Background: Empiric extended-spectrum antibiotics are routinely given to patients with cancer despite low risk of infection with multidrug-resistant organisms (MDROs). This secondary analysis of the four INSPIRE (INtelligent Stewardship Prompts to Improve Real-time Empiric Antibiotic Selection) trials evaluated how computerized physician order entry (CPOE) prompts providing patient- and pathogen-specific MDRO risk estimates affected empiric extended-spectrum antibiotic use in patients with cancer. Methods: We identified non-critically ill hospitalized adults (> Results: Including all trials, 36,861 (18,272 baseline; 18,589 intervention) patients had cancer. Mean age was 69.0 (13.6); 48.0% (17,675) were male. Extended-spectrum antibiotic days-of-therapy decreased by 27% (95% CI:20-34%, PPPP Conclusions and Relevance: An antibiotic stewardship bundle that included CPOE prompts recommending standard-spectrum antibiotics for patients at low risk for antimicrobial-resistant infections reduced extended-spectrum antibiotic use in non-critically ill patients with cancer who were hospitalized with community-acquired pneumonia, UTI, abdominal infection, or SST, without observed differences in safety outcomes.

Background: Skin changes can precede central line infections by days to weeks, making early identification essential for prevention. Routine nursing assessments help prevent CLABSIs in hospitals, but comparable surveillance is lacking for patients managing central lines at home, leading to preventable infections and readmissions. Hypothesizing that artificial intelligence (AI) can be trained to reliably detect visible inflammation/infection from a photo, we developed algorithms for auto-detection of early signs of localized skin inflammation or infection. Methods: We conducted a secondary analysis of photos collected from 3 cohorts of adult patients with central venous catheters (CVCs) at a large academic hospital, an outpatient oncology clinic, and 6 nursing homes between January 2014-June 2017. Skin tone was recorded using the Fitzpatrick Scale, as erythema may be harder to detect in darker skin tones (types IV–VI). Insertion-site inflammation or infection was assessed in each photo using the Central Line Insertion Site Assessment (CLISA) score (Table 1) by trained research staff, with two-physician review. A convolutional neural network model was trained de novo from random weights (binary cross-entropy loss) to predict binarized CLISA score, defined as normal/low risk (non-actionable) scores of 0 or 1 vs high risk (actionable) score of 2 or 3. Five-fold cross-validation estimated model performance for accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve receiver operating characteristic (AUC/ROC) with 95% confidence intervals. Results: Among 5,551 photographs of 964 CVCs in 874 adults, there were 1,191 (21%) photos from hospitalized patients, 2,539 (46%) from outpatient oncology patients, and 1,821 (33%) from nursing home residents. Mean (SD) age was 60 (17), 54% were male, and 183 (21%) patients had darker skin tones (Fitzpatrick skin type IV-VI), Table 2. Among all photos, 1,585 (29%) had localized inflammation/infection (CLISA 2 or 3) and 298 (0.1%) had purulence. Compared to gold standard clinician assessment, AI model performance optimized for accuracy was able to distinguish between normal/low risk (CLISA 0-1) and inflamed/infected catheters (CLISA 2 or 3): accuracy 0.82, sensitivity 0.52, specificity 0.94, PPV 0.83, NPV 0.78, AUC 0.87 (95% CI 0.86-0.88); results were similar for models detecting purulence, Figure 1A-B. Conclusion: AI algorithms can identify CVCs with photographic signs of inflammation or infection and signal the need for intervention to prevent CLABSI. AI-autodetection of high-risk catheters can extend hospital CLABSI prevention to settings with limited monitoring, using photographs alone and minimizing reliance on patient self-assessment or care escalation.

Background: Microbiome restoration through fecal microbiota transplantation (FMT) is a promising decolonization strategy that reduces multidrug-resistant organism (MDRO) colonization and infection. However, the strains mediating MDRO decolonization remain poorly defined, and long-term follow-up (LTF) data after FMT for MDRO decolonization are limited. We enrolled participants from a completed randomized trial of FMT for MDRO decolonization (PREMIX, NCT02922816) into an LTF study to characterize long-term engraftment dynamics of donor-derived anaerobic taxa and their association with sustained MDRO decolonization. Methods: Participants provided stool samples every six months for up to five years following completion of the trial. Samples underwent selective culturing for MDROs using chromogenic agars, with organism identification and susceptibility confirmation by MALDI-TOF and Vitek2. MDRO isolates underwent whole-genome sequencing (WGS), and stool samples underwent metagenomic sequencing. To determine similarity between baseline and LTF MDROs, pairwise comparison of baseline and LTF MDRO isolates was performed with a unique strain defined as < 99.5% average nucleotide identify difference (ANI) to other strains. To determine engraftment of donor derived anaerobic taxa construction of metagenome-assembled genomes (MAG) from donor and participants samples was performed. Donor MAGs detected at <50% breadth in LTF metagenome samples were compared to corresponding species-level MAGs from participant LTF samples, with unique MAGs defined as <99.5% ANI like strains above Results Six PREMIX participants were enrolled to the LTF study, five of whom received FMT and one control. 80% (4/5) of FMT treated patients have remained decolonized (culture negative) while 0% (0/1) of control patients have remained decolonized at most recent follow up (median[IQR] 3.6 [3.4,4.0] years). The single FMT-treated participant with MDRO detection in LTF samples had evidence of a new acquisition compared to the baseline MDRO, whereas the MDRO detected in the control participant was identical to the baseline strain based on ANI cut offs. Among FMT-treated participants, metagenomic analysis demonstrated persistent detection of donor-derived anaerobic strains at <50% breadth, with high ANI between donor MAGs and participant LTF MAGs for multiple key taxa, including Acetatifactor sp., Akkermansia muciniphila, Alistipes putredinis, Barnesiella intestinihominis, Eubacterium siraeum, Mesosutterella massiliensis, Odoribacter splanchnicus, and Phascolarctobacterium faecium, consistent with long-term engraftment (Figure 1). No donor-derived MAGs were detected in control participants at <99.5% ANI. Conclusions: FMT was associated with long-term durable decolonization potentially mediated by the engraftment and persistence of key donor derived anaerobic strains. Our findings of persistence of discrete taxa highlights the potential for developing rationally constructed strain-based microbiome therapeutics for decolonization and infection prevention.

