Salmonella, E. coli, and Yersinia infections all went up in 2021, according to new data from the European Centre for Disease Prevention and Control (ECDC).

A previous article covered statistics for Hepatitis A, Campylobacter, and Listeria.

Thirty countries reported 61,236 salmonellosis cases, of which 60,494 were laboratory-confirmed in 2021. This was an increase of 14 percent from 53,163 cases in 2020.

The highest notification rates were reported by Czech Republic and Slovakia, followed by Malta, Hungary, and France. The lowest rates were in Greece, Romania, Bulgaria, Ireland and Portugal.

Hospitalization status was reported for 31,357 cases and 38 percent needed hospital treatment. Cyprus, Greece, and Lithuania had the biggest proportion of hospitalized cases. At least 73 people died in 2021.

The top notification rate was among young children aged 0 to 4. The rate in this group was three times more than in older children, and 11 times higher than in adults aged 25 to 64. As in previous years, the three main Salmonella types were Salmonella Enteritidis, Typhimurium, and monophasic Salmonella Typhimurium. Young children and the elderly generally suffer the most severe illnesses.

Out of 45,177 cases with known travel history, 1,591 were travel-associated, the lowest rate ever reported. The highest proportion of travel-related cases was in France, Iceland, Sweden, and Slovenia. Among cases with information on the probable country of infection, Türkiye, Spain, and Italy were the most frequent destinations.

Eggs and egg products continue to be the highest-risk foods in outbreaks but several large incidents were linked to contaminated vegetables, fruits, and sesame seeds.

Overall, 44 events with Salmonella infections were reported and 18 involved multiple countries. The largest with 348 cases was a Salmonella Braenderup outbreak due to Galia melons from Honduras.

Six different Salmonella types were involved in an outbreak linked to tahini and halva from Syria that has been ongoing since 2019. People also fell sick in different countries in a Salmonella Chester outbreak in mid-July and August and Salmonella Montevideo caused sporadic cases from January 2021 to January 2022 but no source was identified.

The largest outbreak was in Finland in June when more than 700 patients from day-care centers across three cities fell ill with Salmonella Typhimurium. All sites were served by the same central kitchen and the outbreak strain was identified in vegetables served at lunch.

E. coli figures
A total of 6,534 confirmed cases of Shiga toxin-producing E. coli (STEC) infections were reported compared to 4,824 in 2020.

Germany recorded the most patients with 1,635 followed by Denmark with 927 and Ireland with 878. The highest country-specific report rates were in Ireland, Denmark, Malta, and Norway.

Overall, 41 percent of 2,575 cases with known information were hospitalized and 18 died. The biggest notification rate was in the age group 0 to 4 years old. The five top serogroups were O157, O26, O103, O145, and O146.

From 365 hemolytic uremic syndrome (HUS) cases, the majority were aged 0 to 4 years old. All four deaths were in this age group. Serogroup O26 was the most common followed by O157. Most E. coli O26 HUS cases were reported by France, Italy, and Belgium, the first two base surveillance mainly on the detection of HUS cases.

Nine alerts on STEC infection were launched in an ECDC system. One multi-country cluster of E. coli O103:H2 was detected between June and August in three countries, with 75 patients.

Data from the European Food Safety Authority (EFSA) shows 275 patients in 36 outbreaks across 11 countries. The serogroups were O157, O26, O103 plus O12, O145, O146 and O91 once each. A food vehicle was reported in five strong-evidence outbreaks; STEC O26 in raw cow’s milk and pre-cut vegetables caused an outbreak of STEC O103, and in two O157 outbreaks the vehicle was ground meat and carpaccio.

Yersinia data
In 2021, 6,876 confirmed patients with yersiniosis were reported compared to 5,747 in 2020.

As in past years, Germany had the most cases with 1,912, followed by France with 1,451. These two countries made up almost half of all patients in Europe. Denmark had the top notification rate, followed by Finland, Lithuania, and the Czech Republic.

A third of 1,649 patients with known information were hospitalized but no deaths were reported.

The highest notification rate per 100,000 population was in those 0 to 4 years old. The rate decreased with age and was lowest in those aged 45 to 64.

Yersinia enterocolitica was the most common species in all countries. The top serotype was O:3 followed by O:9. Eleven countries reported 115 Yersinia pseudotuberculosis patients.

Four outbreaks were reported to ECDC officials and one outbreak was considered multi-country based on WGS analysis of clustering isolates. Overall, 25 outbreaks were reported to EFSA involving 125 cases in 11 countries.