Antimicrobial Antimicrobial resistance resistance surveillance in surveillance in Ireland Ireland Results of invasive Staphylococcus aureus infection (blood) surveillance (2009Q1-4) **** Data as of 14/04/2010 **** **** Data as of 14/04/2010 **** Ireland is a member of the European Antimicrobial Resistance Surveillance System (EARSS)
Antimicrobial resistance surveillance in Ireland. Results of invasive Staphylococcus aureus infection (blood) surveillance (2009Q1-4) **** Data as of 14/04/2010 ****. - PowerPoint PPT Presentation
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Antimicrobial resistance Antimicrobial resistance surveillance in Irelandsurveillance in Ireland
Results of invasive Staphylococcus aureus infection
(blood) surveillance (2009Q1-4)**** Data as of 14/04/2010 ******** Data as of 14/04/2010 ****
Ireland is a member of the European Antimicrobial Resistance Surveillance System (EARSS)
EARSS EARSS S. aureusS. aureus::Objective and case definitionObjective and case definition
Objective:
To determine the proportions of S. aureus isolates from blood that are resistant to meticillin
Case definition:
EARSS collects data on the first invasive isolate (from blood only) of S. aureus per patient per quarter
Caveats in interpreting EARSS dataCaveats in interpreting EARSS data
Care must be exercised when interpreting the raw figures, i.e. increases in numbers of isolates, as the numbers of laboratories reporting to EARSS has increased over the years
EARSS data does not distinguish clinically significant isolates from contaminants
If MRSA is isolated subsequent to MSSA within the same quarter, then that isolate is not counted (and similarly if MSSA is isolated subsequent to MSSA) [similarly for other pathogen-antibiotic resistance combinations]
For further information on antimicrobial resistance and EARSS in Ireland, including quarterly and annual reports, plus reference/ resource material on the individual pathogens under surveillance, see:
SAU, Staphylococcus aureusMRSA, Meticillin-Resistant S. aureusMSSA, Meticillin-Susceptible S. aureusVISA, Vancomycin-Intermediate S. aureus
Numbers and proportions of Numbers and proportions of S. aureusS. aureus/MRSA /MRSA from bacteraemia with 95% confidence from bacteraemia with 95% confidence Intervals (CI), 1999-2009Q1-4* Intervals (CI), 1999-2009Q1-4*
S. aureusS. aureus/MRSA bacteraemia trends, /MRSA bacteraemia trends, 1999-2009Q1-4*1999-2009Q1-4*
* Data for 2009 provisional up to the end of Q4Number of laboratories participating by year-end and quarter are indicated above the bars
0%
10%
20%
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50%
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200
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800
1000
1200
1400
1600
%M
RSA
Num
ber o
f iso
late
s
Time periodTotal S.aureus MRSA %MRSA
18 282320 424241 4411 43 4444 4444 44
S. aureusS. aureus/MRSA bacteraemia trends by quarter, /MRSA bacteraemia trends by quarter, 2002-2009Q1-4*2002-2009Q1-4*
* Data for 2009 provisional up to the end of Q4;Number of laboratories participating by year-end indicated above the Q4 bars
20%
25%
30%
35%
40%
45%
50%
55%
0
50
100
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300
350
400
450
Q1
2002
Q2
2002
Q3
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Q4
2002
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2007
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2008
Q2
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2008
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2008
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2009
Q2
2009
Q3
2009
Q4
2009
%M
RSA
Num
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s
QuarterTotal S.aureus MRSA %MRSA
23 28 41 42 42 44 43 44
S. aureusS. aureus/MRSA bacteraemia trends, /MRSA bacteraemia trends, 2002-2009Q1-4*: 4-quarterly moving average2002-2009Q1-4*: 4-quarterly moving average
* Data for 2009 provisional up to the end of Q4;Number of laboratories participating by year-end indicated above the Q4 bars
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45%
50%
55%
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Q4
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2009
