Methicillin resistant Staphylococcus aureus (MRSA) in the Nordic countries

1
Methicillin resistant Staphylococcus aureus
(MRSA) in the Nordic countries

• Petter Elstrøm
• Advisor
• Norwegian Institute of Public Health

2
Objective

• Prevent establishment of MRSA in hospitals
• Increased rate of MRSA enforce changes in empiric
  treatment of S. aureus-infections
• Changes in antibiotic-guidelines will lead to
  more resistant bacteria and increase the cost

3
Historical overview

• Penicillin G introdused in 1941
• Penicillin resistant (?-lactamase prod.)
  S.aureus isolated in 1942
• Meticillin introdused in 1959 as the first
  ?-lactamase resistant penicillin
• Meticillin resistant S.aureus first described
  in 1961
• In late sixties MRSA was identified as a
  nosokomial pathogen
• In late nineties reduced sensitivity against
  Vancomycin (VISA) was reported
• Vancomycin resistant S.aureus (VRSA) isolated
  in 2002

4
Historical overview

• First MRSA-wave
• Meticillin resistant first described in 1961
• Worldwide spread of a single arcaic clone
• Second MRSA-wave
• Outbreaks in hospitals
• 5 dominant clones
• Third MRSA-wave
• CA-MRSA
• Evolution of old clones
• Continually new MRSA-strains discovered

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CA-MRSA

• Both epidemiological and microbiological
  definition
• Increased incidence among people outside
  hospitals
• Young people with no known risk factors for MRSA
• Differ genetically from strains inside hospitals
• SCCmec IV, PVL
• Less resistant
• Mainly skin- and soft tissue infections
  Occasionally severe infections (necrotizing
  pneumonia)

6
Changed epidemiology

• Earlier
• Imported cases
• Related to hospital admission or employment
• Now
• Most domestic cases
• Increasing rate of cases not related to hospitals
• Often no known risk factors for MRSA
• Outbreaks in nursing homes

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MRSA in western Europe
Proportion of invasive isolates resistant to
methicillin 2003
Source www.earss.rivm.nl
8
MRSA in England og Wales
Proportion () of MRSA i blood culture, 1989-2002
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MRSA in the Nordic countries
Estimated for 2005
Source http//www.srga.org/SSAC/doc/2005/SSAC_MRS
Areport_2004.pdf
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MRSA in Denmark
Distribution by place of transmission
Source Robert Skov, State serum institute, Sept.
2005
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MRSA i Danmark
Distribution by age group, 2003
Source Robert Skov, State serum institute, Sept.
2005
12
MRSA in Sweden
Distribution by place of transmission
2003
2004
Source Otto Cars, Smittskyddsinstitutet, sept.
2005
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MRSA in Norway
No. of cases, 1995 15.nov. 2005
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MRSA in Norway
Proportion by county, 2004 - 2005
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MRSA in Norway
Distribution by place of transmission
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MRSA in Norway
Distribution by place of infection onset
Hospitalized
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MRSA in Norway
Reported outbreaks in health care institutions
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2003 2 hospitals, 3 nursing homes
2004 2 hospitals, 4 nursing homes
2005 8 nursing homes
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Challenges

• Increasing incidence of MRSA
• Changing epidemiology
• Bacterial evolution
• Laboratorial methods are not optimal
• Lack in knowledge
• Differs in national and regional guidelines
• Compliance of infection control measures are not
  optimal

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Actions

• Coordinate the guidelines in the Nordic countries
  
• Discuss and coordinate advices and guidelines in
  Norway
• Better survey through genotyping of all isolates
• Continue rational use of antibiotics
• Science
• High quality in hygiene and other infection
  control measures