Background: Healthcare environmental services (EVS) staff play a critical role in infection prevention and control (IPC) through environmental cleaning and disinfection. However, EVS staff are often excluded from structured, role-specific IPC education. Insufficient IPC knowledge among EVS staff may compromise environmental hygiene and increase the risk of healthcare associated infection transmission. This study aimed to assess IPC knowledge and education needs among EVS staff to provide an evidence-based foundation for targeted IPC education programs. Methods A descriptive cross-sectional study was conducted among EVS staff at a tertiary-care university hospital in Seoul, Republic of Korea. Participants completed a self-administered questionnaire assessing demographic characteristics, IPC knowledge, and perceived IPC education comprehension (current level) and education need (required level). IPC knowledge was measured using a 20-item instrument developed based on national IPC guidelines. Education needs were analyzed using the Borich’s needs assessment model and the Locus for Focus model to identify priority education topics. Descriptive statistics and nonparametric analyses were performed. Results A total of 81 EVS staff participated. The median IPC knowledge score was 17.0 (IQR, 16.0-18.0) out of 20. Notably, despite the high overall score, critical knowledge deficits were identified in high-risk IPC areas, including personal protective equipment (PPE) doffing protocols after cleaning an isolation room (42.0% correct) and management of infectious medical waste (17.3%). Education comprehension scores were lowest for management of suspected infection in staff, blood spill disinfection, and the safe use of disinfectants, whereas education need scores were highest for PPE related to various transmission-based precautions, as well as responses to needlestick injuries. Needs assessment using the Borich and Locus for Focus model identified procedures for managing suspected infection in staff (Borich score, 2.47), PPE for airborne precaution (2.00), and PPE for contact precaution (1.94) as the highest-priority IPC education topics, all of which were located in the high importance–high discrepancy (HH) quadrant; needlestick injury management and blood spill disinfection were also identified as high-priority areas. Conclusions Despite relatively high overall IPC knowledge, EVS staff demonstrated significant knowledge–practice gaps in high–risk IPC practices and expressed a substantial need for clearer guidelines essential for self-protection. The discrepancy between current understanding and perceived educational needs underscores the importance of structured, role–specific IPC education. Targeted IPC education programs focusing on isolation precautions, PPE donning and doffing, and occupational exposure management are crucial to enhancing both staff safety and the integrity of hospital-wide infection prevention.

Background: Blood culture contamination leads to increased healthcare costs and patient harm. Routine practice at our institution oftentimes involves placement of a new peripheral intravenous catheter (IV) followed by immediate blood culture collection from the catheter. Published guidelines discourage routine blood culture collection from central venous catheters, but do not address collection from new IV starts. We hypothesized higher contamination rates in cultures collected from new IV starts. To evaluate, mandatory documentation of blood culture collection site was implemented and contamination rates were analyzed. Methods: A prospective observational study was conducted from September to December 2025 at a large quaternary medical center. Peripheral blood culture contamination rates were measured using the CLSI definition. Mandatory documentation of collection site was implemented September 2025 and included an option for “new IV start”. Contamination rates by collection site were compared using chi-squared tests. An estimated cost of $4,538 for each contamination event was based on pooled published cost analyses data. Results: During the study period, 15,926 peripheral blood culture sets were collected and 234 (1.47%) met contamination criteria. Table 1 shows the new IV start contamination rate was significantly higher than all other sites combined (p-value <0.001 with an odds ratio of 1.86 [1.34-2.54]). The difference remained when comparing new IV start to individual anatomic sites. Per year, an estimated 89 contaminations would be avoided if cultures are not obtained from new IV starts with an estimated savings of $403,882 and 267 antimicrobial days. Conclusions: At our institution, it is common practice to collect blood cultures immediately after inserting a peripheral IV. The contamination rate of new IV starts was nearly double the contamination rate of dedicated upper extremity venipuncture leading to increased costs and unnecessary antimicrobial use. The large sample size provides robust data that collecting blood cultures from a new IV start should be avoided and this compelling data should be used to update published guidelines.

