Antimicrobial Resistance - what does it all mean?

1. Antimicrobial Resistance- what does it all mean? Professor Peter Silley MB Consult Ltd & University of Bradford p-s@mbconsult.co.uk

2. Overview What do we mean by resistance? definitions, issues, questions Does surveillance help? national, industry Some concluding thoughts

3. Dual Focus Animals – a dual focus foodborne pathogens & commensal organisms the major focus re resistance, in terms of public health target animal pathogens little available data although some national surveillance programs do consider some pathogens

4. The Importance of Language! Foodborne pathogens & commensals in animals “resistance” defined in European surveillance (EFSA) by epidemiological cut off values, not clinical breakpoints In the US programs (NARMS), resistance historically defined by clinical breakpoints impacts the scientific literature

5. So How Important is Language? • One of the greatest challenges to data interpretation arises from the lack of agreement on what is meant by “resistance” • Figures denoting % resistance in national surveillance systems cannot always be compared as they have been calculated in different ways • Extent of differences depends on antibacterial compound being investigated, bacterial species & breakpoints used • Particularly relevant to extended spectrum cephalosporins & fluoroquinolones, which have different clinical breakpoints & ECVs

7. Resistance or Decreased Susceptibility?

8. Language is Important! • Use of epidemiological cut-off values is important for early detection of decreased susceptibility BUT it is inappropriate to use to determine % clinical resistance • Need to use different terminology to differentiate decreased susceptibility from clinical resistance

9. What Does the Future Hold? • Discussions ongoing regarding European surveillance for target animal pathogens • OIE Workshop, Paris, March 2013 • Much yet to be decided to determine the critical issues

10. Surveillance Data • Important to emphasize that all surveillance systems have merit, especially when considering resistance trends within the countries in which surveillance has been instigated, however, there can be challenges when comparing data across countries

11. Industry/Government Joint Initiative GermVet Program – data available on the web http://www.bvl.bund.de/SharedDocs/Downloads/09_Untersuchungen/Bericht_Resistenzmonitoring_2009.pdf?__blob=publicationFile&v=2 Wide spread of target animal pathogen/animal species data available Extensive Data from Germany

12. in a timely fashion, and showing raw data Data Must Be Reported

13. Are All Countries The Same? • Country to country differences in resistance are apparent & whilst expected as a function of • differing management systems • disease incidence • antimicrobial usage ….. how important is this data? • Some differences cannot be so easily explained • EASSA surveillance data (component of the CEESA pharma industry initiative) presents an opportunity to review comparative data across Europe

14. Given some of the discrepancies encountered while comparing data from national surveillance programs the CEESA programs aim to generate Pan-European antibiotic susceptibility data that can be compared across the EU by: • Using an identical sampling point in all EU countries • Using a single lab to generate susceptibility data • Using uniform interpretive criteria to analyse data

15. EASSA (European Antimicrobial Susceptibility Surveillance in Animals) • examines the antimicrobial susceptibility of foodborne and commensal bacteria in food animals • VetPath • examines antimicrobial susceptibility of major disease causing bacterial pathogens in food animals

16. Antimicrobial Usage

17. Does Antimicrobial Use = Antimicrobial Resistance? Published company data

18. Mannheimia haemolytica Tulathromycin

19. Mannheimia haemolytica Ceftiofur

20. Other Issues - Isolate origin

21. Fluoroquinolone use in food animals is very low in Denmark; data for 2010 shows 1 kg used in cattle. Fluoroquinolone decreased susceptibility levels are similarly very low in all animal species and clinical resistance is absent Challenging To Interpret The Data – but the big picture shows ..

22. But Don’t Forget the Big Picture

23. Conclusions

24. And Remember ……… the “Confusogram” adapted from Prescott, 2000 from Boerlin & Reid-Smith, 2008

25. So ……….. • Resistance is an inevitable consequence of antimicrobial use, prudent, appropriate use is crucial • correct dosing on a mg/kg bw basis • Urgent need to harmonize methodology & analysis such that surveillance data can be used as an input into risk analysis • Harmonized surveillance provides opportunity to implement appropriate risk management steps in response to public health issues arising from changes in antibiotic resistance in foodborne pathogens and commensal organisms

26. FINALLY …. well almost • Data sources for resistance must be relevant • All data is not comparable • Resistance is not a disease • but we must relate the data to public health

27. Hot Off The Press

28. Hot Off The Press

29. Thanks for your attention