Surveillance of antimicrobial resistance

1. Surveillance of antimicrobial resistance Liselotte Högberg Swedish Institute for Infectious Disease Control E-mail: liselotte.hogberg@smi.ki.se

2. OVERVIEW Basic principles Why, what, how and who? Antimicrobial surveillance in Sweden Different types of surveillance Validity of surveillance data Sensitivity, specificity

3. Basic principles WHY? - Defining/updating treatment guidelines - Identifying needs for infection control measures - Monitoring the impact of interventions to improve antimicrobial use and control spread of infection

4. Basic principles WHAT? • Should be focused on pathogens of greatest public health importance • Should include pathogens that are readily transmissible • Should provide information for action at local and national levels

5. Basic principles HOW ? • Comprehensive surveillance • Sentinel surveillance • Point-prevalence studies

6. Basic principles Comprehensive surveillance • Includes the whole population at risk • Aiming to capture all cases • Involves large number of clinicians and laboratories – only limited set of data

7. Basic principles Sentinel surveillance • Indicator data for rest of population • Suitable when prolonged and detailed data is required • Target approach (instead of representative sample) might be suitable

8. Basic principles Point prevalence studies • Useful for validation of representativity of surveillance data • Evaluation of interventions

9. Basic principles WHO ? • General population vs. hospital in-patients • Clinical reports • Laboratory reports

10. Basic principles DATA SOURCE Laboratory data Clinical data • + timely information on clinical disease • + possibility to get detailed patient information • dependent on accuracy and consistency in diagnosis and timely and complete reporting • + objective confirmation of the diagnosis • + opportunity for detailed characterisation of the causative organism • less timely • often few clinical details

11. Basic principles Numerators for surveillance • Data should relate to a single episode of illness in a patient • Microbiological data: only the first positive culture from the patient from each disease episode should be reported • Microbiological data: qualitative or quantitative

12. Basic principles Examples of antimicrobial surveillance projects ANNUAL REPORTS DANMAP – Denmark FIRE – Finland NORM – Norway SWEDRES – Sweden EARSS (www.earss.rivm.nl) RESEARCH/INDUSTRY INITATIVES Alexander project Sentry

13. Basic principles Examples of antimicrobial surveillance systems ANNUAL REPORTS DANMAP – Denmark FIRE – Finland NORM – Norway SWEDRES – Sweden EARSS (www.earss.rivm.nl) RESEARCH/INDUSTRY INTITATIVES Alexander project Sentry

14. AMR surveillance in Sweden Antimicrobial resistance surveillance in Sweden 1. Mandatory case notification 2. Annual resistance surveillance and quality control programme (RSQC) 3. Sentinel surveillance 4. EARSS

15. AMR surveillance in Sweden Antimicrobial resistance surveillance in Sweden Mandatory case notification Comprehensive surveillance of all cases of MRSA, VRE and penicillin-resistant pneumococci (PRP) to the Swedish Institute for Infectious Disease Control Mandatory for both the clinician having seen the patient and the laboratory diagnosing the pathogen Basic patient data: age, sex, place of residence Data presented as incidence figures (population denominator)

16. AMR surveillance in Sweden Antimicrobial resistance surveillance in Sweden Annual resistance surveillance and quality control programme (RSQC) Each laboratory report resistance data for at least 100 consecutive bacteria per year Includes S. pneumoniae, S. aureus, E. coli, S. pyogenes, H. pylori, E. faecalis/faecium No patient data avilable Detailed resistance data Data presented as proportion (% resistant isolates/ all isolates)

17. AMR surveillance in Sweden Antimicrobial resistance surveillance in Sweden Sentinel surveillance Data mainly derived from special investigations by devoted laboratories At present includes salmonella, shigella, campylobacter, N. gonorrhoeae, N. meningitidis Quality of data varies

18. AMR surveillance in Sweden Antimicrobial resistance surveillance in Sweden EARSS Funded by DG SANCO of the European Commission Surveillance of antmicrobial susceptibility of invasive infections of S. aureus, S. pneumoniea, E. coli, E. faecalis/faecium 27 countries participates www.earss.rivm.nl

19. EARSS: Proportion PRP isolates in year 2000

20. AMR surveillance in Sweden INFORMATION FEEDBACK ResNet (www.srga.org/resnet_sok.htm) Electronic database containing data from RSQC, EARSS and sentinel surveillance SwedRes (www.smittskyddsinstitutet.se) Annual report on Swedish antibiotic utilisation and resistance in human and veterinary medicine

21. Data validity PRP (penicillin-resistant pneumococci) Streptococcus pneumoniae MIC PcG >= 0,5 mg/L Notifiable in Sweden since 1996 Increasing resistance problem internationally Surveillance data available from mandatory data, RSQC and EARSS

22. Data validity Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L)

23. Data validity Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L) RSQC rate (PRP MIC >= 0,12 mg/L)

24. Data validity Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L) RSQC rate (PRP MIC >= 0,12 mg/L) EARSS rate (Invasive PRP >= 0,12 mg/L)

25. Data validity Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L) RSQC rate (PRP MIC >= 0,12 mg/L) EARSS rate (Invasive PRP >= 0,12 mg/L) PRP rate (PRP MIC PcG >= 0,5 mg/L)

26. Data validity Nasopharyngeal cultures/1000 inhabitants in Sweden 1998-2003

27. Data validity Changes in culturing propensity

28. Data validity Ideal surveillance data • Maximum specificity • Limit false positives • Maximum sensitivity • Captures all true positives • Determination of break-points at laboratories • Transient nasal carriage (MRSA)

29. Data validity Specificity • Methodological problems at the laboratory • Reporting bias from laboratories

30. Data validity Determinants for sensitivity • Contact with health care services 2. The pathogen is isolated 3. The case is reported There is a risk for bias in each step!

31. Data validity Contact with health care services • Accessibility • Better access to physicians in large cities • Costs • Free health care for children, cost recovery systems • Socio - economy, tradition • Screening/contact tracing initiatives

32. Routines for contact tracing for PRP MIC PcG > 0,5 mg/L Multi-resistance or high MIC-values Individual

33. Data validity Isolation of the pathogen • Cultures from all cases/only on therapeutic failures? • Tradition in culturing propensity • Economical obstacles • Fear of time-consuming contact tracing

34. Data validity Nasopharyngeal culturing propensity in Sweden 1998-2002 (Number of nasopharyngeal cultures/1000 inhabitants)

35. Data validity Who is sampled? Treatment failure Disease Carriage Antibiotic treatment

36. Data validity PRP incidence/1000 inhabitants (all cases) in area G and M

37. Data validity PRP incidence (only index cases) in area G and M

38. Summary Summary: Basic principles • Obtaining appropriate specimens from the infected individual • Successful isolation of the causative organisms • Accurate determination of antimicrobial resistance • Data collection, collation and analysis • Dissemination of appropriate information for action