Background: We had a large-scale measles exposure event affecting 626 patients. Management of exposed patients was urgent, involving quarantine, post-exposure prophylaxis (PEP), and symptom monitoring on a case-by-case basis. Cases were initially tracked and managed using a combination of multiple spreadsheets amongst stakeholders as well as lists within the electronic health record (EHR). Using shared spreadsheets and lists created significant challenges with maintaining and editing multiple copies and updating workbooks simultaneously. Methods: Infection Prevention and Control (IPAC) worked with primary care personnel and EHR developers to create a shared registry that would prioritize communication and follow-up for exposed patients based on age and immunity. Patients are initially added to the shared registry within the EHR by reviewing non-registry reports and tagging patients, identified using exposure timeframes that overlapped with the index measles cases, in a manner that transferred them to the shared registry. From this registry, measles, mumps, and rubella vaccine status can be confirmed, immune status can be identified, and criteria for PEP assigned. High-risk patients are then contacted with recommendations from IPAC and primary care. Communication and follow-up are tracked directly within the shared registry to ensure appropriate patient management. The exposure management registry is further leveraged throughout the measles outbreak timeframe by allowing real-time monitoring of patients that require additional precautions or guidance related to their exposure. Result: The shared registry enhanced documentation accuracy and transparency between stakeholders. It led to availability of real-time status of exposed patients for the duration of the measles outbreak timeframe. Overall, the registry enabled time-sensitive patient communication to all exposed patients and rapid identification of those who needed PEP. Communication could happen rapidly and seamlessly between care teams within the organization, and the necessary information could be shared quickly with public health authorities as required. Conclusion: Large scale exposures are a challenge to manage and ensure appropriate action and communication occurs. Errors can be prevented by having a single shared exposure management registry. A registry enables care teams to quickly identify and prioritize patients for measles follow-up, communication, PEP, and ongoing management across outbreak timeframes. This process reduces both time and operational burdens of exposure follow-up tracking outside of the EHR.

Background: Central line-associated bloodstream infections (CLABSIs) remain a significant challenge in long-term acute care hospitals (LTACHs), where patients have extended lengths of stay, high device utilization, and complex medical conditions. In 2024, our 11-hospital LTACH system had a CLABSI standardized infection ratio (SIR) of 1.23, performing above (worse than) the national benchmark. A comprehensive, system-wide initiative was needed to reduce preventable infections and improve patient outcomes. Methods: In January 2025, we implemented a multi-modal intervention bundle across 11 LTACHs spanning multiple states. Key components included: (1) A standardized mini-root cause analysis (Mini-RCA) process requiring facility infection preventionists to complete a structured review within 48 hours of each CLABSI event, examining insertion and maintenance bundle compliance, contributing factors, and preventability. Findings were shared with frontline staff and reported to each facility's QAPI committee. (2) Beginning August 2025, corporate infection prevention oversight calls were initiated to review events and identify system-wide patterns. (3) In-house vascular access training was expanded to three facilities, enabling nurses to insert PICCs and midlines under ultrasound guidance, reducing reliance on external contractors and empowering staff to evaluate line necessity and step-down opportunities from central lines to less invasive devices. (4) A blood culture stewardship program was implemented in partnership with pharmacy, emphasizing appropriate culturing indications, transitioning from line draws to two peripheral sticks when feasible, and antibiotic stewardship principles. Results: Comparing full-year 2024 data to January-November 2025, CLABSI events decreased from 56 to 22 (61% reduction). The system SIR improved from 1.23 to 0.53, representing a 57% improvement and performance significantly better than the national benchmark. Central line days decreased by 8% (40,825 to 37,570), and the standardized utilization ratio (SUR) improved from 0.77 to 0.73. Conclusions: Implementation of a multi-modal intervention bundle featuring standardized event review, corporate oversight, enhanced vascular access capabilities, and blood culture stewardship achieved significant and sustained CLABSI reduction across a geographically dispersed LTACH system. The Mini-RCA process created accountability and rapid feedback loops, while in-house line placement empowered clinical staff to critically evaluate device necessity. This approach demonstrates that meaningful infection prevention improvements are achievable in the challenging LTACH setting through systematic, multi-level interventions.

