Global food trade and emerging foodborne pathogens: The example of STEC O104

Transcription

1 Global food trade and emerging foodborne pathogens: The example of STEC O104 Stefano Morabito EU Reference Laboratory for E. coli Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare Istituto Superiore di Sanità Rome, Italy

2 ETEC STEC EIEC ExPEC K/12 Commensal EAEC list_uids=167

3 Shigatoxin-producing E. coli One of the most dangerous foodborne pathogens! Life-threatening clinical manifestation Very low infectious dose ( CFU!) Large community outbreaks

4 STEC: Clinical manifestation Intestinal - Asymptomatic - Watery Diarrhoea - Hemorrhagic Colitis Systemic Hemolitic Uremic Syndrome (HUS) Neurological involvement Istituto Superiore di Sanità - Dip. Sanità Pubblica Veterinaria e Sicurezza Alimentare EU Reference Laboratory for E.coli

5 Hemolytic Uremic Syndrome (HUS) Hemolytic Anemia Thrombocytopenia Acute Renal failure Main cause of renal failure in childhood and usually requires dialysis Antibiotic treatment is not effective and is not recommended Istituto Superiore di Sanità - Dip. Sanità Pubblica Veterinaria e Sicurezza Alimentare EU Reference Laboratory for E.coli

6 Pathogenesis of STEC infections Ingestion 2-4 days Adhesion/colonization Abdominal cramps, diarrhea 1-2 days Transfer of the VT in the bloodstream Action on the colonic endothelium Hemorragic Diarrhea 90% Recovery 5-7 days 10% HUS Action of the VT on the renal endothelium

7 STEC Genomic Complexity Adhesion Hemolysin LEE OI-122 OI-57 E-hly toxb Mobile genetic elements: Phages Genomic islands Plasmid B A B B B A B B A B B B Shiga toxin-production

8 Are all VTEC pathogenic to humans? VTEC ASSOCIATED WITH SEVERE DISEASE (BD, HUS) VTEC >100 serogroups in the reservoir Additional virulence properties Attaching/Effacing adhesion O157 O26, O45, O111, O103, O121, O145 Courtesy of Prof. Helge Karch

9 STEC O104:H4 outbreak, Germany EWRS on 22 May Source: Robert Koch Institute. Report: Final presentation and evaluation of epidemiological findings in the EHEC O104:H4 outbreak, Germany Berlin Urgent inquiry on 24 May STEC-Gastroenteritis HUS Number of cases May June July Date of disease onset 2011 (Diarrhea)

10 Incidence of HUS during the VTEC O104 outbreak German cases /100,000 population Source: Robert Koch Institute. Report: Final presentation and evaluation of epidemiological findings in the EHEC O104:H4 outbreak, Germany Berlin 2011.

11 VTEC O104:H4 outbreak, Germany ,842 cases 2987 non-hus STEC 18 deaths (0.6%) 855 HUS 35 deaths (4.1%) Of HUS cases, - 68% women - Median age 42 years (0-91 years) - Bloody diarrhoea in 79%

12 Emergence of a new STEC type

13 Pathogenic STEC attaching/effacing adhesion EAEC Entero-aggregative adhesion

14 Stx-producing EAEC Stacked brick Adhesion Aai EAST-1 Agg EAEC Genomic Backbone acquired a Stx-Phage B A B B B A B B A B B B Shigatoxin-Production

15 EAEC are human pathogens

16 STEC are zoonotic pathogens Food of animal origin: Primary contamination

17 STEC are zoonotic pathogens Environmental contamination Soil Surface waters

18 STEC and EAEC should not share environmental niches

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20 From: Nutrition and Health in Developing Countries. Richard D. Semba and martin W. Bloem Eds. Humana Press. 2008

21 Taken from: Hungry Planet: What the World Eats by Peter Menzel and Faith D'Aluisio (Sep 1, 2007)

22 Stx-producing EAEC O104 entered the EU with the Fenugreek seeds German Outbreak. No microbiological confirmation but strong epidemiologic evidence 16 cases of infection in a school in France Tracing Back exercise EFSA

23 How is the food market changing?

24 EU food market is largely based on import (2009, millions) Source: Eurostat Comext New pathogens may be imported with particular food commodities (or raw materials) from developing countries

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26 The food trade paradox

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28 Carte sur la géographie des grands flux migratoires. Atlas des migrations, Le Monde-La Vie / CNHI / Sciences-Po

29 Foodborne outbreak of diarrhea by enteroinvasive E. coli (EIEC) April 2012

30 Foodborne outbreak of diarrhea by enteroinvasive E. coli (EIEC) Outbreak of severe diarrhea among firefighters in the city of Milan, associated with the corps canteen 107 cases, including 3 kitchen-workers Isolation of ipah-positive, enteroinvasive E.coli O96:H19 Cooked vegetables significantly associated with disease. Kitchen-workers as the likely source of EIEC Vegetable contamination during preparation, favored and amplified by uncorrect storage procedures

31 Emerging E. coli types and Global food trade Global trade increasingly include low income countries as providers of food commodities or raw materials This may facilitate the introduction of human-borne pathogens into the food chain triggering severe consequences (e.g. STEC O104)

32 Emerging E. coli types and Global food trade Events should be confined to the batch of the food commodity contaminated (no new cases of STEC O104 infections since August 2011) Establishment of these pathogens in the niche represented by foodproducing animal farming may cause pandemics (Salmonella enteritidis in poultry, STEC O157 in cattle??)

33 Thank you for your attention! The EU-RL VTEC folks