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2009
%M
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Num
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4-Quarter period ending…..Total S.aureus MRSA %MRSA
23 28 41 42 42 44 43 44
Numbers of Numbers of S. aureus S. aureus bacteraemia isolates bacteraemia isolates and %MRSA by Hospital Network, 2009Q1-4and %MRSA by Hospital Network, 2009Q1-4
Dub/M, Dublin Midlands; Dub-N, Dublin North; Dub-S, Dublin South; MW, Mid Western; NE, North Eastern; NW, North Western; S, Southern; SE South Eastern; W/NW, West/North Western
Proportion of Proportion of S. aureus S. aureus bacteraemia isolates bacteraemia isolates by Hospital Network, 2009Q1-4 (n=1309)by Hospital Network, 2009Q1-4 (n=1309)
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Dub/M Dub-N Dub-S MW NE S SE W/NW Other Private ROI TOTAL
%M
RSA
Num
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s
Hospital NetworkTotal S.aureus %MRSA
Numbers of Numbers of S. aureus S. aureus bacteraemia isolates, bacteraemia isolates, %MRSA and rates by Hospital Network, %MRSA and rates by Hospital Network, 2009Q1-42009Q1-4
Dub/M, Dublin Midlands; Dub-N, Dublin North; Dub-S, Dublin South; MW, Mid Western; NE, North Eastern; NW, North Western; S, Southern; SE South Eastern; W/NW, West/North Western
Numbers, proportions and rates of MRSA Numbers, proportions and rates of MRSA bacteraemia by hospital type, 2009Q1-4bacteraemia by hospital type, 2009Q1-4
*Single speciality hospitals; ** Denominator data (BDU, Bed Days Used) not available;*** Complete denominator data not available;^ includes all private hospitals/quarters for which no activity data were available
Rates of Rates of S. aureus S. aureus bacteraemia isolates by bacteraemia isolates by Hospital Network*, 2009Q1-4 (n=1253)Hospital Network*, 2009Q1-4 (n=1253)
0.00
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0.35
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0.45
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Dub/M Dub-N Dub-S MW NE S SE W/NW ROI TOTAL
MSS
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ate
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Num
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Hospital NetworkTotal S.aureus SAU rate
* excludes private hospitals and other non-acute facilities
Rates of MRSARates of MRSA bacteraemia isolates by bacteraemia isolates by Hospital Network, 2009Q1-4 (n=350)Hospital Network, 2009Q1-4 (n=350)
* excludes private hospitals and other non-acute facilities
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
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Dub/M Dub-N Dub-S MW NE S SE W/NW ROI TOTAL
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Use
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Num
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Hospital NetworkTotal S.aureus MRSA rate
Rates of MSSARates of MSSA bacteraemia isolates by bacteraemia isolates by Hospital Network, 2009Q1-4 (n=903)Hospital Network, 2009Q1-4 (n=903)
* excludes private hospitals and other non-acute facilities
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Dub/M Dub-N Dub-S MW NE S SE W/NW ROI TOTAL
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Hospital NetworkTotal S.aureus MSSA rate
Susceptibility data for Susceptibility data for S. aureus S. aureus bacteraemia bacteraemia isolates, 2009Q1-4 (n=1309)isolates, 2009Q1-4 (n=1309)
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AntibioticResistant Susceptible
3.5%
27.1%
27.6%
30.1% 2.3%
0.0%
2.0%87.6%
0.0%
0.5%
0.0%
1.9%19.2%
4.6%
0.1%
Susceptibility data for MRSASusceptibility data for MRSA bacteraemia bacteraemia isolates, 2009Q1-4 (n=355)isolates, 2009Q1-4 (n=355)
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350
400N
umbe
r of i
sola
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AntibioticResistant Susceptible
10.0%
100.0%
92.5%
72.6%
5.3%
5.1%98.3%
0.0%
1.1%
1.8%
0.0%
9.5%
38.1%
0.0%0.0%
Susceptibility data for MSSASusceptibility data for MSSA bacteraemia bacteraemia isolates, 2009Q1-4 (n=954)isolates, 2009Q1-4 (n=954)
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Num
