Clostridioides difficile (C. difficile) negatively impacts patient care and health care costs. Monitored as a safety metric, hospital onset- C. difficile infections (HO-CDI) occur after day 3 of admission. Standardized Antimicrobial Administration Ratio values for antibacterial agents posing highest risk for C. difficile infection (CDI SAAR) provides national benchmarking and assesses the impact of interventions aimed at improving prescribing practices to reduce C. difficile rates. We implemented several antimicrobial stewardship interventions to evaluate whether these reduced CDI SAAR values and C. difficile rates. Before 2023, C. difficile testing consisted of PCR alone after meeting certain criteria. This changed so that a positive PCR test reflexes to an EIA for toxin B; if negative, CDI is ruled out. Stewardship interventions in 06/2023 provided targeted education and feedback on CDI SAARs to ICU pharmacists to improve antimicrobial use. In 10/2023, a second intervention targeted high SAARs in the medical step-down unit (MSD) through daily patient review for antibiotic optimization. By early 2025, the antimicrobial stewardship pharmacist and physician initiated twice-weekly meetings to assess antimicrobial appropriateness. Patients were identified via chart review or pharmacist referral, and recommendations were communicated to the providers and documented in the chart. HO-CDI decreased both in the ICU and hospital wide after changing to two-step testing, decreasing from 0.55 to 0.25 infections/10,000 patient days (PD) hospital wide (Figure 1) and from 1 to 0.5/10,000PD in ICUs (Figure 3). In 2023, prospective audit and feedback by stewardship pharmacists in MSD patients resulted in a decrease in CDI SAAR from 1.26 to 1.12 (Figure 2). In October 2023, targeted education to ICU pharmacists coincided with reduction of ICU CDI SAAR from 1.57 to 1.43 (Figure 4). After biweekly stewardship rounds were implemented in 2025, HO-CDI decreased from 0.25 to 0.12/10,000PD hospital wide (Figure 1) and from 0.5 to 0.12/10,000PD in our ICUs (Figure 3). Special cause with 5 points at or below the line is noted in our hospital wide SAAR (Figure 2). Also noted special cause with increase in our hospital wide HO-CDI in November 2025 but an investigation did not identify a known cause. Interventions that reduce CDI SAAR values decreased HO-C difficile infections. Targeted interventions like prospective audit and feedback and educating team pharmacists on SAARs improved antibiotic utilization. Handshake stewardship rounding not only reduced SAAR but also decreased HO-CDI in our experience. Antibiotic Stewardship Programs help hospitals improve clinical outcomes and minimize harm by improving antibiotic prescribing.

Background: Prosthetic joint infection (PJI) is a serious complication of joint arthroplasty, typically requiring both surgical management and prolonged antimicrobial therapy which has historically been administered via outpatient parenteral antibiotics (OPAT). Recent studies have shown that oral (PO) antibiotics are non-inferior to intravenous (IV) antibiotics in the treatment for PJI and result in fewer catheter related complications. We aimed to examine the impact of a pilot institutional PJI guideline designed to encourage the use of PO antibiotics for PJI treatment on provider ordering practices at a specialty orthopedic hospital. Methods: In November 2024, our antimicrobial stewardship committee created and published institutional PJI guidelines which outlined appropriate use of PO antibiotics for PJI. Concurrently, we educated Infectious Diseases (ID) providers who practiced at the hospital. We identified all patients who had an ICD-10 code for prosthetic joint infection (T84.5) in the 12 months pre- (November 2023 – October 2024) and post- (November 2024 – October 2025) guideline implementation. Antibiotic days of therapy (DOT) were defined as the number of days where a patient received 1 or more antibiotics on a given calendar day. Primary outcomes were proportion of patients with OPAT orders and number of Peripherally Inserted Central Cathter (PICC) lines placed. Chi-squared (or when indicated, Fisher’s exact) tests examined proportions of patients who had OPAT orders placed and PICC line orders placed in the pre-guideline period compared with the post-guideline period. Student t-tests compared means for length of stay (LOS), outpatient IV and PO DOT in the pre-guideline period compared to the post-guideline period. Results: There were 82 PJI cases identified in the pre-intervention period and 94 in the post-intervention period. There were no differences in the number of OPAT orders placed (30 v. 45, p=0.25), proportion of PICC lines placed [37 (SD 45.1%) v 43 (SD 45.7%), p = 0.25] and mean LOS [5.9 (SD 4.2) v. 6.2 (SD 4.0), p = 0.68] between pre- and post-intervention periods (Table) Outpatient IV DOT [22.5 (SD 58.0) v 22.8 (SD 42.1), p=0.97) and outpatient PO DOT [25.6 (SD 52.9) v 28.0 (SD 35.7), p=0.73) did not significantly change between pre- and post-intervention periods. Conclusions: At a specialty orthopedic hospital, implementation of pilot guidelines for PJI was not sufficient to change ID provider ordering practices for PJI treatment. Future work will evaluate the utility of individualized feedback to increase appropriate use of PO antibiotics for PJI.

