Background: Candida auris is an emerging, healthcare?associated pathogen that persists on skin and in the environment. Early identification of colonized patients is central to interrupting transmission, but the optimal screening cadence in cluster settings is uncertain. We evaluated whether intensifying targeted screening and transitioning to in?house PCR were associated with changes in clinical cases at a large quaternary academic medical center. Methods: We conducted a retrospective study from November 2022 through March 2024 in hospital units experiencing C. auris clusters. Screening frequency was escalated in phases—from biweekly to weekly—and later transitioned to in?house PCR to enable faster turnaround and earlier implementation of infection?prevention actions (e.g., isolation/cohorting and enhanced environmental cleaning) per institutional protocol. The primary outcome was the monthly number of new clinical C. auris cases, defined as non?screening clinical isolates with urine and sputum excluded. The secondary outcome was colonization detected by screening PCR or by urine or sputum cultures. Monthly outcomes were monitored with statistical process control (control charts centered on phase?specific means), and effects across phases were summarized as percentage changes versus baseline. Results: Thirty?eight clinical cases were identified; median age was 55 years (IQR 44–65), and 66% were male. Most clinical isolates originated from blood and wound/tissue sources. Fifteen cases (39%) had a prior positive surveillance test; the median time from first positive screen to subsequent clinical isolate was 27 days (IQR 17–120). Monthly clinical cases decreased from 2.5 during biweekly screening to 2.0 with weekly screening (?20%) and to 1.7 after adoption of in?house PCR (additional ?15%; -32% overall vs baseline) (Figure 1). Colonization detections increased when screening frequency changed from biweekly to weekly (5.3 to 13.8 per month; +160%) and then declined after in?house PCR (to 10.2 per month; -26%). These patterns were concordant with control?chart signals at the phase changes. Conclusions: Targeted, more frequent screening coupled with rapid in?house PCR was associated with fewer clinical C. auris cases and with higher detection of colonization, consistent with earlier identification and response. Because the clinical?case metric is less sensitive to testing intensity and speciation practices than colonization counts, it may better capture the impact of hospital interventions on transmission. Findings are limited by the single?center, retrospective design, potential confounding from concurrent infection?prevention measures, and use of monthly counts rather than rates; nonetheless, the phased approach provides actionable evidence to guide surveillance strategies during C. auris clusters.

We compared plasma microbial cell-free DNA sequencing (mcfDNAseq) with an amplicon-based blood next-generation sequencing (NGS) assay for 10 patients with suspected bloodstream or endovascular infection. Plasma testing detected pathogens in eight (seven clinically meaningful), whereas amplicon testing was negative in all. Plasma mcfDNAseq provided higher test yield and overall sensitivity.

Candida auris screening in units meeting a prespecified cluster threshold was intensified from biweekly to weekly and paired with rapid in-house PCR (November 2022-March 2024). Monthly incident clinical cases decreased by 32%. Colonization detections increased with weekly screening and declined after in-house testing, supporting earlier case finding and response.

Background: Diagnosing invasive mold infections (IMI) is challenging because they typically occur as opportunistic infections in immunocompromised patients who often present with non-specific symptoms. Furthermore, no single test can definitively diagnose IMI, and a proven diagnosis often requires invasive sampling. This sampling can be unsafe and difficult to perform, especially in the immunocompromised population most at risk for these infections. Objectives: The objective of this study is to assess the clinical utility of plasma microbial cell-free DNA next-generation sequencing (mcfDNA-NGS) for diagnosing invasive mold infections in the context of conventional diagnostic methods. Design: Retrospective observational study at a quaternary care center (2017–2025). Methods: The charts of 30 patients with mold-positive mcfDNA-NGS (Karius™ Spectrum; Redwood City, CA, USA) were reviewed, with IMI adjudicated per 2020 EORTC/MSGERC criteria. Provider documentation, medication orders, and patient outcomes were used to assess clinician interpretation of mcfDNA-NGS result accuracy (true positive vs false positive) and its impact on diagnostic and therapeutic decision-making. Turnaround time (TAT) and molecules per microliter (MPM) were summarized. Results: IMI final classifications were proven (6), probable (8), possible (5), and unclassified (11). Overall, 23/30 (77%) results were true positives. Among these 23 patients with true positive results for mold, 5 (22%) received a new clinical adjudication of IMI that had been entirely missed by conventional diagnostic testing. Furthermore, mcfDNA NGS provided species-level pathogen identification in 9 of the 23 (39%) true positive cases where conventional testing detected fungal elements or elevated biomarkers but could not identify the specific organism. Median TAT was 102 h; median MPM 657. MPM did not differ between true and false positives ( p = 0.86). mcfDNA-NGS changed diagnostic classification in 7/30 (23%) and antimicrobial management in 16/30 (53%). Conclusion: mcfDNA-NGS provided noninvasive, actionable information, informing diagnosis and therapy. Future studies should define optimal stewardship and cost-effectiveness.