Background: Social deprivation may affect both infection severity and the quality of antibiotic prescribing, but its influence on downstream outcomes and the role of stewardship processes in this pathway remain uncertain. Methods: We conducted a retrospective cohort study of 1,365,957 emergency department (ED) encounters among older adults across multiple U.S. hospitals, 2013–2022. We assessed the impact of community social deprivation on clinical outcomes and identified mediation through antibiotic prescribing (guideline-concordant empiric use). Social deprivation was quantified using a z-scored Social Deprivation Index (SDI). Outcomes were log-transformed length of stay (LOS), 30-day ED revisit, 30-day mortality, 30-day C. difficile infection, and DOOR (Desirability of Outcome Ranking; 1=alive with LOS at or below the median and no 30-day events, 2=alive with LOS above the median and no events, 3=30-day ED revisit, 4<=i>C. difficile infection, 5=death). We fitted multivariable ordinary least squares models with state- and month-fixed effects and clustered standard errors, controlling for demographics, comorbidities, clinical severity, travel time, hospital characteristics, and rurality. We applied regression-based mediation analysis to partition the SDI–outcome relationship into direct effects and indirect effects mediated by prescribing concordance. Secondary models substituted antibiotic overuse or underuse for concordance. Results: Concordant prescribing occurred in 83% of encounters; overuse and underuse occurred in 9.5% and 7.4%, respectively. Higher SDI was associated with slightly worse outcomes: each 1-SD increase corresponded to modestly longer LOS, higher risk of 30-day ED revisit and mortality, and worse DOOR scores, with minimal association with C. difficile infection (Figure 1). Concordance was strongly associated with better outcomes, including shorter LOS, fewer ED revisits, lower mortality, and lower DOOR scores. Mediation analyses (Figure 2) indicated that concordance explained about 11% of the SDI–LOS association and <5% of the associations with ED revisit, mortality, and DOOR. In secondary models (Figure 3), overuse was consistently associated with worse outcomes—longer LOS, higher mortality, and higher DOOR scores—independent of SDI. Underuse showed inverse associations with LOS and DOOR but only tiny, clinically negligible increases in ED revisit and mortality, patterns likely reflecting residual confounding and selection of lower-acuity patients. Conclusion: We found that social deprivation was associated with worse health outcomes, with antibiotic concordance serving as a partial pathway linking deprivation to harm. Stewardship efforts that improve concordance and curb overuse—particularly in socially deprived communities—may help reduce outcome disparities without encouraging under-treatment.

Background: The National Healthcare Safety Network Antimicrobial Resistance Option (NHSN AR) is the nation’s primary tracking system for antimicrobial resistance. As of December 2025, 89% of Washington (WA) acute care hospitals are reporting antimicrobial susceptibility data to the AR option. The AR option provides a feature to generate antibiograms, a clinical tool to guide empiric antibiotic selection. However, the NHSN generated antibiograms do not adhere to the Clinical and Laboratory Standards Institute’s widely used M39 (CLSI M39) guidelines, which are best practices for antibiogram creation. Due to concerns of limited clinical applicability, we sought to create a CLSIM39 compliant antibiogram dashboard using NHSN AR data to support hospitals to make informed clinical decisions and track local resistance data. Methods: We downloaded the line list for All Antimicrobial Resistance Events from NHSN, transformed the data in R, and imported it into PowerBI to generate interactive antibiogram reports. The initial dashboard focused on the most commonly reported Gram-negative pathogens in WA: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa. We included isolates from blood, cerebrospinal fluid, lower respiratory tract, skin and soft tissue, wound, musculoskeletal, and urine specimens. Following CLSI M39 guidelines, we retained only the first isolate per organism per patient per calendar year. For specimen-specific reporting, we applied specimen filters by source prior to isolate selection. We selected antimicrobials and final susceptibility interpretations to calculate percent susceptible based on CLSIM39 and M100 guidelines. We suppressed organism-agent combinations with fewer than 30 isolates tested or lack of clinical relevance. To improve interpretability, we included the median and range of isolates tested for each organism. Three antibiograms were available: all-specimen sources, blood only, and urine only. To ensure data security, we assigned hospital alias codes and hosted the dashboard on a secure PowerBI platform. Results: WA DOH launched the NHSN AR Antibiogram Dashboard in December 2025. The dashboard displays susceptibility data based on analysis of 209,836 isolates collected between 1/1/2020 and 11/30/2025. We generated 74 all-specimen, 43 blood, and 74 urine-specific facility antibiograms. Currently, 93 antimicrobial stewards representing 80 hospitals have dashboard access, enabling them to track antimicrobial resistance trends year-to-year and compare resistance patterns by specimen source. Conclusion: The dashboard equips antimicrobial stewards with actionable data to monitor local resistance trends and inform facility-specific antimicrobial use guidelines. We plan to expand the dashboard to include additional organisms and specimen-specific reports.

