The number of E. coli O157 infections declined in 2019 but non-O157 cases rose and two people died, according to figures from the UK Health Security Agency (UKHSA).

In 2019, there were 1,720 confirmed cases of Shiga toxin-producing E. coli (STEC) reported in England and Wales. Five patients were infected with multiple serogroups.

A total of 539 confirmed cases of STEC O157 were recorded in England and Wales compared to 607 in 2018. It continues a downward trend seen since 2015 and is the lowest annual figure since 1996.

Of 515 /confirm/ied STEC O157 cases in England, 280 were female. Children aged 1 to 4 years old were the most affected. Females had a higher incidence across all age groups, except for those between 1 to 4 years old and 10 to 19.

A total of 147 people were hospitalized with the stay in hospital ranging from one to 10 days with median of two days.

Hemolytic uremic syndrome (HUS) occurred in 13 confirmed and five probable cases. Four were younger than the age of 5 with a range of 1 to 75 years old. No deaths were recorded among STEC O157 cases. HUS is a type of kidney failure associated with E. coli infections that can result in lifelong, serious health problems and death.

Overall, 154 cases were travel-related. The top destinations included Turkey, Egypt, and Cyprus.

Non-O157 findings
Detection of and testing for non-O157 STEC increased. In 2019, 768 culture-positive non-O157 STEC cases, with 655 in England and 113 in Wales, were reported. Of 5,760 samples received for testing, 1,002 non-O157 cases were confirmed in England. Of these, 655 culture positive cases of 72 serogroups were /confirm/ied.

The most commonly isolated non-O157 STEC serogroup was E. coli O26, followed by O146, O128ab and O91. A total of 85 people were hospitalized.

HUS occurred in 22 confirmed and one probable STEC non-O157 case. From these, O26 and O145 were the main serogroups isolated.

Seven percent of /confirm/ied STEC O26 cases developed HUS. Cases ranged from 5 months to 65 years old and 13 were between 1 and 4 years old. There were two deaths reported.

For 413 cases, samples were confirmed as STEC by testing positive by PCR for Shiga toxin (stx) genes, but STEC was not cultured.

Outbreaks
Five outbreaks of STEC involving 65 people in England were investigated. Despite epidemiological investigations, it was not possible to find the source of infection. There were three associated HUS cases but no deaths.

Four outbreaks were because of E. coli O157, meaning they caused 9 percent of /confirm/ied cases. The largest affected 28 people, including seven in 2020, with nine needing hospital treatment.

A STEC O26 outbreak sickened 32 people, including 16 in England with five hospitalized. The outbreak strain had stx1a only and cases were mostly healthy adults with a median age of 28.