Background: Diarrhea is common among patients with cancer, and rapid diagnosis of gastrointestinal (GI) infections using a multiplex stool enteric pathogen panel (EPP) may expedite clinical decision-making and inform infection prevention measures. However, the diagnostic yield of EPPs in patients with cancer with hospital-onset diarrhea is not well defined. At our center, inpatient diarrhea testing guidelines recommend EPP testing primarily in those with community-onset diarrhea. We aimed to assess adherence to these EPP testing guidelines and describe EPP diagnostic yield in hospitalized patients with cancer to identify opportunities for diagnostic stewardship. Methods: We retrospectively reviewed EPP and stand-alone C. difficile (SACD) tests ordered between July 1, 2021 – May 23, 2025 among hospitalized patients (age ≥18 years) with a malignancy diagnosis. Our center recommends EPP testing (BIOFIRE® FILMARRAY® GI Panel) for community-onset diarrhea (on or before hospital day [HD] 3) and SACD testing for hospital-onset diarrhea (after HD 3). EPPs may be ordered after HD 3 for patients with unexplained prolonged or bloody diarrhea. Results: A total of 3338 stool tests (1433 EPP, 1905 SACD) were performed among 2131 patients. Among EPPs, 468 (33%) were ordered after HD 3 whereas 1621 (85%) SACD tests were ordered after HD 3 (Figure 1). The proportion of EPPs ordered after HD 3 was highest among patients with hematologic malignancies (44%) compared to other cancer types and higher among hematopoietic cell transplant (HCT) recipients versus non-HCT recipients (54% vs. 22%; Figure 2). Among EPPs ordered after HD 3, 102/468 (22%) were positive for ?1 pathogen compared to 288/965 (30%) EPPs ordered on HD 1-3. At least 1 non-C. difficile pathogen was detected in 49/468 (10%) EPPs ordered after HD 3 compared to 146/965 (15%) on HD 1-3 (Table 1). Among EPPs with non-C. difficile pathogens detected after HD 3, norovirus was most frequent (26/468; 6%; Table 1). Conclusion: EPP detection of non-C. difficile pathogens among hospitalized patients with cancer was lower in patients with hospital-onset diarrhea compared to those with community-onset diarrhea. Most EPP orders after HD 3 at our center occurred in HCT recipients and patients with hematologic malignancies. Additional studies are needed to determine the clinical significance of positive EPP results beyond HD 3 and understand which patients may benefit most from EPP testing beyond HD 3.

Background: Candidozyma auris is an emerging multidrug-resistant pathogen characterized by environmental persistence and healthcare-associated transmission. Genomic epidemiology can help clarify transmission networks linking clinical isolates, shared equipment, and contaminated surfaces. Methods: We integrated environmental surveillance culturing with whole-genome sequencing (WGS) to characterize environmental reservoirs and genomic diversity of C. auris at University Hospitals Cleveland Medical Center, a tertiary-care hospital. Environmental surveillance samples were collected from high-touch surfaces, shared equipment, and other environmental sites within patient care areas and C. auris clinical isolates were obtained. All C. auris isolates underwent whole-genome sequencing. Dendrograms were constructed using single nucleotide polymorphism (SNP) distances to assess genetic relatedness (isolates with <13 SNP differences were considered related) and evaluate overlap between clinical and environmental isolates to infer transmission-relevant patterns. Results: Two genetically distinct C. auris clades, Clade III and Clade IV, circulated concurrently in April to May 2025. Three patients were infected with genomically related Clade III isolates (Figure 1.A) and 3 were infected with related Clade IV isolates (Figure 1.B). For both clades, multiple related isolates were present in the environment, including patient room surfaces, portable equipment, floors, and shoes of personnel. For Clade III, a distinct isolate (31 SNP difference from prior isolates) was detected in the environment in June 2025 with no concurrent clinical isolates. Conclusions: Our findings are consistent with previous evidence that high-touch surfaces and portable equipment frequently become contaminated with C. auris and suggest that floors and shoes may be an underappreciated source of dissemination. Integrating environmental surveillance with whole-genome sequencing can help identify likely reservoirs, clarify transmission dynamics, and guide targeted infection prevention interventions.

Background: Mycobacterium chelonae and other non-tuberculous mycobacteria (NTM) isolated from ice/water dispensers have been implicated in healthcare outbreaks. We present the results of mitigation activities utilized to reduce M. chelonae from ice/water dispensers as part of an outbreak response. Methods: Interventions were performed in phases. Phase 1 involved ensuring compliance with the manufacturer’s ice/water dispenser cleaning protocol for 11 dispensers involved in the outbreak. Phase 2 compared monthly, bi-monthly, and quarterly cleaning outcomes of seven dispensers. Phase 3 evaluated point source controls on four dispensers in a test environment, two with a 0.005 µm microbial filter either solo (single stage) or in combination with a particle filter (two stage) and two with an ozone treatment system (each with a particle filter). In all phases, monthly environmental culturing for NTM was performed from four sources (water before the filter, water after the filter, ice and water from the spout) on each dispenser for four months. Additionally, swab samples of the waterspouts were collected in Phase 1. Several incoming water sources were also assessed for NTM. Identification of NTM from culture was performed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Results: Phase 1 revealed one NTM positive sample from an ice/water dispenser in the first month with an increasing number of positive results each subsequent month with 40 /44 samples with NTM including 10 M. chelonae in month four. Phase 2 results did not show a significant difference in NTM results between groups by cleaning frequency. Phase 3 results continued to show positive NTM across all dispensers with the single stage microbial filter outperforming the other point source controls (Figure 1). The hospital incoming water results confirmed the presence of M. chelonae along with other species of NTM. Conclusions: Recovery of NTM including M. chelonae from the incoming water supply highlights the known risk from municipal water. Upon implementation of point source controls, the single stage filter had no NTM recovered from water immediately after the filter which may be beneficial. Despite robust and increased cleaning frequency, NTM was still recovered from all dispensers which suggests the presence of biofilm. Improved cleaning protocols are needed from ice/water dispenser manufacturers to address NTM biofilm issues in healthcare settings. Additionally, national guidance on management of NTM in hospital water systems to reduce risk to vulnerable patient populations is overdue.