Background: Intravenous penicillin G is the preferred first-line agent for intrapartum Group B streptococcus prophylaxis; however, many pregnant patients carry unverified penicillin allergy labels. Although approximately 10% of the general population reports a penicillin allergy, only about 1% have a true allergy, and these inaccurate labels often lead to unnecessary use of broader-spectrum antibiotics, highlighting the need for improved allergy verification and de-labeling in obstetric care. Methods: A retrospective chart review was conducted from January 2022 to December 2024 evaluating documented penicillin allergies in pregnant patients who received care and delivered within a state-wide health system. Patients were excluded if they had a penicillin allergy documented during or after the encounter, or if the allergy was identified as an erroneous entry. A study-specific allergy risk assessment was used to stratify patients into no allergy, low risk, moderate-to-high risk, and severe risk categories, using a conservative approach as the true severity of historical reactions could not be definitively verified through retrospective chart review alone. Patients categorized as no allergy were considered eligible for de-labeling. Results: Of 303 birth encounters screened, 285 met inclusion criteria; ten patients with previously removed penicillin allergy labels were excluded from the primary outcome analysis. Among the remaining included encounters, 51 patients (18.5%) were identified as eligible for penicillin allergy de-labeling based on chart review alone. Eligibility was driven by documentation consistent with non-allergic reactions, including intolerance symptoms (5.8%), history of prior penicillin tolerance (10.5%), and reported familial allergy without personal reaction history (2.2%). Referral patterns for allergy evaluation were assessed to identify additional de-labeling opportunities. Only 12 patients were referred to an allergist during pregnancy; however, 11 of these patients underwent penicillin challenge testing and were successfully de-labeled. The high success rate among referred patients highlights frequent mislabeling of penicillin allergies and suggests substantial missed opportunities for broader de-labeling in the obstetric population. Conclusion: Nearly one in five pregnant patients (18.5%) with documented penicillin allergies were eligible for de-labeling based on chart review alone. Low referral rates for allergy evaluation also indicate significant opportunities to expand penicillin allergy testing in obstetric care, further improving antibiotic selection and antimicrobial stewardship.

Background: Pediatric solid organ transplant recipients receive broad-spectrum antibiotics. The CDC NHSN Antimicrobial Use and Resistance (AUR) Module reports days of therapy (DOT) by pediatric Standardized Antimicrobial Administration Ratio (SAAR) categories, but those unit-level summaries do not identify the contexts that drive broad-spectrum DOT. We used a procedure-anchored framework to quantify post-prophylaxis broad-spectrum exposure and attribute it to blood-culture evaluation, surgical site infection (SSI), and subsequent procedures. Methods: We analyzed 164 pediatric transplant procedures (heart 59, liver 58, kidney 29, intestinal 8, multivisceral 10) with follow-up through postoperative day (POD) 365. Medication administration records were linked to procedures and transformed into an agent-day dataset with POD assignment. Organ-specific protocols defined a prophylaxis-window end day; post-prophylaxis analyses included antibiotic-days when POD exceeded end day. Broad-spectrum categories included Ped_SAAR_BSHO plus HighestRisk [Ped_SAAR_XDR (extensively drug-resistant) plus carbapenems]. SSI was chart-reviewed. A hierarchy assigned each post-prophylaxis broad-spectrum agent-day a primary context (culture, SSI, subsequent procedure, or residual unclassified). Antibiotic episodes (courses) used a locked gap rule (split if exposed-day gap ?3 days) and were linked to culture-days, SSIs or subsequent procedures to classify episode outcomes. Results: Over POD 0–365, patients contributed 10,064 hospital-days and received 9,774 antibacterial DOT (971.2/1,000 hospital-days); Ped_BSHO contributed 2,529 DOT (251.3/1,000 hospital-days). Ped_BSHO rates varied by organ (DOT/1,000 hospital-days: 76.3 heart, 273.0 liver, 105.4 kidney, 355.5 intestinal, 494.2 multivisceral). Following completion of index procedure prophylaxis, broad-spectrum exposure totaled 2,379 DOT-days; HighestRisk accounted for 667 DOT-days (435 multivisceral). Primary attribution classified post-prophylaxis broad-spectrum DOT-days as unclassified (982; 41.3%) or blood-culture rule-out (979; 41.1%); SSI treatment windows contributed 215 DOT-days (9.0%), and subsequent procedures contributed 66 DOT-days (2.8%). Unclassified DOT was concentrated (top 10 patients 64.8%) and occurred largely in intensive care units; piperacillin–tazobactam and meropenem predominated, and 24.5% of unclassified DOT-days were HighestRisk. From 1,390 blood culture accessions we defined 1119 sets, of which 94.7% (n=1060) were no growth, 3.4% (n=38) positive and 0.5% (n=6) contaminant. In the episode-based analysis, antibiotic courses that overlapped a blood-culture day were usually rule-out rather than culture-confirmed, and rule-out episodes contributed substantially more antibiotic burden than culture-positive episodes (DOT 1,510 vs 248). Culture intensity was high in multivisceral/intestinal PICU patients and PCICU heart patients. Conclusions: After prophylaxis ends, broad-spectrum exposure is dominated by evaluation-driven care and a large residual unclassified burden, while SSI-associated exposure remains a smaller, safety-anchored signal. This procedure-anchored, episode-based framework quantifies organ-specific burden and prioritizes targets for paired diagnostic and antibiotic stewardship.

