Changing Diagnostic Methods and Increased Detection of Verotoxigenic Escherichia coli, Ireland.

Thomas Rice,Roy D Sleator,Noreen Quinn,Brigid Lucey

doi:10.3201/eid2209.160477

Abstract

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.

Highlights

Verotoxigenic Escherichia coli (VTEC) can cause severe disease in humans, with signs and symptoms including diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome [1]
These infections were included under specified infections caused by enterohemorrhagic E. coli (EHEC), comprising any strains of serogroups O157, O26, O103, O111, and O145 [3]; since an amendment of September 2011, these infections have been specified as VTEC infections [4]
Data on VTEC infections in Europe have been provided since 2008 from the member states to the European Centre for Disease Prevention and Control. These data indicate that Ireland had the highest annual incidence of VTEC infection during 2009–2014, with the exception of 2011, when a large outbreak of E. coli O104:H4 infections occurred in Germany [5]

Summary

Introduction

Verotoxigenic Escherichia coli (VTEC) can cause severe disease in humans, with signs and symptoms including diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome [1]. We conducted a survey of clinical microbiology laboratories in Ireland during 2014 to assess laboratory practices for the detection and confirmation of VTEC infection. The survey included 45 questions, arranged in 4 categories: laboratory details (e.g., contact details, address, and public/ private status); sample type, selection, and requirements for VTEC testing; current methods (i.e., utilization and description of enrichment, culture, biochemical characterization, antimicrobial susceptibility testing, serotyping, molecular testing, and verotoxin detection methods), past changes to methods, and intended future changes to methods for VTEC analyses; and referral and reporting procedures.

Results

Conclusion