Methicillin-resistant Staphylococcus aureus nasal swabs: trends in use and association with outcomes

Objective:To investigate patterns of early methicillin-resistant Staphylococcus aureus (MRSA) nasal swab use in US hospitals and the association with de-escalation of MRSA-specific antibiotics.Design:Retrospective cohort study.Setting:PINC-A1 Healthcare Database (2008–2021).Participants:Adults with sepsis present on admission who received invasive mechanical ventilation by hospital day 1.Methods:We assessed interhospital variation and time trends in early polymerase chain reaction-based MRSA nasal swab use using bivariable regression. Next, we used competing risks multivariable regression to assess the association of early (started by hospital day 2) anti-MRSA antibiotic duration with care in a high (≥90%) versus low (<10%) swab use hospital.Results:We included 699,474 patients across 788 hospitals to evaluate trends in early swab use; 151,205 (21.6%) received a swab. Use of swabs varied across hospitals (median use: 6.0% [interquartile range: 0–37.6%; full range: 0%–98.0%]; median odds ratio [95% CI]: 84.7 [63.3–115.6]) and overall use increased over time (3.5% in 2008 quarter 1 increasing to 29.5% in 2021 quarter 4; regression coefficient [95% CI]: 0.14% [0.12%–0.15%]). Considering 41,599 patients (9,796 [23.6%] in 33 hospitals where ≥90% received swabs and 31,763 [76.4%] in 67 hospitals with <10% use), anti-MRSA antibiotic durations were shorter in hospitals where ≥90% (vs < 10%) received a swab (adjusted sub-hazard ratio for discontinuation of antibiotics [95% CI]: 1.17 [1.04–1.31], P = .007).Conclusions:Use of early polymerase chain reaction-based MRSA nasal swabs varied across US hospitals and increased over time. Receiving care in a hospital with higher swab use was associated with shorter anti-MRSA antibiotic duration

Aseptic meningitis in adults and children: Diagnostic and management challenges

•Aseptic Meningitis have unknown etiologies in 81% of patients.•Currently available virological tools are underutilized.•The majority of patients undergo unnecessary cranial imaging and antibiotic therapy.•All patients had a good clinical outcome. Aseptic meningitis represents a common diagnostic and management dilemma to clinicians. To compare the clinical epidemiology, diagnostic evaluations, management, and outcomes between adults and children with aseptic meningitis. We conducted a retrospective study from January 2005 through September 2010 at 9 Memorial Hermann Hospitals in Houston, TX. Patients age≥2months who presented with community-acquired aseptic meningitis with a CSF white blood cell count >5cells/mm3 and a negative Gram stain and cultures were enrolled. Patients with a positive cryptococcal antigen, positive blood cultures, intracranial masses, brain abscesses, or encephalitis were excluded. A total of 509 patients were included; 404 were adults and 105 were children. Adults were most likely to be female, Caucasian, immunosuppressed, have meningeal symptoms (headache, nausea, stiff neck, photophobia) and have a higher CSF protein (P <0.05). In contrast, children were more likely to have respiratory symptoms, fever, and leukocytosis (P <0.05). In 410 (81%) patients, the etiologies remained unknown. Adults were more likely to be tested for and to have Herpes simplex virus and West Nile virus while children were more likely to be tested for and to have Enterovirus (P <0.001). The majority of patients were admitted (96.5%) with children receiving antibiotic therapy more frequently (P <0.001) and adults receiving more antiviral therapy (P=0.001). A total of 384 patients (75%) underwent head CT scans and 125 (25%) MRI scans; all were normal except for meningeal enhancement. All patients had a good clinical outcome at discharge. Aseptic meningitis in adults and children represent a management challenge as etiologies remained unknown for the majority of patients due to underutilization of currently available diagnostic techniques

The clinical effectiveness of REGEN-COV in SARS-CoV-2 infection with Omicron versus Delta variants