Introduction: Clinicians often order a variety of tests for hospitalized patients, including urinalysis with urine cultures. However, fever has limited diagnostic value for urinary tract infection (UTI); pooled estimates indicate that fever has likelihood ratios near 1, offering minimal discriminatory value for ruling UTI in or out. We evaluated the diagnostic yield of inpatient urine cultures by fever status in an acute care safety-net hospital in Denver, Colorado. Methods: We analyzed inpatient urine culture events from April 2016 through December 2025 using an automated electronic medical record report. Fever was captured within the National Healthcare Safety Network (NHSN) infection window period (+/- 3 calendar days). Culture positivity was defined per NHSN UTI criteria as ?10 colony forming units of one or two organisms; cultures with no growth or reported as yeast/Candida spp. or mixed flora were classified as negative. Antibiotic exposure was extracted from medications given up to 3 days after culture collection, and urinary infection-related diagnoses from problem/diagnosis entries up to 7 days after culture collection. To scale adjudication, we used deterministic text classification of medication and diagnosis fields. Medication strings were normalized and parsed with regular expressions to extract generic drug names (token preceding dose/formulation), then matched to a curated antibiotic dictionary. Urinary diagnoses were identified by regular-expression matching to UTI-related terms (e.g., UTI/urinary tract infection, cystitis, pyelonephritis, urosepsis). Results: Across 17,629 inpatient urine cultures, fever within the NHSN infection window period was documented in 37.1% of episodes and UTI diagnoses were documented in 29.6%. Overall, 7,983 cultures (42.1%) were positive for a bacterial pathogen, and antibiotics were prescribed in 77.8% of episodes. Culture positivity was similar to, or higher than, that among afebrile vs febrile episodes (44.1% vs 38.8%) and was higher with documented UTI diagnoses (58.5% vs 35.2% without). Culture positivity varied by strata: UTI diagnoses were more common among culture-positive episodes (60.9% with fever; 57.1% without fever), while febrile episodes without UTI diagnoses had the lowest positivity (29.4%) (Figure 1). Antibiotic exposure remained common across the fever–culture result combinations, including 22.5% of all episodes occurring in afebrile, culture-negative patients who nevertheless received antibiotics and 18.9% in febrile, culture-negative patients who received antibiotics (Figure 2). Conclusion: Fever was not reliably associated with urine culture positivity, whereas UTI diagnosis (clinical suspicion) was. Antibiotic use remained common after negative urine cultures, supporting opportunities to refine inpatient urine culture ordering and antimicrobial stewardship.

Background: Hospital acquired infections are known to increase hospital stays and increase morbidity and mortality. Historically, Methicillin-resistance Staphylococcus aureus (MRSA) screening and contact precautions have been the primary strategy to prevent the spread of MRSA in healthcare systems. Increasing evidence supports the role for MRSA decolonization to decrease the spread of this important pathogen. The COVID-19 pandemic and related personal protective equipment conservation has led to many programs re-examining contact precautions for MRSA. Methods: In February of 2024 MRSA screening was discontinued for new admissions and an MRSA decolonization protocol was implemented for patients at high risk for MRSA infection as defined in the SHEA compendium for reducing MRSA infections. Decolonization included nasal Mupirocin 2% ointment and 2% Chlorhexidine Gluconate (CHG) bathing for five days in the adult inpatient population. High risk patients targeted for this intervention included patients transferred from another healthcare facility, admitted from home health, on dialysis, prior history of MRSA infection or those with central venous catheters. Contact isolation precautions for MRSA colonization were discontinued but maintained for active infection with MRSA. Results: After implementation, MRSA nares screening tests declined by 24.4% while utilization of mupirocin increased 5.85 times the pre-implementation average. In the twelve months prior to the intervention there were 221.1 new MRSA infections per 1000 inpatient admissions and in the 12 months following intervention there were 155.4 new MRSA infections per 1000 inpatient admissions. The rate of MRSA infections had been increasing prior to intervention and the rate of increase decreased by 54.8% after implementation. We estimated a cost savings of $194,745 if all patients that were previously screened were instead decolonized. We additionally noted an approximate 18% reduction in isolation gown use resulting an additional estimated annual cost savings of $115,369 per year if sustained. Conclusions: The implementation of a MRSA decolonization program resulted in significant cost savings without any associated increase in clinical MRSA cultures. The program appeared to have far greater buy-in than the previous screen and isolate program despite having similar patient selection criteria. This may reflect a greater perceived importance of screening relative to a treatment strategy. A decolonization strategy was found to be effective at decreasing the rate of new MRSA infections even with the removal of isolation precautions for colonization. Low compliance with isolation precautions for colonization are thought to be a contributing factor in the limited efficacy of a screen and isolate strategy.

