Relationship between blood culture time to positivity, mortality rate, and severity of bacteremia

Abstract

Objectives

We investigated the association between patient severity or mortality and time to positivity in bacteremia caused by various pathogens.

Patients and methods

This single-center retrospective study included patients with positive blood culture results.

Results

Longer time to positivity was associated with 30-day mortality for Staphylococcus aureus (221 cases, time to positivity: 17.4 h in the 30-day mortality group vs. 14.1 h in the survival group). Age, chronic kidney disease, cerebrovascular disease, hypertensive drug use, consciousness disorder, and minimal systolic blood pressure were significant predictors of 30-day mortality. For S. aureus, mortality within 30 days was significantly higher when time to positivity was > 24 h (p = 0.04). The time to positivity of Streptococcus pneumoniae, α, β-hemolytic Streptococcus, Enterococcus sp., Enterobacteriaceae, glucose-nonfermenting Gram-negative rods, Candida sp., and anaerobe was not significantly associated with 30-day mortality.

Conclusions

Among various pathogens, time to positivity > 24 h was associated with 30-day mortality for S. aureus.