Open Access Highly Accessed Research article

Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Sweden 2000–2003, increasing incidence and regional differences

Mikael Stenhem12*, Åke Örtqvist3, Håkan Ringberg4, Leif Larsson5, Barbro Olsson-Liljequist6, Sara Hæggman6, Karl Ekdahl27 and The Swedish Study Group on MRSA Epidemiology

Author Affiliations

1 Department of epidemiology, Swedish Institute for Infectious Disease Control, Karolinska Institutet, Solna, Sweden

2 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden

3 County Medical Officer for Communicable Disease Control, Stockholm County, Stockholm, Sweden

4 Deputy County Medical Officer for Communicable Disease Control, Skåne County, Malmö, Sweden

5 Department of Hospital Hygiene, Sahlgrenska University Hospital, Göteborg, Sweden

6 Department of bacteriology, Swedish Institute for Infectious Disease Control, Solna, Sweden

7 European Centre for Disease Prevention and Control (ECDC), Solna, Sweden

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BMC Infectious Diseases 2006, 6:30  doi:10.1186/1471-2334-6-30

Published: 21 February 2006



The occurrence of methicillin-resistant Staphylococcus aureus (MRSA) has gradually become more frequent in most countries of the world. Sweden has remained one of few exceptions to the high occurrence of MRSA in many other countries. During the late 1990s, Sweden experienced a large health-care associated outbreak which with resolute efforts was overcome. Subsequently, MRSA was made a notifiable diagnosis in Sweden in 2000.


From the start of being a notifiable disease in January 2000, the Swedish Institute for Infectious Disease Control (SMI) initiated an active surveillance of MRSA.


The number of reported MRSA-cases in Sweden increased from 325 cases in 2000 to 544 in 2003, corresponding to an overall increase in incidence from 3.7 to 6.1 per 100000 inhabitants. Twenty five per cent of the cases were infected abroad. The domestic cases were predominantly found through cultures taken on clinical indication and the cases infected abroad through screening. There were considerable regional differences in MRSA-incidence and age-distribution of cases.


The MRSA incidence in Sweden increased over the years 2000–2003. Sweden now poises on the rim of the same development that was seen in the United Kingdom some ten years ago. A quarter of the cases were infected abroad, reflecting that international transmission is now increasingly important in a low-endemic setting. To remain in this favourable situation, stepped up measures will be needed, to identify imported cases, to control domestic outbreaks and to prevent transmission within the health-care sector.