Background: Staphylococcus aureus (SA) is a leading cause of infection-related mortality worldwide and remains one of the most common pathogens in healthcare settings, particularly methicillin-resistant SA (MRSA). Approximately 30% of patients are colonized with SA in the nares, and these asymptomatic carriers serve as a reservoir for invasive infections, including bloodstream infections, pneumonia, and surgical site infections. Targeted strategies, such as nasal decolonization, are essential to reduce colonization and prevent subsequent infection. We evaluated the impact of SA nasal decolonization on overall SA infection rates and healthcare facility-onset (HO) MRSA bacteremia, a laboratory-identified (LabID) event. Methods: In this pre–post quasi-experimental retrospective study, we compared overall SA, MRSA, and methicillin-susceptible SA (MSSA) infection rates per 1,000 patient days and the HO-MRSA bacteremia Standardized Infection Ratio (SIR) between the preintervention period (January 2020–June 2021) and the intervention period (October 2023–September 2025) at a 5-hospital healthcare system in Michigan. HO-MRSA bacteremia was determined using National Healthcare Safety Network (NHSN) criteria. SA infections included positive clinical cultures in hospitalized patients. Previously, our protocol consisted of daily chlorhexidine (CHG) bathing only, and HO-MRSA bacteremia SIR remained above goal. In a two-phased approach, we implemented nasal decolonization with an alcohol-based nasal antiseptic twice daily in addition to CHG for all ICU patients in August 2021, followed by all general practice unit patients with central lines in August 2023. Results: Following implementation, the cumulative HO-MRSA bacteremia SIR decreased 50% from 1.148 to 0.571 (95% CI, 0.336–0.73; p. Conclusion: Adding nasal decolonization to daily CHG bathing significantly reduced SA infection rates and HO-MRSA bacteremia. These findings confirm the effectiveness of a bundled decolonization strategy in mitigating both MRSA and MSSA infections. Broader adoption of nasal antiseptic protocols, alongside CHG bathing, should be considered a critical component of infection prevention strategy for high-risk hospital populations.

Background: During the 2024 national shortage of BD BACTEC blood culture bottles, many hospitals implemented ordering restrictions to conserve supplies. While prior studies have evaluated overall blood culture utilization and patient outcomes, less is known about how such restrictions affected the observed epidemiology of bloodstream infections (BSIs) across organism groups. Understanding these effects is important for interpreting surveillance data and anticipating downstream clinical implications during diagnostic supply disruptions. Methods: We conducted an interrupted time series analysis of BSI episodes at two tertiary-care hospitals from June 26, 2023 through June 25, 2025. A systemwide electronic order restriction implemented from June 26, 2024 through December 23, 2024 limited clinicians to one blood culture set per patient every 24 hours. We grouped blood culture results into episodes and categorized by organism group. Outcomes included organism group-specific episode incidence, hospital outcomes (e.g., in-hospital mortality/hospice discharge), and blood culture utilization. We used segmented regression models with Newey-West standard errors to estimate level and slope changes associated with restriction onset and withdrawal. Results: We identified 5,391 BSI episodes among 4,484 patients, with baseline characteristics stable across study periods (Table 1). Organism group incidence, hospital outcomes, and blood culture utilization varied by period (Table 2). During the restriction period, the relative incidence of enterococci, fungi, gram negative rods, and Staphylococcus aureus/lugdunensis increased, while anaerobes, streptococci, coagulase-negative staphylococci/common commensals, and polymicrobial infections decreased (Figure 1). Interrupted time series analyses demonstrated an overall decrease in BSI incidence during the restriction, with declines for gram negative rods, streptococci, coagulase-negative staphylococci/common commensals, and polymicrobial infections (Figure 2). We observed statistical significance only for a 51.7% decrease in streptococci incidence upon restriction onset (P=.04) and a 3.5% per month decrease in gram negative rod incidence during restriction (P=.02) (Table 3). Estimates for other organism groups were limited by small numbers of observations, resulting in imprecise effect estimates or potentially artifactual findings. Conclusions Single-set blood culture restriction during the 2024 national supply shortage was associated with changes in the observed epidemiology of BSIs, including an overall decrease in incidence and heterogeneous effects across organism groups. Although interrupted time series analyses for several groups were limited by low power, combined visual and quantitative findings suggest that restrictive diagnostic practices may differentially affect BSI detection by organism type. These findings underscore the need for cautious interpretation of surveillance data during diagnostic disruptions and highlight the importance of resilient diagnostic supply chains and evidence-based mitigation strategies.

Background: Clostridioides difficile infection (CDI) remains a leading healthcare-associated infection (HAI) in the United States. To prevent outbreaks and transmission within healthcare facilities, providers must quickly recognize signs of CDI, correctly diagnose it, and implement measures to contain it. Nucleic acid amplification tests (NAATs) are highly sensitive but may over diagnose CDI, while toxin enzyme immunoassays (EIAs) risk false negatives. Two-step diagnostic algorithms have been recommended to improve diagnostic accuracy; however, national trends in their adoption have not been well described. Method: We conducted a secondary analysis of data from the Preventing Infections Through Appropriate Staffing (PITAS) study, which includes annual National Healthcare Safety Network (NHSN) hospital survey data from 347 U.S. acute-care hospitals from 2011-2024. Hospitals reported CDI testing methods annually, which were categorized as one-step, two-step, or other algorithms. Temporal trends in two-step testing adoption were assessed using mixed-effects linear regression with hospital as a random effect and adjustment for bed size and academic affiliation. Stratified analyses were performed by hospital size and academic status. Result: A total of 347 acute care hospitals contributed data from 2011-2024. In 2012, the predominant testing method was NAAT alone, which was utilized by 58% of hospitals while only 6.25% of hospitals utilized two-step methodologies. In 2017, the year of publication of the updated Infectious Disease Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) Clinical Practice Guidelines, 28.75% of hospitals used two-step methods. By 2024, 66.18% of surveyed hospitals utilized two-step methodologies for CDI. Academic hospitals consistently demonstrated higher adoption rates than non-academic hospitals (11.11% vs 2.92% in 2012 and 67.35% vs 59.18% in 2024). Hospitals with 501-1000 beds had significantly higher odds of adopting two-step testing compared with the smallest hospitals. Conclusion: Use of two-step CDI testing methods increased substantially in U.S. acute-care hospitals from 2011- 2024, particularly following the 2017 IDSA and SHEA guideline update. As hospitals increasingly adopt two-step testing, policymakers and healthcare epidemiologists should consider how testing methods influence reported infection rates.

