Imported methicillin-resistant Staphylococcus aureus, Sweden

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health

Background:

• Sweden, a low-prevalence country for methicillin-resistant Staphylococcus aureus (MRSA), provides a unique setting to study imported MRSA transmission.
• Understanding the epidemiology of imported MRSA is crucial for preventing its spread in healthcare and community settings.

Purpose of the Study:

• To analyze the risk and characteristics of imported MRSA cases in Sweden between 2000 and 2003.
• To identify geographical and acquisition-related factors influencing MRSA transmission in travelers.

Main Methods:

• Retrospective analysis of 444 imported MRSA acquisition cases reported in Sweden.
• Calculation of MRSA risk per million travelers based on destination.
• Correlation analysis between travel regions, acquisition type (healthcare vs. community), and MRSA strain characteristics.

Main Results:

• The risk of MRSA acquisition for returning travelers varied significantly by destination, from 0.1 per million to Nordic countries to 59.4 per million to North Africa and the Middle East.
• The majority of imported cases (55%) were healthcare-associated, but higher-risk travel regions showed a stronger correlation with community acquisition (r = 0.81, p = 0.001).
• MRSA strains differed based on geographic origin and whether they were acquired in healthcare or community settings.

Conclusions:

• Imported MRSA cases in Sweden are influenced by travel patterns and destination-specific risks.
• Community acquisition is a significant factor in high-risk travel regions, necessitating tailored surveillance and control measures.
• Understanding regional and acquisition-specific differences in MRSA transmission is key to improving the control of imported infections.