Germany and the United Kingdom accounted for almost half of STEC/VTEC cases in 2016, according to European statistics. The two countries also reported the most number of cases in 2015.

A total of 6,619 confirmed cases of infections with Shiga-toxin/verocytotoxin-producing E. coli (STEC/VTEC) were recorded in Europe in 2016, the most recent year for which complete data is available.

The highest number of confirmed cases was reported by Germany with 1,843 followed by the UK  with 1,373. The two countries accounted for 47.7 percent of all EU/EEA cases.

Only Cyprus, Bulgaria and Portugal did not report any cases, according to the European Centre for Disease Prevention and Control (ECDC) surveillance report. On average, a third of people with STEC infections, with known information, were hospitalized. Ten people died.

Notification of STEC infections is mandatory in most EU/EEA countries except for five member states where it is either voluntary, as is the case in France, Italy, Luxembourg and Spain, or based on another system as it is in the UK.

Between 2012 and 2016, the number of confirmed STEC cases remained stable at the EU level but was markedly higher than at the beginning of surveillance in 2007 and before a large outbreak in 2011. The ECDC said part of the increase may be explained by improved clinical awareness of STEC infection following the outbreak seven years ago.

“Other contributing factors could be the increasing number of laboratories that were testing for serogroups other than O157 and the shift in diagnostic methods from cultures to culture-independent methods, with PCR being more commonly used,” according to the report.

A clear seasonal trend in the number of confirmed STEC cases was observed, with substantially more in summer months, June to September.

The highest rate of confirmed cases was reported in the age group newborn to 4 years old. The notification rate in this group was four to nine times higher than the rate in the older age groups.

In 2016, STEC was the fourth most commonly reported zoonosis in the EU.

The proportion of E. coli serotype O157 continued to decrease while the proportion of non-O157 STEC serogroups increased in 2016. Reporting of STEC O26 infections has been steadily increasing in the EU since 2007 in human and food samples.

Raw meat, unpasteurized milk and dairy products are known potential sources of STEC infections.

In 2016, nine STEC outbreaks were reported with known causative agents. The two largest outbreaks occurred in Finland with 237 cases and the UK with 170 cases. In both outbreaks, leafy green vegetables were implicated as the vehicle of infection.

Three smaller outbreaks were caused by bovine meat and products thereof (STEC O157), two were caused by cheese (STEC O157 and O26), and one was connected to milk (STEC O80).

(To sign up for a free subscription to Food Safety News, click here.)