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AntibioticResistant Susceptible
1.2%
0.0%
5.8%
15.7% 1.2%
0.0%
1.0%
0.0%
0.1%
1.9%
0.0%
3.1%
12.8%
0.1%
84.5%
Antibiogram results for MRSA isolates Antibiogram results for MRSA isolates referred to NMRSARL, 2009Q1-4 (n=321) referred to NMRSARL, 2009Q1-4 (n=321)
Data provided by National MRSA Reference Laboratory, St James’s Hospital
0%
10%
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30%
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100%
CHL CIP ERY FUS GEN LIN LNZ MUP RIF TCY TMP VAN
% o
f iso
late
s
Antibiotic
Resistant Intermediate Susceptible
Trends in proportion of gentamicin resistance Trends in proportion of gentamicin resistance among MRSA isolates^, 1999-2009Q1-4among MRSA isolates^, 1999-2009Q1-4
YearTotal MRSA tested for GEN-R GEN-R MRSA %GEN-R MRSA
18 282320 424241 4411 43 44
^ Data from National MRSA Reference Laboratory; Changes in the numbers of participating laboratories are indicated above the bars; * 2009 data are provisional
Trends in proportion of fusidic acid resistance Trends in proportion of fusidic acid resistance among MRSA isolates^, 1999-2009Q1-4among MRSA isolates^, 1999-2009Q1-4
^ Data from National MRSA Reference Laboratory; Changes in the numbers of participating laboratories are indicated above the bars; * 2009 data are provisional
YearTotal MRSA tested for FUS-R FUS-R MRSA %FUS-R MRSA
18 282320 424241 4411 43 44
Assume proportion or rate stable over time (i.e. in control)
Mean calculated from data for quarters (data points) up to the previous quarter, i.e. excluding latest quarter
Warning limits and action limits are equal to 2 and 3 Standard Deviations (SD), respectively
These are used to determine if:◦ the trends in proportions or rates are behaving as
expected, i.e. the process is in control. The variation observed here is due to chance (common cause or natural variation)
or◦ the trends are not behaving as expected and something
unusual is happening, i.e. the process is out of control. The variation observed here is unlikely to be due to chance alone. Special circumstances are more likely to operate (special cause variation) warranting further investigations
Statistical Process ChartsStatistical Process Charts
Special cause variation occurs if:One value above or below the action limits (±3SD)3 consecutive values between upper warning and
action limits (or lower limits)5 consecutive values in top or bottom 2/3 (between 1
and 3 SD, or -1 and -3 SD) 13 consecutive values in top or bottom middle 1/3
(between mean and 1 SD, or mean and -1 SD)8 consecutive values on the same side of the mean12 of 14 consecutive values on same side of the mean8 consecutive values either increasing or decreasingCyclic or periodic behaviour
Statistical Process ChartsStatistical Process Charts
Statistical Process ChartStatistical Process ChartNational MRSA proportions: P-Chart National MRSA proportions: P-Chart
Mean proportion calculated from data for Q1 2002-Q3 2009;UWL and LWL, Upper and Lower Warning Limits; UAL and LAL (±2 Standard Deviations), Upper and Lower Action Limits (±3 Standard Deviations)
20%
25%
30%
35%
40%
45%
50%
55%
Q1
2002
Q2
2002
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2002
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2002
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Prop
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Quarter%MRSA Mean %MRSA UWL LWL UAL LAL
Statistical Process Chart Statistical Process Chart National MRSA rates: U-Chart National MRSA rates: U-Chart
Mean rate calculated from data for Q1 2004-Q3 2009; UWL and LWL, Upper and Lower Warning Limits (±2 Standard Deviations); UAL and LAL, Upper and Lower Action Limits (±3 Standard Deviations)
0.00
0.05
0.10
0.15
0.20
0.25Ra
te p
er 1
,000
Bed
Day
s U
sed
QuarterMRSA rate Mean rate UWL LWL UAL LAL
P-chart: The proportion of MRSA bacteraemia was above its
upper control limit in Q2 2002, Q2 2003 and Q3 2006 and below its lower control limit for Q4 2007 and Q2 2008–Q4 2009. These indicate that the process is out of control - if true, the former represents a worsening situation and the latter an improving situation regarding %MRSA
U-chart The rate of MRSA bacteraemia was above its upper
