Surveillance of antimicrobial resistance Liselotte Högberg Swedish Institute for Infectious Disease Control E-mail: [email protected]
Mar 27, 2015
Surveillance of antimicrobial resistance
Liselotte Högberg
Swedish Institute for Infectious Disease Control
E-mail: [email protected]
OVERVIEWBasic principles
Why, what, how and who?
Antimicrobial surveillance in Sweden
Different types of surveillance
Validity of surveillance data
Sensitivity, specificity
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
Basic principles
Basic principles
• 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
WHAT?
Basic principles
HOW ?
• Comprehensive surveillance
• Sentinel surveillance
• Point-prevalence studies
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
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
Basic principles
Point prevalence studies
- Useful for validation of representativity of surveillance data
- Evaluation of interventions
Basic principles
WHO ?
• General population vs. hospital in-patients
• Clinical reports
• Laboratory reports
Basic principles
Clinical data Laboratory 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
DATA SOURCE
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
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
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
Basic principles
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
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)
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)
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
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
EARSS: Proportion PRP isolates in year 2000
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
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
Data validity
0
1
2
3
4
5
6
7
1997 1998 1999 2000 2001 2002 2003
Year
Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L)
Data validity
0
1
2
3
4
5
6
7
1997 1998 1999 2000 2001 2002 2003
Year
Incidence/ 100 000 inh (PRP MIC PcG >= 0,5 mg/L)
RSQC rate (PRP MIC >= 0,12 mg/L)
Data validity
0
1
2
3
4
5
6
7
1997 1998 1999 2000 2001 2002 2003
Year
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)
Data validity
0
1
2
3
4
5
6
7
1997 1998 1999 2000 2001 2002 2003
Year
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)
Data validity
Nasopharyngeal cultures/1000 inhabitants in Sweden 1998-2003
0
5
10
15
20
25
1998 1999 2000 2001 2002 2003Year
NP
H c
ult
ure
s /
10
00
in
ha
bit
an
ts
Changes in culturing propensity
0
10000
20000
30000
40000
50000
60000
70000
80000
0 2000 4000 6000 8000 10000 12000
S. pneumoniae
Nas
op
har
yng
eal
cult
ure
s
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)
Data validity
Specificity
• Methodological problems at the laboratory
• Reporting bias from laboratories
Data validity
Determinants for sensitivity
1. Contact with health care services
2. The pathogen is isolated
3. The case is reported
There is a risk for bias in each step!
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
Data validity
Routines for contact tracing
for PRP
MIC PcG > 0,5 mg/L
Multi-resistance or high MIC-values
Individual
Isolation of the pathogen
• Cultures from all cases/only on therapeutic failures?
• Tradition in culturing propensity
• Economical obstacles
• Fear of time-consuming contact tracing
Data validity
Nasopharyngeal culturing propensity in Sweden 1998-2002
(Number of nasopharyngeal cultures/1000 inhabitants)
Data validity
Who is sampled?
CarriageDiseaseAntibiotic treatment
Treatment failure
Data validity
PRP incidence/1000 inhabitants (all cases) in area G and M
0
5
10
15
20
25
30
35
40
1998 1999 2000 2001 2002
Year
PR
P in
cid
en
ce
/ 1
00
00
0 in
h
G
M
Data validity
PRP incidence (only index cases) in area G and M
0
1
2
3
4
5
6
1998 1999 2000 2001 2002
Year
PR
P i
nc
ide
nc
e /
10
0 0
00
in
h G
M
Data validity
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
Summary