Infection Control Aspects of VRE & ESBL-producing Organisms

1
Infection Control Aspects of VRE ESBL-producing
Organisms

• Dr Miles Denton
• Consultant Microbiologist
• Leeds Teaching Hospitals NHS Trust

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ESBL-producing organisms

• Escherichia coli CTX-M
• Klebsiella species TEM/SHV variants
• Pseudomonas aeruginosa
• Acinetobacter baumanii
• Other Enterobacteriaceae

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Why are VRE and ESBL-producing organisms
important?

• Increasing clinical problem
• They cause outbreaks, particularly in critical
  areas e.g. ICUs, neonatology
• Often multi-resistant - can be difficult to treat
• Associated with increased mortality
• Associated with increased LOS

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Available guidance

• VRE
• Guidelines for the control of glycopeptide-resista
  nt enterococci in hospitals. Combined Working
  Party HIS/ICNA/BSAC, 2004.
• ESBLs
• No equivalent guidance

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VRE UK situationVancomycin resistance in
Enterococcal bacteraemia, England, Wales,
Northern Ireland, Voluntary reporting to HPA
Centre for Infections, 2003-4.
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VRE European situationEARSS Annual Report 2002
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ESBLs VRE an emerging problem Diekema et al,
Clin Infect Dis 2004 38 78-85
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ESBLs VRE association with hospital size and
complexityDiekema et al, Clin Infect Dis 2004
38 78-85
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ESBLs VRE association with hospital size and
complexityDiekema et al, Clin Infect Dis 2004
38 78-85
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ESBLs European situationEARSS Annual Report
2002
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ESBLs an emerging problemGlasswell et al,
Healthcare-associated Infection and Antimicrobial
Resistance Dept Antimicrobial Resistance
Monitoring and Reference Laboratory, Health
Protection Agency, Colindale, London
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ESBLs an emerging problemGlasswell et al,
Healthcare-associated Infection and Antimicrobial
Resistance Dept Antimicrobial Resistance
Monitoring and Reference Laboratory, Health
Protection Agency, Colindale, London
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Bacteraemia isolates Leeds Teaching Hospitals
Trust, 2004
ESBLs have become a much more significant
clinical problem than VRE
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Scottish trends and routine diagnostic detection
of ESBLs. FM MacKenzie. SCIEH Weekly Report
2004/50
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Identification of ESBLs (and VRE) is a problem.
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Laboratory issues

• Isolation/identification of ESBL-positive
  organisms
• Laboratory Detection and Reporting of Bacteria
  with Extended Spectrum Beta-lactamases, QSOP 51.
  Issued by Standards Unit, Evaluation Standards
  Laboratory, Health Protection Agency, February
  2005
• Many gram negative organisms not subjected to
  susceptibility tests does this matter?
• Many gram negative organisms not routinely
  identified to species level does this matter?
• Are all enterococci tested versus vancomycin?
• Recognition of outbreaks availability of
  genotyping
• Concept of high risk areas (e.g. ICU) no
  longer valid with emergence of CTX-M in the
  community

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Infection Control Strategies

• Handwashing
• Patient screening
• Staff screening
• Environmental screening
• Isolation rooms/wards
• Environmental cleaning
• Ward closure
• Antibiotic prescribing policies
• Education
• Others

?
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Guidelines for the control of glycopeptide-resista
nt enterococci in hospitals. Combined Working
Party HIS/ICNA/BSAC, 2004.

• Risk factors for GRE infection outlined
• Previous antibiotic therapy glycopeptides,
  cefalosporins
• Prolonged hospital stay
• Admission to ICU, haematology, renal, liver
• Carriage large bowel
• Transmitted via hands colonised/ infected
  patients, contaminated environment

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Managing hospital outbreaks of GRE Combined
Working Party HIS/ICNA/BSAC, 2004.

• Screening patients faeces (rather than rectal
  swabs)
• Urine, wound, line sites, HVSs also used
• Uncertainty regarding media/method
• Incorporate bile salts and selective agents
• Optimum vancomycin concentration debated NCCLS
  recommends 6mg/l
• Outbreak isolates to be typed - PFGE

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Managing hospital outbreaks of GRE Combined
Working Party HIS/ICNA/BSAC, 2004.

