More details about the impact of seven kinds of foodborne infections in Europe in 2022 have been released.

The reports cover Campylobacter, Salmonella, Yersinia, Shiga toxin-producing E. coli (STEC), Listeria, Shigella, and Hepatitis A. They were published by the European Centre for Disease Prevention and Control (ECDC).

Listeria and STEC are increasing in Europe and the European Economic Area (EEA), and in 2022, they were at higher levels than before the COVID-19 pandemic. 

For listeriosis, one explanation for this trend is the growing elderly population, who are at higher risk of severe disease. The rise in STEC cases is partly due to a change to more sensitive genetic methods, which can detect the bacteria more easily, said ECDC.

No major increase was observed for Salmonella and Campylobacter, which typically cause the most infections annually.

Campylobacter and Salmonella findings
Salmonellosis, campylobacteriosis, and shigellosis cases are still below pre-pandemic numbers. One explanation might be a change in behavior after the pandemic, such as people working from home, eating out less frequently, and a decrease in traveling, said ECDC.

In 2022, 30 countries reported 140,241 confirmed cases and 35 deaths from campylobacteriosis. Czech Republic and Luxembourg had the highest notification rates, while Bulgaria, Greece, Poland, and Romania had the lowest. Germany had the most cases, with almost 43,500. A total of 255 outbreaks were reported to the European Food Safety Authority (EFSA) by 17 countries, involving 1,097 cases and 83 hospitalizations.

For Salmonella, 65,967 laboratory-confirmed cases were reported, and 81 were fatal. The highest notification rates were in the Czech Republic, Slovakia, Malta, Hungary, Croatia, and Spain, while Portugal, Bulgaria, and Latvia reported the lowest. France had the most cases, with 11,162.

Of 39 outbreaks, 24 were multi-country. Salmonella Mbandaka and Virchow outbreaks were linked to chicken meat, a Salmonella Senftenberg outbreak to cherry-like tomatoes, a Salmonella Agona outbreak to cucumbers, a Salmonella Ball outbreak to undercooked hamburgers, and a Salmonella Schwarzengrund outbreak to black pepper. Goat’s cheese and milk caused a national Salmonella Ajiobo outbreak, and no sources were found for the Salmonella Pomona and Blockley outbreaks.

Salmonella Enteritidis accounted for 395 of 513 outbreaks reported to EFSA. Eggs and egg products remain the most common source.

In detail on Listeria and E. coli
Notification rates for listeriosis and yersiniosis in 2022 were the highest in more than 10 years. For STEC infections and STEC-associated hemolytic uremic syndrome (HUS) cases, higher rates were only reported in 2011, when there was a sizeable multi-country outbreak.

In 2022, 30 countries reported 2,770 confirmed listeriosis cases. Germany, France, and Spain had the most cases, but Denmark, Finland, and Sweden had the highest incidence rates.

Of four multi-country incidents, two were linked to processed meat products and one each to salmon and almond milk cheese. The analysis found that although multi-country clusters tend to be small and affect only a few countries, they often persist for several years, even decades.

Listeria monocytogenes was behind 17 strong-evidence and 18 weak-evidence outbreaks that affected 296 people, with 242 hospitalizations and 28 deaths, according to EFSA. This was the highest since the agency started collecting data.

For STEC, 29 countries reported 8,565 confirmed cases. Denmark, Germany, and Ireland accounted for almost half of these. Germany had the most, with 1,873. Denmark, Ireland, Malta, and Liechtenstein had the highest notification rates.

The six most frequent E. coli serogroups were O157, O26, O103, O146, O145, and O91. Five multi-country clusters, all O157, were reported to ECDC. Seventy-one outbreaks were reported to EFSA, including 37 in France. Poland recorded an E. coli O104 outbreak with 16 cases, five hospitalizations, and one death, but the source was unclear. It is the first E. coli O104 outbreak in Europe since 2011.

Overall, 28 people died, and 20 of them had hemolytic uremic syndrome (HUS). For cases with HUS, O26 was the top serogroup, followed by O157, O80, and O145.

A sharp decline in Hepatitis A cases has been evident in Europe over the past five years. Contributing factors include preventive measures such as good hand hygiene, increased vaccine uptake among at-risk groups, and better awareness of transmission.

In 2022, 30 countries reported 4,548 cases. Transmission can occur through contaminated food and water or via person-to-person contact. Hungary had the highest notification rate, followed by Croatia, Bulgaria, and Romania. Romania had the most cases, with 917, followed by 705 in Germany and 533 in Hungary.

Six outbreaks were recorded. In one cluster, epidemiological and microbiological data suggested human-to-human transmission and possibly also transmission via contaminated frozen berries. By September 2022, more than 300 cases were identified in six EU countries and the UK.

Two other clusters were linked to frozen fruit, possibly berries. The source of infection for two multi-country clusters was not found, but food was suspected. Another cluster involving at least 23 people in one EU country and New Zealand was reported. Information from patient interviews and traceback investigations identified frozen berries as the suspected vehicle.