Background: Infection prevention and control (IPC) is essential for patient safety across all healthcare settings, yet implementation varies by patient population and care environment. Behavioral health settings present unique and underrecognized IPC challenges related to the care environment and the unique nature of psychiatric care. Patient behaviors and cognitive conditions may hinder adherence, while safety- and therapy-focused features complicate implementation of IPC best practices. Evidence tailored to behavioral healthcare environments remains limited, underscoring the need for contextually appropriate, patient-centered strategies. Method: We conducted a cross-sectional, web-based survey to examine barriers and facilitators influencing implementation of IPC practices in behavioral health settings. The survey was distributed to U.S. and Canadian healthcare organizations participating in the SHEA and APIC Research Networks. Eligible respondents included individuals responsible for IPC programs or institutional policy development. The survey was developed using REDCap and distributed via email through the APIC/SHEA Research Networks over six weeks. Participation was voluntary, anonymous, and uncompensated. Result: A total of 140 respondents completed the survey (response rate: 13%, n=140/1095). Respondents were predominantly hospital epidemiologists (17%, n=21) and infection preventionists (76%, n=96) representing public (34, n=42%), academic/teaching (33, n=41%), non-profit private (25%, n=31), and for-profit private healthcare systems/hospitals (7%, n=9). 81% of respondents reported implementing IPC mitigation plans for outbreaks in the past year, with COVID-19 (76%, n=107), Influenza (52%, n=73), and Norovirus (37%, n=52) being the most cited pathogens. The most identified barriers to IPC implementation/adherence were patient factors (89%, n=124) and environmental constraints (79%, n=111). More than 75% of respondents reported that patient adherence to transmission-based precautions, isolation practices, masking, and hand hygiene were “moderately” or “very” challenging. Participants identified the most effective facilitators to effective IPC in behavioral health settings as IPC protocols tailored to behavioral health, clear outbreak-response guidance specific to behavioral health, and physical space or environmental modifications to better support IPC practices. Conclusion: This study highlights the substantial and distinct barriers to implementing infection prevention and control best practices in behavioral health settings, driven by the unique care environment and patient population. Despite having foundational IPC infrastructure in place, organizations face persistent challenges with practical implementation, including patient adherence to precautions and isolation, as well as environmental and physical design constraints. Our findings underscore the need for context-specific IPC protocols, targeted environmental adaptations, and dedicated IPC expertise to improve patient safety in these often underrecognized healthcare settings.

Background: On April 1, 2024, the U.S. Centers for Medicare and Medicaid Services mandated the implementation of Enhanced Barrier Precautions (EBP) in all nursing homes. EBP, which are intended to reduce MDRO transmission while avoiding the adverse effects associated with prolonged use of contact precautions, require the use of gowns and gloves during high-contact resident care activities for individuals with a history of MDRO colonization or infection, non-healing wounds, or indwelling medical devices. While EBP may offer important infection prevention benefits, concerns exist about increased costs, staff workload, and potential resident stigmatization. To date, there are no published data examining infection preventionists’ perceptions of EBP, and few studies have looked at methods of EBP implementation. Methods: To address these gaps, this study assessed experiences, challenges, and perceptions related to EBP implementation in nursing homes across Florida (UCF IRB 00007601). From May through September 2025, individuals with responsibility for infection control and EBP in their facilities were invited to take a cross-sectional, 42-item Qualtrics survey. The survey invitation was mailed to 578 free-standing nursing homes in Florida with 60 or more beds, and 90 responses were received (15.6% response rate). Results: Among the demographic results, the majority (96.7%) of respondents worked in infection control, with most (45.3%) having 1 to 3 years of experience as an infection preventionist and approximately 25% holding a certification in infection control from the Certification Board of Infection Control and Epidemiology. Regarding implementation of EBP, the most frequently targeted pathogens were ESBL–producing Enterobacterales (87.3%), VRE (85.9%), MRSA (84.5%), and drug-resistant Streptococcus pneumoniae (84.5%). Some methods of initial staff education included posted guidelines/signage (83.3%), structured in-person sessions (77.4%), and informal staff meetings and discussions (72.6%). Facilities mainly used signage outside the resident’s door (93%), documentation in the resident’s care plan (79.1%), and EHR alerts (77.9%) to indicate EBP. When assessing perceptions of EBP, most respondents (47.3%) reported a somewhat or very negative perception of staff attitudes towards EBP, while (33.3%) reported a somewhat or very positive perception. Over half of respondents (58.3%) believed that EBP increases the overall cost of care in their facility. Conclusion: These findings provide important insight into real-world EBP implementation in nursing homes and identify perceived barriers and facilitators to adoption. Understanding infection preventionist perspectives is essential to refining EBP guidance, improving implementation strategies, and ensuring that MDRO prevention efforts in long-term care settings balance effectiveness with staff feasibility and resident-centered care.

