Epidemiology of MRSA and VRETuesday, April 22, 2008, 13:54 - 14:06Prevalence of ST398 and other genotypes of methicillin-resistant Staphylococcus aureus in Dutch hospitalsM.W.M. Wassenberg, A. Troelstra, J.A.J.W. Kluytmans, M.J.M. Bonten (Utrecht, Breda, NL)
Objectives: To determine prevalence of ST398 MRSA (associated with professional exposure to animals) and other MRSA isolates within Dutch hospitals.
Methods: A prevalence survey in 51 Dutch hospitals from July 2006 to January 2007 (3 months retrospectively and 3 months prospectively), monitoring all patients and health care workers (HCWs; only in post-exposure surveys) screened for and identified with ST398 or other MRSA strains (including several clinical characteristics) was carried out. Participating hospitals were divided into tertiles based on pig-density in the catchment area.
Results: During 306 months of observation 7802 patients were screened; 12% (642/5543) because of a risk factor for ST398 (79% out-patient department). Of the 498 new MRSA patients identified (65% with screening; 35% unexpected carriers) 31% carried ST398 MRSA (92% detected through screening). The overall prevalence of MRSA in the screened population was 3.6% (95%-BI: 3.2-4.0). Prevalence were 2.5% (95%-BI: 1.9-3.1), 3.8% (95%-BI: 3.1-4.5; p=0.007) and 4.6% (95%-BI: 3.7-5.5; p=0.000), respectively, in low, moderate and high pig density region hospitals. Prevalence of ST398 MRSA was 12.4% in patients screened in hospitals in regions with a high or moderate pig density and 0% in hospitals in regions with a low pig density. The prevalence of other MRSA isolates in patients screened in these hospitals was between 1.1 – 2.9%. In post-exposure screenings, unrelated ST398 MRSA carriers (index case had different genotype) were found in 0.06% (3/4794) of HCWs and none of the patients (0/1951). Other MRSA isolates (genotype different from index case and excluding ST398) were detected in 0.1% (8/5758) of HCWs and 0.5% (10/2134) of patients.
Conclusion: In this first large survey of ST398 MRSA in Dutch hospitals we found that MRSA is more prevalent in regions with a high or moderate pig density, solely because of an increase of ST398 MRSA. Almost 80% of new carriers are detected in out-patient departments and 92% because of active surveillance. ST398 MRSA colonization is rarely encountered in HCWs and patients during post-exposure screenings of index cases with different genotypes.
|