Background: Community acquired pneumonia (CAP) is a common and frequently serious infection. Guidelines recommend empiric anti-MRSA and/or anti-pseudomonal therapy in patients with severe CAP who have previously grown those organisms in the last year or recently received intravenous antibiotics, as well as respiratory cultures for those on anti-MRSA and/or anti-pseudomonal antibiotics or with severe CAP. We previously showed overutilization of anti-MRSA and anti-pseudomonal antibiotics and underutilization of respiratory cultures in patients with CAP admitted to the ICU. Anti-MRSA antibiotics were readily de-escalated with negative MRSA nares PCR testing, but anti-pseudomonal therapy persisted even with respiratory culture data demonstrating absence of Pseudomonas. These findings were disseminated to ICU teams via departmental talks, bi-weekly in-person stewardship handshake, and an EMR nudge (for anti-pseudomonal prescribing). Here, we performed a timed reassessment of antibiotic use in this population following these educational initiatives while investigating additional factors that may influence empiric choice and de-escalation practices. Methods We performed an IRB approved single-center retrospective chart review including adult patients who were admitted to the ICU and received intravenous pneumonia-directed antibiotics within two calendar days of admission between January 1st, 2024 and August 31st, 2025. Patients were excluded if they were transferred from an acute care facility, were discharged or transitioned to comfort care within 48 hours of admission, had lung transplant or BMT, CF, PJP, lung abscess, empyema, suspicion for extra-pulmonary infection, any recent neutropenia (ANC<500), or were chronically ventilated. Data was collected from internal dashboards and manual electronic medical record review. Results Of the 658 encounters reviewed, 234 patient encounters were included in our primary analysis. 80% (187/234) and 77% (179/234) of patients received empiric anti-pseudomonal and anti-MRSA therapy, while only 28% (52/187) and 30% (54/179) had risk factors for Pseudomonas and MRSA, respectively. 43% (89/208) of patients with an indication for respiratory culture collection had one obtained within 48 hours of admission. Of the patients who grew only normal flora (with reported absence of MRSA and/or Pseudomonas) from their respiratory cultures, de-escalation of anti-pseudomonal antibiotics lagged behind that of anti-MRSA antibiotics (Figure 1A). Anti-MRSA de-escalation was associated with negative MRSA Nares PCR testing (Figure 1B). Conclusion Educational interventions were ineffective strategies to improve guideline concordant management of critically ill patients with CAP. Respiratory cultures remain infrequently utilized. Growth of normal flora on respiratory culture rarely results in de-escalation away from anti-pseudomonal therapy the way that negative MRSA nares testing does for anti-MRSA therapy.

Background: In response to mounting antibiotic resistance and overuse, antimicrobial stewardship continues to serve as a major evolving initiative within healthcare institutions. Handshake stewardship utilizes in-person feedback to help facilitate intervention communication, in hopes of fostering clinician-ASP relationships and providing real-time education. This “face-to-face” approach has been demonstrated to improve antibiotic days of therapy (DOT) while also being perceived by treating teams as more favorable when compared to written feedback. Methods: Integrated ID/Pharmacy rounds occurred daily Monday – Friday, excluding holidays during the months of December 2024 to March 2025. The current hospital admitting structure separates individual hospitalist teams and internal medicine teaching resident teams. Teaching and hospitalist teams each have their own designated floors. To assess the long-lasting impact of ongoing antimicrobial stewardship education and intervention, an alternating checker box design was utilized, where ID/pharmacy rounds alternated between both designated teaching floors and used a hospitalist floor as control, where routine ASP review occured daily. Primary endpoints were antibiotic discontinuation, antibiotic deescalation and intravenous to oral conversion. Patients with an Infectious Diseases consultation were excluded. Results: Primary endpoints were antibiotic discontinuation, antibiotic deescalation and intravenous to oral conversion. Secondary endpoints included impact on length of stay and associated hospital acquired infections (C difficile). Overall: 196/388 patients (50.5%). Hospitalist control floor: 69/190 (36.3%). Teaching: 127/198 (64.6%); for the active teaching rounding group (75/106 (70.8%)) vs ASP education only (52/92 (57.6%)). For Hospitalist control floor vs teaching floor: p < 0.00001. Active teaching rounds vs ASP education: p = 0.037 Conclusion: Active participation and strong presence of ID pharmacy and ID physicians in daily medicine rounds, posiively impacts antibiotic utilization. It secures a direct line of communication and fosters strong relationships between departments, that ultimately benefits patient care, reduces lenght of stay and optimizes antibiotic utilization in terms of deescalation, duration of treatment and targeted antibiotic selection. Limitations include low availability of ID physicians for daily rounds, limited number of ID pharmacists for dailys ASP review and occasional disregard of recommendations by medicine teams.

Background: Prospective audit and feedback (PAF), a cornerstone of antimicrobial stewardship programs (ASP), relies on infectious disease (ID) clinicians’ direct review of electronic health records (EHR). We assessed the consistency of ID clinicians’ EHR-based assessments on real-world patient data. Methods: Antibiotic orders were randomly selected from a list of hospitalized adults at UCSF medical center. ID specialists (physicians and pharmacists) independently reviewed orders in real time using data from the EHR. Reviewers assessed the stated need for antibiotics, their agreement with necessity and choice, and overall appropriateness as defined by the National Antimicrobial Prescribing Survey (NAPS) tool. We measured agreement with either Cohen’s kappa or weighted Cohen’s kappa for ordinal observations. Results: Conclusion: We observed only modest agreement between independent ID clinicians’ reviews of antibiotic orders in a real-world assessment of inter-rater agreement. Discrepancies in assessments likely reflect a mixture of practice pattern variation, the intrinsic difficulty of assessing antibiotic choice without directly evaluating the patient, and variation due to the instruments used to collect information. Reference: Khanina A, Douglas AP, Yeoh DK, et al. Validation of the Antifungal National Antimicrobial Prescribing Survey (AF-NAPS) quality assessment tool. J Antimicrob Chemother. 2023;78(6):1367-1377. doi:10.1093/jac/dkad085