Background: Nursing homes residents are at high risk of severe COVID-19 infections. Age-related immunosenescence blunts the response to routine vaccinations, such that the estimated vaccine effectiveness for COVID-19 is <33% in nursing home residents. We assessed risk factors associated with breakthrough COVID-19 infections (BT) among previously vaccinated residents of Veterans Affairs (VA) nursing homes, termed Community Living Centers (CLCs). Methods We characterized residents who had received the primary COVID vaccine series and were present in VA CLCs at four census dates: 1/1/21, 7/1/21, 1/1/22, and 7/1/22 which included the Delta (mid-2021), Omicron BA.1 (early 2022) and BA.4/BA.5 (mid-2022) peaks. In each of these census cohorts, we assessed COVID-19 booster vaccines and identified laboratory confirmed COVID cases. We identified time-at-risk for BT starting at 14 days post-primary series vaccination or the beginning of the 6-month interval; and extending until death, BT, 7 days after discharge, or the end of the 6-month interval. For each census date, we characterized risk factors for BT and death following BT using survival and logistic regression models, respectively. Results We identified Table 1). Cases of BT infection increased from 41 pre-Delta to <800 during the Omicron BA.1 and BA.4/BA.5 waves. Survival models indicated an increased risk of BT among residents aged ≥Figure 1). We did not detect significant effects of sex, race and ethnicity, or Charlson Comorbidity Index (CCI). Compared to the primary series alone, a single booster dose had a protective effect against BT infection during the July 2021 and January 2022 eras; we did not detect effects of additional boosters. Mortality models from all census dates included 2011 residents with BT. Age ≥Figure 2). Discussion Among vaccinated nursing home residents, age ≥

Background: Following the COVID-19 pandemic, the University of Kentucky (UKY) experienced elevated rates of methicillin-resistant Staphylococcus aureus (MRSA). To drive rapid improvement, an MRSA escalation program was developed incorporating targeted contact precautions for units not meeting decolonization thresholds, enhanced MRSA surveillance testing, and data-driven reports to support unit leadership. Methods: The UKY Infection Prevention and Control Program (IPAC) implemented a data-driven MRSA escalation strategy. At baseline, all patients in intensive care units, patients with indwelling lines or tubes, and patients testing positive for MRSA were expected to undergo daily chlorhexidine bathing and intranasal povidone iodine decolonization. Upon review, gaps were identified in decolonization performance and screening of at-risk populations. The intervention addressed these gaps by including electronic health record (EHR)–prompted MRSA screening for at-risk patients, development of aggregate decolonization compliance dashboards, and real-time performance dashboards for unit supervisors. A monthly decolonization performance threshold of 70 percent was established. Units with persistent compliance below 70 percent were placed on contact precautions with an “MRSA Escalation” designation in the EHR. IPAC met with identified units to provide toolkits and education on dashboard utilization and integration of MRSA metrics into routine huddles and sprints. In March 2025, intranasal decolonization was transitioned from povidone iodine to mupirocin. Monthly hospital-onset MRSA bacteremia counts, chlorhexidine bathing compliance, and nasal decolonization compliance from July 2023 through December 2025 were analyzed using simple linear regression with time in months as the independent variable. Results: Multidisciplinary education was conducted across nursing, physician, and leadership groups from August 2023 through January 2024, with program go-live in February 2024. Chlorhexidine bathing compliance increased significantly over time, with an average improvement of 0.39 percentage points per month (95% CI 0.24–0.55, p < 0.001, R² = 0.48, Figure 1). Nasal decolonization compliance also increased significantly, with an average improvement of 0.30 percentage points per month (95% CI 0.16–0.44, p < 0.001, R² = 0.40). Hospital-onset MRSA bacteremia demonstrated a significant downward trend (slope –0.089 cases per month, p = 0.012, R² = 0.20), corresponding to an average reduction of approximately one case every 11 months. Quarterly SIR decreased from 1.10 in Q3 2023 to 0.54 in Q4 2025. Conclusions: Implementation of an MRSA escalation program incorporating decolonization performance thresholds, targeted contact precautions, enhanced education, real-time data reporting, and transition to mupirocin for nasal decolonization was associated with significant improvements in decolonization compliance and a sustained reduction in hospital-onset MRSA bacteremia.

Background: Candida auris (CA) poses an urgent public health threat due to its multidrug-resistance, associated mortality, and ability to persist in the inanimate healthcare environment. We sought to ascertain factors associated with a prolonged multi-facility outbreak that was not amenable to previously successful containment measures involving Clade 1. Methods: Contact tracing and testing, environmental sampling, cleaning observations with intensified cleaning, and whole genome sequencing were performed. Additionally, dry hydrogen peroxide units (Synexis DHP® Overland Park, KS) were installed, damaged furniture was replaced, and availability of dedicated equipment was increased. Standard urine culturing protocols were changed to better detect and identify yeast. Exposed patients that remained uncolonized were compared to exposed colonized patients in a nested case control exploratory analysis using multivariable logistic regression with excess antibiotic days as the primary exposure in the adjusted model. Covariates were selected based on prior understanding of the pathogen, biological plausibility, and univariable analyses to explore crude associations. We created one primary adjusted model, with additional sensitivity analyses conducted to avoid overfitting due to the small sample size and potential confounding. Model discrimination was evaluated using the area under the curve. Results: All isolates in the initial clusters were Clade III and highly genetically related to each other. Later a small cluster of highly related Clade 1 emerged. Patient variables and descriptive statistics appear in Table 1. After adjusting for age, sex, number of rooms the patient occupied, and Charlson comorbidity score, each additional day of unjustified antibiotics prior to culture was associated with a 63% increase in the odds of CA positivity (OR=1.63 per day, 95% CI: 1.22-2.53, p=0.007). Number of patient rooms occupied prior to culture was also strongly associated with positivity (OR=1.83 per additional room, 95% CI 1.37-2.82, p=0.0007). Discussion We applied the same containment measures that had previously succeeded, along with those described above, but were unable to control this outbreak. At the time of this submission, CA continued to be detected sporadically in clinical cultures, supporting our hypothesis that clade III is more difficult to contain than Clade I. This report is notable because it confirms our earlier findings of CA emergence linked solely to excess antibiotic exposure, using a more robust study design. As excess antibiotic days was independently associated with CA positivity, it underscores the importance of aggressive antimicrobial stewardship to prevent emergence. Once CA establishes itself, containment may be impossible.