• Managing patients
• Differentiate colonisation from infection
• Use antibiotics ONLY for infection
• Remove/drain sources of infection
• Gut carriage can persist for months/years
• Attempts at clearance are usually unsuccessful
• Screening staff for stool carriage is of no value

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Managing hospital outbreaks of GRE Combined
Working Party HIS/ICNA/BSAC, 2004.

• Risk assessment sporadic/epidemic/endemic
• Area involved, infection/colonisation
• Hand hygiene paramount
• Disinfectant-based products more effective than
  soap
• Alcohol gel most convenient provided hands not
  visibly soiled

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Managing hospital outbreaks of GRE Combined
Working Party HIS/ICNA/BSAC, 2004.

• Isolation dependent on risk assessment, single
  rooms or cohorts
• Diarrhoea/incontinence
• Thorough cleaning or room/bay/ward after incident
• Optimal cleaning regimen undefined e.g. 500ppm
  available chlorine/1-2 phenolics
• Laundry bedding/curtains
• Inform colleagues receiving transfers
• Appropriate use of antibiotics glycopeptides
  and cefalosporins

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A simultaneous outbreak on a neonatal unit of two
strains of multiply antibiotic resistant
Klebsiella pneumoniae controllable only by ward
closure. Macrae et al, J Hosp Infect 2001 49
183-92

• Outbreak of two amoniglycoside-resistant K.
  pneumoniae strains (one ESBL)
• UK neonatal unit 22 neonates affected, one died

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A simultaneous outbreak on a neonatal unit of two
strains of multiply antibiotic resistant
Klebsiella pneumoniae controllable only by ward
closure. Macrae et al, J Hosp Infect 2001 49
183-92

• Outbreak control group
• Closed to transfers from other units
• Unable to cohort allocation of nurses
• Glove/gowns for all patient contacts
• Alcohol chlorhexidine handrub
• Weekly screening of all patients
• Empiric therapy changed from gent/pen to amik/mer
• Environmental screening
• Improved cleaning
• Outbreak continued

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A simultaneous outbreak on a neonatal unit of two
strains of multiply antibiotic resistant
Klebsiella pneumoniae controllable only by ward
closure. Macrae et al, J Hosp Infect 2001 49
183-92

• Ward closed to admissions
• Satellite unit opened to manage all sick neonates
  born at the hospital, staff screened negative for
  enteric carriage
• Second satellite unit opened to take remaining
  KP patients to allow complete closure/cleaning
  of neonatal unit
• Re-screening of environment reopened
• All new admissions screened for carriage of
  multiply resistant GNBs

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Rectal carriage of ESBL-producing organisms on
the General and Neurosurgical ICUs, Leeds General
Infirmary, MZali et al, ECCMID 2005
Ten (62) of the 16 patients ESBL on admission
had been in hospital lt 48h
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Impact of a county-wide outbreak of
ESBL-producing Eschrichia coli. Warren et al,
SCIEH Weekly Report 38 2004/50

• Fourteen month period outbreak of
  CTX-M-producing Escherichia coli in Shropshire
• Four subclones of E. coli O25
• High prevalence of quin/trim resistance (98)
• Uropathogenic
• 281 patients infected, 16 had bacteraemia
• 50 of cases community-based
• 5/16 bacteraemic patients died, 64/244 other
  evaluable patients died
• One third of community patients no hospital
  link
• Restrictions on the reporting of cefs/quins
• Increased use of carbapenems
• Control hampered by lack of isolation facilities
  and high bed-occupancy rates

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Global spread of vacomycin-resistant Enterococcus
faecium from distinct genetic complex Willems et
al, Emerg Infect Dis 2005 11 821-9.
Many outbreaks of GRE may be due to related group
of highly successful strains COMPLEX-17 Ampicill
in-resistant Pathogenicity island Association
with outbreaks Found globally mainly Europe
and USA
0 Animal surveillance 1 Human community
surveillance 2 Human hospital surveillance 3
Human hospital clinical 4 Hospital outbreak
samples
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