755. Clostridioides difficile Testing and the Use of Laxatives in Immunocompromised Adults

Abstract Background Clostridioides difficile infection (CDI) rates have plateaued at historical highs in the United States since 2010 and remains a major health problem. While optimal CDI testing remains unclear, current literature recommends testing patients whose symptoms are not clinically attributable to underlying conditions, e.g., laxatives. At Moffitt Cancer Center, a soft-stop alert was implemented to alert the provider if the patient received a laxative within the previous 48 hours of CDI testing. We aim to evaluate the incidence of CDI rates with prior laxative use in immunocompromised patients, as well as, the impact of the soft-stop alert in reducing CDI testing. Methods Retrospective, single-center, review of adult patients who were tested for CDI after the implementation of the soft-stop alert from October 1, 2020 to December 21, 2020. These patients were compared to a historical cohort of patients who were tested for CDI prior to the alert implementation from October 1, 2019 to December 31, 2019. The primary outcome was the percent of patients that received a laxative within 48 hours of CDI testing pre-alert compared to post-alert. Secondary outcomes included the percent of colonization versus active infection in this immunocompromised population, number and type of laxatives administered prior to testing, and the frequency of alert and reduction of CDI tests ordered. A cost-benefit analysis was also performed. Results In the historical cohort (n=480), 14.8% received a laxative within 48 hours of CDI testing (Figure 1). Within patients who received a laxative in this group, 4.2% had a definitive active infection. After the alert was implemented, a total of 630 CDI tests were ordered from October 1, 2020 to December 31, 2020, and the alert was fired for 123 (19.5%) tests ordered (Figure 2). Of the tests where the alert was fired, the CDI test was removed for 42.3% and continued for 57.7% of orders resulting in savings of &3,263. In this cohort, 5.6% of patients had a definitive active CDI infection who received a laxative and testing was continued (Figure 3). Figure 2: CDI Test and Laxative Administration Alert Figure 3: Post-Alert Laxatives Administered and CDI Test Result Conclusion The soft-stop alert implemented reduced CDI testing in patients who received a laxative in the last 48 hours correlating with a financial benefit, improvement in guideline adherence, and reduction in laboratory labor. Disclosures All Authors: No reported disclosures