Background: There is no gold standard approach to Clostridioides difficile (C. difficile) testing clinically. The National Healthcare Safety Network (NHSN) uses the last test in a series to determine if positive testing will be considered a healthcare associated infection (HAI) and there is concern that this may impact testing choice. Increasingly, healthcare facilities are considering 2-step testing algorithms, but limited data exists on clinical or surveillance motivations for algorithm choice. Methods: In October and November 2023, we distributed electronic surveys to Veterans Affairs Medical Center (VAMC) infection preventionists and infectious diseases physicians asking about current facility C. difficile testing practices, motivations for their current strategy, and considerations for change. Only one response was included per facility. Duplicate responses from the same facility were combined. Data were analyzed using Chi-squared tests. Results: Among 126 VAMCs, 72 (57%) completed the survey. The most common testing strategies were polymerase chain reaction (PCR) with reflex to toxin (n=31, 43%) and PCR with reflex to glutamate dehydrogenase (GDH)/toxin (n=20, 28%) when PCR is positive. Less common strategies included PCR alone (n=9, 13%), GDH/toxin with reflex to PCR when discordant (either GDH or toxin positive) (n=5, 7%), GDH/toxin alone (n=1, 1%), and other (n=6, 8%). Factors associated with testing strategy selection were avoidance of overdiagnosis (78%), to decrease rate of C. difficile HAIs (56%), and ease of interpretation (33%) (Figure 1). When comparing 2-step testing algorithms, avoiding overdiagnosis was a motivation for positive PCR with reflex to toxin or GDH/toxin (84%) as well as GDH/toxin with reflex to PCR (80%) (p=0.8). When compared to PCR with reflex to toxin or GDH/toxin, sites using GDH/toxin with reflex to PCR more frequently reported test turn-around-time (80% vs 14%, p≤0.001) and cost (60% vs 8%, p≤0.001) as motivating factors. Sites using PCR with reflex to toxin or GDH/toxin were more motivated by decreasing HAIs than GDH/toxin with reflex to PCR (63% vs 40%), although not statistically significant. Notably, 40% of facilities reported switching their testing strategy within 2 years of survey and 24% were actively considering a change. Conclusion: The most common testing strategy among VAMCs is a 2-step algorithm starting with PCR, then reflex to either toxin or GDH/toxin when PCR positive, driven by desire to avoid overdiagnosis and decrease HAI rates. It is unclear how this actually impacts rates or if this will change if facilities move to healthcare facility-onset, treated C. difficile infection metrics.

Background: Clostridioides difficile infection (CDI) is an important cause of morbidity and mortality worldwide, and in the United States (US) has been declared an “urgent public health threat” by the Centers for Disease Control and Prevention (CDC). The most recently published CDC estimate of the number of CDI infections, hospitalizations, and in-hospital deaths in the US is for 2017. However, CDC’s Emerging Infections Program (EIP) provides ongoing surveillance data; we used EIP annual reports to derive estimates of the number of medically-attended CDI cases, hospitalizations, and deaths in the US in 2017-2022. Methods: Age- and healthcare-associated and community-associated stratified, population-based incidence rates of laboratory-confirmed CDI cases from EIP annual reports were multiplied by age-stratified US Census estimates to derive national estimates of CDI cases in 2017-2022. The percentage of CDI cases hospitalized on the day of or within 6 days of specimen collection, and the in-hospital mortality rates reported in EIP annual reports, were multiplied by the estimated number of CDI cases to calculate hospitalizations and in-hospital deaths for the same years. A similar approach was used to estimate cases, hospitalizations, and in-hospital deaths among persons ≥65 years-of-age. All estimates were compared with published 2017 CDC estimates. Results: We estimated that there were 449,946 laboratory-confirmed CDI cases in 2017, compared to 462,100 cases in the CDC estimate; estimated hospitalizations and in-hospital deaths in 2017 were also similar to the CDC estimate (Figure 1). We estimated 406,130 CDI cases in 2022; 210,079 CDI cases in persons ≥65 years-of-age. We also estimated 170,575 CDI hospitalizations and 9,914 in-hospital deaths in 2022; 88,233 hospitalizations and 5,128 in-hospital deaths in persons ≥65 years-of-age. From 2017-2020, the estimated number of CDI cases, hospitalizations, and in-hospital deaths declined by 22%, 33%, and 58%, respectively, and from 2020-2022 estimates increased by 16%, 8%, and 8%, respectively. Among persons ≥65 years-of-age, estimated CDI cases declined by 14% from 2017-2020, and increased by 6% from 2020-2022; from 2017-2020, estimated hospitalizations and in-hospital deaths declined by 34% and 67%, respectively, and remained stable from 2020-2022 (Figure 2). Conclusion: CDI burden estimates from EIP annual reports were comparable to CDC estimates, supporting the use of EIP data to derive national estimates. The US CDI disease burden is high and has increased since the COVID-19 pandemic. Interventions are needed to reduce the US CDI disease burden, particularly in older age groups.