Background: The U.S. is on track to lose measles elimination status after experiencing the highest number of cases in <30 years. With ongoing transmission and falling vaccination rates, health systems must prepare for measles, focusing on minimizing secondary cases and maximizing prevention. We describe a taskforce approach for comprehensive measles (with a lens towards all-hazard)preparedness across our enterprise. Methods: Our mitigation and preparedness taskforce included four workstreams (Figure 1): Early MMR vaccination for children with international travel: Consistently offer and administer initial or second MMR vaccine, as appropriate, for infants and children travelling abroad. Optimize exposure and testing management: Develop tools to expedite the identification of exposed non-immune patients and optimize processes for high volume testing and result tracking. Optimize screening processes at points of entry (POE): Develop streamlined processes for reliable travel and exposure screening at all enterprise wide POEs. Contingency planning for larger scale exposure events/community spread: Develop post-exposure prophylaxis (PEP) delivery procedures to respond to large-scale community exposure events and establish partnerships with local public health (PH) departments. Results: Increase in vaccination for non-immune travelers in primary care: We built an EMR (electronic medical record) prompt into all child visits to screen for travel, which interfaced with vaccine clinical decision support to offer/administer vaccines. From May through 12/28/25 we administered 1325 early MMRs to travelling children (Figure 2). EMR-based report to identify exposed individuals and their immune status: This report allows all sites to rapidly identify patients needing PEP after exposure. We also developed processes for pre-emptive approval for large scale testing, result tracking, and high-volume patient notification. Optimization of Screening and POE with EMR upgrades, PPE kits: We are upgrading our EMR to better integrate travel & exposure screening. We developed additional resources including screening supports for non-English languages and PPE kits for immediate use at POE when patients screen positive. Development of PEP clinics and PH Collaboration: We developed processes to stand up PEP clinics at our hospitals to expedite large volume PEP administration. We worked with PH to outline roles, capabilities and resources for response to community outbreaks, optimized staff fit testing and developed drills across all care settings. Conclusions: Preparedness for highly contagious infectious diseases and emerging PH threats is critical. A taskforce approach provides a structured framework for collaboration and mobilization of resources. By utilizing an all-hazards lens, this framework is broadly applicable for vaccine preventable infections and other infectious threats.

Background: Nontuberculous mycobacteria (NTM) are ubiquitously found throughout the environment, including healthcare facilities, and disproportionately affect immunocompromised hosts. We have a limited understanding of healthcare-associated transmission. Detailed outbreak investigations may yield insights into transmission risk. Method: An investigation of a Mycobacterium abscessus outbreak began after identifying a higher-than-expected frequency of infections among solid organ transplant recipients in September 2024. Cases were defined as individuals with a first-time positive M. abscessus culture from any anatomical site and a prior inpatient admission to our hospital. Our epidemiologic investigation included creating a case line list with potential exposures during the 90 days preceding microbiologic diagnosis, direct observations of patient care, a case-control study to identify potential point sources and transmission routes, and environmental cultures to test source/transmission hypotheses. Whole-genome sequencing (WGS) of case isolates was performed to confirm genetic relatedness (defined as ?10 single nucleotide variant difference). Prospective microbiologic surveillance was used to identify new cases. Result: Between May 2023 and the ongoing investigation through December 2025, 31 cases were identified. Twenty (65%) were solid organ transplant recipients, including 12 (60%) lung transplants (Figure 1, Table 1). Our epidemiologic investigation did not identify any other geographic, procedural, or point source exposures with commonality among <20% cases. The case-control study identified transplant status as a significant risk factor for transmission. We hypothesized transmission occurred through contaminated water exposure in inpatient rooms during routine care; environmental cultures demonstrated M. abscessus in potable water sources throughout the hospital (Figure 2). WGS identified 2 distinct clusters comprising 3 and 14 patients, with genetic relatedness to environmental M. abscessus isolates. Sequential flushing and chlorination of the facility-wide water system were performed without significant changes in the frequency of NTM isolation. To mitigate exposure risk, point-of-use filters were installed and tap water avoidance was enforced on units predominantly caring for patients with immunocompromising conditions. Following implementation of tap water avoidance, only 4 genetically related cases have been identified within 11 months of follow-up. Conclusion: Water exposure during routine patient care among susceptible hosts increases NTM risk. Eradication of NTM from aging plumbing systems is challenging; tap water avoidance combined with POU filtration appeared to have abated this outbreak. Infection prevention programs should consider routine monitoring of NTM infection rates, particularly M. abscessus, to detect a higher-than-expected frequency. Routine water quality surveillance should include NTM cultures. Studies are needed to identify effective methods of NTM eradication from potable water supplies.

