PCR offers a faster alternative for pathogen identification, potentially improving patient outcomes. The rapid turnaround time for PCR results, particularly in detecting Clostridioides difficile (CDI), facilitates the timely initiation of appropriate antibiotic therapy. Early identification of acute gastroenteritis (AGE) pathogens is crucial for managing patients effectively in the emergency department (ED). This study supports using PCR as an effective tool in managing AGE in the emergency department setting, with a notable impact on treating elderly patients and those affected by clinically significant infections.
The most frequently identified pathogen was C difficile, found in 20 patients (15%). Of those testing positive for C difficile, 14 were aged over 65 years. 17 out of the 20 C difficile-positive patients (85%) were diagnosed with a clinically relevant infection, receiving treatment with antibiotics, predominantly oral vancomycin, within a median time of 11.37 hours after ED admission.
“According to international guidelines, the diagnosis of CDI was based on the criteria of a positive laboratory test in the presence of diarrhea and/or pseudomembranous colitis, taking into account additional parameters such as fever, elevated white blood cell (WBC) count, and a 50% increase in serum creatinine level,” according to investigators. “In 3 patients (15%), including 2 children, the positive PCR result was not clinically relevant due to the absence of characteristic symptoms or symptoms of other causes. 11 patients (55%) were diagnosed with CDI for the first time.”
3 Key Takeaways
- Using PCR testing, specifically, is shown to significantly speed up the process of identifying pathogens, including CDI which is critical for initiating the appropriate treatment as soon as possible.
- The research underscores the efficiency of PCR testing over traditional culture methods, with a notable reduction in the time to report results (6.17 hours for PCR vs. 57.28 hours for culture).
- The study indicates that prompt identification of CDI via PCR can lead to immediate treatment decisions and infection control measures, such as isolation and adherence to hygiene practices, thus preventing the spread of infections and the development of severe disease.
Researchers conducted a retrospective analysis of data from 133 patients who presented to the ED with symptoms of AGE and underwent testing using the BD MAX automated PCR system. The criteria for inclusion involved patients presenting with symptoms suggestive of AGE who were tested for bacterial and viral pathogens using PCR. The time to result for PCR and traditional culture methods was recorded, and the types of pathogens were identified and the subsequent management of patients with positive test results.
Out of 133 patients analyzed, 56 (42%) tested positive for at least one bacterial or viral pathogen via PCR. The median time to report PCR results was significantly shorter at 6.17 hours, compared to 57.28 hours for culture results for bacterial pathogens.
“The decision was made to include C difficile in the PCR panel as a one-step testing strategy to reduce the workload and spare time. C difficile testing is not routinely recommended for children as standard diagnostics but was included in this study to simplify the workflow,” according to investigators. “The ED is critical for the early identification of CDI in patients presenting with AGE. Reassessment of admitted patients in the following days may not be the optimal method for CDI diagnosis and the timely initiation of antibiotic treatment to prevent the development of severe or fulminant disease.”
Important highlights include that vancomycin was administered before receiving PCR results in multiple instances. Additionally, 1 patient hospitalized with a positive C difficile result was not isolated according to guidelines. For the remaining patients, the median isolation duration was 182.33 hours (IQR 140.44–235), while the median duration of hospital stay was 193.98 hours (IQR 143.06–264.16). There were no fulminant CDI cases reported in this study.
In summary, this research demonstrates that PCR testing for emergency department patients with AGE significantly enhances early identification of CDI among the elderly. Given that CDI can lead to serious illness, increased mortality, and likelihood of hospital readmission, especially in older patients with preexisting conditions, diagnosing C difficile based on PCR testing, when clinical symptoms are present, is sufficient for treatment decisions. Furthermore, prompt communication of positive PCR findings can also increase awareness regarding hygiene practices and encourage adherence to specific infection control measures.
Reference
1. Iffland A, Zechel M, Lewejohann J. Edel B, Hagel S, et al. Experience with PCR Testing for Enteric Bacteria and Viruses of Emergency Department Patients with Acute Gastroenteritis: Are There Implications for the Early Treatment of Clostridioides difficile Infection? Antibiotics. Published March 6, 2024. Accessed March 20, 2024. doi: https://doi.org/10.3390/antibiotics13030243
