Category Archives: E.coli O113

Research – Shiga toxin-producing Escherichia coli (STEC) data: 2019

UKSHA

Main points for 2019

The main points of the 2019 report are:

1. A total of 539 confirmed cases of Shiga toxin-producing Echerichia coli (STEC) O157 were reported in England and Wales in 2019.

2. The lowest incidence of STEC O157 was in the East Midlands region (0.56 per 100,000 population) and the highest in the Yorkshire and Humber region (1.51 per 100,000 population).

3. Children aged 1 to 4 years had the highest incidence of infection (3.28 per 100,000 population, CI 95% 2.63–4.04).

4. Nearly one-third of confirmed STEC O157 cases in England were hospitalised and 3% were reported to have developed haemolytic ureamic syndrome (HUS).

5. In England and Wales, detection of non-O157 STEC increased in line with the growing number of NHS labs implementing gastrointestinal (GI) diagnostics using polymerase chain reaction (PCR); in 2019, 768 culture-positive non-O157 STEC cases (655 in England, 113 in Wales) were reported.

6. A further 347 specimens in England and 66 in Wales were positive for Shiga toxins (stx) genes on PCR at the Gastrointestinal Bacteria Reference Unit (GBRU) but an organism was not cultured.

7. The most commonly isolated non-O157 STEC serogroup was STEC O26 (England: n=109/655, 17% and Wales: n=28/113, 25%).

8. Five outbreaks of STEC involving 65 cases in England were investigated in 2019.

Cases of STEC in England and Wales in 2019

In 2019, 1,720 confirmed cases of STEC were reported in England and Wales; these comprised 539 culture-confirmed cases of STEC serogroup O157 (515 cases in England and 24 in Wales) and 768 cases (655 in England, 113 in Wales) where a serogroup other than O157 was isolated (non-O157). For a further 413 cases, samples were confirmed as STEC by testing positive by PCR for stx genes, but STEC was not cultured (347 in England, 66 in Wales).

Five confirmed cases were infected with multiple serogroups:

  • O157 and O26
  • O26 and O103
  • O76 and O113
  • O91 and O128ab
  • O146 and O91

There were 13 probable cases with serological evidence of STEC infection, with antibodies detected to O157 lipopolysaccharides in 11 cases (England: 10, Wales: 1), for O111 lipopolysaccharides in one case, and for O26 lipopolysaccharides in another case.

The crude incidence rate of confirmed STEC O157 in England and Wales was 0.91 per 100,000 cases (95% CI 0.83–0.99), continuing the downward trend observed since 2015 (Figure 1). It is the lowest number of cases reported annually since 1996, when testing began in England for STEC O157 on all faecal specimens from patients with suspected gastrointestinal infection (7).

Non-O157 STEC cases in England and Wales
Historically, cases of non-O157 STEC have been under ascertained, with 89 cases of STEC non-O157 reported between 2009 and 2013, prior to PCR being implemented.

Following the increase in recent years in frontline laboratories using PCR, there has been a significant increase in the detection of non-O157 STEC in England. It is not possible to estimate a denominator for incidence calculations for non-O157 STEC because details of contract arrangements for referral of samples from primary care and catchment areas of each diagnostic laboratory using PCR are not known.

In 2019, of 5,760 samples received at GBRU for STEC testing, 1,002 non-O157 STEC cases were confirmed in England. Of the 1,002 non-O157 cases, 655 culture positive cases of 72 different serogroups were confirmed. For 21 isolates, a serotype could not be identified as the genes encoding the somatic O antigen did not match any known sequence in the database. Specimens for a further 347 cases in England were positive for stx genes on PCR at GBRU but an organism was not cultured (PCR positive-culture negative).

In Wales, 113 non-O157 cases of 40 different serotypes were confirmed and a further 66 were PCR positive-culture negative. The most common non-O157 serogroups isolated in 2019 were O26 (28/113, 25%), O146 (15/113, 13%), O128ab (10/113, 9%) and O91 (8/113, 7%) followed by O111 (4/113, 4%), O113 (4/113, 4%) and O156 (4/113, 4%).

Research – Shiga toxin-producing Escherichia coli (STEC) and food: attribution, characterization, and monitoring

WHO

Strains of pathogenic Escherichia coli that are characterized by their ability to
produce Shiga toxins are referred to as Shiga toxin-producing E. coli (STEC). STEC
are an important cause of foodborne disease and infections have been associated with a wide range of human clinical illnesses ranging from mild non-bloody
diarrhoea to bloody diarrhoea (BD) and haemolytic uraemic syndrome (HUS)
which often includes kidney failure. A high proportion of patients are hospitalized,
some develop end-stage renal disease (ESRD) and some die.
The Codex Committee on Food Hygiene (CCFH) has discussed the issue of STEC
in foods since its 45th Session, and at the 47th Session, in November 2015, it was
agreed that it was an important issue to be addressed (REP 16/FH, 2015)2
. To
commence this work, the CCFH requested the Food and Agriculture Organization
(FAO) and the World Health Organization (WHO) to develop a report compiling
and synthesizing available relevant information, using existing reviews where
possible, on STEC. The CCFH noted that further work on STEC in food, including
the commodities to be focused on, would be determined based on the outputs of
the FAO/WHO consultation.
The information requested by CCFH is divided into three main areas: the global
burden of disease and source attribution; hazard identification and characterization; and monitoring, including the status of the currently available analytical
methods. This report provides an overview of the work undertaken in response to
the request from the CCFH and provides the conclusions and advice of the Expert
Group based on the currently available information.

RASFF Alerts – STEC E.coli – Filet Americaine – Chilled Boneless Meat

RASFF-Logo

RASFF – shigatoxin-producing Escherichia coli (stx +, eae + /25g) in filet americaine from Belgium in Belgium

RASFF – shigatoxin-producing Escherichia coli (O113: H21 – stx2+ /25g) in chilled boneless meat from Argentina in Germany