Background:Emergency department (ED) urine culture stewardship may reduce low-value testing, but downstream effects on antibiotic use and postdischarge utilization remain uncertain. Methods:We evaluated an intervention in which an infectious diseases physician and microbiologist reviewed pyuric urinalysis-with-reflex encounters, assessed culture indications, and contacted clinicians to recommend cancellation when absent. Adult ED encounters from February-July 2025 to September 2025-February 2026 were included; August was washout. Outcomes were urinalysis with reflex within 24 hours, urine culture within 24 hours, antibiotic days of therapy (DOT) per 100 patient-days, length of stay (LOS), and 30-day ED revisit among ED discharges. We fit biweekly interrupted time series models. Results:Among 17,621 encounters, the intervention was associated with lower postintervention slopes for urinalysis with reflex within 24 hours (-0.5 percentage points per biweekly period; 95% CI, -0.9 to -0.1) and urine culture within 24 hours (-0.2 percentage points; 95% CI, -0.4 to -0.0). DOT showed no sustained change (postintervention slope change, 0.00; 95% CI, -0.23 to 0.24). LOS showed a lower postintervention slope (-0.05 d; 95% CI, -0.08 to -0.02). Thirty-day ED revisit showed a higher postintervention slope (0.8 percentage points; 95% CI, 0.3 to 1.3). Conclusions:The intervention reduced urinary testing but did not reduce antibiotic DOT and was associated with increased 30-day ED revisit. Diagnostic stewardship in the ED may need to be paired with antimicrobial stewardship and prospective safety monitoring.

During an 87-week interrupted time series, we evaluated screening positivity after de-escalating dedicated cohort units for Candida auris and later implementing enhanced nursing engagement. Discontinuing cohort units did not increase adjusted screening positivity, whereas enhanced engagement was associated with lower positivity. Findings support sustained frontline engagement and clear screening/isolation workflows when cohorting is de-escalated.

Chronic Q fever can present as culture-negative aortic endograft infection with osteomyelitis. Plasma microbial cell-free DNA sequencing unexpectedly detected Coxiella burnetii before serology, prompting exposure reassessment and targeted therapy. Later operative cultures grew Eikenella corrodens, underscoring the need to pair molecular results with serology and source-control microbiology.

BACKGROUND:Hospital-onset bacteremia and fungemia (HOB) has been proposed as an electronic surveillance outcome, but deidentified electronic health record data require transparent organism handling when chart review is unavailable. METHODS:We analyzed deidentified HOB records from Epic Cosmos and retained the first positive blood-culture event per admission on or after hospital day 4. Organism text was standardized and linked to a locally developed workbook based on common-commensal organism logic and review by infectious diseases physicians and laboratory directors. Events were assigned to 4 algorithm-defined operational classes: likely pathogen, possible pathogen, likely contaminant, or unclassified. We summarized class distribution and organism patterns. A logistic model comparing likely contaminant with likely pathogen events was exploratory. RESULTS:Among 77,261 event-level records, 69,303 first events per admission comprised the analytic cohort. Events were likely pathogen (44,239; 63.8%), possible pathogen (6,093; 8.8%), likely contaminant (663; 1.0%), or unclassified (18,308; 26.4%). Unclassified events lacked usable organism tokens. Staphylococcus epidermidis accounted for 10.4% of classifiable organism tokens and 66.5% of likely contaminant tokens. The likely contaminant class was intentionally narrow. CONCLUSIONS:A transparent electronic algorithm classified HOB events into operational surveillance classes at scale. Site-level validation is needed before benchmarking or reporting.

From 2017 to 2025, we reviewed plasma microbial cell-free DNA sequencing (mcfDNA NGS) results detecting Toxoplasma gondii. Five patients were identified. Median turnaround was 3 days (2-5). mcfDNA initiated therapy in two and supported empiric treatment in three but required clinical context for interpretation.

Tropheryma whipplei was identified by plasma microbial cell-free DNA sequencing within 4 days in severe culture-negative endocarditis after antibiotics had already been started. The result supported earlier diagnostic clarification and antimicrobial de-escalation before valve pathology was available, illustrating a practical diagnostic-stewardship role for noninvasive sequencing in high-acuity endocarditis.