Background: Infection prevention (IP) workflows and staffing continue to be largely designed to provide retrospective surveillance with improvement strategies implemented after infections have occurred despite strong evidence that near real time feedback on clinical care and prevention bundles result in improved clinical care and prevention of infections. While some organizations have implemented centralized surveillance teams to manage chart abstraction for state and national reporting, few have moved toward a prospective surveillance model with their facility-based IP teams. Having implemented a centralized surveillance team in 2015, and an ambulatory specialty IP team in 2017 across a large multi-state healthcare system, a comprehensive IP model redesign was undertaken in 2025 to further transition to a prospective surveillance approach. Methods: Starting January 2025, a prospective surveillance program was launched, combining centralized surveillance, hospital-based generalists, and zone-based specialists in IP. Specialty teams were developed for surgical and procedural services, adult critical care, ambulatory and emergency medicine, and oncology, womens, and pediatric services. Facility-based generalists provide coverage for observation and general medical-surgical units. Staff were assigned roles based on preference and qualifications. About 85% of work hours shifted to direct clinical observation with real-time feedback and coaching of clinical teams. Results: Standardized electronic rounding tools were utilized by both generalist and specialist IPs. Bundle compliance opportunities and trends were displayed on an electronic dashboard and emailed weekly to department leaders. Departments with consistent performance below expectations had to submit action plans to improve performance. In 2025 compared with 2024, total number of IP rounding observations increased 36.8%, CLABSI prevention bundle compliance improved by 8.7% with a 79% increase in the number of lines observed each month, urinary catheter care being completed increased 7.7% with a 52% increase in catheters observed each month, and SSI prevention bundle compliance improved by 8% with a 117% increase in surgical procedure observations. Conclusion Implementing a prospective generalist-specialist model in infection prevention led to significantly more clinical care observations and steady improvements in prevention strategy compliance. Increased visibility and presence on the units resulted in IPs becoming trusted members of the clinical care team. Having a specialist IP role also resulted in improved recruiting of IPs with specific clinical experience and boosting their credibility with the clinical teams. Limitations of this study include the staggered implementation of specialist roles per quarter that may have slowed improvement in specific locations.

Background: Mycobacteria are widely distributed in the environment, and colonization of medical devices using water poses a risk in healthcare settings. Hospital outbreaks linked to ventilators and extracorporeal systems have been reported. At our hospital, dental unit water is routinely cultured every three months. In January 2024, unexpected mycobacterial detection prompted an investigation of dental unit waterlines, tanks, and water sources. Objective: To investigate the presence of mycobacteria in dental unit waterlines and evaluate clinical implications. Methods: Water samples (300ml) from six dental unit waterlines were tested by culture before and after changes in flushing frequency, heater use, and filter replacement. Additional samples from the hospital annex water tanks, main building tank, and nearby parks sharing the same water source were analyzed. Results: Mycobacteria were isolated from all six dental unit waterlines, including M. frederiksbergense, M. chelonae complex, M. mageritense, and M. mucogenicum/phocaicum, with concentrations up to 25 CFU/mL. Increasing flushing from weekly to daily and discontinuing heater use did not eliminate contamination. However, quantitative cultures after filter replacement showed marked reduction, with most lines becoming negative or <0.5 CFU/mL. Mycobacteria were also detected in external water sources: annex water tank (10 CFU/mL), main building tank (<2.5 CFU/mL), and nearby parks (<5 CFU/mL). These findings suggest mycobacteria are not unique to dental units but are ubiquitously present in tap water. Discussion: Detection in both dental units and external water sources indicates widespread colonization rather than isolated contamination. Filtration proved effective in significantly reducing mycobacterial load, emphasizing its role in infection control. Given the pathogenic potential of environmental mycobacteria, especially in immunocompromised patients such as those with neutropenia or hematopoietic cell transplantation, exposure via dental unit water may carry clinical risks. For these patients, use of sterile water instead of tap water during dental treatment is strongly considered. Conclusion: Mycobacteria are present in tap water and dental unit waterlines. Filter replacement effectively reduces contamination. Strict precautions, including sterile water use, are warranted to protect vulnerable patients from opportunistic mycobacterial infections.

