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

5. 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

7. 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

9. MRSA in the Nordic countries *Estimated for 2005 Source: http://www.srga.org/SSAC/doc/2005/SSAC_MRSAreport_2004.pdf

10. MRSA in Denmark Distribution by place of transmission Source: Robert Skov, State serum institute, Sept. 2005

11. 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

13. MRSA in Norway No. of cases, 1995 – 15.nov. 2005

14. MRSA in Norway Proportion by county, 2004 - 2005

15. MRSA in Norway Distribution by place of transmission

16. MRSA in Norway Distribution by place of infection onset Hospitalized:

17. MRSA in Norway Reported outbreaks in health care institutions

18. 2003: 2 hospitals, 3 nursing homes 2004: 2 hospitals, 4 nursing homes 2005: 8 nursing homes

19. 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

20. 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