Contemporary infection prevention practices for methicillin-resistant Staphylococcus aureus (MRSA) infections were surveyed across 12 mostly academic medical center burn units using the SHEA Research Network. There was variability in surveillance and decolonization practices, with 58% reporting active MRSA surveillance. More evidence-based data for burn MRSA infection prevention practices are needed.

Introduction: The American College of Obstetricians and Gynecologists (ACOG) and Society of Healthcare epidemiology (SHEA) recommend cephalosporins as the standard antibiotic for preoperative prophylaxis for abdominal hysterectomy (AH-includes Laparoscopic and open cases) . However, anaerobic organisms are prevalent in vaginal and intraabdominal flora and can contribute to development of surgical site infections (SSIs). Limited data suggest that including anaerobic coverage may reduce SSI risk. In May 2024, we implemented anaerobic containing regimens as first-line preoperative antibiotic prophylaxis for all AH cases. This study evaluates whether adding anaerobic coverage to the preoperative antibiotic protocol reduces National Healthcare Safety Network (NHSN)-defined SSI after AH surgeries. Methods: We conducted a retrospective cohort study of all patients who underwent inpatient or outpatient from January 2023 through September 2025. Preoperative antibiotic choice and timing as well as patient demographics and comorbidities were obtained from medical records. SSI were determined by NHSN definitions by trained infection preventionists. First line antibiotics with anaerobic coverage were defined as cefazolin plus metronidazole, or vancomycin plus aztreonam plus metronidazole in patients with penicillin allergies. SSI in patients who received first line antibiotics with anaerobic coverage were compared to those who received alternative antibiotic regimens (Around 80% of alternative regimen consisted of only cefazolin). Multivariate logistic regression and overlap weighting methods were applied to evaluate the independent impact of first-line therapy. Results: Among 11,444 hysterectomy procedures, the overall SSI rate was 1% (n=109 cases). Unadjusted SSI rate in patients receiving first-line antibiotics was significantly lower than those receiving alternate prophylaxis (0.7% vs 1.3 %, p =0.001). Individuals who received first-line antibiotics were generally younger, more frequently identified as Caucasian, and exhibited greater rates of diabetes and cancer compared to those who received alternative regimens. Patients who received first line antibiotics also had longer surgeries, a higher frequency of elective and laparoscopic procedures, and higher rates of adherence to preoperative protocols such as chlorhexidine bathing, vaginal preparation, and maintenance of normothermia (see Table 1). After adjusting for baseline differences between groups through multivariate logistic regression and overlap weighting, first-line therapy was associated with a 50% reduction in SSI risk compared to alternative regimens (OR 0.51; 95% CI 0.34–0.76; p=0.001). (Table 2) Conclusion: Compared to alternative regimens for preoperative antibiotic prophylaxis, the routine inclusion of metronidazole to cefazolin was associated with a reduced risk of SSI following AH surgeries even after adjusting for demographic, procedural and clinical differences between groups.

Introduction: Surgical site infections (SSI) account for 20% of all healthcare-associated infections (HAIs). SSI are associated with increased patient mortality, morbidity, length of hospitalization and risk of readmission with an associated total healthcare cost of $3.3 billion annually. Of the reported SSIs, colorectal (COLO) surgeries have been among the highest risk procedures. A crucial element to prevent HAI is the accurate identification of true events. This allows for comparison of facility-specific performance metrics with peer groups and the development and implementation of targeted interventions to reduce SSI burden. In this abstract, we assessed the impact of multidisciplinary intervention to accurately identify, and document visualized infections on SSI rates and Standardized Infection Ratios (SIR) at a tertiary care teaching facility. Methods: A quasi-experimental study was conducted from 02/01/2024 to 06/30/2025 to improve the accuracy of operative note documentation of visualized infections. Indicators to evaluate possible SSI events included readmission(s), chief complaint, surgical logs, diagnostic codes, antibiotic use, lab/culture data and keywords that may indicate a surgical site infection. Subsequently identified procedures were evaluated by the Surveillance Infection Preventionist team, the Medical Director of Infection Prevention, and the Surgical Quality Officer. If indicated, the operating surgeon was consulted to determine whether visualized infection criteria were met and/or correctly documented. Turnaround time for case reviews was determined. We compared the observed SSI rates and Standardized Infection Ratios (SIR) with the uncorrected rates and SIR accounting for the clarified events. Results: Of 1,142 procedures, 55 were initially identified as COLO SSI. After multidisciplinary review, 12 (22%) of the 55 were found to be present at the time of surgery (PATOS). An additional two events (4%) were determined to not meet SSI criteria. The table summarizes the results of the review process showing a statistically significant correction in SSI event rates from 4.82/100 surgeries to 3.59/100 surgeries (p<0.0001). The turnaround time from identification of a potential SSI event to final determination was four days (range: 1-6 days). Conclusion: Surgical site infection events are critical quality outcome measures for both regulatory and reputational agencies. However, the misclassification of SSIs, such as observed in our study, can create a misleading picture of institutional performance, divert attention from preventable cases, and undermine confidence in surveillance systems. Our multidisciplinary approach ensures a more accurate identification of SSI events. This method can serve as a model for enhancing surveillance accuracy and reliability across healthcare settings.