Background: Legionella is the etiologic agent of Legionnaire’s disease and Pontiac fever with an environmental niche in potable water systems. Globally, Legionella mortality is estimated to have increased fourfold since 1990. Several regulations have emerged to try and counteract this increase, with six countries (Netherlands, Germany, England, France, Australia, and Canada) enacting laws that target the growth of legionella from environmental samples for primary prevention. The effectiveness of these laws in mitigating legionella mortality has not been evaluated. We performed an interrupted time series analysis to evaluate the effect of laws with specific colony forming unit (CFU) thresholds on the legionella mortality rate in the country. Methods: We extracted legionella mortality rate estimates produced by the Global Burden of Disease project for the six countries with legionella laws with defined CFU thresholds for the ten years before the laws were enacted and ten years after the laws were enacted (or up to 2020). We then performed an interrupted time series analysis for these six countries. All analysis was performed in R version 4.5.2. Results: The median legionella mortality rate for the six countries included in analysis in the decade before laws were enacted was 2.86 deaths per 100,000 (IQR1.6-3.75). In the decade following law enactment the mortality rate was 3.35 legionella deaths per 100,000 (IQR 2.01-4.77). In the interrupted time series, there was an increase in legionella mortality of 0.17 deaths per 100,000 (95%CI 0.14 – 0.2) per year in the decade before CFU laws were introduced. The rate of increase did not statistically significantly change after law enactment with an annual increase of 0.102 per 100,000 (95%CI 0.03 – 0.17) persons. A country specific analysis found that the rate of annual increase in legionella mortality rates was statistically significantly lower following enactment of CFU specific laws in Germany, Netherlands, and the United Kingdom (Figure1). Discussion: We found that, collectively, laws including CFU thresholds had no significant effect on the rate of change in legionella mortality. However, at the individual country level, three countries did see a significant decrease in the rate of change in legionella mortality following enactment. One possible explanation for this heterogeneity is that several of these laws include additional mitigation measures and may confound the effect of the CFU based monitoring. Future studies should focus on these additional mitigation measures and compare legionella outcomes in countries with and without CFU thresholds in water safety laws.

Background: Candidozyma auris is an emerging multidrug-resistant organism often associated with multi-facility outbreaks. We identified an outbreak in southeast Georgia spanning September 2024-August 2025. Although early response efforts focused on one long-term acute care hospital (LTACH) with extensive colonization, clinical cases were also identified in four acute care hospitals (ACHs), another LTACH, and one outpatient center within the public health district. Two ACH laboratories were only speciating Candida from blood cultures. We expanded the investigation to assess whether inter- and intra-facility transmission contributed to ongoing spread, to inform targeted testing, colonization screening, and infection control recommendations. Method: Colonization was detected in LTACH-A-LTACH-B via Polymerase Chain Reaction by Tennessee Laboratory Services, and clinical cases were identified via MALDI-TOF spectrometry at the Georgia Public Health Laboratory or clinical laboratories. Whole-genome sequencing (WGS) was conducted on 24 isolates. Clade data were analyzed alongside patient healthcare exposure histories to identify transmission clusters. Case data were managed in Excel, and healthcare exposure networks were visualized using visNetwork in RStudio. Result: C. auris cases were identified across 7 facilities, including ACH-A-ACH-D, LTACH-A-LTACH-B, and Outpatient-A. We identified 26 clinical and 62 screening cases. Clinical specimen sources included 31% blood, 27% wound, 23% urine, 15% respiratory, and 4% unknown. LTACH-A identified 3 clinical cases in Oct./Nov. 2024, leading to screening identifying 60 cases between 12/3/24-8/5/25. Of 60 screening cases in LTACH-A, 37% had prior exposure to ACH-A, 25% ACH-B, 17% ACH-C, and 2% ACH-D. 17 clinical cases were identified in ACH-A-ACH-D between 9/4/24-7/23/25; no screening was conducted. Review of patient healthcare exposure history uncovered 12 overlap clusters of 2-6 cases: 8 ACH-A (multiple high-acuity unit overlaps), 3 ACH-B (ICU & Med/Surg), and 1 ACH-C (no shared unit). Clinical cases in each cluster overlapped with ≥1 cases that later screened positive in LTACH-A. WGS results showed 10 (42%) clade-I and 14 (58%) clade-III. 3 ACH clusters were identified with clade-III cases, 4 had clade-I and clade-III, and 7 lacked WGS results. Conclusion: Integration of healthcare network analysis with limited WGS data demonstrated that C. auris transmission occurred within ACHs and across the public health district, rather than confined to one LTACH. Patient overlap clusters and temporal sequencing of clinical ACH cases preceding LTACH-A colonization results supported ACH-driven transmission contributing to downstream spread. These findings informed targeted recommendations for speciating non-blood cultures, implementing admission screening at ACHs, and increasing WGS capacity to strengthen multi-facility outbreak detection and response.

Background: Antimicrobial resistance (AMR) is increasingly concentrated in hospital settings, where severe infections, older patients and extensive antibiotic exposure converge. While antimicrobial stewardship programs (ASPs) are central to mitigation, long-term global evidence linking resistance patterns to actionable stewardship priorities (and especially for Gram-negative pathogens) has been limited. We assessed three decades (1990–2021) of global AMR trends to identify stewardship-relevant signals for hospital epidemiology and policy, and also developed forecasts scenarios to 2050. Methods: We estimated deaths and disability-adjusted life-years (DALYs) attributable to and associated with bacterial AMR for 22 pathogens, 84 pathogen-drug combinations and 11 infectious syndromes across 204 countries from 1990–2021, using the Global Burden of Diseases 2021 framework. Analyses integrated 520 million microbiology, hospital discharge, mortality, pharmaceutical sales and antibiotic use records. AMR burden was quantified under two counterfactuals: replacement of resistant infections with drug-susceptible infections (attributable burden) and replacement with no infection (associated burden). Forecasts to 2050 evaluated a reference scenario, a Gram-negative drug development scenario, and a better-care scenario reflecting improved infection management and access to appropriate antibiotics. Results: In 2021, an estimated 4.71 million deaths (95% UI 4.23–5.19) were associated with bacterial AMR, including 1.14 million deaths (1.00–1.28) directly attributable to resistance. Hospital-relevant trends were dominated by Gram-negative resistance: carbapenem-resistant infections showed the largest absolute increase in burden, with associated deaths rising from 0.62 million in 1990 to 1.03 million in 2021. In contrast to declines exceeding 50% among children younger than 5 years, AMR mortality increased by over 80% among adults aged 70 years and older – a population disproportionately affected by bloodstream, respiratory and intra-abdominal infections managed in acute-care settings. By 2050, attributable AMR deaths are projected to reach 1.91 million globally under the reference scenario. Importantly, the better-care scenario (reflecting strengthened stewardship, timely appropriate therapy and improved quality of care) could avert an estimated 92.0 million cumulative deaths between 2025 and 2050, compared with 11.1 million deaths averted under a Gram-negative drug development scenario alone. Conclusion: The global AMR burden is increasingly driven by carbapenem-resistant Gram-negative infections in older, hospitalized populations. These findings indicate that antimicrobial stewardship and hospital infection prevention offer substantially greater population-level mortality benefits than reliance on new antibiotic development alone. Policy efforts should prioritize robust ASP implementation, optimization of empiric therapy for severe infections, rapid de-escalation, as well as system-wide improvements in care quality to curb the projected rise in hospital AMR mortality.

