Pathogenicity assessment of Shiga toxin-producing Escherichia coli (STEC) and the public health risk posed by contamination of food with STEC

EFSA BIOHAZ Panel, Kostas Koutsoumanis, Ana Allende, Avelino Alvarez-Ordóñez, Sara Bover-Cid, Marianne Chemaly, Robert Davies, Alessandra De Cesare, Lieve Herman, Friederike Hilbert, Roland Lindqvist, Maarten Nauta, Luisa Peixe, Giuseppe Ru, Marion Simmons, Panagiotis Skandamis, Elisabetta Suffredini, Claire Jenkins, Sara Monteiro Pires, Stefano MorabitoTaina Niskanen, Flemming Scheutz, Maria Teresa da Silva Felício, Winy Messens, Declan Bolton

Research output: Contribution to journalArticlepeer-review

168 Citations (Scopus)
136 Downloads (Pure)


The provisional molecular approach, proposed by EFSA in 2013, for the pathogenicity assessment of Shiga toxin-producing Escherichia coli (STEC) has been reviewed. Analysis of the confirmed reported human STEC infections in the EU/EEA (2012–2017) demonstrated that isolates positive for any of the reported Shiga toxin (Stx) subtypes (and encoding stx gene subtypes) may be associated with severe illness (defined as bloody diarrhoea (BD), haemolytic uraemic syndrome (HUS) and/or hospitalisation). Although strains positive for stx2a gene showed the highest rates, strains with all other stx subtypes, or combinations thereof, were also associated with at least one human case with a severe clinical outcome. Serogroup cannot be used as a predictor of clinical outcome and the presence of the intimin gene (eae) is not essential for severe illness. These findings are supported by the published literature, a review of which suggested there was no single or combination of virulence markers associated exclusively with severe illness. Based on available evidence, it was concluded that all STEC strains are pathogenic in humans, capable of causing at least diarrhoea and that all STEC subtypes may be associated with severe illness. Source attribution analysis, based on ‘strong evidence’ outbreak data in the EU/EEA (2012–2017), suggests that ‘bovine meat and products thereof’, ‘milk and dairy products’, ‘tap water including well water’ and ‘vegetables, fruit and products thereof’ are the main sources of STEC infections in the EU/EEA, but a ranking between these categories cannot be made as the data are insufficient. Other food commodities are also potentially associated with STEC infections but rank lower. Data gaps are identified, and are primarily caused by the lack of harmonisation in sampling strategies, sampling methods, detection and characterisation methods, data collation and reporting within the EU.

Original languageEnglish
Article numbere05967
JournalEFSA Journal
Issue number1
Publication statusPublished - 29 Jan 2020

Bibliographical note

Funding Information: No Funding Information

Open Access: This is an open access article under the terms of the Creative Commons Attribution-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited and no modifications or adaptations are made.

Publisher Copyright: © 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Citation:EFSA BIOHAZ Panel, Koutsoumanis, K, Allende, A, Alvarez-Ordóñez, A, Bover-Cid, S, Chemaly, M, Davies, R, De Cesare, A, Herman, L, Hilbert, F, Lindqvist, R, Nauta, M, Peixe, L, Ru, G, Simmons, M, Skandamis, P, Suffredini, E, Jenkins, C, Monteiro Pires, S, Morabito, S, Niskanen, T, Scheutz, F, da Silva Felício, MT, Messens, W and Bolton, D, 2020. Scientific Opinion on the pathogenicity assessment of Shiga toxin-producing Escherichia coli (STEC) and the public health risk posed by contamination of food with STEC. EFSA Journal 2020;18(1):5967, 105 pp.



  • STEC
  • methods
  • pathogenicity
  • ranking associated foods
  • source attribution


Dive into the research topics of 'Pathogenicity assessment of Shiga toxin-producing Escherichia coli (STEC) and the public health risk posed by contamination of food with STEC'. Together they form a unique fingerprint.

Cite this