Scotland – VTEC E.coli in Scotland 2014: enhanced surveillance, reference laboratory and clinical reporting data

Introduction

Reported rates of Escherichia coli O157 (E. coli O157) infection in Scotland rose substantially in the mid-1990s and remain consistently high compared to other countries within the UK and Europe. Although large foodborne outbreaks have occurred in Scotland,^1,2 sporadic infection predominates. Serious outcomes of infection can include haemolytic uraemic syndrome (HUS) which is a major cause of acute renal failure in children in Scotland.

The potential for E. coli O157 to cause both secondary spread³ and large outbreaks is exacerbated by its low infectious dose^1,2 and asymptomatic infection can also occur.⁴

Although E. coli O157 is the only serogroup of verotoxin-producing E. coli (VTEC) routinely detected by diagnostic laboratories in Scotland, in recent years verotoxigenic strains of non-O157 serogroups (non-O157 VTEC) have also been identified in Scotland, and can be associated with significant morbidity including HUS.⁴

Health Protection Scotland (HPS) has established enhanced surveillance of E. coli O157 in close collaboration with the Scottish E. coli O157/VTEC Reference Laboratory (SERL). This surveillance was extended in 2003 to include non-O157 VTEC. Data is also integrated with other surveillance functions at HPS, in particular with ObSurv,⁵ the system for surveillance of all general outbreaks of infectious intestinal disease.