EARSS Annual report 2005, On-going surveillance of S. pneumoniae, S. aureus, E. faecalis, E. faecium, E. coli, K. pneumoniae and P. aeruginosa

Abstract

The European Antimicrobial Resistance Surveillance System (EARSS) is an international initiative funded by the Director General for Health and Consumer Protection (DG SANCO) of the European Commission and the Dutch Ministry of Health, Welfare and Sports. It maintains a comprehensive surveillance and information system that links national networks by providing comparable and validated data on the prevalence and spread of major invasive bacteria with clinically and epidemiologically relevant antimicrobial resistance in Europe. EARSS collects routinely generated antimicrobial susceptibility (AST) data, provides spatial trend analyses and makes timely feedback available via an interactive website at www.rivm.nl/earss. Routine data for major indicator pathogens (Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) are regularly submitted by over 900 laboratories serving around 1400 hospitals in 32 European countries. By the end of 2005 two new countries joined the EARSS initiative, Lithuania and Turkey. Based on a previous laboratory/hospital questionnaire, the overall hospital catchment population of the EARSS network is estimated to include over 100 million inhabitants in the European region, with national coverage rates that ranged between 20-100% for individual countries. In 2005, information on the laboratory demands for external quality assessment (EQA) was collected by questionnaire. Several countries do not have formal agreements on national or international quality assessment schemes in place. Among the international providers of EQA the British UK-NEQAS scheme was most frequently named by countries. Alternatively, different national schemes are in place, either alone or in combination with one of the international programs. Importantly, the majority of laboratories that participate in EARSS utilise some type of EQA, demonstrating their commitment to diagnostic accuracy. In Europe the proportion of antibiotic resistant S. pneumoniae keeps changing with decreasing penicillin-resistance in some highly endemic countries and with continuous loss of susceptibility against penicillin and erythromycin in others. The main resistance phenotypes in pneumococci are confined to few serogroups, all of which are included in the currently promoted conjugate vaccines. This suggests that vaccination, especially in young children, may represent an effective additional means of controlling antibiotic resistance in pneumococcal disease in Europe. The increase of MRSA is consistent throughout Europe and includes countries with high, medium and low baseline MRSA endemicity. At the same time it appears that the MRSA pandemic is not an irreversible secular trend as two European countries (Slovenia and France) succeeded in constantly reducing the proportion of MRSA among S. aureus blood stream infections over the past five or six years. The speed with which fluoroquinolones loose their activity against E. coli is next to no other compound pathogen combination in the EARSS database. Combined resistance is a frequent occurrence, with co-resistance to three antimicrobial classes including third generation cephalosporins already among the four most common resistance patterns encountered in invasive E. coli in Europe, and undeniably these resistance traits are on the increase as well. In K. pneumoniae a high prevalence of resistant strains to third generation cephalosporins, fluoroquinolones and aminoglycosides becomes evident in Eastern and Southeastern Europe. Combined resistance is the dominant threat imposed by invasive P. aeruginosa. Our data suggest that the same geographical gradient exists for all gramnegative pathogens and shows that lower resistance prevails in the Northwest with increasing resistance towards the Southeast of Europe. It appears that the overall threat imposed on European communities by the increasing loss of antimicrobial effectiveness continues unabated with the same speed as has been previously described by our network. This is shown most convincingly among the pathogens that are frequently transmitted in health care settings (MRSA and VRE) and for antimicrobial compounds that are available for oral administration and hence preferred in ambulatory care (aminopenicillins, macrolides, and fluoroquinolones). The growing availability of third-line antimicrobial drugs as oral formulations is in this context a matter of concern and underscores the need of locally or nationally advised prescribing practices for both ambulatory and hospital-based care.