In vitro studies suggesting that REGEN-COV (casirivimab plus imdevimab monoclonal antibodies) had poor efficacy against Omicron-variant SARS-CoV-2 infection led to amendment of REGEN-COV's Emergency Use Authorization to recommend use only in regions without high Omicron prevalence. REGEN-COV's relative clinical effectiveness for Omicron is unknown. We conducted a retrospective cohort study of non-hospitalized adults who tested positive for SARS-CoV-2 by polymerase chain reaction at the University of Miami Health System from July 19 -November 21, 2021 (Delta period) and December 6, 2021 -January 7, 2022 (Omicron period). Subjects were stratified be REGEN-COV receipt within 72h of test positivity and by time period of infection. We constructed multivariable logistic regression models to assess the differential association of REGEN-COV receipt with hospitalization within 30 days (primary outcome) and ED presentation; all models included three exposure terms (REGEN-COV receipt, Omicron vs Delta period, interaction of REGEN-COV with time period) and potential confounders (vaccination status, vaccine boosting, cancer diagnosis). Our cohort consisted of 2,083 adults in the Delta period (213 [10.2%] received REGEN-COV) and 4,201 in the Omicron period (156 [3.7%] received REGEN-COV). Hospitalization was less common during the Omicron period than during Delta (0.9% vs 1.7%, p = 0.78) and more common for patients receiving REGEN-COV than not (5.7% vs 0.9%, p<0.001). After adjustment, we found no differential association of REGEN-COV use during Omicron vs Delta with hospitalization within 30d (adjusted odds ratio [95% confidence interval] for the interaction term: 2.31 [0.76-6.92], p = 0.13). Similarly, we found no differential association for hospitalization within 15d (2.45 [0.63-9.59], p = 0.20) or emergency department presentation within 30d (1.43 [0.57-3.51], p = 0.40) or within 15d (1.79 [0.65-4.82], p = 0.30). Within the limitations of this study's power to detect a difference, we identified no differential effectiveness of REGEN-COV in the context of Omicron vs Delta SARS-CoV-2 infection

Inter-rater agreement of CAUTI (catheter-associated urinary tract infections) diagnosis among Infectious disease physicians

Background: CAUTIs constitute forty percent of nosocomial infections, yet their direct link with mortality remains debated. In 2009, NHSN estimated the economic burden of CAUTIs in the U.S. to be over $340 million. Limited data exist on inter-physician concordance in diagnosing CAUTIs, especially in patients with abnormal genitourinary (GU) anatomy. Our study assessed inter-provider variability in diagnosing CAUTI in 50 such patients, including those meeting NHSN(National healthcare safety network) criteria. Methods: We included a random set of 50 adults (18+) with abnormal GU anatomy admitted to the University of Miami hospitals from January 2018 to November 2021 who had a urinary foley catheter and at least one positive urine culture during their hospitalization. Three Infectious disease fellows and three board-certified Infectious disease physicians independently reviewed each patient’s chart, classifying them as having or not having a CAUTI. Inter-physician reliability was assessed using kappa statistics. Results: Our findings highlight substantial variation in clinician-determined CAUTI incidence among the 50 patients with abnormal GU anatomy, ranging from 8% to 32% (Figures 2,3). Inter-rater agreement on CAUTI diagnosis was generally poor (Kappa Hollenbeak CS, et al. The attributable cost of catheter-associated urinary tract infections in the United States: A systematic review. Am J Infect Control. 2018 Jul;46(7):751-757. Trautner BW, et al. Development and validation of an algorithm to recalibrate mental models and reduce diagnostic errors associated with catheter-associated bacteriuria. BMC Med Inform Decis Mak. 2013 Apr 15;13:48. Gafary M, et al. Catheter Associated Urinary Tract Infections (CAUTI) in Bladder Cancer Patients Post Cystectomy With a Neobladder, Open Forum Infectious Diseases, Volume 2, Issue suppl_1, December 2015, 293

Improving Consistency and Accuracy: A Novel C. auris Colonization Screening Strategy Using a Nares + Hands Composite Swab