We examine the impact of microbial cell-free DNA (mcfDNA) NGS for the diagnosis of Histoplasma capsulatuim in a quaternary referral center in Texas. Of eight included patients, five had a change in their antifungal coverage after mcfDNA NGS results with faster turnaround times than antigen testing and cultures.

Background:Invasive candidiasis including candidemia is a common healthcare-associated infections with significant morbidity and mortality. The USA does not have mandatory national surveillance for mucocutaneous or invasive candidiasis which complicates estimation of epidemiology and outcomes. The aim of this project was to describe the epidemiology, mortality, and Candida-associated hospital readmissions in hospitalized patients with Candida species infections. Methods:This secondary database analysis used clinical microbiology data from adults hospitalized at three large health systems (25-hospitals) in the Greater Houston area totaling over 1.6 million hospitalization days per year from 2018 to 2023. Proportion and rates of Candida cultures per 10,000 hospitalization days were calculated. Risk factors for mortality and Candida-associated readmissions were assessed by multivariable logistic regression. Results:Within the study period, 7514 hospitalized patients aged 64 ± 16 years (mean± standard deviation (SD)) with 10,183 unique Candida cultures were identified. Majority of Candida cultures were nosocomial (59%) with wide variability in mean time to positive culture (9 ± 44 days) after admission. Candida specimens were from blood (32%), abdomen (29%), or mucocutaneous (24%) cultures and most commonly C. albicans (44%) or C. glabrata (21%). C. auris increased significantly from 2% of cultures from 2018-20 to 5% in 2021-23 (p < 0.0001). Length of hospital stay was 21 ± 34 days and inpatient mortality was 17%. Multivariable analyses identified hospitalization variables and Candida species predictive of inpatient all-cause mortality and Candida-associated readmissions after initial hospitalization. Conclusion:These analyses highlight the significant burden of candidiasis and the emergence of new strains, including C. auris. Ongoing surveillance can refine burden estimates and assess the impact of stewardship and infection control interventions.

Background: Human herpesvirus-8 (HHV8) can present with cutaneous or extracutaneous manifestations. While violaceous skin lesions characterize cutaneous Kaposi sarcoma, extracutaneous HHV8 is challenging to diagnose due to nonspecific symptoms. Objectives: We evaluated the role of microbial cell-free DNA next-generation sequencing (mcfDNA NGS) in diagnosing HHV8-related illness. Design: Retrospective analysis. Methods: Between 2017 and 2024, we reviewed the medical charts of 10 immunosuppressed patients at a quaternary care center who had positive HHV8 mcfDNA NGS results. Results: The clinical and laboratory turnaround times of mcfDNA NGS were 3 and 1 days, respectively (8.5 and 7 days for immunohistochemistry vs 5.5 and 2 days for serum HHV8 polymerase chain reaction). Eight patients received HHV8-related diagnoses, while two had unrelated conditions. Management changed in six patients post-testing due to outpatient specialist referral or adjusting antimicrobials. Conclusion: mcfDNA NGS can aid clinicians in identifying HHV8-related diseases before tissue sampling and adjusting treatment plans in patients with nonspecific disease manifestations.

Background: While broad gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels can test for various bacterial, viral, and parasitic pathogens, their overuse may yield a high financial burden on hospital systems without clear clinical relevance of all covered organisms. This study aims to assess whether a multifaceted quality improvement intervention directing clinicians to a more limited panel and requiring several restriction criteria would reduce direct hospital costs for patients with suspected infectious diarrhea. Methods: Our quasi-experimental study included patients from a quaternary academic medical center in Texas. In the pre-intervention period (March 2024-June 2024), the Biofire® FilmArray® Gastrointestinal Panel (BioFire Diagnostics, Salt Lake City, UT) was the preferred test for patients presenting with suspected infectious diarrhea and had minimal ordering restrictions (Figure 1). In the post-intervention period (August 2024- November 2024), a second narrower panel (GI Common Pathogen PCR panel) was introduced as the preferred test with some restrictions, while the Biofire® FilmArray® GI Panel was only available to severely immunosuppressed patients and required Infectious Diseases consultation. The restriction criteria were built in the Epic electronic health system (Epic System Corporation, Verona, WI). Information on the intervention was distributed through email memorandums and an internal secure clinical messaging platform. Count control charts were used to visualize the number of FilmArray® GI Panels conducted, while individual control charts were used for the direct laboratory costs of both GI panels. Results: 893 patients had suspected infectious diarrhea in the study period (451 pre-intervention, 442 post-intervention). The average number of weekly FilmArray® GI Panel tests performed dropped from 24.8 to 1.9 (Figure 2), and an average of 21.9 GI Common Panel tests per week were performed in the post-intervention period. The average weekly testing cost decreased from $3,418.10 to $940.40 after the intervention (Figure 3). The two control charts demonstrated the presence of special cause variation for both outcomes (weekly FilmArray® GI Panel tests and combined costs), indicating a change after the intervention. Conclusion: Although the total number of tests did not change after adjusting the restriction criteria, this intervention significantly reduced the direct laboratory costs of the GI Panels after guiding clinicians to a more economical test (GI Common Panel), with an estimated annual savings of $128,840. This study provides a diagnostic stewardship opportunity for cost reduction in healthcare systems. Future evaluation will analyze its impact on antimicrobial utilization and infection control metrics.

