hepatitis E reported eating products from Kotivara more often than a comparison group randomly seleced from the population.

THL has typed the hepatitis E virus found in samples of 64 infected people. The majority belonged to the genotypes HEV-3f and HEV-3e.

Hepatitis E ends up in mettwurst or salami via a raw virus material. However, officials have not identified the raw material that caused the contamination. The production method is insufficient to inactivate the virus, which is destroyed when products are thoroughly cooked. The hepatitis E virus typically occurs in pigs but has also been found in wild boars and deer.

Between 20 and 60 hepatitis E cases are reported to the Infectious Disease Register in Finland annually. In 2023, there were 33 cases. Ruokavirasto, THL, and local food control authorities continue investigating the incident.

In February, the European Centre for Disease Prevention and Control (ECDC) said it monitored the situation after some countries reported a spike in hepatitis E infections.

In January, more patients than usual were seen in Belgium and the Czech Republic. More than 350 cases were recorded in Germany, 63 in the Czech Republic, and 36 in Belgium.

Hepatitis E infection is a liver disease caused by the hepatitis E virus (HEV). The mean incubation period for HEV is five to six weeks, with a range of two to nine weeks, and can persist for one to four weeks. Symptoms include fatigue, poor appetite, stomach pain, nausea, and jaundice. However, some people, especially young children, have no symptoms.