Background: Over-utilization and inappropriate interpretation of urinalyses and urine dipsticks drives unnecessary urine cultures, leading to unnecessary treatment of asymptomatic bacteriuria (ASB), avoidable antibiotic associated adverse drug effects, and risk of antimicrobial resistance. The urinalysis with reflex order set (UA w/ reflex) is a stewardship intervention to reduce unnecessary cultures. Providers can elect to bypass the reflex criteria by selecting specific clinical indications (e.g., pregnancy) to culture urine regardless of urinalysis results. We aimed to assess the appropriateness of provider bypass selection and the effect on appropriate antibiotic prescribing for urinary tract infections (UTIs). Methods: From a dataset of adult outpatient encounters in which the UA w/ reflex order set was used at Vanderbilt University Medical Center (VUMC) between June 1, 2022 and June 30, 2024, 120 patients were randomly selected for review as part of an ongoing study. Of those, patients <16 years of age, hospitalized within 2 days of UA, with delay of UA acquisition, or with incomplete encounter documentation were excluded (N=20). Patient and provider demographics, patient symptoms, physical exam findings, urine diagnostic testing, and antibiotics prescribed were extracted from the electronic medical record (EMR) and via manual chart review and analyzed. Results: Of the 100 included patients, the average age was 48.9 years and 64% were female. Of the 32 (32%) who received antibiotics, 24 (75%) had a possible UTI or indication for treatment of ASB (“appropriate”), and 8 (25%) had nonspecific or no symptoms (“inappropriate”). Among 13 patient encounters which inappropriately bypassed the reflex criteria, 1 (14%) received “inappropriate” antibiotics compared to 2 (33%) who received “appropriate” antibiotics (p = 0.559), see Table 1. Among those where the culture reflexed per protocol (n = 59), 45 had non-specific or no symptoms (76%) and 41 (91%) did not receive unnecessary antibiotics (p<0.0001). This difference was not seen in bypass appropriate or bypass inappropriate groups (p=1.00 and p=0.559 respectively), see Table 1. Conclusions: In this preliminary analysis, we observed high (~1/3) rates of inaccurate selection of bypass criteria; however, this was not associated with increased inappropriate antibiotic prescribing, which may have been due to the small sample size. Antibiotic prescribing was lowest when the reflex order was used appropriately. Additionally, high rates of orders without UTI symptoms were noted, suggesting potential diagnostic mis-stewardship. Behavioral drivers and clinical triggers for ordering UA w/ reflex need to be better understood to target reducing inappropriate testing.

Background: Previously published data demonstrate the need to improve education and training of healthcare workers in antimicrobial stewardship (AMS). The aim of this evaluation was to explore the perceptions of healthcare workers from across the globe concerning various components of AMS training courses including technical content. Methods: This was an electronic cross-sectional survey sent to a convenience sample of 238 healthcare workers with expertise in infectious diseases (ID) and AMS from October to November 2025. Respondent demographic data, assessment of various components of AMS training courses using a 4-point Likert scale (Not Important, Somewhat Important, Important, Very Important), and ranking of AMS course content (1=most important to 9=least important) were collected. Descriptive analyses were used. Results: A total of 57 healthcare workers responded (24% response rate) including 32 physicians (58.2%) and 12 pharmacists (21.8%), mostly working in academic hospitals (73.2%) [Table 1]. The majority of respondents were aged 41-60 years (53.6%), and currently practicing in South America (31.5%), North America (24.5%), and South Asia (12.2%). The AMS course characteristics deemed very important by the majority of respondents included: free/low cost (69.5%), goals and aims described (66.1%), certificate of completion (64.3%), regularly updated materials addressing emerging issues in infectious diseases (63.6%), antimicrobial resistance specific to respondent’s country or community(62.5%), examples of implementation in the respondent’s specific geographical region (60.7%), no expiration on access to course content (58.2%), and appropriate time commitment (53.6%) [Table 2]. The course content topics identified as most important were AMS program fundamentals (45.5%) and application/implementation (34.5%), whereas ID basics (16.4%) was most frequently reported as least important. Conclusion: These data support the need for multi-faceted AMS training courses as most assessed components were identified as “important” or “very important” by this cohort of respondents. It also provides insights on what characteristics of a global AMS training course should be prioritized.