Background: In adult hospitals, daily disinfection using a sporicidal agent in patient rooms has resulted in sustained reduction in Clostridioides difficile infection (CDI) rates. No studies have evaluated the impact of this intervention in a pediatric setting. Objectives: We sought to evaluate the impact of daily sporicidal disinfection of high-touch surfaces in rooms of hospitalized pediatric oncology and stem cell transplant (SCT) patients on the incidence density of hospital-onset CDI, and to identify strategies to optimize reliability of disinfection by clinical staff. Methods: We introduced a quality improvement intervention in which nurses disinfected 6 high-touch surfaces in patient rooms with bleach wipes twice daily. PDSA cycles were used to improve reliability of disinfection. We used a controlled interrupted time-series analysis with a non-equivalent control group (pediatric ward housing solid organ transplant recipients in which no sporicidal disinfection was introduced) and also tracked a non-equivalent dependent variable (catheter-associated UTI rate) expected to be unaffected by the intervention. Autocorrelated segmented regression models were used to compare CDI rates in each period (pre: June 2022-January 2024, post: February 2024-November 2025), adjusting for total antibiotic days of therapy. Other potential confounders (including reliability of hand hygiene, personal protective equipment, and room cleaning) were also monitored. Results: Sociodemographic and clinical characteristics among encounters on intervention units were similar pre- and post-intervention. The overall CDI rate on the oncology and SCT units was 20.5 per 10,000 patient days with no difference pre- vs post-intervention (19.0 vs. 21.9, p=0.46). The average monthly reliability of sporicidal disinfection across the post-intervention period was 56%. The model-estimated monthly trend in CDI rate on the intervention units decreased from 1.00 (pre) to 0.32 (post) (p=0.24) and showed a greater but non-significant month-over-month decline in trend compared with the control unit (β=-0.28, p=0.74). Hand hygiene and other confounders were similar across periods. There was no change in control unit CDI trend pre- vs post-intervention (p=0.48) (Figure 1). The CAUTI rate did not change between periods on intervention or control units. Conclusions: Introduction of daily sporicidal disinfection of high-touch surfaces by nurses in the rooms of pediatric oncology and stem cell transplant patients was followed by a modest (but not statistically significant) decrease in monthly trend of hospital-onset CDI rate, despite only moderate reliability of disinfection. Our results suggest a potential benefit to including sporicidal disinfection as a routine component of CDI prevention in a pediatric hospital.

Background: Clostridioides difficile infection (CDI) remains a major healthcare challenge, particularly in resource-limited settings. Methods: This retrospective, single-centre study analyzed CDI epidemiology and treatment outcomes among 528,887 hospitalized patients at the University Hospital in Kraków Poland, between 2016 and 2022. Results: A total of 2,341 CDI cases were confirmed, with an overall incidence of 4.32 per 1,000 admissions. The highest rates were observed in geriatric and infectious diseases units. During the COVID-19 pandemic, healthcare-associated CDI cases surged, accounting for up to 89.2% of infections in 2020 with incidence rate 3.8 per 1000 admissions, compare with 2,5 per 1000 admissions in 2016. Vancomycin-based therapy was associated with significantly lower mortality (OR 0.73, 95% CI 0.56-0.95) compared to metronidazole, while combination therapy (vancomycin + metronidazole) showed the highest recurrence rate (17%). Fidaxomicin use was minimal (0.4%) due to limited availability. Recurrent CDI occurred in 14.2% of cases, with a relapse-free survival advantage observed in vancomycin-treated patients. The overall in-hospital case fatality rate associated with CDI was 22.5%. Conclusions: Despite stable overall CDI incidence, the study highlights the impact of increased antibiotic consumption during the pandemic on HA-CDI dynamics. Findings underscore the need for improved antimicrobial stewardship, broader access to advanced therapies such as fidaxomicin and bezlotoxumab, and enhanced diagnostic protocols. In settings with restricted therapeutic options, vancomycin remains a valuable treatment, particularly for reducing mortality.

Background: Clostridioides difficile is one of the most common healthcare associated infections. Due to diagnostic uncertainty, patients are often treated for colonization instead of infection. Colonization is not believed to be a direct precursor for a Clostridioides difficile infection (CDI) and does not require treatment. The aim of this study is to analyze factors associated with overtreatment for Clostridioides difficile colonization, and whether these factors contribute to recurrence. Methods: This study examined fully abstracted incident Clostridioides difficile cases, defined as the first positive stool test for persons at least one year of age residing in Davidson County, Tennessee from 2018–2022. Colonization was determined by negative enzyme immunoassay test combined with positive polymerase chain reaction test. Overtreatment was defined as receiving treatment for colonization. Recurrence was defined as a positive stool specimen between two to eight weeks of the last positive specimen. Overtreatment and recurrence were analyzed with two separate logistic regression models using SAS 9.4. Results: There were 1,097 patients examined. Of these patients, 61% were overtreated for colonization. Patients without comorbidities and with increasing age had lower odds of overtreatment (OR=0.6, 95% CI [0.4–0.9]; OR=0.7, 95% CI [0.6–0.8]). Patients with hospitalizations on the day of or in the six calendar days after the specimen collection or with diverticulitis or inflammatory bowel disease were significant for higher odds of overtreatment (OR=1.3, 95% CI [1.0–1.8]; OR=1.6, 95% CI [1.1–2.4]; OR=2.1, 95% CI [1.2–3.8]). There was no significance found for predicting overtreatment with other demographics or comorbidities (e.g., diabetes mellitus, chronic kidney disease, chronic pulmonary disease). Increasing age had higher odds of recurrence (OR=1.3, 95% CI [1.0–1.6]). No other factors associated with overtreatment were associated with recurrence. Conclusion: Overtreatment was common in this population. Hospitalization contributed to increased overtreatment of Clostridioides difficile colonization, and it is important to consider patient comorbidities that may present similarly to clinical CDI when considering treatment. Future studies should examine how overtreatment can affect other CDI outcomes and additional evaluation of general prevalence in the population, incidence of CDI, and mortality rates following overtreatment.

