bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-2107. Diagnostic accuracy of Nucleic Acid Amplification Tests for detection of Mycobacterium leprae in suspected leprosy patients from northern region of India
Authors: Yadav Rakesh , Saini Gurmeet , Kaur Manjot , Narang Tarun , Dogra Sunil , Sethi Sunil 
Published: January 2025

Abstract

Background
Leprosy is a chronic infectious disease, still remains a significant health problem in several parts of the world. A rapid and accurate diagnosis of the disease is essential for better management of Leprosy cases. In this study we compared three molecular methods i.e. PCR, Real TIME PCR and Loop-mediated isothermal amplification (LAMP) assay for detection of mycobacterium leprae.

Methods
A total of 114 samples were taken from 92 clinically leprosy suspected patients and contacts. DNA was extracted from the samples and molecular assays i.e. PCR, Real TIME PCR and LAMP was performed in parallel. Diagnostic accuracy of each test and Cohen's kappa coefficient was calculated using medcal online software.

Results
Among the 114 samples tested, the M leprae was detected in 35.09%(40/114), 34.2% (39/114) and 32.4%(37/114) by LAMP, conventional PCR, and real-time PCR, respectively. The overall agreement between conventional PCR and LAMP for detection of M leprae was 97.3% with a Cohen's kappa coefficient of 0.94, indicating perfect agreement. Similarly, the agreement between real-time PCR and LAMP for detection of M leprae was 97.3% with a Cohen's kappa coefficient of 0.94. However, the overall diagnostic accuracy of PCR, Real Time PCR and LAMP for detection of M leprae was 83.2%, 81.2% and 81.2%, respectively.

Conclusion
All molecular assays i.e. PCR, Real TIME PCR and LAMP had shown a similar diagnostic accuracy for detection of mycobacterium leprae.

Disclosures
All Authors: No reported disclosures
P-2108. Risk Factors for Indeterminate Tuberculosis (TB) Testing Results Among Immunocompromised Children in an Area of Low TB Endemicity
Authors: De Souza Randal , Hegde Shweta , Shimamura Masako , Dotson Jennifer L , Driest Kyla , McNicol Megan , Wise Kelly , Ouellette Christopher 
Published: January 2025

Abstract

Background
Tumor necrosis factor α inhibitors (TNFαi) are immunosuppressants used to treat autoimmune (AI) conditions and inflammatory bowel disease (IBD). TNFαi initiation requires tuberculosis infection (TBI) screening, often performed by interferon-γ release assays (IGRA) including the QuantiFERON Gold Plus (QFT) and T-SPOT.TB (T-SPOT). The rate of and risk factors for indeterminate (IND) testing results, as well as the optimal TBI screening assay, among immunocompromised children (ICC) with AI or IBD in an area of low TB endemicity remain poorly defined. We performed a retrospective analysis of QFT testing at our institution to identify rates of and risk factors for IND results. We also prospectively evaluated the performance of QFT versus T-SPOT in an area of low TB endemicity.

Methods
A retrospective analysis of children (ages 0-21 years) with AI or IBD on immunosuppression cared for at Nationwide Children’s Hospital (NCH) from 1/2010-12/2023 who underwent TBI screening with QFT. Patients were excluded if they had prior TBI, BCG vaccine, and organ or stem cell transplant. Demographic, laboratory results, and medication history were recorded. Prospectively, QFT-eligible patients were consented for concurrent testing utilizing the T-SPOT test, run in parallel. Single variable statistical analysis was performed.

Results
662 patients (372 (56.2%) male) had 2011 unique QFT tests performed. 148 patients (22.4%) had a total 191 (9.5%) IND QFT result at any time in the study interval. Younger age, lower absolute lymphocyte counts (ALC), and corticosteroid exposure at testing were observed more frequently in those with IND QFT results [TABLE 1]. At an interim assessment of the prospective study, 117 patients underwent tandem screening by QFT and T-SPOT; 5 total IND results were observed [QFT (n=4), T-SPOT (n=1)] [TABLE 2].