Background: Recent research has investigated the role of sinks (including sink taps, filters, water traps, etc.) in the spread of multidrug-resistant organisms (MDROs) and other pathogens. As part of a larger study on hand hygiene (HH) and personal protective equipment (PPE) adherence, we explored healthcare professionals’ (HCP’s) interactions with water and wet surfaces during patient care processes in intensive care units (ICUs). Methods: We conducted ethnographic observations of HCP’s patient care processes in the medical and surgical ICUs of a large academic hospital, and we conducted mini-interviews (~ 3-7 minutes) with a subset of these HCP. Observations focused on HH and PPE adherence during contaminating tasks. We also captured additional relevant data (e.g., room layouts, care activities, fomite/device interactions). We documented observations and interview responses in fieldnotes that we imported into MAXQDA qualitative software and coded activities using a combined deductive-inductive approach. We conducted data collection and analyses iteratively, with early analysis informing later data collection. HCP interactions with water emerged inductively as a topic of interest during this process. Results: Between 3/2022-5/2023, we observed 104 HCP engaged in patient care and conducted 31 mini-interviews. Interactions with sinks and sink-adjacent counters were common. We observed HCP placing pillows and other items on wet counters, water remaining in sinks after use, HCP contacting water droplets on sink walls and counters, and HCP setting items (e.g., IV bags, used towels) in the sink that they later carried to trash or laundry bins. HCP also leaned against surfaces, including sink-adjacent counters and patient-adjacent areas (e.g., beds, bed rails). Such activities could transfer contaminated water droplets to HCP’s clothing, floors, or other surfaces. We also observed water splashing due to sink design or the water pressure when HCP did activities like filling drinking cups or rinsing containers. During mini-interviews, HCP discussed their preference for soap-and-water handwashing (versus hand sanitizer) in specific situations, which they often performed at the same in-room sinks they used during patient care activities as outlined above. Splash back from sink drains could spread pathogens to HCP’s hands. Conclusion: Our study focused on HH and PPE adherence, therefore, we did not systematically collect observations on water in ICUs. Nonetheless, we observed HCP interacting with sinks, water, and wet surfaces in ways that highlight the potential for water-borne pathogen transmission. Infection prevention programs and hospitals should consider these interactions when developing infection prevention guidelines and designing construction and renovation projects.

Background: Guideline-concordant, first-line antibiotic prescribing is a core antimicrobial stewardship strategy to reduce unnecessary broad-spectrum use, antibiotic resistance, and adverse events. Community-acquired pneumonia (CAP) is a common indication for outpatient antibiotics, yet first-line prescribing patterns and equity remain understudied. This analysis assessed associations between first-line prescribing and patient, clinician, and community characteristics in urgent care settings. Methods: Electronic health records from 28 urgent care clinics within an integrated academic healthcare system (January 2023–April 2025) were analyzed. Adults (18+ years) with pneumonia diagnoses and at least one prescribed antibiotic were included. ‘Community-acquired pneumonia’ refers to pneumonia diagnosed in urgent care, though some cases may not meet formal CAP criteria. Episodes were classified by first-line use (CAP without comorbidities: amoxicillin or doxycycline; CAP with comorbidities: either amoxicillin/clavulanate plus doxycycline or a macrolide, or respiratory fluoroquinolone monotherapy). Cluster-adjusted logistic regression assessed differences in first-line prescribing by patient, clinician, and community factors. Results: Among 9,670 episodes (4,966 no comorbidities), first-line prescribing occurred in 90.8% of CAP with no comorbidities and 54.4% of CAP with comorbidities. Mean age was 48.4 years (SD 17.4) for patients without comorbidities and 60.7 years (SD 17.5) for patients with comorbidities; 23% and 48% of episodes occurred among adults ≥65 years. The most common non–first-line antibiotics were amoxicillin-clavulanate and clindamycin, for CAP with and without comorbidities respectively. For CAP without comorbidities, fully adjusted models showed higher odds of first-line prescribing for episodes managed by Advanced Practice Registered Nurses (APRNs) compared to physicians and lower odds among patients with higher neighborhood disadvantage (ADI 26–49 vs 1–25 percentile) as seen in Figure 1. The Area Deprivation Index (ADI) quantifies neighborhood socioeconomic disadvantage (1-100 is least to most disadvantaged). For CAP with comorbidities, Black and Hispanic patients (vs. White) and those treated by APRNs (vs. physicians) had higher odds of receiving first-line antibiotics, while patients in neighborhoods with higher ADI scores had lower odds (vs. 1–25 percentile; Figure 1). Across both groups, no differences were observed by age, gender, or payer. Conclusion: First-line prescribing for outpatient CAP was high among patients without comorbidities but substantially lower among those with comorbidities, with disparities by clinician type, race/ethnicity (comorbidities only), and neighborhood deprivation. These findings reveal systemic inequities in antibiotic stewardship and reinforce the need for equity-focused strategies to support guideline-concordant prescribing. Additional work is warranted to clarify prescribing variation and evaluate relevant modifiers.

