Elsevier

Journal of Infection

Volume 70, Issue 2, February 2015, Pages 135-143
Journal of Infection

Clinical characteristics and outcome of elderly patients with community-onset bacteremia

https://doi.org/10.1016/j.jinf.2014.09.002Get rights and content

Summary

Objectives

To evaluate characteristics and prognostic factors of community-onset bloodstream infection (Co-BSI) in elderly patients (≥65 years).

Methods

Analysis of a prospective series of Co-BSI at a tertiary hospital (2005–2011). Predictors of 30-day mortality were established by logistic regression analysis.

Results

A total of 2605 episodes of Co-BSI were identified and empirical antibiotic treatment was inappropriate in 404 (15.5%). Thirty-day mortality was 11.4% and was independently associated with age (75–84 years OR 1.9, 1.37–2.67; ≥85 OR 2.85, 1.93–4.21), previous hospitalization (OR 1.45, 1.05–2.00), a fatal underlying disease (OR 2.81, 2.10–3.76), neutropenia (OR 2.62, 1.54–4.43), absence of fever (OR 1.99, 1.26–3.12), shock (OR 7.96, 5.83–10.89), inappropriate empirical treatment (OR 1.49, 1.03–2.16), isolation of Staphylococcus aureus (methicillin-resistant OR 2.83, 1.38–5.78; methicillin-susceptible OR 3.24, 1.98–5.32), enterococci (OR 2.02, 1.14–3.59) or Enterobacteriaceae resistant to third-generation cephalosporin (3GCR-E) (OR 1.96, 1.16–3.32) and having endovascular non-catheter (OR 4.64, 2.51–8.59), abdominal (OR 3.65, 2.12–6.27), skin/soft tissue (OR 3.48, 1.90–6.37), respiratory (OR 2.80, 1.75–4.50) or unknown (OR 1.83, 1.17–2.87) source.

Conclusions

Age is a prognostic factor and appropriateness of empirical treatment is the only modifiable variable. S. aureus, enterococci and 3GCR-E may be the microorganisms with major prognostic significance; hence efforts should be made to improve their management.

Introduction

Bacteremia is a leading cause of morbidity and mortality,1 being the eleventh cause of death in the United States.2 The incidence of sepsis increases with age, most markedly in people over 85 years3 and multiple factors contribute to this phenomenon, such as comorbidities, altered immune function, institutionalization and declining performance status.4 Aging is also a predictor of mortality in patients with sepsis and bacteremia.3, 5, 6 It is expected that by 2060 the number of people aged 65 years or over will account for 29.5% of the EU-27's population (17.5% in 2011) and therefore bacteremia and sepsis may become a major public health issue.7 Despite all this facts, there is a shortage of studies on sepsis specific to older patients.8

In patients with bloodstream infections, appropriate empirical antibiotic treatment has been commonly associated with a better outcome.9 In order to choose an appropriate empirical antibiotic treatment it is fundamental to be aware of the pathogen distribution at different infection sites and of major local resistance trends.10 It is important to take into account that age may influence both of these factors.

Although several studies on bacteremia in the elderly have been recently published, most of them have compared younger with elderly patients.5, 6, 11 The present study represents the largest series focused specifically on patients over 65 years aimed to describe the age-related characteristics of community-onset bacteremia and the predictors of 30-day mortality in this population.

Section snippets

Setting and data collection

The study was performed in a 700-bed university center that provides specialized and broad medical, surgical, and intensive care for an urban population of 500,000 people. Since 1991 our institution has carried out a blood culture surveillance program identifying and monitoring all patients with bacteremia. The collected data was entered in a specific database designed for this program. Patients were prospectively followed-up for 30 days after the onset by a senior infectious disease specialist

Clinical characteristics of patients ≥65 years-old with community-onset bacteremia

Out of 4598 consecutive episodes of community-onset bacteremia, 2605 (56.7%) occurred in patients aged 65 years or over. The mean (SD) age of the study group was 78.06 (7.71) years (range, 65–106 years) and 1378 (52.9%) were male. According to age, 921 (35.4%) episodes were observed in age-group I (65–74 years), 1109 (42.6%) in group II (75–84 years) and 575 (22.1%) in group III (≥85 years). The main characteristics of patients are presented in Table 1. The proportion of males decreased with

Discussion

It is expected that in the near future the population aged 65 year or over will be on the increase. To our knowledge, this study is the largest one focusing on patients over 65 years with community-onset bacteremia, describing its characteristics, outcome and factors associated with mortality.

Consistent with previous reports, the prevalence of some comorbidities change with age, increasing some, such as neurologic impairment and cardiovascular disease, and decreasing others like diabetes,

Transparency declarations

None to declare.

Acknowledgments

This work was presented as a poster at the XVIII SEIMC (sociedad española de enfermedades infecciosas y microbiología clínica) congress (Abstract 443) (2014).

This study was supported in part by the “Fundación Máximo Soriano Jiménez” (Barcelona, Spain).

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    C.H. and C.F. contributed equally to this work.

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