Background: Candida auris is often identified in healthcare settings through bilateral composite of axilla/groin skin swabs screening. Re-screening the same patient has demonstrated inconsistent results over time, complicating the understanding of longitudinal colonization and limiting confidence in negative Results: Previous studies have described identification of colonized patients using other anatomical sites. Here, we compare bilateral composite of nares/hands with bilateral composite of axilla/groin screenings in a cohort of hospitalized patients in Miami, Florida, to assess the use of screening other body sites for C. auris surveillance. Methods: This study took place in a 560-bed academic acute-care facility and included patients previously colonized with C. auris who were cohorted on a 30-bed unit. Bilateral composite samples from both the axilla/groin and nares/hands were obtained simultaneously. Swabs were collected at six different time points at biweekly intervals between March and May 2023 (Figure 1) and sent to the Centers for Disease Control and Prevention for testing with culture and Real-time PCR-based methods. Results: A total of 102 swabs (51 from each swab type) were collected from 19 patients who were each sampled a median of twice (IQR: 1-5). Among the 102 swabs, 35 of 51 (69%) axilla/groin swabs were positive compared with 45 of 51 (88%) nares/hands swabs using culture (Figure 2). Furthermore, 48 of 51 (94%) swabs were positive by culture for both methods, with 15 positive from the nares/hands and one positive from the axilla/groin (Figure 3). Among 11 patients who were tested ≥2 times with nares/hands swabs, 9/11 (81%) tested positive on all sequential swabs via culture and 10/11 (90%) tested positive via PCR (Ct threshold < 3 6.9). Among the same 11 patients but using the axilla/groin swabs, 3/11 (27%) patients tested positive on all sequential swabs using culture, and 5/11 (45%) tested positive using PCR (Figures 2-4). On average, samples collected from nares/hands swabs had lower Ct values (mean=27) compared to axilla/groin swabs (mean=31) (p-value=< 0.001) (Figure 5). Discussion: Identifying the swab site with most consistent C. auris detection is important for surveillance purposes. In our study, there were more positives and consistent positivity for nares/hands by both culture and PCR-based methods, as well as lower Ct values, suggesting that these swabs provide more reliable detection of C. auris colonization. Alternative screening methods deserve consideration as CDC continues to explore whether swabbing of other body sites (e.g., nares, hands) would improve accuracy and consistency when identifying colonized patients

2039. Evaluation Of Diagnostic Considerations In The Evaluation Of Hospital Acquired Pneumonia

Abstract Background Hospital-Acquired Pneumonia (HAP), defined as pneumonia that occurs 48 hours or more after hospital admission, is considered a part of the health care-associated infections (HAIs). HAIs are one of the top ten causes of death in the United States. Correct diagnosis of HAIs is key to reducing its impact, however, the diagnosis of HAP is challenging because clinical findings are nonspecific and there is no combination of signs, symptoms, and laboratory or imaging results that can predict this diagnosis with a good sensitivity or specificity. This study aims to clarify the prioritization of clinical elements considered in the diagnosis of HAP by physicians at our center. Methods This is a cross-sectional study at a large, tertiary care academic center in Miami, Florida. The target population included hospitalists, internal medicine residents, critical care and infectious disease fellows. REDCap was used to administer the survey and collect data. A rank individual analysis was conducted to assess for the most significant diagnostic criteria overall. Kruskal-Wallis analysis was conducted to assess for significance of the individual diagnostic criteria. Results At the end of the survey period, 130 people responded (45.8% of sent surveys). Overall Kruskal-Wallis rank sum test of the systemic factors showed significant differences between the diagnostic criteria chosen. The presence of a new or worsening infiltrate on imaging was selected as most important. After that, fever, a positive respiratory culture, worsening hypoxia and new cough and shortness of breath were in the second tier of important criteria (Figure 1). The median number of factors needed to have HAP in the differential diagnosis and start empiric treatment was 3, while the needed number to secure the diagnosis of HAP was 4. In an immunocompromised patient, the median number of factors needed was 2 (Figure 2). Color red, represents selection 1 - meaning, the larger the tab, it means that specific factor was highly considered as the first factor in the diagnosis of HAP. Color green represents second most selected factor Color blue represents third most selected factor Upper box: median number of factors needed to secure the diagnosis of HAP Mid box: median number of factors needed to include HAP as the differential diagnosis in an immunocompromised patient Lower box: media number of factors needed to have HAP in the differential and start empirical treatment Conclusion In this study, we observed that the most highly considered criteria for the diagnosis of HAP are new or worsening infiltrate on imaging, new or worsening hypoxia, and respiratory cultures with growth of a classical respiratory pathogen. Most of these criteria are part of the IDSA guidelines on the evaluation and treatment of HAP. Future directions include developing a decision support tool for diagnosing HAP. Disclosures All Authors: No reported disclosures