Redundant and low-value cerebrospinal fluid analysis for suspected meningitis can increase costs and antimicrobial use. Our diagnostic stewardship intervention limited available infectious disease cerebrospinal fluid assays to seven common tests, including a multiplex polymerase chain reaction panel. There was no significant difference in the cost of testing or clinical outcomes.

We examine the performance of microbial cell-free DNA (mcfDNA) next-generation sequencing (NGS) testing on patients admitted to a quaternary care hospital in Houston, Texas. The test was 75.0% sensitive and 97.8% specific for all mycobacterial infections. mcfDNA NGS results led to adjustments in antimicrobial therapy for seven of nine patients with positive results.

Background: Cerebrospinal fluid (CSF) cultures are commonly performed to evaluate patients with suspected bacterial meningitis. These cultures, however, can take up to 72 hours, leading to delays in antibiotic de-escalation and increased antimicrobial utilization. The turnaround for the BioFire® FilmArray® Meningitis/Encephalitis(FA/ME) panel is less than an hour, which may facilitate early de-escalation. Our study aimed to assess whether the use of FA/ME panels in combination with CSF cultures could impact antimicrobial therapy compared to cultures alone in patients treated for suspected bacterial meningitis. Methods: Our retrospective study included patients from five hospitals in Texas (2017-2023) who received empiric antibiotics for suspected community-acquired meningitis and underwent a lumbar puncture within 96 hours of admission. Patients with ventricular drains, traumatic brain injury, and non-central nervous system infections were excluded. Cases comprised patients who had an FA/ME panel performed, while controls included patients without the panel. Outcomes were defined as the empiric duration of antimicrobial therapy (days) and total days of antibiotic therapy (DOT). Wilcoxon Rank Sum test and multiple linear regression models were applied to assess the relationship between the use of the FA/ME panel and study outcomes. Independent variables comprised demographics, institution type, acuity, clinical presentation, CSF values, and FA/ME panel use. Imputation was performed using multiple imputation by chained equations. Results: A total of 193 patients were included in our study. Seventy-one patients received the FA/ME panel (along with the CSF culture), while 122 patients received the CSF culture alone (controls). The median empiric duration of antibiotic therapy in the cases and controls were 1.71 days and 1.18 days, respectively (p = .160). The median DOT in the cases and controls were eight days and six days, respectively (p = .045). After adjusting for confounders, the FA/ME panel was not significantly associated with changes in the empiric duration of antibiotic therapy (B= 0.18, p = .669, Figure 1) or DOT (B= 1.28, p = .170, Figure 2).Conclusion: Providing FA/ME panel testing without active antimicrobial stewardship interventions did not result in a change in antimicrobial prescribing patterns. The difference from prior literature could be explained by the smaller sample size, limiting the power of the study. Further prospective antimicrobial stewardship efforts should focus on training providers on interpreting FA/ME panel results and providing prospective audits and feedback.

The BioFire® FilmArray® meningitis/encephalitis (FA/ME) panel provides rapid testing for common cerebrospinal fluid pathogens. We compared empiric antibiotic utilization between patients with suspected community-acquired meningitis with and without an FA/ME panel ordered. No significant differences in antibiotic use were found.

We report 9 patients with invasive Bartonella infections, including 5 with endocarditis, who were diagnosed with microbial cell-free DNA next-generation sequencing and Bartonella serology studies. Diagnosis with plasma mcfDNA NGS enabled a faster clinical and laboratory diagnosis in 8 patients. Prompt diagnosis impacted antibiotic management in all 9 patients.

Variations in the literature support the benefit of contact precautions for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) infections in the hospital setting. During personal protective equipment shortages throughout the COVID-19 pandemic, contact precautions were discontinued for MRSA and VRE-infected patients. Rates of hospital-acquired MRSA and VRE infections were compared before and after this intervention, along with hand hygiene proportions. Contact precaution discontinuation did not lead to an increase in hospital-acquired MRSA or VRE infections.