Mortality of S. aureus bacteremia and infectious diseases specialist consultation – A study of 521 patients in Germany
Introduction
Staphylococcus aureus is a major pathogen causing both community- and hospital-acquired bloodstream infection with substantial morbidity and mortality.24 The incidence of S. aureus bacteremia has been estimated to be 20–35 cases annually per 100,000 population. Recent studies from different parts of the world indicate increasing incidence rates, particularly due to the emergence of methicillin-resistant S. aureus (MRSA) bacteremia in hospitals and the community.4, 22, 32
S. aureus bacteremia (SAB) carries a high risk of complications such as metastatic disease with deep-seated foci of infection, endocarditis, severe sepsis or recurrences.9, 10, 18 The reported in-hospital mortality has remained surprisingly high over the last decades, ranging between 20% and >30% in the more recent studies.1, 8, 28, 32 Several factors have been reported to be associated with a poor outcome of SAB. Among these are community acquisition, unknown portal of entry, inadequate treatment, MRSA, persistent bacteremia and failure to remove intravascular devices.3, 6, 14, 19, 20, 21
Infectious disease (ID) specialist consultation has been investigated as a strategy to improve the quality of care for SAB patients. Better adherence to diagnostic guidelines and management/treatment standards such as removal of catheters or use of echocardiography after ID consultation has been shown in a few studies.11, 17 Nevertheless, whether survival of patients with SAB can be improved by ID consultation has remained unclear.
In 2002, a new ID service was established in our hospital. Initially, ID specialist consultations for SAB were performed on request of the primary physician only. In 2005, we started the policy to offer routine ID specialist consultations for all patients with SAB, and increased the proportion of cases with SAB seen by an ID expert. In the present paper we evaluated the epidemiology, clinical characteristics and outcomes of SAB admitted to our institution between 2002 and 2007 with a focus on the impact of ID specialist consultation on mortality of this highly prevalent and severe cross-specialty infection.
Section snippets
Setting, case identification and study design
The study was conducted at the University Hospital in Freiburg, Germany, a 1600-bed tertiary care center with 54,000 admissions and 300,000 outpatient contacts per year. During the 6-year period all adult patients with clinical evidence of infection and blood cultures growing S. aureus were included. Identification and susceptibility testing of all S. aureus blood culture isolates was performed according to standard protocols.
For the period from January 1, 2002 to December 31, 2004, SAB cases
Clinical characteristics
A total of 521 patients were included and evaluated. The median age was 65 years, ranging from 17 to 90 years. Patient characteristics are shown in Table 1. Cardiac diseases including coronary artery disease and congestive heart failure, malignancies including hematological and solid tumors, diabetes mellitus, and renal diseases represented the most prevalent underlying conditions. Forty-six percent of SAB cases were classified as McCabe non-fatal.
Many of the infections were hospital-acquired
Discussion
ICU admission, a diagnosis of endocarditis, patient age and methicillin resistance were identified to be independently associated with a fatal outcome of SAB. ID specialist consultation was associated with improved early and 90-day survival. Importantly, the impact of ID consultation was still present after adjustment for comorbidities.
Clinical epidemiological findings in this study as well as the observed in-hospital mortality rate of 22% were comparable to those reported from other sites in
Conflict of interest
None of the authors declares any conflict of interests.
Acknowledgements
This study was in part supported by grant 01KI9951 from the Federal Ministry of Education and Research and from the Paul-Ehrlich-Society for Chemotherapy.
References (32)
- et al.
Increasing incidence but decreasing in-hospital mortality of adult Staphylococcus aureus bacteraemia between 1981 and 2000
Clin Microbiol Infect
(2007) - et al.
Community and hospital acquired Staphylococcus aureus septicaemia: 115 cases from a Dublin teaching hospital
J Infect
(1996) - et al.
Course and outcome of Staphylococcus aureus bacteraemia: a retrospective analysis of 308 episodes in a Swiss tertiary-care centre
Clin Microbiol Infect
(2006) - et al.
Evaluation of clinical guidelines for the management of Staphylococcus aureus bacteraemia
Intern Med J
(2002) - et al.
A prospective multicenter study of Staphylococcus aureus bacteremia: incidence of endocarditis, risk factors for mortality, and clinical impact of methicillin resistance
Medicine (Baltimore)
(2003) - et al.
Staphylococcus aureus bacteremia, Australia
Emerg Infect Dis
(2005) - et al.
Risk factors for mortality in Staphylococcus aureus bacteremia
Infect Control Hosp Epidemiol
(1998) - et al.
Comparison of mortality associated with methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteremia: a meta-analysis
Clin Infect Dis
(2003) - et al.
Long-term outcome and quality of care of patients with Staphylococcus aureus bacteremia
Eur J Clin Microbiol Infect Dis
(2004) - et al.
Staphylococcus aureus endocarditis: a consequence of medical progress
JAMA
(2005)
Clinical identifiers of complicated Staphylococcus aureus bacteremia
Arch Intern Med
Outcome of Staphylococcus aureus bacteremia according to compliance with recommendations of infectious diseases specialists: experience with 244 patients
Clin Infect Dis
Health care–associated bloodstream infections in adults: a reason to change the accepted definition of community-acquired infections
Ann Intern Med
Impact of methicillin resistance on the outcome of patients with bacteremia caused by Staphylococcus aureus
Arch Intern Med
Persistent Staphylococcus aureus bacteremia: an analysis of risk factors and outcomes
Arch Intern Med
Prospective study of 424 cases of Staphylococcus aureus bacteraemia: determination of factors affecting incidence and mortality
Intern Med J
Cited by (163)
Impact of neutropenia on clinical manifestations and outcome of Staphylococcus aureus bloodstream infection: a propensity score-based overlap weight analysis in two large, prospectively evaluated cohorts
2022, Clinical Microbiology and InfectionCitation Excerpt :The day of the first blood culture positive for S. aureus was defined as the onset of SAB infection. Mode of acquisition was classified into community-acquired (CA), community-onset health care-associated (COHA), or hospital-acquired (HA), as previously described [17]. Comorbidities were evaluated using the Charlson comorbidity index [18].
PET imaging in cardiovascular infections
2022, Nuclear Medicine and Molecular Imaging: Volume 1-4A Needs Assessment for Infectious Diseases Consultation in Community Hospitals
2023, Infectious Diseases and TherapyPredictors of mortality of Staphylococcus aureus bacteremia among patients hospitalized in a Swiss University Hospital and the role of early source control; a retrospective cohort study
2023, European Journal of Clinical Microbiology and Infectious Diseases