Background: Overuse of antibiotics in hospitals leads to resistance to antibiotics, increased consumption of healthcare resources, and adverse drug events. Antibiotic Time-Outs (ATOs) are a recommended antimicrobial stewardship strategy that encourages regular reassessment of antimicrobial therapy that includes indication, spectrum, route, and duration after antibiotic initiation. We evaluated the effect of a hospitalist-led weekly ATO on antibiotic utilization and patient safety outcomes on a high-utilization medical unit. Methods This quality improvement project was conducted on an adult inpatient medical unit with historically high antibiotic use. Baseline antibiotic utilization data were collected from January to March 2025, followed by implementation of weekly hospitalist-led ATO rounds from April-June 2025 with a post-intervention observation phase planned for sustainability assessment. During the ATO rounds, all inpatients receiving systemic antibiotics (excluding those on Infectious Diseases service) were reviewed for indication, microbiology, clinical status, route, and duration. Stewardship recommendations included discontinuation, de-escalation, intravenous-to-oral (IV-to-PO) conversion, and duration optimization. Antibiotic utilization was measured as days of therapy (DOT) per 1,000 patient-days for five targeted agents: ceftriaxone, cefepime, piperacillin-tazobactam, ampicillin-sulbactam, and amoxicillin-clavulanate. Process measures included number and acceptance of stewardship recommendations within 24–48 hours. Clinical outcomes included mortality, length of stay (LOS), and 30-day readmissions for pneumonia, urinary tract infection, cellulitis, sepsis, and diabetic foot infection DRGs. Results Across three months of ATO implementation, 34 patients were reviewed, and 30 stewardship recommendations were issued with 24 recommendations (80%) accepted within 24-48 hours. The most frequent interventions were antibiotic discontinuation, de-escalation of spectrum, and intravenous-to-oral conversion. Compared with the pre-ATO period, the combined DOT for the five targeted antibiotics declined during the ATO phase and was sustained post-intervention, corresponding to an overall ~8% reduction in broad-spectrum IV antibiotic exposure across the study period. Importantly, this reduction was not associated with any signal of harm: mortality, LOS, and 30-day readmission rates for sepsis, pneumonia, UTI, cellulitis, and diabetic foot infections remained stable or improved during both the intervention and post-intervention phases. Conclusion Implementation of a hospitalist-led weekly Antibiotic Time-Out resulted in high acceptance of stewardship recommendations and produced a sustained reduction in broad-spectrum antibiotic exposure without adverse effects on mortality, readmissions, or length of stay. This low-resource, physician-driven intervention represents a scalable and effective approach to improving antimicrobial use and patient safety on high-utilization inpatient units.

