# P-999. Differences in Epidemiology and Outcomes Between Toxin-Positive and Toxin-Negative Clostridioides difficile Infections

## TL;DR

This study compares toxin-positive and toxin-negative Clostridioides difficile infections and finds higher mortality in toxin-positive cases despite similar recurrence rates.

## Contribution

The study identifies higher mortality in toxin-positive CDI patients, offering new insights into clinical outcomes and management.

## Key findings

- Toxin-positive CDI patients had significantly higher mortality compared to toxin-negative patients.
- Toxin-positive patients were older and had longer hospital stays with more high-risk medication exposure.
- CDI recurrences and post-treatment diarrhea were more common in toxin-positive patients but not statistically significant.

## Abstract

Epidemiological characteristics and clinical outcomes of patients with PCR positive/toxin EIA-negative C. difficile infection (CDI) are poorly defined and treatment decisions in this subgroup often vary widely. Here, we assess differences in epidemiology and outcomes between toxin-positive and toxin-negative CDI.

We performed a retrospective analysis of adult patients with a positive Clostridioides difficile PCR test at RWJUH from 1/1/2018 to 12/31/2024. We assessed differences in epidemiology and outcomes between patients with toxin-positive and toxin-negative CDI.

We identified 747 patients with positive C. difficile PCR; 190 were toxin EIA-positive and 557 were toxin EIA-negative (Table 1). No significant differences were noted between the groups regarding gender, ethnicity or BMI. Toxin-positive patients were older compared to toxin-negative patients (Table 1). Comorbid conditions were similar between groups except for malignancies which were more common in toxin-negative CDI. The toxin-positive group had a longer length of stay prior to CDI and more frequent high-risk medication exposure (immunosuppressive medications, antibiotics). As expected, toxin-positive patients more frequently received anti-CDI therapy compared to toxin-negative group (Table 2). CDI recurrences and diarrhea within 90 days of treatment were more common in toxin-positive group but this did not reach statistical significance. Notably, toxin-positive group had a significantly higher incidence of mortality than the toxin-negative group (OR 3.41, 95% CI 2.15-5.40). In multivariate analysis, after controlling for differences between the two groups, toxin positivity remained significantly associated with mortality (OR 2.49, 95% CI 1.38-4.55).

Patients with toxin-positive CDI were older and had a longer length of hospital stay with increased exposure to immunosuppressive medications and antibiotics. CDI recurrences and diarrhea within 90 days post treatment were more common in the toxin-positive group, but these differences were not statistically significant. Patients with toxin-positive CDI had a significantly higher mortality rate compared to those with toxin-negative CDI, despite the latter group having more chronic comorbid illness.

Keith S. Kaye, MD, MPH, AbbVie: Advisor/Consultant|GSK: Advisor/Consultant|Merck: Advisor/Consultant|Shionogi: Advisor/Consultant