Background: Inpatient psychiatric units (IPUs) present unique challenges for prevention of respiratory virus illness (RVI) transmissions due to shared living spaces, group-based therapeutic activities, and limited ability to isolate or mask patients. Evidence-based infection prevention (IP) strategies in these settings are limited. We evaluated trends in hospital-onset (HO) RVIs on an IPU across pre-pandemic, pandemic, and post-pandemic masking eras and describe implementation of a unit-specific RVI mitigation playbook. Methods: We conducted a retrospective review of respiratory viral testing on the IPU from January 2018 through December 2025 at a 943-bed academic medical center. The IPU is comprised of 25 private rooms, two semi-private rooms, and shared common areas. Respiratory viral testing was performed on a reverse-transcriptase polymerase chain reaction (RT-PCR) assay (BioFire Respiratory Pathogen Panel, BioFire, Salt Lake City, UT or Xpert® Xpress CoV-2/Flu/RSV plus, Sunnyvale, CA) utilizing a nasopharyngeal swab. Patients were tested for respiratory viruses prior to IPU admission beginning March 2020 regardless of symptoms. Patients with positive results were not admitted to IPU due to the inability to accommodate isolation. Following a SARS-CoV-2 outbreak on the unit in December 2021-January 2022, a psychiatry-specific HO-RVI mitigation playbook was implemented to define response thresholds (Figure 1). HO-RVI was defined as symptom onset and/or a positive test occurring more than 48 hours after admission, with classification informed by virus-specific incubation periods based on published literature. A cluster was defined as two epidemiologically linked positive tests, including patient–patient or patient–healthcare worker combinations. An outbreak was defined as three or more patients and/or healthcare workers with HO-RVIs whose epidemiology indicates shared time and space. Results: On the IPU, HO-RVIs occurred sporadically (Figure 2). Since January 2022, no RVI outbreaks have occurred on this unit, despite periods without universal masking, continued identification of HO cases, and mitigation of seven RVI clusters. SARS-CoV-2 accounted for the majority of identified cases, though most were asymptomatic and detected through routine pre-procedural electroconvulsive therapy testing, without progression to outbreaks. Conclusions: Sustained prevention of RVI outbreaks on an IPU is achievable despite ongoing viral circulation and limited feasibility of patient isolation or masking. A tailored mitigation playbook incorporating early identification of cases and thresholds for implementing IP interventions may reduce outbreak risk while preserving the therapeutic milieu. These findings support development of setting-specific IP strategies for inpatient psychiatric environments. Additional studies are needed to inform best practices for preventing RVI transmissions in these settings.

Background: Surgical Site Infections (SSI) are one of the most significant morbidities following surgical procedures, contributing substantially to prolonged length of stay, mortality and increased healthcare costs. Prevention bundles tailored to colon surgery have proven to be effective quality improvement interventions when implemented with high adherence, yet sustained compliance remains challenging across healthcare systems. Methods: A comprehensive colon-specific SSI prevention bundle was implemented across a large multi-state health system in 2019. The bundle encompasses perioperative interventions including preoperative measures (surgical antibiotic prophylaxis, mechanical and oral bowel preparations, appropriate hair removal, chlorhexidine bathing), intraoperative protocols (normothermia maintenance, chlorhexidine skin preparation, wound protectors, oxygen optimization), and closure techniques (separate sterile instrument sets, gown/glove changes, triclosan-coated sutures, silver dressings), with perioperative glycemic management maintained throughout. Bundle compliance was systematically monitored from 2019-2025, with SSI outcomes tracked using National Healthcare Safety Network (NHSN) criteria. Standardized Infection Ratios (SIRs) and compliance trends for key bundle elements were analyzed to assess intervention effectiveness. Results: From 2019-2025, implementation of the comprehensive SSI bundle across 14,355 colon procedures resulted in a 36.1% reduction in colon SIR (0.821 to 0.525). Significant improvements in key bundle compliance were observed: Surgical Antibiotic Prophylaxis (SAP) adherence increased 40.5% (41.9% to 82.4%), mechanical bowel preparation compliance rose 39% (64.2% to 89.3%), and oral bowel preparation adherence demonstrated a 119% increase (38.2% to 83.6%). Strong correlation was observed between bundle compliance rates and sustained SSI reduction, with the greatest improvements occurring in facilities achieving ?80% adherence with the SSI prevention bundle interventions. Conclusion: Sustained adherence to a comprehensive colon SSI prevention bundle significantly reduces postoperative infections, as demonstrated by a 36.1% SIR reduction over six years. Success requires systematic implementation, real-time compliance monitoring, institutional commitment to quality improvement, and ongoing evaluation of prevention bundle components to ensure adherence with current evidence-based national standards. The data suggest that optimizing SAP timing, mechanical bowel preparation, and oral antibiotic prophylaxis represent high-impact interventions warranting prioritization in resource-limited healthcare settings.