Background: After an 18-month period with no Central Line-Associated Bloodstream Infections (CLABSIs), the Critical Care Unit (CCU) at OUMC experienced a cluster of two CLABSIs and one related non-CLABSI event in the first quarter of 2025. This occurred despite established prevention protocols, including daily line necessity rounds, use of MAGIC guidelines for vascular access, universal decolonization, and ongoing staff education, which had successfully lowered infection rates since 2022. All three affected patients were intubated, had an internal jugular (IJ) central venous catheter, and presented with Candida species in their blood and sputum, signaling a potential common etiology. Methods: In response, a multidisciplinary team was convened in April 2025 to conduct a proactive risk assessment using the Failure Modes and Effects Analysis (FMEA) methodology. The FMEA focused on ensuring adherence to the evidence-based policy for central line insertion and maintenance. The team comprised intensivists, interventional radiologists, chief residents, nursing leadership, infection prevention specialists, and a patient safety coordinator to represent all facets of the central line process. Results: The FMEA systematically evaluated potential failures in central line necessity, insertion, maintenance, removal, and environmental cleaning. By calculating Risk Profile Numbers (RPNs), the team identified several high-risk process steps. The highest initial RPN (486) was attributed to the potential for insufficient ultrasound probe cleaning due to improper technique and reliance on visual inspection alone. Other significant failure modes included inconsistent terminal cleaning of patient rooms (RPN 315), potential contamination of IJ lines from patient secretions (RPN 216), lack of role clarity during the insertion procedure (RPN 192), and the use of a single needle for multiple insertion attempts (RPN 189). The cumulative initial RPN for all identified failure modes was 2798. Conclusion: The FMEA proved to be an effective tool for identifying systemic vulnerabilities that contributed to the CLABSI cluster. The analysis led to the implementation of targeted corrective actions, including re-education on and audited monitoring of ultrasound probe cleaning, the introduction of single-use gel packets and individual introducer needles, clarification of the safety observer's role during insertion, and enhanced protocols for protecting IJ dressings. Following these interventions, the total RPN was successfully reduced to 1763. This proactive, systematic approach enabled the team to address specific gaps in practice and reinforce safety protocols to prevent future CLABSI events. No further CLABSIs have been identified since these interventions.

Background: Traditional antimicrobial stewardship (AS) metrics focus on utilization and therapy optimization, but rarely capture the true impact on patient outcomes. Experience from safety initiatives, such as central line-associated bloodstream infections and serious safety events, has shown that metrics quantifying patient harm are essential to drive meaningful change. Related to AS, there is a need for novel measures to quantify antimicrobial-associated adverse drug events (ADE) to inform prescribing behavior. Prior research by infectious diseases (ID) experts found ADEs occurred in 21% of pediatric inpatient antibiotic courses, with risk increasing each day of therapy. Our objective was to assess harm events and identify opportunities for developing antimicrobial-associated harm measures to inform improvement efforts. Methods: We conducted a retrospective chart review to determine the incidence and classify antimicrobial-associated ADEs among hospitalized children. Three non-ID reviewers evaluated a random cohort of patients (<18 years) hospitalized ≤ 60 days between November 2019 and January 2020 who received oral or intravenous antimicrobials for ≥ 24 hours. Sampling was stratified by overall length of stay (LOS) tertiles (1-3, 4, 5+ days). ADEs were defined using clinical criteria from prior literature as occurring within 30 or 90 days of index hospitalization. Reviewers were trained by a nurse informaticist and an ID pharmacist prior to data collection. Weekly case reviews ensured consistency, with ID experts validating 10% of data for interrater reliability. ADEs were categorized by clinical type and antimicrobial class. The frequency of ADEs were compared across LOS category and patient-level total days of antimicrobial therapy (DOT). Result: Of the 411 patients evaluated, (median age: 4 years; 50.9% female) 16.8% (n=69) experienced ≥ 1 ADE. There were 78 total ADEs identified, mostly gastrointestinal (GI) (n=43, 55.1%), dermatologic (n=12, 15.4%), Clostridioides difficile infection (n=8, 10.3%), and vascular device-related events (n=7, 9.0%). GI ADEs were most often associated with fluroquinolones (n=3, 30%), penicillins (n=3, 22.6%), and 3rd generation cephalosporins (n=17, 13.8%). Median DOT was 3 [IQR: 1, 7]; differences in antimicrobial duration between patients with and without ADEs were considered non-significant (p <=/i< 0.2425). ADE incidence increased with LOS tertiles: 1-3 days (n=17, 11.6%), 4 days (n=21, 16.9%), and 5+ days (n=31, 22%). Conclusion: We demonstrated that antimicrobial-associated ADEs are frequent among pediatric inpatients. Developing standardized surveillance systems for antimicrobial ADE detection that are reliably incorporated into AS metrics may be a useful strategy to improve antimicrobial prescribing.