control limit in Q2 2005 and below its lower control limit for Q2 2008–Q4 2009, (except for Q1 2008) indicating that out of control - if true, the former represents a worsening situation and the latter an improving situation regarding %MRSA
Worsening/improving situations warrant further investigation to determine reasons why
Statistical Process ChartsStatistical Process Charts
Rates of Rates of S. aureusS. aureus and MRSA bacteraemia, and MRSA bacteraemia, 2004-2009Q1-42004-2009Q1-4
* Acute public hospitals only
** Bed days used (BDU) calculated from Acute Public Hospital Activity data for acute
public hospitals participating in EARSS
*** Per 1,000 bed days used
YearNo. hospitals*
(Total hospitals)Bed Days
Used**Total
S.aureus MRSA %MRSAMRSA rate***
2004 57 (58) 3,728,566 1282 545 42.5% 0.15
2005 57 (58) 3,792,972 1367 577 42.2% 0.15
2006 53 (53) 3,722,832 1353 572 42.3% 0.15
2007 52 (52) 3,747,184 1339 526 39.3% 0.14
2008 50 (51) 3,693,026 1259 425 33.8% 0.12
2009Q1-4 48 (48) 3,685,647 1253 350 27.9% 0.09
VVancomycin-ancomycin-IIntermediate ntermediate SS. . aaureusureus (VISA) (VISA) reports from EARSS in 2009*reports from EARSS in 2009*
In 2008, no MRSA isolates with reduced susceptibility to vancomycin were detected by the Etest macromethod
In 2006, two VISA isolates were detected, which were the first reports of VISA from EARSS in Ireland:
• both were confirmed as VISA by CDC• one was shown to be VISA and the other to be h-VISA by population analysis profiling (PAP) studies
*Data from the National MRSA Reference Laboratory, where all EARSS MRSA isolates submitted by participating laboratories are tested for reduced susceptibility to vancomycin
Age distribution of patients with MRSA and Age distribution of patients with MRSA and MSSA bacteraemia in MSSA bacteraemia in 20082008
0
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80
90N
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Age GroupMRSA MSSA
Age-specific incidence rates of MRSA Age-specific incidence rates of MRSA and MSSA bacteraemia in and MSSA bacteraemia in 20082008
Mean, median, mode and range of ages of Mean, median, mode and range of ages of patients with patients with S. aureusS. aureus (MRSA and MSSA) (MRSA and MSSA) bacteraemia in bacteraemia in 20082008
The difference in median ages for patients with MRSA and MSSA bacteraemia is significant as the confidence intervals do not overlap
MRSA MSSA SAU
n 435 854 1289
n with age 434 852 1286
Mean 66.5y 52.7y 57.4y
Median 72y (70-74y) 59y (57-61y) 64y (62-66y)
Mode 78y 0y 0y
Range 0-96y 0-97y 0-97y
Relative risk of developing MRSA bacteraemia Relative risk of developing MRSA bacteraemia associated with age in associated with age in 20082008
In patients with laboratory-confirmed S. aureus bacteraemia in 2008, the probability that the infecting organism was MRSA as compared to MSSA was over 2-times greater in patients aged ≥65years than in those aged <65 years
MRSA MSSA Total
>=65y 290 337 627
<65y 144 515 659
Total 434 852 1286
Relative risk (RR) = (347/669)/(190/724)2.116671
= 2.12 (95% CI: 1.79-2.50)
Chi-squared 85.9
P-value <0.0001
Sex distribution of patients with Sex distribution of patients with S. aureusS. aureus (MRSA and MSSA) bacteraemia in (MRSA and MSSA) bacteraemia in 20082008
In patients with laboratory-confirmed S. aureus bacteraemia in 2008, males were approximately 1.6-times more likely to get an infection (1.5-times for MRSA and 1.7-times for MSSA) than females. These findings were significant (P<0.0001)
MRSA MSSA SAU
No. male 260 535 795
%male 40.1 62.7 61.8
No. female 174 318 492
%female 59.9 37.3 38.2
m/f ratio 1.49 1.68 1.62
z-test 4.21 7.68 8.69
P-value <0.0001 <0.0001 <0.0001
Distribution of MRSA in EARSS countries Distribution of MRSA in EARSS countries in 2008in 2008
Map downloaded from http://www.rivm.nl/earss/database/ on 24/08/2009
Distribution of MRSA in EARSS countries Distribution of MRSA in EARSS countries in 2007in 2007
Map downloaded from http://www.rivm.nl/earss/database/ on 26/08/2008
Distribution of MRSA in EARSS countries Distribution of MRSA in EARSS countries in 2006in 2006
Map downloaded from http://www.rivm.nl/earss/database/ on 22/08/2007