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: vSNFs are known reservoirs of MDROs. However, data are lacking on how MDRO carriage may differ between residents in ventilator-capable (vBed) and non-ventilator-capable (non-vBed) areas within vSNFs. Methods: We conducted two point-prevalence MDRO sweeps in two vSNFs (Facility A: 44 vBeds/55 non-vBeds; Facility B: 31 vBeds/167 non-vBeds) from May-June 2025. All occupied beds were sampled except for Facility B’s non-vBeds which randomly sampled 50 beds due to size. Sampling involved hands, axilla/groin and peri-rectal areas cultured for MRSA, ESBL, VRE, C. auris, CRAB, and CRE, plus bilateral nares swabs cultured for MRSA and C. auris. Descriptive statistics summarized overall and MDRO-specific prevalence across body sites, with differences between vBed and non-vBed residents evaluated using t-tests and chi-square tests. Results: Overall MDRO prevalence was higher in vBeds (83.9%, 115/137) than non-vBeds (73.2%, 145/198; p=0.029) although the rank order of carriage was similar: MRSA > ESBL > VRE > C. auris > CRAB > CRE. vBed residents had significantly higher prevalence for all pathogens except MRSA (Figure). Multi-MDRO burden was greater in vBeds (mean 2.3 MDROs/resident) than non-vBeds (1.3; p<0.001); vBeds had a substantially higher likelihood of carrying ≥3 (46.0% vs 13.6%; p<0.001), ≥4 (24.1% vs 4.0%; p<0.001), or ≥5 MDROs (10.9% vs 1.0%; p<0.001). Emerging MDROs (CRE, CRAB, C. auris) were more prevalent in vBeds (43.1% vs. 19.7%; p<0.001), and were highly associated with endemic MDRO co-carriage (98.3% [58/59] vBeds; 97.4% [38/39] non?vBeds). The mean number of positive body sites was higher in vBeds (2.4 vs 2.0; p=0.003), with a higher likelihood of being positive at ≥2 sites (73.0% vs 59.6%; p=0.009), ≥3 sites (51.1% vs 39.4%; p=0.017), or 4 sites (35.0% vs 23.7%; p=0.010). vBed residents were more likely to have axilla/groin carriage (79.6% vs 58.1%; p<0.001) with non-significantly higher carriage at other sites (Figure). Nasal carriage patterns differed by organism: MRSA prevalence was similar between vBed and non?vBed residents (29.2% vs 32.8%; p=0.559), whereas C. auris was markedly higher in vBeds (29.2% vs 4.0%; p<0.001). Conclusion: Carriage of both endemic and emerging MDROs is widespread in vSNFs, affecting ~75% of residents regardless of ventilator status. However, vBed occupants were more likely to harbor an MDRO, and more likely to harbor multiple MDROs at multiple body sites. Emerging pathogens were also more common in vBed occupants, and were almost always associated with co-carriage of endemic MDROs. Guidance is needed for comprehensive MDRO response in vSNFs.

Background: vSNFs are known for exceedingly high MDRO prevalence, raising questions about the role of environmental contamination and persistence in this healthcare setting. Methods: Environmental sampling was conducted May-June 2025 in two vSNFs. High-touch objects in common areas (mobile/shower equipment, staff breakrooms, dining rooms, rehabilitation gyms) and resident rooms were swabbed using spongesicles, homogenized in trypticase soy broth, incubated 18-24 hours, and cultured for MRSA, VRE, ESBL, C. auris, CRAB, and CRE. On the same day, resident carriage of the same organisms was assessed at nares, hands, axilla/groin, and peri?rectal sites. All ventilator-capable (vBed) and non-vBed occupied beds were sampled except for one facility’s non-vBeds, which randomly sampled 50 beds due to size. The proportion of positive common area objects was compared with MDRO carriage prevalence using two-sample tests of proportions. Within resident rooms, object contamination was compared among carriers and non-carriers for each pathogen, overall and stratified by vBed status, using Fisher’s exact tests. Results: Sampling included 96 common area objects and 245 objects from 39 resident rooms (20 vBed, 19 non-vBed). MDRO contamination of high-touch objects in common areas was extensive (73.9%), including 77.8% of mobile equipment and 58.3% of common area objects (37.5% staff breakroom, 87.5% rehabilitation gym, 50.0% dining objects). The most frequently detected MDROs on objects were MRSA>CRAB>VRE>ESBL>C. auris>CRE, which differed from the sequence of MDRO carriage among residents: MRSA>ESBL>VRE>C. auris>CRAB>CRE. Object contamination and resident carriage were similar for MRSA (65.6% vs. 60.5%, p=0.43), VRE (19.8% vs. 23.3%, p=0.54), and CRE (1.0% vs. 4.1%, p=0.27). In contrast, contamination was markedly lower than carriage for ESBL (8.3% vs. 43.6%, p<0.001) and C. auris (3.1% vs. 25.6%, p<0.001), while CRAB contamination far exceeded carriage (21.9% vs. 11.0%, p=0.02) (Figure 1). Among bedrooms, all sampled rooms had some MDRO contamination, including all rooms of non-carriers. MRSA contamination was similar in the rooms of carriers and non-carriers; all other pathogens, contamination was substantially greater in rooms of carriers (Figure 2). Conclusions: The relationship between MDRO contamination and resident carriage in vSNFs showed clear pathogen?specific patterns. MRSA and VRE contamination closely mirrored resident carriage, whereas ESBL and C. auris were less frequent on surfaces despite high carriage. Notably, CRAB was disproportionately common in the environment, suggesting environmental persistence. Bedrooms of carriers had higher contamination, yet MDROs were also present in non-carrier rooms, contributing to ongoing transmission risk. Effective containment likely requires universal strategies supplemented by targeted, pathogen-specific efforts.