Background: Clostridioides difficile infection (CDI) is a common healthcare-associated infection. Despite its well-characterized nature, literature remains divided on the impact of obesity on CDI. Through the Emerging Infections Program’s CDI surveillance, we investigated the influence of obesity — with and without comorbidities, on CDI compared to non-obese patients residing in Davidson County, Tennessee. Methods: Fully abstracted CDI cases, defined as the first positive stool test for persons at least 1 year old, residing in Davidson County, Tennessee from 2016–2023, were examined. Study groups included BMI ≥ 30 with no comorbidities (BMI30), BMI ≥ 30 with at least 1 comorbidity (BMI30C), and BMI < 30 (BMI<30). Pairwise comparisons of characteristics and outcomes were made via logistic regression custom hypothesis tests for categorical variables and Tukey-Kramer test for continuous variables. All outcomes were adjusted for age; stepwise logistic regression determined significantly associated patient characteristics for further adjustments. Statistics were conducted using SAS 9.4. Results: There were 623 patients identified (BMI30: n=45, BMI30C: n=136, BMI<30: n=442). BMI30 had the highest proportion of female patients (BMI30: 77.8%, BMI30C: 61.0%, BMI<30: 59.5%) and were the youngest group (BMI30: 47.0 years, BMI30C: 57.8 years, BMI<30: 59.0 years). BMI30C were more likely to be Black than BMI<30 (BMI30C: 36.0%, BMI<30: 16.7%). BMI30C were more likely than BMI<30 to be diagnosed with diabetes, chronic kidney disease, neuropathy, or a chronic ulcer/wound of the skin. BMI30 were the most likely to be community-onset (adjusted: BMI30: 78.9%, BMI30C: 59.4%, BMI<30: 66.8%) and least likely to be community-onset healthcare facility associated (adjusted: BMI30: 15.5%, BMI30C: 34.4%, BMI<30: 27.7%). BMI30C were more likely to have diarrhea (≥3 unformed stools in one day) than BMI<30 (BMI30C: 64.9%, BMI<30: 51.2). BMI30 were least likely to be admitted (adjusted: BMI30: 44.0%, BMI30C: 71.8%, BMI<30: 68.1%). Among admitted patients, there were no significant differences in ICU admissions or length of stay. There were no significant differences in 90-day mortality, number of cases, proton pump inhibitor, H2 blocker, or antibiotic use in any groups. Detailed statistics are available in tables 1–3. Conclusion: Variances in symptoms, case classification, and admissions, paired with similarities in mortality and length of stay between groups, demonstrate that providers should consider a patient’s unique health history when managing CDI, rather than adopting a uniform approach for all obese patients. Future studies with more diverse patient populations could guide clinicians in bettering the treatment and prevention of CDI in at-risk populations.

Background: Clostridioides difficile infection (CDI) is a major healthcare-associated infection. Although guidelines recommend multistep diagnostic algorithms and symptom-based management with contact precautions, diarrhea assessment is subjective and adherence to diagnostic algorithms may be inconsistent in clinical practice, potentially leading to unnecessary testing and prolonged contact precautions. This study aimed to evaluate real-world practices of CDI testing, symptom assessment, and contact precautions in hospitalized patients. Methods: We conducted a retrospective descriptive study using electronic medical record data from January through December 2025 of adult patients (≥18 years) hospitalized for at least 3 days at a university-affiliated tertiary-care hospital in South Korea with a positive Clostridioides difficile nucleic acid amplification test (NAAT). Collected variables included patient demographics, hospital unit, toxin A/B enzyme immunoassay (EIA) results, presence of diarrhea, CDI treatment, duration and reasons for discontinuation of contact precautions, and symptom status at discontinuation. Diarrhea was defined as three or more episodes of watery or loose stool within 24 hours. Cases were classified as clinically relevant CDI if they had (1) a positive NAAT and positive toxin A/B EIA result, regardless of symptoms, or (2) a positive NAAT and negative toxin A/B EIA result with documented diarrhea, consistent with clinical practice. CDI treatment was defined as ≥10 days of oral vancomycin or metronidazole (oral or intravenous). Contact precautions was discontinued after ≥48 hours without diarrhea. Results: A total of 269 NAAT-positive episodes were identified in 214 patients (mean age, 63.5 ± 17.5 years), most from general wards (68.4%). Toxin A/B EIA was performed in 94.8% of episodes, with 21.2% positivity, and 60.6% were classified as clinically relevant CDI. Diarrhea was documented in 61.3% of episodes, whereas contact precautions were implemented in 95.9%, including 36.1% of episodes without diarrhea. CDI treatment was administered in 75.1% of episodes, although only 49.4% of treated episodes had documented diarrhea at treatment initiation. Contact precautions were discontinued in 94.1% of episodes, with a mean duration of 12.0 ± 11.1 days. Symptom improvement was the most common reason for discontinuation (64.8%). The mean interval between the last documented diarrhea episode and contact precaution discontinuation was 7.7 ± 30.3 days, exceeding the guideline-recommended 48-hour diarrhea-free period. Conclusions: Contact precautions were often implemented without documented diarrhea and discontinued later than recommended. These findings indicate limitation of symptom-based CDI management in routine practice and underscore the need for more objective, standardized symptom assessment to support appropriate diagnostic stewardship and contact precautions.

