The Shiga toxin-producing E. coli infection rate in Europe jumped by 40 percent in 2018 compared to the previous year, based on data from ECDC’s annual surveillance report.

After a stable period from 2014 to 2017, the rate increased by 41 percent in 2018. This made STEC the third most common zoonosis in Europe after Campylobacter and Salmonella.

A contributing factor may be the shift from culture to culture-independent diagnostic methods, with PCR more commonly used to diagnose cases, according to the European Centre for Disease Prevention and Control (ECDC).

STEC infection is mainly acquired through eating contaminated food and contact with animals and/or their feces. Adequate cooking of food, particularly beef, and use of pasteurized milk may reduce the risk of foodborne infections, added the agency.

Most infections in Germany and UK
Thirty countries reported 8,811 cases, of which 8,658 were confirmed Shiga toxin-producing E. coli (STEC) infections. The top country notification rates were in Ireland, Norway, Sweden, Malta and Denmark.

Most infections were reported by Germany and the U.K., which together accounted for 47 percent of all cases. The former had 2,226 infections while the latter recorded 1,840. Bulgaria, Cyprus and Lithuania all reported no infections.

A total of 36 percent of 3,536 STEC patients were hospitalized and eleven people died. More than 80 percent of 6,546 STEC cases with information on country of infection were domestically acquired.

The five most common serogroups were O157, O26, O103, O91 and O145. As in previous years, O157 was the most common serogroup in 2018 and accounted for most of the increase. Like in 2016, O26 was a more common cause of hemolytic uremic syndrome (HUS) than O157.

Notification of STEC infections is mandatory in most countries except four member states. It is voluntary in France and Luxembourg and based on another system in Italy and the United Kingdom. Surveillance systems for STEC infections have national coverage in all EU countries except for France, Italy and Spain.

In France and Italy, surveillance only covers cases of HUS, which mainly affects small children and is characterized by acute kidney failure requiring hospital care. In 2018, the average proportion of hospitalized STEC cases was at 36 percent. The highest proportions of hospitalizations were in countries only reporting HUS cases and having the lowest numbers of cases and notification rates, indicating that their surveillance systems focus only on the most severe cases.

Children mostly affected
Among the 8,257 confirmed STEC cases for which gender was reported, 46 percent were males and 54 percent females.

The highest rate of confirmed cases was in the age group 0 to 4 years. This group accounted for 2,274, or more than a quarter, of the patients for whom information on age was available. An even larger proportion of children was seen among the HUS cases, where two-thirds were reported in 0 to 4 year-olds. The notification rate decreased with age and was lowest in the 45 to 64 year olds.

Eight urgent inquiries on STEC infection were launched through the Epidemic Intelligence Information System for foodborne and waterborne diseases and zoonoses (EPIS-FWD) but no multi-country outbreaks were detected or investigated.

In 2018, 48 STEC outbreaks were reported to the European Food Safety Authority (EFSA), involving 381 cases in 10 countries. Five of the 43 strong-evidence foodborne outbreaks had a known vehicle: two were caused by cheese and one each by milk, red meat, and vegetables.

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