Background RSV vaccine effectiveness (VE) has not been described among nursing home (NH) residents, despite their increased risk for severe disease related to age and chronic heart and lung disease. We assessed bivalent RSVpreF VE in Veterans Affairs (VA) NH residents, overall and stratified by age and comorbidities. Methods We conducted a retrospective cohort study of NH residents over two RSV seasons (October 2023–April 2024; October 2024–April 2025). Inclusion criteria were a confirmed RSVpreF vaccination status (received RSVpreF or no RSV vaccine; other formulations and unconfirmed status excluded) and residing in a NH with RSV testing during the study period. Vaccination status was a three-level time-varying exposure: unvaccinated, vaccinated in current season, or vaccinated in the prior season. Time-at-risk for RSV was limited to continuous stays in VA NH or acute care settings. The primary outcome was laboratory-confirmed RSV infection; severe infections were defined as those requiring transfer to acute care or escalation within acute care. VE was calculated as 1 minus the hazard ratio from Cox models stratified by age and cardiopulmonary disease defined by diagnoses of congestive heart failure (CHF) and/or chronic obstructive pulmonary disease (COPD), adjusted for demographics, calendar year, and conditional on calendar month. Results Among 15,078 unique residents, those aged 60-74 had similar VE when vaccinated in the prior season vs current season, while those aged ≥Figure 1). Similarly, current-season model-adjusted VE was similar for those with and without cardiopulmonary disease. VE for vaccination in the prior season declined modestly among those with cardiopulmonary disease (76% [51–89] to 54% [4–78]). Of 220 total laboratory-confirmed RSV infections, 15 were severe (Table 1). Of the infections, 29 occurred among vaccinated residents of which 1(3%) was severe. Among unvaccinated residents, 14/191 infections (7%) were severe. Residents with severe infections were more likely to be ? Conclusion In this first RSV Vaccine VE study among NH residents, a frail population at high risk for severe RSV disease, bivalent RSVpreF vaccination was associated with a meaningful reduction in laboratory-confirmed RSV infection risk that persisted across two seasons, but with some diminished second-season protection for those with advanced age or cardiopulmonary disease. These subgroups were also overrepresented among those with severe disease and remain an important target for disease prevention.

Background: Healthcare facility-level wastewater surveillance (WWS) is a relatively novel tool for pathogen surveillance. The most sensitive methods for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater remain unknown. In this study at skilled nursing facilities (SNFs), two wastewater concentration methods were evaluated for SARS-CoV-2 detection by droplet digital polymerase chain reaction (ddPCR): Electronegative membrane filtration (enMF) and Nanotrap® Magnetic Virus Particles (NP). SARS-CoV-2 case surveillance data from the SNFs was incorporated into this evaluation. Methods: Wastewater samples were collected weekly from manholes at three SNFs over 25 weeks in 2022. Samples were split and concentrated by both enMF and NP, then virus concentration was determined by ddPCR. We utilized a weekly questionnaire and each facility’s National Healthcare Safety Network COVID-19 Report to identify the number of resident and healthcare personnel cases in each facility. Differences in the median SARS-CoV-2 concentration were compared across the enMF and NP methods using the Wilcoxon signed-rank test (?=0.05). Spearman’s correlation (?) was used to evaluate the relationship between the SARS-CoV-2 concentration in wastewater and SARS-CoV-2 case counts. Results: For each facility separately, as well as overall, median virus concentration in wastewater from enMF was higher than that from NP (SNF A: 2.84 vs. 1.49 genome copies [gc]/100 mL; SNF B: 8.50 vs. 6.08 gc/100 mL; SNF C: 5.3 vs. 3.86 gc/100 mL; overall: 5.3 vs. 3.86 gc/100 mL). The Wilcoxon signed-rank test confirmed that the difference in median virus concentrations was statistically significant for SNF B (p=0.001) and overall (p=0.001). Spearman’s correlation results showed overall higher correlations with enMF than with NP and a greater number of statistically significant results among subpopulations. For example: using enMF, the correlation among residents and healthcare personnel combined at SNF A was ?=0.86 (p=<0.0001), at SNF B was ?=0.50 (p=<0.01), and at SNF C was ?=0.59 (p=<0.01), whereas using NP, the correlation at SNF A was ?=0.54 (p=<0.01), SNF B was ?=0.46 (p=0.02), and SNF C was ?=0.23 (p=0.26). Conclusions: enMF yielded higher SARS-CoV-2 concentrations than NP and produced stronger correlations between wastewater signal and case counts, though both methods yielded acceptable results. enMF should be considered as an effective virus concentration method for healthcare facility-level WWS to strengthen and complement clinical methods of case detection.