Background: Staphylococcus aureus (SA) colonization affects about 30% of U.S. adults and increases surgical-site infection risk 2 - 10 fold. A prior study by Kline et al. (2018) laid the foundation for evaluating efficacy and cost effectiveness of pre-operative decolonization interventions. This study evaluates an expanded set of up-to-date interventions, including: Strategy 1 - Individuals screening positive for SA receive a 5-day, 3-drug bundle. Non-SA carriers receive 2 pre-operative chlorhexidine gluconate (CHG) showers. Strategy 2 - All individuals receive the 3-drug bundle for 5 days. Strategy 3 - All individuals receive day-of-surgery nasal povidone iodine plus 2 CHG showers. Strategy 4 - All individuals receive day-of-surgery nasal alcohol gel plus 2 CHG showers. The 3-drug bundle consists of daily CHG showers, twice-daily CHG mouth rinse, and twice-daily nasal mupirocin ointment for 5 days leading up to surgery. Methods: A decision analytic model (Figure 1) simulated a U.S. adult population undergoing elective surgery over a 150-day horizon to evaluate the impact of the four strategies on surgical-site infections, SSI-related deaths, and healthcare-associated costs. Model parameters (Table 1) were derived from Kline et al. (2018), supplemental literature, and expert opinion. The model was used to determine SSI cases and costs per 10,000 population. One-way and probabilistic sensitivity analyses were conducted to determine the impact of uncertainty on choice of strategy. Results: Results are summarized in Table 2 and Figure 2. Strategy 2: Treat-all with 3-drug bundle, had the lowest healthcare-associated costs and prevented the most SSI cases, followed successively by Strategies 1, 3 and 4. These findings were robust across a series of one-way sensitivity analysis; the model was most sensitive to SSI probability and the relative risk associated with S. aureus colonization, while treatment efficacy parameters demonstrated limited impact on the overall results. In probabilistic sensitivity analyses, in which multiple parameters were varied, Strategy 2 remained the optimal strategy, whereas Strategy 4 was identified as the most expensive and least effective strategy. Conclusion: The results of this cost effectiveness analysis, combined with the results of our recent survey showing decolonization strategies vary nationally, highlight an opportunity to improve decolonization practices and outcomes.

Background: Carbapenem-resistant organisms (CRO) and Candida auris are multidrug-resistant organisms (MDRO) that can spread between patients and environments, posing a threat to health care systems, including acute care hospitals and nursing homes. However, their impact on non-nursing home congregate residential facilities, such as homeless shelters and assisted living facilities, is poorly understood. These facilities traditionally lack infection prevention and control (IPC) capacity as compared with health care facilities, have multi-occupancy rooms, and may have high censuses, all of which facilitate disease spread. Methods: To inform opportunities for public health intervention, clinical CRO and C. auris cases were enumerated from results reported to the New York City Health Department during 2019–2024. Patients’ geocoded addresses were matched to a list of non-nursing home congregate residential facilities. Cases were counted once during the study period, in alignment with the 2023 Council of State and Territorial Epidemiologists Carbapenemase-Producing Organisms and C. auris case definitions. CRO cases were counted separately for each organism/carbapenemase combination among patients where multiple combinations were reported. Cases’ demographic, isolate, and residential facility characteristics were summarized using univariate statistics. Results: During 2019–2024, 97% (11507/11858) of CRO and 100% of 1848 C. auris cases were reported with complete addresses. Of those, 471 (4%) CRO and 89 (5%) C. auris cases’ addresses matched a non-nursing home congregate residential facility at the time of diagnosis. Most CRO (63%) and C. auris (70%) cases were male. The median age at diagnosis for CRO cases was 64 years (interquartile range: 52–100 years) and for C. auris cases was 60 years (interquartile range: 51–69 years). Most laboratory tests originated from inpatient facilities for both CRO (65%) and C. auris (71%) cases. Among CRO and C. auris cases whose addresses matched to a congregate setting, the most common non-nursing home congregate facility types were group homes for people with intellectual and developmental disabilities (33% and 38%, respectively), shelters for people experiencing homelessness (25% and 26%), assisted living facilities (22% and 15%), and housing for people with mental health conditions (14% and 18%). Conclusion: More research is needed regarding CRO and C. auris in congregate settings. People residing in these environments may benefit from tailored approaches to MDRO case management. Enhanced surveillance by health departments in the form of routinized geocoding and address matching, which is low-cost and uses existing data sources, can identify facilities that could benefit from IPC support, education, and resource distribution.

Background: A measles case requires immediate action to identify and administer prophylaxis to exposed individuals in healthcare settings. Infection preventionists (IPs) often balance proactive contact tracing with waiting for a positive test result. Objective: To develop a tool that enables IPs to stratify suspect measles cases by risk level, thereby supporting the decision to prioritize or defer active intervention while awaiting test results. Methods: In spring 2025, we developed a preliminary matrix and used 19 additional suspect patients to further refine the scoring of the tool. In August 2025, we deployed a finalized tool. The two-dimensional risk matrix incorporated both epidemiological risk factors and clinical risk factors, each scored numerically based on yes or no questions. The sum of both categories was used to assign a final risk level that determined the recommendations for IPs (Figure 1). The study population included patients tested for measles during the implementation period. Descriptive statistics were used to summarize the distribution of risk categories and outcomes. Among the whole cohort, Firth’s logistic regression was used to evaluate the association between clinical or epidemiological risk score and measles diagnosis. Among the production cohort, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to evaluate the diagnostic performance. Results: Since implementation, the matrix was applied to 56 patients tested for measles. Of these, 10.7% (n=6) were categorized as high risk, 32.1% (n=18) as medium, and 57.1% (n=32) as low. Four of the 56 patients were positive for measles, 3 were categorized as high-risk and 1 as medium risk. Each one-unit increase in epidemiological risk was associated with a 2 folds increase in the odds of a positive measles diagnosis (odds ratio = 2.0; 95% CI, 1.3–3.6). The low-risk category had an NPV of 1, indicating that all low?risk patients tested negative, thus supporting safe workload reduction by deprioritizing these cases. Conclusion: The Measles Exposure Response Risk Matrix effectively stratified cases and supported IP prioritization efforts. Low-risk groups required no action, expedited testing was reasonable for medium-risk cases, and proactive actions were reserved for high-risk cases. Clinical and epidemiologic risk scores progressed from arbitrary assignment to validated metrics, confirmed by statistical analysis. The flexible design permits adaptation to other infectious diseases, including avian influenza and mpox. With rising measles incidence, tools like this matrix will be essential to support rapid, evidence-based actions by infection prevention teams.

