# Dynamic shifts in pathogen ecology of catheter-related bloodstream infections: temporal trends and ward-specific risk landscapes

## TL;DR

This study examines trends in catheter-related bloodstream infections, identifying risk factors and pathogens linked to mortality.

## Contribution

The study introduces a predictive nomogram model for 28-day mortality in CRBSI patients and highlights evolving pathogen trends.

## Key findings

- CRBSI incidence declined from 2021 to 2024, with high-risk wards being nephrology, ICU, and gastroenterology.
- Gram-positive pathogens like Staphylococcus aureus were most common, while carbapenem-resistant Gram-negatives correlated with higher mortality.
- APACHE II score and cardiovascular disease were strong predictors of 28-day mortality.

## Abstract

Catheter-related bloodstream infections (CRBSIs) represent a severe clinical complication with high mortality and pose a significant public health challenge due to increasing multidrug-resistant organisms (MDROs). This study aimed to systematically analyze the epidemiology, pathogen distribution, and independent predictors of 28-day mortality in CRBSI to support early risk warning and precise intervention. A retrospective cohort study included 172 patients with confirmed CRBSI, defined per CDC criteria. Data were extracted from electronic health records. Blood cultures used the BACT/ALERT® 3D system; pathogen identification and antimicrobial susceptibility testing utilized the VITEK®2 COMPACT platform. Statistical analysis with SPSS 26.0 employed univariate and multivariate logistic regression to identify mortality risk factors, including evaluating a nomogram model for predictive performance. The 28-day mortality rate was 19.77%. Epidemiological surveillance revealed a significant year-by-year decline in CRBSI incidence from 2021 to 2024 (p < 0.01). High-risk wards included Nephrology (34.88%), ICU (22.67%), and Gastroenterology (12.21%), accounting for 69.76% of cases. Gram-positive microorganisms predominated (51.74%, 89/172), with Staphylococcus aureus as the leading pathogen (41.28%, 71/172); Escherichia coli and Klebsiella pneumoniae showed significant increasing trends (p < 0.05). Independent predictors of 28-day mortality were APACHE II score (OR = 1.771, 95% CI: 1.328–2.360) and cardiovascular disease (CVD) (OR = 19.426, 95% CI: 1.248–52.270); among microbiological variables/MDROs, only carbapenem-resistant Acinetobacter baumannii (CR-AB) infection (OR = 3.549) and carbapenem-resistant K. pneumoniae (CR-KP) infection (OR = 5.301) remained independently associated with mortality, while Gram-positive microorganism infection was protective (OR = 0.081). The nomogram demonstrated excellent predictive performance (C-index = 0.979), identifying APACHE II score as the most influential predictor; ROC analysis confirmed disease severity as the core mortality determinant. Findings confirm APACHE II score and CVD are strong mortality predictors, while Gram-positive infections correlate with favorable outcomes. Strengthening infection control effectively reduced incidence, highlighting the need for enhanced surveillance in high-risk departments and continuous monitoring of pathogen distribution and antimicrobial resistance, with particular emphasis on carbapenem-resistant Gram-negative organisms. These results support risk stratification and individualized treatment, though multicenter validation remains necessary.

Overview of the epidemiological evolution and 28-day mortality risk in catheter-related bloodstream infections (CRBSIs). Created with BioRender.com.Infographic illustrating factors in catheter-related bloodstream infections. It shows a declining incidence rate from 2021 to 2024, pathogen spectrum details with E. coli and Klebsiella pneumoniae, and high-risk departments: renal (34.88%), ICU (22.67%), and gastrointestinal (21.21%). Mortality risk factors include APACHE II score, cardiovascular disease, with a predictive model indicating a 28-day mortality rate of 19.77%. The C-index indicates risk prediction.

Overview of the epidemiological evolution and 28-day mortality risk in catheter-related bloodstream infections (CRBSIs). Created with BioRender.com.