Background: Social vulnerability factors have been associated with negative health outcomes. However, it remains unclear how they affect device-related infections in different population groups. Methods: This retrospective observational cohort study included Central-Line Associated Bloodstream Infections (CLABSI) and Catheter Associated Urinary Tract Infections (CAUTI) in an 850-bed, academic tertiary care facility. Information was collected on patient demographics, the CDC Social Vulnerability Index (SVI), hospitalization, comorbidities, and COVID-19 status. SVI analysis included overall vulnerability comprised of the four themes: socioeconomic status, household characteristics, racial/ethnicity minority status, and housing type/transportation. Chi-square and Wilcoxon rank-sum tests were used for categorical and continuous variable comparisons. GEE models compared pre- and pandemic periods by interrupted time series analysis. Results: Between 1/1/2018 to 5/31/2022 98,791 patients were admitted 151,550 times. Of those, 17,796 patients received 29,483 central lines and 45,180 patients had 65,422 Foleys. 314 patients developed 338 CLABSI and 216 patients had 217 CAUTI. 1,552 patients tested positive for COVID-19 with 22 developing CLABSI and 14 CAUTI. The pre-pandemic downward trend in CLABSI and CAUTI was reversed during COVID-19 (p Throughout the study Black patients had higher device days (p In the SVI analysis the socioeconomic theme was associated with higher risk of device-related CLABSI across the entire study (p=0.03). During COVID-19 overall SVI and the household characteristics theme were associated with higher device-related CLABSI rates (p=0.03; p=0.03). Adjusting for race or ethnicity dissolved those associations. For CAUTI race/ethnicity minority status was linked to an event throughout the study (p=0.03). This held true after adjusting for individual race or ethnicity status. No associations were detected in the pre- and pandemic periods for CAUTI. Conclusions: Health outcome disparities affected Black (CLABSI and CAUTI) and Hispanic/Latino (CLABSI) patients. Of note, both groups had significantly higher device utilization rates. Per-patient infections increased during the pandemic without altering race/ethnicity differences. Higher race/ethnicity minority status SVI was linked to CAUTI. However, CLABSI were driven by the socioeconomic SVI. The findings can help clarify the relationships between race/ethnicity and other demographic and socioeconomic factors associated with device-related infections on the community and individual level.

Background: Burn injuries pose a significant risk for infections. Nasal decolonization with mupirocin nasal ointment (MNO) is an established method to prevent infections with Methicillin-resistant Staphylococcus aureus (MRSA). We compared the effectiveness of an alcohol-based nasal sanitizer (ABNS) to MNO against MRSA bacteremia in burn patients. Methods: This was a retrospective before/after study comparing the impact of an MNO (study arm 1; Bactroban 2%, GlaxoSmithKline, NC; application: twice daily for five days after admission) and an ABNS (study arm 2; Nozin, Bethesda, MD; application: twice daily for entire stay on Burn unit) on Healthcare Associated (HA-) MRSA bacteremia events in burn patients. The Burn unit consists of eight intensive care beds for burn care and 15 regular beds in an 885 bed, tertiary care, academic hospital. Inclusion criteria were all burn patients 18 years of age and older admitted under the burn service for more than four consecutive days. No mandatory MRSA screening was performed. Outcome measure was HA-MRSA bacteremia acquired > four days after admission. Patient characteristics included demographics, BMI, intensive care need, MRSA colonization at admission, type and degree of burn, inhalation injury, total burn surface area, Baux score, inpatient mortality, length of stay by total, burn mixed acuity and burn ICU were documented. Daily compliance with treatments was extracted from patient records (EPIC, Verona, WI). Continuous patient characteristics were compared using t-tests or Wilcoxon signed-rank test (for factors with skewed distributions), and chi-square tests for categorical factors. Product-limit time-to-event analysis and log-rank test were used to compare the outcome measure between groups. Results: From 08/01/2021 to 07/31/2024 a total of 920 patients were enrolled (MNO arm: 448; ABNS arm: 462) with 239 and 217 meeting inclusion criteria. No differences in patient characteristics were detected between the two groups at all patients and >80% treatment compliance levels (MNO: 121 encounters; ABNS: 98 encounters). Patients in the MNO arm encountered 14 events compared to one event in the ABNS arm (p=0.0021). The figure displays the product-limit time to event estimates for developing HA-MRSA bacteremia at the >80% adherence level (p= 0.021). Lower adherence levels (50%, 60%, 70%) did not show significance (p>0.05) in the time-to-event analysis. Conclusion: Providing ABNS >80% of the time resulted in a significant decrease in HA-MRSA bacteremia events in burn patients compared to an MNO. The daily application throughout hospitalization may offer additional protection against MRSA in patients hospitalized for extended periods of time.