Background: Antimicrobial resistance in Clostridioides difficile threatens frontline therapies, particularly vancomycin and metronidazole. Rapid genomic screening can flag putative resistance mechanisms, informing infection prevention and stewardship. We present pilot WGS data focused on vancomycin- and metronidazole-associated determinants. Methods A multicenter collection included the University Hospital in Kraków and five long-term care facilities in Małopolska, in 2022-2023. Sixty-six C. difficile strains were sequenced (WGS, AVITI PE300) and analyzed bioinformatically (Genpax IDEM, version 2.6); eight originated from colonized individuals, the remainder from CDI cases. We extracted the prevalence of vancomycin-associated genes (vanR-Cd, vanS-Cd, vanT-Cd, vanG, vanZ1, and vanS-Cd_T369I variant) and the metronidazole-associated gene nimB-Cd. Results Markers linked to vancomycin resistance were frequent: vanR-Cd (93.9%), vanT-Cd (71.2%), vanS-Cd (63.6%), vanG (59.1%), vanZ1 (51.5%), and vanS-Cd_T369I (4.5%). The metronidazole resistance marker nimB-Cd occurred in 95.5% of isolates. Notably, only one strain lacked any vancomycin resistance gene, and this isolate was recovered from a patient with CDI. These pilot genomic findings suggest widespread carriage of loci associated with reduced susceptibility to vancomycin and metronidazole in our regional C. difficile population. Conclusions In this pilot dataset, C. difficile isolates frequently carry genomic elements associated with vancomycin and metronidazole resistance. However, the mere presence of these markers, such as nimB or genes under vanRS regulation, may not independently indicate phenotypic resistance without specific functional mutations or regulatory changes. Phenotypic confirmation remains essential to establish clinical relevance; standardized susceptibility testing and integration of genotypic–phenotypic correlations with clinical data will follow in the next phase. Until then, these preliminary WGS results should be interpreted with caution and primarily guide prioritization of surveillance and stewardship actions.

Background: As part of the Centers for Disease Control and Prevention’s (CDC’s) Emerging Infections Program (EIP), the Tennessee Department of Health (TDH) conducts surveillance on Clostridioides difficile infection (CDI) in a designated catchment area. As part of ongoing surveillance, select TDH staff have access to Centers for Medicare and Medicaid Services (CMS) patient-level data under a CDC-CMS data use agreement. The aim of this study was to assess the alignment between the most prevalent chronic conditions among CDI cases reported through EIP and those reported through CMS. Methods: We matched patients who were 65 years and older from 2022 EIP data with Medicare beneficiaries on date of birth, sex, county of residence, and ZIP code, and retained unique matches for our study. Comorbidities present in both the CMS 30 CCW Chronic Conditions list and in the CDI case report form were included. The most prevalent chronic conditions in each dataset were identified. We employed Cohen's Kappa to assess inter-rater reliability between chronic conditions reported through EIP chart abstractions and those reported via CMS claim submissions. A Cohen’s Kappa greater than 0.4 indicates moderate or greater inter-rater reliability. Analysis was conducted using SAS Studio. Results: Of the 431 EIP CDI patients in 2022, 196 patients were 65 years or older and eligible for inclusion. 130 of these patients matched uniquely to a Medicare beneficiary ID on the demographics listed above (66.3%). The most prevalent chronic conditions identified among CDI patients were cardiovascular disease (CVD) (n=31), diabetes mellitus (n=26), chronic kidney disease (CKD) (n=21), and chronic pulmonary disease (CPD) (n=14). Diabetes mellitus diagnoses between the two datasets had the highest concordance with a Cohen’s Kappa of 0.5226 (p<0.0001), followed by CKD at 0.3984 (p<0.0001), CPD at 0.2313 (p=0.0081), and CVD at 0.1371 (p=0.1162). Conclusions: Only diabetes mellitus diagnoses showed moderate concordance between EIP and CMS datasets. EIP processes utilize chart review to generate surveillance data, which is person-power intensive. This limited study indicates that comorbidity data for CDI patients may not be completely captured if surveillance was conducted through secondary analyses using CMS data rather than complete chart review by trained public health staff.

Background: Clostridioides difficile Infection (CDI) is one of the leading causes of hospital-acquired infections. The Veterans Health Administration launched a national CDI prevention initiative in 2012 that bundled core practices such as environmental cleaning, strict hand hygiene, and contact precautions. In contrast to prior studies which have noted a decline in CDI rates during the COVID-19 pandemic, rates of hospital-onset (HO)-CDI increased at our Veterans Administration Hospital, and we sought to address this issue with a multi-pronged approach. Methods: We assessed multi-modal approaches implemented to reduce HO-CDI rates at Veterans Affairs North Texas Health Care System (VANTHCS), a large, academic VA medical center from 2021 to 2025. This approach included laboratory changes to CDI testing, updates to infection prevention practices, and antimicrobial stewardship program (ASP) rounds for prospective audit and feedback for antibiotics (including those considered high-risk for CDI by the National Healthcare Safety Network). Our primary objective was to assess the impact of these interventions on the incidence of HO-CDI, comparing HO-CDI rates before (Q2 2020–Q4 2022) and after (Q2 2023–Q3 2025) their implementation. HO-CDI was defined as a LabID event collected from an inpatient location < 3 days after admission (i.e., on or after hospital day 4), and rates were reported as number of HO-CDI/10,000 bed days of care (BDOC). Cases were extracted from the Computerized Patient Record System. Results: In October 2021, VANTHCS switched from a standalone nucleic acid amplification test (NAAT) to a 2-step algorithm wherein an initial NAAT was reflexed to a toxin immunoassay if positive. The Infection Prevention and Control Program developed standard operating protocols for room cleaning and disinfection, and hand hygiene was reinforced. In February 2023, the facility ASP implemented thrice-weekly rounds. Institutional antimicrobial guidelines were developed for common infections, and educational presentations were delivered to providers, using illustrative cases to highlight key stewardship principles. ASP team members audited 2,282 patient charts from April 1, 2023, through September 30, 2025. Interventions were made for 1,215 (53%) patients, and prescribers accepted 972 (80%) recommendations. Common interventions consisted of either antibiotic discontinuation or de-escalation in 74% of patients. Mean quarterly high-risk CDI antibiotic use declined from 95 to 71 per 1,000 BDOC (25%, p<0.01), and HO-CDI rates declined 59% from 3.81 (pre) to 1.55 (post) infections per 10,000 BDOC. Conclusion: A multipronged approach of reinforcing IPC practices, 2-step testing, and targeted feedback for antibiotics use led to significant decreases in HO-CDI rates.

