P-32. Risk Factors for Mortality with Coagulase-negative Staphylococcus Bacteremia in Cancer Patients

TL;DR

This study identifies risk factors for true bloodstream infections and higher mortality in cancer patients with coagulase-negative Staphylococcus blood cultures.

Contribution

The study identifies specific clinical factors associated with true CoNS bacteremia and mortality in cancer patients.

Findings

Risk factors for true CoNS bloodstream infection include presence of a central venous catheter and persistent bacteremia.

Higher in-hospital mortality is associated with true CoNS bacteremia.

Unknown infection source and lack of infectious disease consultation correlate with increased mortality.

Abstract

Coagulase-negative Staphylococcus species (CoNS) are commensal skin flora that frequently contaminate blood cultures and may not always be indicative of bloodstream infection (BSI). However, in specific high-risk populations, such as patients with malignancies, CoNS is the leading cause of BSI, and has previously been identified as an independent risk factor for mortality. The purpose of this study was to identify risk factors for true CoNS BSI and associated mortality.Table 1:Baseline demographicsTable 2:Patient features at time of infection

Baseline demographics

Patient features at time of infection

This was a retrospective chart review of patients with solid and hematologic malignancy and positive CoNS blood culture from 2013-2023 at Cooper University Hospital. CoNS was deemed to be pathogenic or a contaminant based on chart documentation by infectious disease (ID) consultants or primary physician. Patients with CoNS deemed a contaminant represented the comparator group. Descriptive statistics, Fisher’s exact test, and Kruskal Wallis testing were performed.Table 3:Factors associated with true BSITable 4:Factors associated with mortality in true infections

Factors associated with true BSI

Factors associated with mortality in true infections

Ninety patients were included in the primary outcome analysis; 47 patients were identified as having a true BSI. Baseline demographics are in Table 1. Risk factors for true BSI included presence of CVC, Pitt bacteremia score, diabetes, increased number of days with positive blood culture, and the use of vancomycin. True BSI was associated with higher hospital mortality. Factors associated with mortality at discharge for true BSI included age, higher Charlson Comorbidity Index, diabetes, unknown source of bacteremia, use of daptomycin, and lack of ID consult.

In cancer patients with blood cultures positive for CoNS, risk factors for true bacteremia included the presence of CVC and persistent bacteremia. This was further associated with a higher risk of in-hospital mortality. Interestingly, unknown source of infection and lack of ID consult were associated with higher mortality.

Alexandra Hanretty, PharmD, Abbvie: Honoraria Madeline King, PharmD, Innoviva: Advisor/Consultant|Shionogi: Advisor/Consultant

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