Methicillin-resistant Staphylococcus aureus in Europe, 1999-2002

Abstract

We explored the variation in proportions of methicillin-resistant Staphylococcus aureus (MRSA) between and within countries participating in the European Antimicrobial Resistance Surveillance System and temporal trends in its occurrence. This system collects routine antimicrobial susceptibility tests for S. aureus. We examined data collected from January 1999 through December 2002 (50,759 isolates from 495 hospitals in 26 countries). MRSA prevalence varied almost 100-fold, from <1% in northern Europe to >40% in southern and western Europe. MRSA proportions significantly increased in Belgium, Germany, Ireland, the Netherlands, and the United Kingdom, and decreased in Slovenia. Within countries, MRSA proportions varied between hospitals with highest variance in countries with a prevalence of 5% to 20%. The observed trends should stimulate initiatives to control MRSA at national, regional, and hospital levels. The large differences between hospitals indicate that efforts may be most effective at regional and hospital levels.

Figure 1

Geographic variation in proportions of methicillin-resistant Staphylococcus aureus (MRSA) (1999–2002).

Figure 2

Statistically significant trends (p < 0.05) in methicillin-resistant Staphylococcus aureus (MRSA) proportions per year by country, 1999–2002, including hospitals participating for at least 3 consecutive years and reporting data of >20 isolates only.

Figure 3

A) Variation in methicillin-resistant Staphylococcus aureus (MRSA) proportions between hospitals with AST results of >20 blood isolates, displayed by ranking of MRSA proportion (from lowest to highest). Only countries with more than one hospital are displayed. Hospital-specific proportions (open diamonds) are grouped per country. The solid horizontal bars represent the mean MRSA proportion per country. B) Local variation, showing the power-transformed variance being independent of the mean MRSA proportion per country, displayed by ranking of MRSA proportion (from lowest to highest). Only hospitals reporting >20 isolates are included. Countries with less than five reporting hospitals are not shown (Iceland and Malta [1], Estonia [3], Bulgaria and Luxembourg [4]).