Background: Clostridioides difficile infection (CDI) has been diagnosed with a variety of test methods that vary in their sensitivity and specificity. Because of concerns over potential overdiagnosis of clinical CDI, a single step method was adopted in May 2023 with glutamate dehydrogenase (GDH) and toxin enzyme immunoassay (EIA) with nucleic acid amplification test (NAAT) only to be ordered by clinicians who had ongoing clinical suspicion of CDI despite indeterminate test results. We aimed to describe the physician response to indeterminate test results, evaluate the percentage of people who had re-admission within 90 days for all-cause mortality and those with re-admission for diarrhea Methods: A multicenter historical cohort study was conducted among patients who were found to have GDH+/toxin- C. difficile results from 6/1/2023 to 12/31/24. Data were collected by retrospective chart review on the initial hospitalization and subsequent episodes of CDI in the following 90 days based on receipt of treatment for the initial episode of GDH+/toxin-. Data were analyzed using Student’s t-test, the Mann-Whitney U test, and the chi-squared test, using SPSS v. 31.0. Results: Of 382 patients, 380 had complete information on treatment history. Of these patients, 25% were treated (95/380). Among 285 patients with indeterminate C.difficile tests who were untreated and had re-admission in 90 days for diarrhea, only 2.1% were diagnosed with C.difficile colitis on the follow up admission. Patients who received vancomycin alone had the highest percentage of re-admission among other treatment options. Patients with chronic steroid use (p=0.05), other immunosuppressive agents (p=0.02) and with inflammatory bowel disease (IBD) (p=0.002) were significantly more likely to be readmitted for diarrhea within 90 days. Conclusion: A physician-based approach reduces overtreatment of indeterminate C. difficile results using a single step reporting method with only a small number of patients readmitted with CDI within 90 days.

Background: Patients with NAAT positive/toxin EIA-negative C. difficile infections (TNCDI) represent a spectrum from fulminant infection to asymptomatic colonization. We assessed differences in patient and provider factors associated with TNCDI treatment. Methods: A retrospective review was performed of all hospitalized patients ≥ 18 years with TNCDI from Jan 1st 2018 to Dec 31st 2024. Patients who received anti-CDI treatment were compared to those who did not using chi squared and Mann-Whitney U test. Variables with P≤0.2 were considered for inclusion in the final multivariable model. Results: We identified 550 patients with TNCDI; 488 (88.7%) received treatment while 62 (11.3%) did not (Table). The annual number of cases of untreated TNCDI significantly increased from 2018 to 2024 (p=0.026) (Figure). There were no significant differences in age, race, BMI, or provider services between the two groups. A higher proportion of untreated TNCDI occurred among women and in community-acquired cases. In multivariate analysis, community-acquired diagnosis of infection (within 72 hours of admission) was the only significant predictor of treatment (OR for treatment 0.50, p=0.03) (Table). In unadjusted analysis, treated TNCDI patients had higher LOS after diagnosis and mortality compared to untreated patients. Conclusion: The vast majority of TNCDI received anti-CDI treatment, though the proportion of untreated TNCDI cases increased significantly over time, likely reflecting antibiotic stewardship-based improvements. Patient and provider factors were similar between treated and untreated TNCDI groups, although small sample size of untreated TNCDI patients limited power. Treated TNCDI was associated with significantly longer LOS and mortality compared to untreated TNCDI.

Background: Clostridioides difficile infection (CDI) remains one of the most common healthcare-associated infections and contributes significantly to morbidity, mortality, and healthcare costs. In 2021, the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) updated their clinical practice guidelines for CDI treatment, recommending fidaxomicin over vancomycin for both initial and recurrent episodes due to comparable cure rates and a lower risk of recurrence. This recommendation is contingent upon institutional resource availability, as fidaxomicin is currently substantially more expensive than vancomycin. In response to these updated guidelines, a treatment algorithm was developed at UMass Memorial Medical Center (UMMMC) to prioritize fidaxomicin use in patients at high risk for recurrence (Figure 1). This study evaluated the adherence to and clinical outcomes of the institutional CDI treatment algorithm following implementation. Methods This retrospective study evaluated 530 patients admitted to UMMMC with a positive C. difficile PCR test during that admission between January 1, 2024, and June 30, 2025. Of those, 396 met inclusion criteria (Figure 2). The primary outcome was clinical cure, defined as resolution of diarrhea without the need for additional treatment within two days following completion of therapy. Secondary outcomes included 30-day mortality, recurrence at 30 and 90 days, hospital length-of-stay, and treatment-related adverse effects. Statistical analysis was performed using chi-square test for categorical variables, or one-way analysis of variance (ANOVA) for continuous variables, with Bonferroni post-hoc testing in GraphPad Prism. Results No significant differences were observed between treatment groups for the primary outcome of clinical cure (Table 1). Similarly, there were no significant differences in secondary outcomes, including recurrence at 30 and 90 days, or hospital length of stay (Table 1). There was no 30-day mortality documented for any of the groups. No adverse effects associated with vancomycin or fidaxomicin therapy were documented. The majority of treatment decisions were adherent to the institutional algorithm (70.2%) (Table 2). Conclusion Restricting fidaxomicin use to CDI patients at high risk for recurrence appears to be a safe and effective approach. This treatment algorithm provides a practical framework that may be adopted by other institutions to balance cost and efficacy, particularly as the high cost of fidaxomicin remains a barrier for both patients and healthcare systems.

