Elsevier

Journal of Infection

Volume 56, Issue 1, January 2008, Pages 27-34
Journal of Infection

Bloodstream infections in adults: Importance of healthcare-associated infections

https://doi.org/10.1016/j.jinf.2007.10.001Get rights and content

Summary

Objective

The objective of this study was to evaluate the characteristics of bloodstream infections occurring among outpatients having recent contact with the health care system compared to hospital and community-acquired infections.

Methods

Prospective observational cohort study of adult patients with bloodstream infections at three teaching hospitals. Bloodstream infection was defined as hospital-acquired if the first positive blood culture was performed more than 48 h after admission. Other bloodstream infections were classified as healthcare-associated or community-acquired.

Results

A total of 1157 episodes of bloodstream infections were studied; 581 (50.2%) were community-acquired, 295 (25.5%) were hospital-acquired, and 281 (24.3%) were health care-associated. Of the 281 health care-associated bloodstream infections, 68 (24%) occurred in patients residing in a nursing home, 104 (37%) in patients receiving intravenous therapy, health care at home, chemotherapy or attending dialysis, and 169 (60%) in patients hospitalized during the 90 days before their bloodstream infection (some patients belonged to more than one risk category). The highest prevalence rate of MRSA infections occurred in healthcare-associated infections (5%) (p < 0.001). A significantly higher mortality rate was seen in the group with healthcare-associated infections (27.5%) than in community-acquired infections (10.4%) (p < 0.001).

Conclusions

Our results confirm that healthcare-associated bloodstream infections show important differences from community-acquired bloodstream infections and suggest that empirical antibiotic therapy should be similar to hospital-acquired bloodstream infections, taking into account the epidemiologic characteristics of each region.

Introduction

Bloodstream infection (BSI) continues to be an important cause of morbidity and mortality, despite the availability of potent antimicrobial agents and sophisticated life-support facilities. In recent years, studies of epidemiology, microbiological etiology, and prognosis have been performed all over the world.1, 2, 3, 4, 5, 6, 7, 8

BSI has traditionally been categorized as community and hospital-acquired infections.9, 10 A hospital-acquired infection is typically acquired in an environment of resistant microorganisms or microorganisms typically found in a hospital setting and it is often associated with a procedure or with instrumentation. A community-acquired infection presumably develops spontaneously, without an association with a medical intervention and occurs in an environment with fewer resistance pressures. However, some infections are acquired under circumstances that do not readily allow for the infection to be classified, as belonging to either of these two categories. Such infections include infections in patients with serious underlying diseases and/or invasive devices receiving care at home or in nursing homes or rehabilitation centers; those undergoing dialysis or chemotherapy in physicians’ offices and those who frequently have contact with healthcare or recurrent hospital admissions. For this reason, a new classification scheme for BSIs has been proposed to characterize these difficult-to-classify BSIs and distinguish between infections occurring among outpatients having recurrent or recent contact with the healthcare system, patients with true community-acquired infections and the inpatients with hospital-acquired infections. The preliminary results have demonstrated that healthcare-associated infections are similar to hospital-acquired infections and consequently the empirical antimicrobial therapy should be different from that in community-acquired infections.11, 12

The objective of this study was to evaluate the usefulness of this new classification to analyze the BSI detected in three hospitals in the same geographic area and to compare the three different categories in terms of comorbid conditions, source of infection, pathogens and their antimicrobial susceptibility patterns, appropriateness of antibiotic therapy and prognosis.

Section snippets

Setting

This prospective, observational, and multicenter study was performed in three hospitals in Catalonia, Spain: Hospital Sabadell (HS), Hospital Mutua Terrassa (HMT), and Hospital Terrassa (HT). All institutions are urban teaching hospitals with intensive care units (ICU) but without any solid organ transplant programs.

Study design

All consecutive adults patients (>18 years) admitted from March 15, 2003 to March 15, 2004, who presented at least one true positive blood culture on admission or developed BSI

Population characteristics

During the study period, a total of 1202 positive blood cultures were detected at the three study hospitals. Of the 1202 cultures, 1157 cultures were considered true BSI; 45 positive blood cultures were excluded from analysis because the patients were transferred to another hospital (n: 31), or because were of unknown clinical significance (n = 14). The 1157 episodes of BSI occurred in 1086 patients, 59 of whom presented more than one episode of bacteremia during the study period.

Of the 1157 BSI,

Discussion

Our results indicate that a quarter of all BSI in our region are healthcare-associated. The characteristics of patients with healthcare-associated BSI in our study show some overlap with community and hospital-acquired BSI. However, differences between community-acquired BSI and healthcare-associated BSI are evident. Healthcare-associated patients are older, have a worse functional status, present a higher proportion of catheter-related BSI and have the highest prevalence of BSI caused by MRSA.

References (25)

  • O. Uzun et al.

    Factors influencing prognosis in bacteremia due to gram-negative organisms: evaluation of 448 episodes in a Turkish university hospital

    Clin Infect Dis

    (1992)
  • J. Vallés et al.

    Nosocomial bacteremia in critically ill patients: a multicenter study evaluating epidemiology and prognosis

    Clin Infect Dis

    (1997)
  • Cited by (0)

    View full text