Increased Prevalence and diversity of VTEC in Ireland: Fact of Artifact?

1. Increased Prevalence and diversity of VTEC in Ireland: Fact of Artifact? Dr Anne Carroll Dr Eleanor McNamara HSE-PHL-Dublin

2. PHL Scope • Official testing laboratory, Food and water (S.I. 85 of 1998 and S.I. 117 of 2010). • Accredited ISO 17025 • National VTEC diagnostic and typing service (Clinical, foods water environmental) • Clinical diagnostic general microbiology service, hospital/GP HSE-PHL-Dublin

3. VTEC Reference Service • National VTEC Service • Stools, Food, Water. • Isolate Confirmation • Accredited • PCR >22,000 tests • PFGE HSE-PHL-Dublin

4. VTEC incidence HSE-PHL-Dublin

5. VTEC incidence HSE-PHL-Dublin

6. HSE-PHL-Dublin

7. 2011 VTEC serogroups 2011: 17 serogroups 15 clinical +2 food 2002-2011 33 serogroups + HSE-PHL-Dublin

8. 2011 HPSC VTEC subgroup • HPSC • Ref lab • 5 labs • Public health • Consensus + recommend standardised methods for VTEC HSE-PHL-Dublin

9. Risk HSE-PHL-Dublin

10. Lab Methods US “all stools submitted for routine testing from patients be simultaneously cultured for O157 and tested with an assay that detects Shiga toxins to detect non-O157 STEC” “Specimens or enrichment broths in which Shiga toxin or STEC are detected but from which O157 STEC are not recovered should be forwarded as soon as possible to a state or local public health laboratory”. HSE-PHL-Dublin

11. Lab Methods ROI HSE-PHL-Dublin

12. Lab 1 HSE-PHL-Dublin

13. Lab 1 2012 HSE-PHL-Dublin

14. Pre 2012 samples referred to ref lab based on risk and not lab findings (stools). HSE-PHL-Dublin

15. Lab 7 HSE-PHL-Dublin

16. Lab 7 STEC CHROMagar HSE-PHL-Dublin

17. Pre 2012 samples referred to ref lab primarily based on lab findings and not risk (Isolates) HSE-PHL-Dublin

18. Lab 2 No changes to methods HSE-PHL-Dublin

19. samples referred to ref lab based on both lab findings and risk (stools and isolates) HSE-PHL-Dublin

20. Issues • PCR Direct from stool • PCR pos culture negative issue • Direct detection of vt1 or vt2 gene(s) (without strain isolation), probable or confirmed depending on clinical criteria (HPSC) HSE-PHL-Dublin

21. Issues • Ref lab • Direct PCR, Enrichment/IMS PCR, colony confirmation. • Direct PCR pos and/or Enrichment/IMS PCR pos + colony confirmed • Direct PCR pos + Enrichment/IMS PCR pos but can’t isolate colony • Direct PCR pos + Enrichment/IMS PCR neg • Do 2 +3 have the same PH implications? HSE-PHL-Dublin

22. Direct PCR pos + Enrichment/IMS PCR pos but can’t isolate colony • Organism seems to be growing viable • Shedding of viable organism possible PH risk • Source of infection HSE-PHL-Dublin

23. Direct PCR pos + Enrichment/IMS PCR neg • Organism not growing not viable • Shedding of non viable organism not a PH risk • May have been infection with organism subsequently dying source of infection • May have been no infection but ingestion of non viable organism e.g. from treated water or processed food HSE-PHL-Dublin

24. If Use PCR only result (2 or 3) may not be true result • O26 vt2 PCR pos • O26 vt2 • O26 vt neg + other serogroup vt2 pos • O26 vt2 + other serogroup vt2 pos HSE-PHL-Dublin

25. Challenges • Methods • Risk • Transport • Facilities • IT HSE-PHL-Dublin

26. Summary •  VTEC in recent years • Particularly in non-O157 VTEC • Introduction of mandatory notification • Increased awareness non-O157 VTEC • Recent increases of non-O157 VTEC can be attributed to more targeted methods • Challenges • Clinical and lab findings need to be taken together • Lab + PH need to communicate HSE-PHL-Dublin

27. Thank You Thank you to dedicated PHL Staff HSE-PHL-Dublin

28. VTEC Reference Service Outbreak Service • Primary High Risk sample analysis • Confirmation and Typing • Medical advisory service • OCT • Data collation HSE-PHL-Dublin