Conclusion. Despite the COVID-19 pandemic, the HO-CDI and C. diff order rates and overall SAAR decreased; however, antibiotic utilization increased in the ICU during the COVID-19 waves. The overall decrease may be multifactorial and related to increased hand hygiene compliance, isolation and personal protective equipment use and overall decreased antibiotic use and C. diff orders.
Disclosures. Rachel Kenney, PharmD, Medtronic, Inc. (Other Financial or Material Support, spouse is an employee and shareholder) 754. A Two-step Testing Algorithm for Hospital-onset Clostridioides difficile Infection (CDI) Reduces Prescribing of C. difficile (CD) Therapy but Its Ability to Guide Background. Determining true CDI versus CD colonization through CD testing is a continuing challenge. A previously introduced decision support tool at UVA Health significantly reduced inappropriate testing without adverse outcomes. More recently, our methodology changed from nucleic acid amplification test (NAAT) alone to an initial NAAT followed by ELISA for toxin to improve specificity. The purpose of this analysis was to assess provider interpretation of test results, using targeted CD therapy as a surrogate.
Methods. This single-center, retrospective study evaluated all patients with a positive NAAT (Cepheid Xpert® C. difficile) on day 4 or later of hospitalization following 2-step algorithm implementation from Feb 2020 through Feb 2021. Toxin negative (TOX-) test results (C. DIFF QUIK CHEK COMPLETE®) were accompanied by a comment that discordance may represent colonization or CDI and to consider ID consult. The proportion of toxin positive (TOX+) versus TOX-patients receiving ≥ 1 dose of CD therapy served as the primary outcome with partial courses considered < 10 days. Clinical outcomes were also compared.
Conclusion. Adoption of a 2-step NAAT plus toxin testing algorithm for hospital-onset CDI reduced the frequency with which TOX-patients received CD therapy but the vast majority were still treated. Most providers considered a positive NAAT indicative of CDI, regardless of TOX status.
Disclosures. Background. Clostridioides difficile infection (CDI) rates have plateaued at historical highs in the United States since 2010 and remains a major health problem. While optimal CDI testing remains unclear, current literature recommends testing patients whose symptoms are not clinically attributable to underlying conditions, e.g., laxatives. At Moffitt Cancer Center, a soft-stop alert was implemented to alert the provider if the patient received a laxative within the previous 48 hours of CDI testing. We aim to evaluate the incidence of CDI rates with prior laxative use in immunocompromised patients, as well as, the impact of the soft-stop alert in reducing CDI testing.
Methods. Retrospective, single-center, review of adult patients who were tested for CDI after the implementation of the soft-stop alert from October 1, 2020 to December 21, 2020. These patients were compared to a historical cohort of patients who were tested for CDI prior to the alert implementation from October 1, 2019 to December 31, 2019. The primary outcome was the percent of patients that received a laxative within 48 hours of CDI testing pre-alert compared to post-alert. Secondary outcomes included the percent of colonization versus active infection in this immunocompromised population, number and type of laxatives administered prior to testing, and the frequency of alert and reduction of CDI tests ordered. A cost-benefit analysis was also performed.
Results. In the historical cohort (n=480), 14.8% received a laxative within 48 hours of CDI testing (Figure 1). Within patients who received a laxative in this group, 4.2% had a definitive active infection. After the alert was implemented, a total of 630 CDI tests were ordered from October 1, 2020 to December 31, 2020, and the alert was fired for 123 (19.5%) tests ordered (Figure 2). Of the tests where the alert was fired, the CDI test was removed for 42.3% and continued for 57.7% of orders resulting in savings of $3,263. In this cohort, 5.6% of patients had a definitive active CDI infection who received a laxative and testing was continued (Figure 3). Background. Clostridioides difficile (C. difficile) is an important cause of morbidity and mortality. C. difficile infection (CDI) may be frequently under-diagnosed because laboratory confirmation requires collection of a stool specimen from a patient with diarrhea and appropriate laboratory testing.
Methods. A prospective population-based CDI surveillance study was launched in 8 adult hospitals in Louisville, Kentucky on September 16, 2019. Surveillance officers in each hospital identified all cases of new-onset diarrhea (≥3 loose stools in the past but not preceding 24 hours) in Louisville residents ≥50 years of age. After informed consent, stool samples were collected and tested at the University of Louisville reference laboratory for 1) glutamate dehydrogenase (GDH) and 2) Clostridioides difficile toxins A and B using C. DIFF QUIK CHEK COMPLETE®, Techlab. We defined CDI as GDH positive and toxin positive. The study was paused on April 3, 2020, due to COVID-19 restrictions.
Results. There were 85,719 eligible patient-days during the study period. A total of 1541 patients had new-onset diarrhea corresponding to 1.8 cases of new-onset diarrhea per 100 eligible patient-days. We enrolled 84% (1291/1541) of patients with new-onset diarrhea and tested stool samples for C. difficile from 82% (1055/1291) for a testing density of 123 per 10,000 patient-days. Of the 1055 tested stool specimens, 73 (7%) were GDH positive and toxin positive (Figure 1) yielding a hospital-based CDI incidence of 8.5 CDI cases per 10,000 patient-days.

Figure 1. Patient Ascertainment Flow Chart
Conclusion. New-onset diarrhea was common among hospitalized adults ≥50 years of age. CDI was frequently identified through stool specimens collected from eligible inpatients with new-onset diarrhea. Further analysis of these data and additional laboratory testing will contribute to a better understanding of the frequency of CDI underdiagnosis and the burden of CDI in the United States. Disclosures