Background: Recurrent urinary tract infections (rUTIs), especially catheter-associated UTIs (CA-UTIs), are common complications in people with neurogenic bladder (NB). The Recurrent UTI Impact Questionnaire (RUTIIQ) includes 5 domains assessing patient-reported quality of life (QoL) impacts from rUTIs: 1.) personal wellbeing, 2.) social wellbeing, 3.) sexual wellbeing, 4.) work and activity interference, and 5.) satisfaction with medical care. The RUTIIQ has only been validated in young women without NB. Our objective was to use cognitive interviews to determine initial adaptations to the RUTIIQ optimizing content validity for people with NB. Methods: This study included adult (age < 18) Veterans from two tertiary care Veterans Affairs Medical Centers who had NB due spinal cord injury/disorder (SCI/D) or multiple sclerosis. Virtual cognitive interviews were conducted between June-September 2025 with patients with rUTI, defined as ≥ 2 face-to-face encounters with a UTI diagnosis in the prior 6 months or ≥ 3 in the prior 12 months. Purposeful sampling was used to recruit from both SCI/D and MS groups. Participants were asked to complete the RUTIIQ using “think aloud” technique to evaluate comprehension, understanding and appropriateness. Results: Out of 55 eligible patients, 10 interviews were completed. One participant was female (10%), 9 were male (90%). Two participants had MS (20%), 6 had SCI/D (60%). Nine (90%) participants used indwelling or intermittent catheterization. Several participants struggled to focus on UTI-specific impacts, instead responding to items based on QoL and functional impacts from their disability in general. In response, we changed the survey instructions to emphasize that respondents should think about UTI-related impacts and broadened the recall timeframe from 2 weeks to 4 weeks to capture more UTI episodes. The term ‘work’ in the Work and Activity Interference domain was poorly applicable to nearly all participants, whose disability precludes traditional employment. This term was revised to ‘daily activities.’ Finally, several participants noted that the sexual wellbeing domain was not relevant for them, given that sexual dysfunction related to their disability prevented sexual activity. Thus, we added a ‘not applicable’ option to bypass that domain. Conclusions: Cognitive interviews with Veterans with NB revealed unique themes primarily related to their underlying disability that affected how rUTIs impact their QoL and functioning. Using these themes, we made substantive changes to the RUTIIQ to adapt it to the NB population. Future work will test the validity and reliability of this adapted RUTIIQ in a national cohort of Veterans with NB.

Background: University Health (UH) Medical Center is a longstanding 238-bed safety net hospital in Kansas City, MO, that uses LabID Event Reporting for Clostridioides difficile infection (CDI), with pre-agreed intuitional testing criteria, and where there was an increase in hospital-onset (HO) CDI in 2024. We sought to examine the factors associated with HO CDI at UH. Methods We conducted a case-control study that included all patients (cases) with a positive polymerase chain reaction (PCR) for toxigenic C. difficile in 2024, on hospital day < 3. We defined HO CDI as positive PCR occurring on hospital day < 3. We matched the cases 1:1, by age and gender, with patients (controls) having a negative PCR for toxigenic C. difficile in 2024, on hospital day < 3. Electronic health record was used to extract data that included demographic and epidemiological variables, Charlson Comorbidity Index (CCI), onset of diarrhea, and timing of stool collection, length of stay, and exposures (within past six months of CDI) to hospitalization, surgery, and/or medications including laxatives, proton-pump inhibitors, immunosuppressants, and antimicrobials. Continuous variables were compared via Mann-Whitney U or t test. Categorical variables were compared using X2 or Fisher’s exact test. Univariate and multivariate logistic regression analyses were performed to assess relationship between dependent and independent variables. Statistical significance was at p< 0.05. Results In 2024, there were 20 cases of HO CDI that were matched in 1:1 ratio with 20 controls. The controls had a higher mean CCI than the cases (5.9 vs 3.5). In univariate logistic regression, eight variables had a p-value < 0.05: CCI; cephalosporin use; specialty consults; infectious disease consult; fever; ICU stay; IV contrast receipt; and liver disease. In a multivariate logistic regression model, adjusted for multicollinearity including just five variables, the CCI (OR = 0.38, p = 0.018), specialty consults (OR = 0.00, p = 0.011), and cephalosporins use (OR = 15.06, p = 0.050) were significant; In a final reduced model (removing consults), only the CCI remained significant (p = 0.023). For each one-unit increase in the index, the odds of being a case decreased by 36% (OR = 0.64). Conclusion Charlson Comorbidity Index was a negative predictor, while cephalosporin use was a positive predictor, of HO CDI at UH. Two-step C. difficile testing and tailored antimicrobial stewardship would help optimize diagnosis and management.