Background: The diagnostic approach for Clostridioides difficile infection (CDI) significantly influences treatment and resource utilization. This study compares clinical characteristics and treatment choices based on three testing algorithms combining antigen and toxin enzyme immunoassay (EIA) tests and nucleic acid amplification tests (NAAT). Methods: We performed a retrospective study of patients tested for CDI between August 2022 and November 2024 in a large health system where multiple CDI testing algorithms are utilized: (arm 1) antigen and toxin EIA with automatic reflex to NAAT if discrepant results; (arm 2) NAAT with automatic reflex to toxin EIA if NAAT positive; and (arm 3) antigen and toxin EIA with NAAT at provider request with approval by Antimicrobial Stewardship. The last step in the testing algorithms determined whether the result was considered positive. We determined positivity rate by algorithm results and compared clinical variables including fever (temperature > 38.0° C) or abnormal white blood cell (WBC) count (12,000) within 48 hours prior to test order, laxative use within 24 hours prior to test order and treatment rates between those who tested toxin positive by EIA and those who tested toxin positive by NAAT only. Treatment was defined as receiving oral vancomycin or fidaxomicin for more than 5 days OR receiving those medications on the day prior to or day of discharge. Results: A total of 16,555 patients were tested. Overall algorithm positivity rate was highest in the EIA with reflex to NAAT (arm 1) at 13.7% compared to 5.7% for arm 2 (NAAT with reflex to toxin EIA) and 5.1% for arm 3 (EIA with NAAT at Provider Request). Toxin EIA positive patients were 1.2 times more likely than NAAT positive patients to display fever or abnormal WBC in the 48 hours prior to test order (p < 0 .001). Toxin EIA positive patients were less likely to receive laxatives compared to NAAT only positive patients. (p=0.11). Among toxin EIA positive cases, 89% received treatment compared to 57% in toxin NAAT only positive cases (p < 0 .001). 46% of patients who tested NAAT positive with a subsequently negative toxin EIA were treated. Conclusion: Patients with toxin EIA positive tests were more likely to exhibit systemic signs of infection and were treated at higher rates compared to NAAT-positive cases. While NAAT-based testing identified additional cases, many may reflect colonization. Treatment of toxin NAAT positive/toxin EIA negative patients was common highlighting opportunities for diagnostic stewardship.

Central line-associated bloodstream infections (CLABSI) pose a significant patient risk. To address incorrect classifications of infectious events as CLABSI, the surveillance process was changed from using finalized blood culture to preliminary blood culture results as trigger of timely, in-depth reviews. This improved the detection of true CLABSI events.

