Characteristics of Staphylococcus aureus Bacteraemia and Predictors of Early and Late Mortality
February
Characteristics of Staphylococcus aureus Bacteraemia and Predictors of Early and Late Mortality
Matteo Bassetti 0 1 2
Maddalena Peghin 0 1 2
Enrico Maria Trecarichi 0 2
Alessia Carnelutti 0 1 2
Elda Righi 0 1 2
Paola Del Giacomo 0 2
Filippo Ansaldi 0 2
Cecilia Trucchi 0 2
Cristiano Alicino 0 2
Roberto Cauda 0 2
Assunta Sartor 0 2
Teresa Spanu 0 2
Claudio Scarparo 0 2
Mario Tumbarello 0 2
0 Current address: Matteo Bassetti: Clinica Malattie Infettive, Azienda Ospedaliera Universitaria Santa Maria della Misericordia , Udine , Italy
1 Infectious Diseases Division, Santa Maria Misericordia University Hospital , Udine , Italy , 2 Institute of Infectious Diseases, Catholic University of the Sacred Heart , Rome , Italy , 3 IRCCS AOU San Martino IST, Department of Health Sciences, University of Genoa; Genoa, Italy, 4 Microbiology Unit, Santa Maria Misericordia University Hospital , Udine , Italy , 5 Institute of Microbiology, Catholic University of the Sacred Heart , Rome , Italy
2 Editor: Karsten Becker , Universitatsklinikum Munster , GERMANY
We aimed to describe the characteristics of patients with Staphylococcus aureus bacteremia and to evaluate the risk factors associated with early (7-day) and late (30-day) mortality. We performed an observational study including all consecutive episodes of Staphylococcus aureus bacteremia diagnosed at two Italian university hospitals during 2010±2014. A total of 337 patients were included. Mean age was 69 years (range, 57±78) and 65% were males. Methicillin-resistant S. aureus (MRSA) was identified in 132/337 (39%)cases. Overall 7- and 30-day mortality were 13% and 26%, respectively. Early mortality was associated with increased Charlson scores (OR 1.3, 95% CI 1.1±1.5), MRSA bacteremia (OR 3.2, 95% CI 1.4±8.1), presentation with septic shock (OR 13.5, 95% CI 5.4±36.4), and occurrence of endocarditis (OR 4.5, 95%CI 1.4±14.6). Similar risk factors were identified for late mortality, including increased Charlson scores (OR 1.2, 95% CI 1.1±1.4), MRSA bacteremia (OR 2.1, 95% CI 1.2±3.9), presentation with septic shock (OR 4, 95%CI 1.7±9.7), occurrence of endocarditis (OR 3.8, 95% CI 1.4±10.2) as well as Child C cirrhosis (OR 3.9, 95% CI 1.1±14.4) and primary bacteremia (OR 2.5, 95%CI 1.3±5). Infectious disease consultation resulted in better outcomes both at 7 (OR 0.1, 95% CI 0.05±0.4) and at 30 days (OR 0.4, 95% CI 0.2± 0.7). In conclusion, our study highlighted high rates of MRSA infection in nosocomial Staphylococcus aureus bacteremia. Multiple comorbidities, disease severity and methicillin-resistance are key factors for early and late mortality in this group. In patients with Staphylococcus aureus bacteremia, infectious disease consultation remains a valuable tool to improve clinical outcome.
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Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: The authors received no specific funding
for this work.
Competing Interests: The authors have declared
no competing interests exist.
Introduction
The distribution of methicillin-sensitive (MSSA) and methicillin-resistant S. aureus (MRSA)
bacteremia varies substantially by geographical region [1] [
2
] [
3
] [
4
] [
5
]. Staphylococcus aureus,
however, remains a leading cause of community- and healthcare-associated bacteremia
worldwide [
3
] [
5
]. Despite efforts to reduce its incidence, S. aureus bacteremia (SAB) remains
frequent and associated with mortality rates up to 25% [
3
]. SAB acquisition and outcome are
affected by patients' comorbidities, infection site, and methicillin-resistance [
6
] [
7
]. In this
patient population, evidence-based bundle interventions demonstrated to have a positive
impact in clinical management and outcome [
8
]. In particular, results from a recent
metanalysis suggested that infectious diseases (ID) consultation might improve clinical care and impact
hospital survival in patients with SAB [
8
]. Most of the studies, however, focused on predictors
of 30- and 60 day-mortality even if high early ( 7 day) mortality rates have been reported
among patients with SAB [
6
] [
7
] [
8
] [
9
] [
10, 11
] [12].Aim of the study was to describe the
epidemiology and clinical characteristics of patients with SAB and assess the prognostic factors
for early (7-day) and late (30-day) mortality.
Material and Methods
Study design, setting and patients
A retrospective, observational, cohort study was performed in two tertiary care university
hospitals in Italy that admit approximately 90,000 patients per year. All episodes of clinically
significant SAB in adult patients (aged 18 years and older) between January 2011 and December
2014 were included. Patients were followed in the participant centers until discharge or death.
Cases were detected through electronic databases, using a standardized protocol including age,
sex, comorbidities, source of infection, setting of acquisition, antimicrobial susceptibilit (...truncated)