Background: Antimicrobial resistance (AMR) is a growing global health threat, yet surveillance systems remain heavily centered on clinical reporting and often overlook environmental transmission pathways. Urban rivers receiving mixed municipal, hospital, and agricultural inputs may act as important reservoirs and dissemination routes for antibiotic resistance genes (ARGs), particularly in resource-limited settings. Understanding spatial patterns of environmental resistomes is essential for advancing One Health–informed AMR surveillance. Methods: We conducted a longitudinal, multi-site investigation of ARG occurrence along the Cuautla River, an urban watershed in Morelos, Mexico, serving the resource-limited city of Cuautla. Surface water samples were collected across six locations spanning urban upstream (L1-2), urban core (L3-5), and urban downstream zones (L6) (Figure 1). Targeted droplet digital PCR (ddPCR) was used to quantify relevant ARGs, including Gram-positives (mecA and vanA), Gram-negatives beta-lactamases (CTX-M and SHV), AmpC-type β-lactamase (CMY), and Carbapenemase (KPC, NDM, VIM, IMP, and OXA-48), tetracycline (tetW) and Polymyxin-resistant (MCR-1). Physicochemical parameters and fecal indicator bacteria were measured concurrently to contextualize microbial contamination. Spatial and temporal trends in ARG abundance and composition were evaluated using non-parametric statistical analyses. Results: ARGs were widely detected across the watershed, with particularly high abundances of tetW, CMY, TEM, and multiple Gram-negative carbapenemase genes, including KPC, OXA-48, and VIM. The plasmid-mediated colistin resistance gene mcr-1 was also detected at multiple sites, highlighting the environmental presence of resistance determinants associated with last-resort antimicrobials (Figure 2). ARG abundances generally increased from urban upstream to urban downstream locations, likely reflecting cumulative inputs from domestic wastewater, healthcare facilities, and densely populated areas. Although ARG loads peaked within the urban core, elevated resistance signals remained detectable in downstream urban edge regions (Figure 3). In contrast to largely compliant physicochemical conditions, fecal indicator bacteria revealed pervasive microbial contamination across urban sites. Conclusions: Our findings demonstrate extensive resistome contamination within an urban river system, encompassing both environmental and clinically important ARGs. The spatial accumulation of resistance signals downstream and the detection of colistin resistance genes underscore the role of river ecosystem as conduits linking human activity to broader environmental AMR dissemination. These results highlight the need to integrate environmental water surveillance into AMR monitoring frameworks and support a One Health approach that connects wastewater management, antibiotic stewardship, and public-health protection in resource-limited settings.

Background: NYC Health + Hospitals (H+H) provides care to large communities experiencing social vulnerability. During the 2022 mpox outbreak, H+H implemented a large-scale, targeted mpox vaccination campaign using electronic health record (EHR) reminders among groups with greatest risk of mpox infection. When demand was high, 25% of available vaccine appointments were reserved for established H+H patients. This study aims to describe patterns of mpox vaccination amongst eligible H+H patient groups. Methods: H+H started vaccinating with JYNNEOS in May 2022 and used EHR reminders to encourage vaccination amongst those eligible, including: (1) Patients with an HIV diagnosis AND who had a sexually transmitted infection in the past year; OR (2) Patients who received at least one mpox vaccine and was due for the second; OR (3) Patients with a sexual orientation in the EHR as Gay, Bisexual, Lesbian, Something else, or Choose not to disclose; OR (4) Patients with a gender identity in the EHR as Transgender Female, Transgender Male, Gender Non-binary/Nonconforming, Other, or Choose not to disclose. We extracted data from the NYC Citywide Immunization Registry through April 30, 2025, into our EHR. We calculated a Pearson correlation coefficient between the 2022 Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) and percentage who received at least one mpox vaccination by zip code with significance set at a p-value <0.05. Results: Figure 1 summarizes key events along the H+H mpox vaccination timeline. There were 112,680 H+H patients eligible for mpox vaccination, of which 25.7% received at least one dose by April 2025, compared to 51.5% amongst patients with HIV (Table). White patients had the highest proportion vaccinated (31.1%), and Hispanic/Latinx patients had the lowest (22.0%). Figure 2 indicates the percentage vaccinated by neighborhood at three time points (September 2022, April 2023, April 2025). As of April 2025, the percentage of eligible individuals vaccinated by zip code was negatively correlated with SVI of the zip code (r= -0.0529; p<0.01) (Figure 3). Conclusion: Amongst eligible H+H patients, we identified disparities in mpox vaccination rates by race/ethnicity, neighborhood, and the zip code SVI. The use of EHR reminders may have helped us achieve a higher vaccination rate amongst eligible patients with HIV, compared to the overall cohort. A limitation may be misclassification of eligible individuals, which relies on structured social history and gender identity data accurately documented in the EHR. Our findings identify areas for quality improvement to optimize vaccine equity.