Background: Ceftriaxone and cefepime resistance among Enterobacterales continues to increase globally, partly due to the rising prevalence of extended-spectrum β-lactamase (ESBL) producing organisms. Surveillance of both resistance patterns and antimicrobial utilization is essential to inform empiric prescribing practices and stewardship strategies. Since carbapenems are frequently used to treat cephalosporin-nonsusceptible Enterobacterales infections, we evaluated trends in ceftriaxone and cefepime susceptibility among Escherichia coli and Klebsiella pneumoniae from 2012–2024 and institutional carbapenem utilization during overlapping years (2019–2025), following outcomes from the MERINO trial for management of ceftriaxone-resistant Enterobacterales infections. Methods: We conducted a retrospective review of annual cumulative inpatient antibiogram data for E. coli and K. pneumonia isolates for 2012-2024. Percent susceptibility to ceftriaxone and cefepime was assessed using Clinical and Laboratory Standards Institute (CLSI) breakpoints among a median of 1,532 E. coli isolates/year and 561 K. pneumoniae isolates/year. (Table 1). Institutional carbapenem utilization (combined meropenem and ertapenem use) was measured as days of therapy (DOT) per 1000 patient-days during 2019–2025 (not specifically representing treatment of E. coli or K. pneumoniae), following implementation of electronic medical record (EMR)–based antimicrobial utilization dashboards. Temporal trends were visualized using line plots. Pearson correlation coefficients (r) were calculated to assess percent susceptibility trends and carbapenem utilization during 2019–2024. Analyses are descriptive; no causal inference was made. Result: During 2012–2024, ceftriaxone susceptibility declined from 89% to 83% among E. coli and from 93% to 82% for K. pneumoniae, while cefepime susceptibility declined from 95% to 88% and 97% to 85% respectively (Figure 1). During the overlapping years 2019–2024, Pearson correlation showed modest downward susceptibility trends for ceftriaxone (E. coli r = −0.900, p = 0.014; K. pneumoniae r = −0.840, p = 0.036) and cefepime (E. coli r = −0.780, p = 0.067; K. pneumoniae r = −0.850, p = 0.033). Institutional carbapenem use increased from 15.2 to 19.3 DOT per 1,000 patient days between 2019 and 2025 (r = 0.79, p = 0.035) (Figure 2). Upon review, carbapenem use was substantially higher in hematology-oncology services (23.7–25.9 DOT/1000 patient-days, during 2022–2025) compared with overall institutional use (15.2–19.3 DOT/1000 patient-days). Conclusion: Ceftriaxone and cefepime susceptibility among Enterobacterales declined over the past decade, coinciding with a modest increase in institutional carbapenem use without a corresponding increase in carbapenem resistance during 2019-2024. Local susceptibility patterns and antimicrobial utilization data provide critical context for stewardship prioritization, especially in high-risk hematology-oncology populations.

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: 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.