Background: Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales are antimicrobial resistant pathogens which cause difficult-to-treat infections. In April 2025, Hospital A notified the Indiana Department of Health about an outbreak of ESBL-Klebsiella pneumoniae. CDC assisted with identifying the sources of the outbreak and recommending control measures. Methods: We defined confirmed cases as ESBL-producing K. pneumoniae multi-locus sequence type (ST) 661 (or closely related ST) by whole genome sequencing (WGS). Suspect cases included 3rd- and 4th-generation cephalosporin-resistant K. pneumoniae without WGS data. All isolates originated from patient cultures collected on or after January 1, 2025, from Hospital A’s network of hospitals and outpatient clinics. An incident case was the first case identified from a patient. Among confirmed incident cases, we abstracted medical charts for 30 randomly selected patients. We assessed infection prevention and control (IPC) practices and sampled the hospital environment to identify potential reservoirs. Results: We identified 70 confirmed and 52 suspect incident cases between January and September. Median patient age was 70 years (range: 19–91 years); 67 (55%) were female. Within 90 days before incident case collection, 28 of the patients with charts abstracted (93%) received care at Hospital A; 27 (90%) received radiologic imaging, mostly CT scans (17/30; 57%) and transthoracic echocardiograms (16/30; 53%). We observed gaps in hand hygiene, personal protective equipment usage, and environmental cleaning. ESBL-K. pneumoniae was recovered from 23 environmental samples, including radiology equipment. WGS revealed that these isolates clustered with patient isolates, showing 0-26 pairwise high-quality single nucleotide variants across a 95.73% core genome. Following the implementation of IPC recommendations, the average number of monthly cases was 21% lower compared to the 9 months prior. Conclusions: Our investigation linked the outbreak to gaps in IPC practices and contamination of the healthcare environment, highlighting the often-overlooked role of the environment in the spread of ESBL-producing pathogens.

Background: Effective infection prevention and control (IPC) strategies are essential for reducing the risk of transmission of infection in healthcare settings. Traditionally, implementation and discontinuation of transmission-based precautions (TBP) have relied on manual review by infection preventionists (IPs) or physicians with IPC expertise. During the COVID-19 pandemic, rapidly evolving protocols and surges in patient volume strained IPC teams, highlighting the need for scalable, automated IPC workflows. Many healthcare systems have adopted clinical decision support systems (CDSS) built into the electronic health record to support non-IPC workflows; however, the extent of CDSS use for IPC is not known.? Methods: We conducted this national survey of healthcare facilities within the SHEA Research Network to broadly assess CDSS use in IPC, identify automated features, and define barriers to implementation. The survey captured IPC tasks supported by CDSS, including initiation and discontinuation of TBP and perceived impact of CDSS on clinical and operational outcomes. To enable cross-institutional comparisons, we defined an “IPC Automation Index” (IAI) score as the number of automated IPC functions at a facility across 7 core tasks assessed. Results: Fifty facilities completed the survey (42% response rate); of these, 42 (84%) reported using a CDSS tool for IPC. Although most used multiple CDSS tools for IPC, automation was largely concentrated at the front-end of workflows, particularly for automated initiation of TBP. In contrast, automated discontinuation of TBP was uncommon, with the majority of facilities relying on manual review. Over 55% of facilities had an IAI score of at least 2, indicating at least 2 fully automated IPC functions by CDSS (Figure A). Automation feature combinations varied widely, with 31 distinct configurations observed among 42 facilities and no dominant combination observed. Facilities with higher IAI scores were more likely to report perceived reductions in workload and cognitive burden among IPs. Finally, the most frequently reported barriers to CDSS adoption included personnel constraints (~45%), challenges integrating CDSS into the EHR (~43%), and financial limitations (~36%). Conclusions: This study provides the first national assessment of CDSS use for IPC, highlighting current practices, key barriers to adoption, and opportunities. We propose a CDSS automation model that conceptualizes IPC workflows along a continuum of low-to-high automation (Figure B). Anchored by the IAI score, this framework enables comparisons of CDSS use for IPC across healthcare facilities and highlights opportunities to advance CDSS adoption for IPC.

Background: Staphylococcus aureus is a leading cause of healthcare-associated infections and is associated with high mortality. While decolonization has been effective in reducing methicillin-resistant S. aureus (MRSA) infections in adult and neonatal intensive care units (NICUs), little is known about the impact of decolonization on transmission of S. aureus. Here, we evaluated whether weekly screening and targeted decolonization reduce genomically defined transmission of S. aureus in a NICU. Methods: Infants admitted in 2022-2024 to the NICU at Tisch Hospital received weekly screening cultures of the nares, axilla and groin for MRSA and methicillin-susceptible S. aureus (MSSA). Colonized infants received topical decolonization with chlorhexidine 2% bathing and nasal, buttock, and umbilical mupirocin, with frequency and duration of decolonization based on postmenstrual age (gestational plus chronological age). Genome sequencing was used to identify transmission events, defined as genetically linked S. aureus isolates with <20 single nucleotide variants identified in two infants with overlapping stays. Transmission risk was analyzed using time-to-event (TTE) analyses, and the absolute risk reduction and number needed to treat (NNT) were estimated. Results: Among 1,597 screened infants, 188 (11.8%) were colonized with S. aureus (85.6% MSSA; 14.4% MRSA). Colonized infants had a median NICU length of stay of 96 days, and 39 (20.7%) were involved in at least one transmission event. Of these infants, 84.6% received full decolonization. Across the cohort, 389 conversions from colonization negative to positive were observed, including 97 recolonization events; 55 (56.7%) of these infants became colonized ? 3 times during their stay, indicating sustained exposure and transmission pressure. TTE modeling predicted a 30-day transmission risk of 0.6% if all patients were decolonized, and 8.9% risk if no patients were decolonized. This corresponds to a 30-day absolute risk reduction for transmission of 8.2% and an NNT of 12; decolonizing 12 infants prevented one S. aureus transmission. Conclusions: Genomically informed modeling indicates that weekly screening and targeted decolonization reduce S. aureus transmission in the NICU. Frequent recolonization supports the importance of weekly S. aureus screening and suggests that decolonization prevents infection partly by limiting spread to susceptible hosts, with implications for the spread of resistant strains. Future analyses incorporating time-varying eligibility and exposure will further refine these transmission estimates.