Introduction: Social disparities have been shown to impact a wide variety of healthcare outcomes. Surgical site infections (SSIs) are associated with substantial patient morbidity, but studies on the intersection of social disparity and SSI are limited. We sought to evaluate the association between SSI and the Center for Disease Control and Prevention’s social vulnerability index (SVI). Methods: Patients with National Health Safety Network (NHSN) procedure codes for colon, abdominal hysterectomy, hip prosthesis, knee prosthesis and spinal fusion surgeries were retrieved from the electronic medical records of 20 hospitals across 4 geographic markets. SSIs were identified by trained infection preventionists using NHSN definitions. Descriptive statistics were used for baseline demographic and clinical characteristics. Univariate logistic regression was performed to assess the association of demographic, clinical, and procedural factors with the outcome of SSI. Further univariate subgroup analysis was completed by procedure. To account for the nonlinear relationship between the social vulnerability index and SSIs, smoothing splines were used in a Bayesian hierarchical logistic regression model, with random effects to account for the different market practices. Nonlinear effects of procedure duration were also investigated while adjusting for the patient age, procedure type, and health system market. Results: 23,864 surgical procedures among 22,319 unique patients identified between 1 August 2022 and 31 August 2023. 96 patients with infection present at time of surgery were excluded. The study population was mostly white (74%) and female (65%) (Table 1). Less than 13% of the patients had more than one procedure during this time. In a univariate analysis, we found evidence of market and procedure effects, with colon surgery being associated with the highest odds of SSI. Procedure duration was significantly associated with SSI in both univariate and multivariable models, with a drastic increase in the odds of SSI for procedures > 150 mins. In the multivariable model we found that SVIs lower than 0.4 (95% CI 0.28 to 0.55) are associated with an adjusted odds ratio (aOR) < 1. (Figure 1) Conclusions: Our study shows that the relationship of social vulnerability and adverse outcomes is highly complex with nonlinear dynamics at play. After adjusting for procedure type, duration, patient age, gender and health system market the odds of SSIs increase sharply in patients with higher SVI until leveling off at an elevated risk.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common etiology of hospital-acquired infections (HAIs). One strategy to reduce HAIs due to MRSA involves a multistep decolonization process. This often involves nasal application of mupirocin 2% ointment. In our institution, when individuals meet criteria for decolonization, we recommend 5 days of treatment given twice daily. High levels of mupirocin resistance have been reported in some hospital systems, with >80% of tested isolates being resistant. To better understand our resistance levels, we selected 238 MRSA isolates from blood cultures to be tested for mupirocin resistance to correlate the presence of resistance and use of mupirocin for decolonization. We choose to assess MRSA blood isolates rather than nasal swabs given that we aim to prevent invasive MRSA infections, including blood stream infections, with decolonization. The blood cultures were collected from 11 acute-care facilities within our system from March 2021 through June 2022. High-level resistance was defined as an MIC >1,024 μg/mL according to Clinical and Laboratory Standards Institute guidelines. Of those, 7.14% showed high level resistance, and 76.47% occurred in those who were exposed to mupirocin and 23.53% occurred in those without mupirocin exposure (P = .0094). On average, those with high-level resistance had had more recent exposure to mupirocin compared to those without resistance, which was statistically significant. Also, those with high resistance, on average, received more doses of mupirocin, although this was not statistically significant. Conclusions: More recent and higher number of doses of mupirocin were associated with the development of resistance, which is consistent with what we know from pharmacodynamics of antibiotic resistance with other agents. These findings may be particularly important for those patients who have frequent hospitalizations and often require decolonization. Understanding baseline mupirocin resistance levels in an institution can assist with determining decolonization strategies.

Disclosures: None

Background: High-efficiency particulate air (HEPA) filters are currently recommended when using recirculated air to eliminate the risk of pathogen transmission such as SARS-CoV-2 from one patient care area to the next. We tested the efficacy of lower-grade air filters in eliminating airborne virus transmission. Methods: We conducted an experiment in 2 adjacent exam rooms in an unoccupied hospital emergency unit. The HVAC system contained a 15,000-cubic-feet-per-minute rooftop air handler. All outside air and exhaust dampers were closed during the trial (full air recirculation). We conducted experiments in 3 tests arms with varying grades of MERV filters (AAF Flanders, Louisville, KY): (1) control without filters, (2) MERV8+14 filters, and (3) MERV8+16 filters. We repeated 20-minute virus challenge runs 3 times per test arm. Live attenuated influenza vaccine (2 mL LAIV, FluMist Quadrivalent 2020/21, AstraZeneca, Wilmington, DE), was aerosolized into the HVAC system via a commercial nebulizer. Air was sampled using 3 six-stage Andersen air samplers placed in the center of the adjacent room. Environmental particle counts were collected using a particle counter (PEC-PCO-1, PCE Americas). Results: Concentrations of viral RNA were determined by qPCR, and viral concentrations (vg/mL) in each stage of each arm were compared directly. Pairwise comparisons of the virus and particle burdens across each stage of each test arm were made using a general linear model. LAIV was detected in the control arm at a virus burden of 2,277 vg/mL, indicating a >6.5 log reduction of the virus released in the HVAC system (8.8×109 total vg). In the second arm, the MERV8+MERV14 filters demonstrated in a 13-fold decrease in viral burden compared to the control arm (mean virus burden: 169 vg/mL, p Our study demonstrates that viral containing particles can be transported via a hospital HVAC system from one patient room to the next. Considering the decrease in detectable virus within the HVAC system, the combination of MERV8+MERV16 filters reduced the virus burden reaching an adjacent room to levels well below the human infectious dosages for influenza and other highly infective viruses. Conclusions: Our findings indicate that MERV8+MERV16 filters provide protection against virus transmission through HVAC systems and are a cost-conscious alternative to HEPA filters.

