title: Clinical impact of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay related to methicillin-resistant Staphylococcus aureus bloodstream infections.
abstract: Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherland. Marlieke.de.Kraker@RIVM.nl
authors.forename: Marlieke E A
authors.initials: ME
authors.lastname: de Kraker
authors.forename: Martin
authors.initials: M
authors.lastname: Wolkewitz
authors.forename: Peter G
authors.initials: PG
authors.lastname: Davey
authors.forename: Walter
authors.initials: W
authors.lastname: Koller
authors.forename: Jutta
authors.initials: J
authors.lastname: Berger
authors.forename: Jan
authors.initials: J
authors.lastname: Nagler
authors.forename: Claudine
authors.initials: C
authors.lastname: Icket
authors.forename: Smilja
authors.initials: S
authors.lastname: Kalenic
authors.forename: Jasminka
authors.initials: J
authors.lastname: Horvatic
authors.forename: Harald
authors.initials: H
authors.lastname: Seifert
authors.forename: Achim J
authors.initials: AJ
authors.lastname: Kaasch
authors.forename: Olga
authors.initials: O
authors.lastname: Paniara
authors.forename: Athina
authors.initials: A
authors.lastname: Argyropoulou
authors.forename: Maria
authors.initials: M
authors.lastname: Bompola
authors.forename: Edmond
authors.initials: E
authors.lastname: Smyth
authors.forename: Mairead
authors.initials: M
authors.lastname: Skally
authors.forename: Annibale
authors.initials: A
authors.lastname: Raglio
authors.forename: Uga
authors.initials: U
authors.lastname: Dumpis
authors.forename: Agita Melbarde
authors.initials: AM
authors.lastname: Kelmere
authors.forename: Michael
authors.initials: M
authors.lastname: Borg
authors.forename: Deborah
authors.initials: D
authors.lastname: Xuereb
authors.forename: Mihaela C
authors.initials: MC
authors.lastname: Ghita
authors.forename: Michelle
authors.initials: M
authors.lastname: Noble
authors.forename: Jana
authors.initials: J
authors.lastname: Kolman
authors.forename: Stanko
authors.initials: S
authors.lastname: Grabljevec
authors.forename: David
authors.initials: D
authors.lastname: Turner
authors.forename: Louise
authors.initials: L
authors.lastname: Lansbury
authors.forename: Hajo
authors.initials: H
authors.lastname: Grundmann
mesh_terms: D000368:Aged; D005060:Europe; D005260:Female; D017052:Hospital Mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000472:pathogenicity*; D008875:Middle Aged; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000401:mortality*