Impact of follow up blood cultures on outcomes of patients with community-onset gram-negative bloodstream infection

Rajiv Amipara; Hana Rac Winders; Julie Ann Justo; P Brandon Bookstaver; Joseph Kohn; Majdi N Al-Hasan

doi:10.1016/j.eclinm.2021.100811

Impact of follow up blood cultures on outcomes of patients with community-onset gram-negative bloodstream infection

EClinicalMedicine. 2021 Mar 30:34:100811. doi: 10.1016/j.eclinm.2021.100811. eCollection 2021 Apr.

Authors

Rajiv Amipara^{1

2}, Hana Rac Winders^{3

4}, Julie Ann Justo^{3

4}, P Brandon Bookstaver^{3

4}, Joseph Kohn⁴, Majdi N Al-Hasan^{1

2}

Affiliations

¹ Department of Medicine, Division of Infectious Diseases, University of South Carolina School of Medicine, Columbia, SC, USA.
² Department of Medicine, Division of Infectious Diseases, Prisma Health-Midlands, Columbia, SC, USA.
³ Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina College of Pharmacy, Columbia, SC, USA.
⁴ Department of Pharmacy, Prisma Health-Midlands, Columbia, SC, USA.

Abstract

Background: The role of follow up blood cultures (FUBC) in the management of gram-negative bloodstream infection (GN-BSI) remains controversial. This retrospective cohort study examines the association between obtaining FUBC and mortality in GN-BSI.

Methods: Hospitalized adults with community-onset GN-BSI at Prisma Health-Midlands hospitals in South Carolina, USA from January 1, 2010 to June 30, 2015 were identified. Patients who died or were discharged from hospital within 72 h were excluded to minimize impact of survival and selection biases on results, respectively. Multivariate Cox proportional hazards regression was used to examine association between obtaining FUBC and 28-day all-cause mortality after adjustment for the propensity to obtain FUBC.

Findings: Among 766 patients with GN-BSI, 219 (28.6%) had FUBC obtained and 15 of 219 (6.8%) FUBC were persistently positive. Overall, median age was 67 years, 438 (57%) were women, 457 (60%) had urinary source of infection, and 426 (56%) had BSI due to Escherichia coli. Mortality was significantly lower in patients who had FUBC obtained than in those who did not have FUBC (6.3% vs. 11.7%, log-rank p = 0.03). Obtaining FUBC was independently associated with reduced mortality (hazards ratio 0.47, 95% confidence intervals: 0.23-0.87; p = 0.02) after adjustments for age, chronic comorbidities, acute severity of illness, appropriateness of empirical antimicrobial therapy, and propensity to obtain FUBC.

Interpretation: Improved survival in hospitalized patients with GN-BSI who had FUBC is consistent with the results of recent publications from Italy and North Carolina supporting utilization of FUBC in management of GN-BSI.

Funding: This study had no funding source.

Keywords: Bacteremia; Enterobacterales; Mortality; Sepsis; Serratia species; Survival.