Funding: None

Disclosures: None

Engineering controls play an important role in reducing the spread of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).1 Established technologies such as air filtration, and novel approaches such as ultraviolet (UV)-C light or plasma air ionization, have the potential to support the fight against the coronavirus disease 2019 (COVID-19) pandemic.2 We tested the efficacy of an air purification system (APS) combining UV-C light and high-efficiency particulate air (HEPA) filtration in a controlled environment using SARS-CoV-2 as test organism. The APS successfully removed the virus from the air using UV-C light by itself and in combination with HEPA air filtration.

This SHEA white paper identifies knowledge gaps and challenges in healthcare epidemiology research related to coronavirus disease 2019 (COVID-19) with a focus on core principles of healthcare epidemiology. These gaps, revealed during the worst phases of the COVID-19 pandemic, are described in 10 sections: epidemiology, outbreak investigation, surveillance, isolation precaution practices, personal protective equipment (PPE), environmental contamination and disinfection, drug and supply shortages, antimicrobial stewardship, healthcare personnel (HCP) occupational safety, and return to work policies. Each section highlights three critical healthcare epidemiology research questions with detailed description provided in supplementary materials. This research agenda calls for translational studies from laboratory-based basic science research to well-designed, large-scale studies and health outcomes research. Research gaps and challenges related to nursing homes and social disparities are included. Collaborations across various disciplines, expertise and across diverse geographic locations will be critical.

Background: Antibiotic stewardship programs (ASPs) have traditionally focused on inpatient prescribing, but they are now mandated to involve ambulatory settings. We developed and tested an educational tool in resident physicians to empower outpatient providers to perform self-reflection stewardship (SRS) to improve their antibiotic use. Results of the first SRS workshop are reported. Methods: A 90-minute SRS workshop focusing on the evaluation and management of sinusitis in ambulatory care was developed for PGY 2-3 internal medicine residents. Participants received a 15-minute didactic on the evaluation and management of adults with sinusitis, including typical microbiology, differentiation of bacterial sinusitis, and guideline recommendations on antibiotic treatment. In a computer lab, participants were instructed how to review charts of patients they had treated with antibiotics for sinusitis during the past year using the SlicerDicer application in Epic. Over 1 hour, they worked in pairs to complete and discuss a self-reflection inventory for 5 patients from each of their respective reviews. They evaluated pertinent history, comorbidities, presenting symptoms and signs, diagnostic testing performed, and a self-assessment of the subsequent antibiotic prescribing, including appropriateness of using an antibiotic, antibiotic choice and duration. In addition, they reflected on potential patient and prescriber challenges. Residents then identified common themes and developed a personal improvement plan for antibiotic prescribing for sinusitis. The last 15 minutes were spent debriefing with ASP faculty on reasons for overprescription of antibiotics for URIs and individual improvement plans. Residents completed workshop evaluations using a Likert scale and open-ended comments. Results: In total, 26 residents participated. All (100%) agreed or strongly agreed that the SRS workshop improved their understanding of how to obtain data on their own practice habits. Moreover, 23 (88%) agreed or strongly agreed that the workshop improved their understanding of when to prescribe antibiotics and how to practice antibiotic stewardship in the outpatient setting. Also, 20 participants (77%) agreed or strongly agreed that the SRS workshop helped them gain insight into reasons why they might overprescribe antibiotics in the outpatient setting. Furthermore, 25 (96%) agreed or strongly agreed that the SRS workshop helped them identify at least 1 way they could improve their antibiotic prescribing in the outpatient setting. Conclusions: The SRS workshop was well received by residents and offers a tool to empower primary care resident physicians to access their own antibiotic prescribing data, perform a structured self-reflection, and enhance their understanding of antibiotic stewardship in the ambulatory setting. SRS is a potential tool to improve ambulatory antibiotic use.

Disclosures: None

Funding: None

N95 respirator masks are recommended for protection against respiratory viruses. Despite passing fit-testing 10% of N95 respirator users encountered breakthroughs with exposure to influenza virus compared to full protection provided by a powered air purifying respirator. The current recommendation of N95 respirators should be evaluated for endemic and emerging scenarios.

Using a validated air sampling method we found Acinetobacter baumannii in the air surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients’ closed-circuit ventilator status, frequent air exchanges in patient rooms, and short sampling time may have contributed to this low burden.

Infect Control Hosp Epidemiol 2015;36(7):830–832

The common cold affects millions of people. Unfortunately, it remains unknown whether cold viruses enter the respiratory tract only through the nose and mouth or whether they can also enter through the tear ducts. Transocular exposure to an airborne infectious dose of human rhinovirus did not lead to infection.