Conclusion
Younger age, lower ALC, and corticosteroid exposure at time of testing were observed more frequently in those with IND QFT results. While interim assessment of T-SPOT vs. QFT does not yield a difference, this may be driven by a high proportion of individuals with adequate disease control. Ongoing prospective assessment may better define an optimal screening IGRA assay for TBI among ICC with AI or IBD in an area of low TB endemicity.

Disclosures
Jennifer L. Dotson, MD, MPH, Pfizer: Grant/Research Support Christopher Ouellette, MD, Oxford Immunotec: Grant/Research Support|UpToDate: Royalties
P-2120. Clinical significance of 16S rRNA sequencing identification of Legionella species
Authors: Steenberge Laura , McBride Joseph 
Published: January 2025

Abstract

Background
Incorporation of 16S rRNA sequencing into clinical diagnostics has improved the ability of clinicians to diagnose fastidious bacteria and facilitates the identification of causative organisms in culture-negative infections. However, its clinical utility is unclear, with estimates of antimicrobial management changes from 16S identification ranging from only 4-15%. Legionella species are fastidious bacteria that can be difficult to identify without prior clinical suspicion, and thus can cause culture-negative infections that lead to 16S sequencing. However, Legionella are found ubiquitously in aquatic environments and its identification on 16S could represent a clinically significant infection, a nonpathogenic sample isolate, or a contaminant from sample processing or analysis. In this study, we reviewed 16S Legionella species results from our institution and determined whether they represented a clinical infection.

Methods
16S results from our institution were queried for Legionella species and a retrospective analysis of the resulting 10 cases was conducted. Multiple factors from the cases were assessed including demographics, comorbidities, type of 16S specimen, and antibiotic regimen change in response to 16S results. Additionally, we identified whether the 16S results represented clinically significant infections or contaminants.

Results
70% of the Legionella identifications were indicative of a clinically relevant infection. Specimens from a pulmonary source were much more likely to represent a true infection, while identifications from extrapulmonary sources were more likely to be a contaminant. The species of Legionella identified on 16S did not impact the likelihood of a true causative agent. The 16S results affected antimicrobial regiments in 60% of the cases and were often the only diagnostic test to point towards Legionella as a causative agent.

Conclusion
Legionella species identification on 16S can be an important diagnostic clue to the etiology of a patient's infection, but various clinical factors should be taken into account when assessing whether the result represents a true infection or contaminant.

Disclosures
All Authors: No reported disclosures
P-2125. Evaluation of MucorGenius® Mucorales Real-Time PCR Assay with Formalin-Fixed Paraffin-Embedded Tissue Specimens
Authors: Ganesan Anuradha , Sercy Erica , Leigh Carson M , Shaikh Faraz , Levine Tiffany , Campbell Wesley , Mende Katrin , Kiley John L , Bialek Ralf , Tribble David , Wickes Brian 
Published: January 2025

Abstract

Background
Early identification of mucormycetes in trauma-related invasive fungal wound infections (IFI) improves outcomes. A commercially available, multiplex, real-time Mucorales assay has the potential to provide results within 3 hours, hence we examined the performance of this assay.

Methods
Formalin-fixed specimens from combat injured that were positive for fungus on histopathology and mucormycetes on sequencing were examined using the PN-700 MucorGenius® assay (PathoNostics B.V, Maastricht, The Netherlands). The assay targets a conservative pan-mucormycetes sequence of the genera Rhizopus, Mucor, Lichtheimia, Cunninghamella, and Rhizomucor. For this analysis, we used a BioRad CFX96 Real-Time PCR Detection System with a positive detection limit of quantitative cycles (Cq) ≤ 30. Control specimens negative for fungus on histopathology and culture were obtained from trauma and non-trauma patients (N=2). MucorGenius® assay and sequencing results were compared.

Results
For this analysis, 31 patients contributed 63 specimens. Fungi of the genus Apophysomyces or Saksenaea were identified in 70% (Table 1). Using sequencing as the reference, Mucorales fungal DNA was detected in 58 specimens with the MucorGenius® assay with 5 false-negative findings (sequencing positive for Apophysomyces elegans [N=3], Actinomucor elegans [N=1], and Mucor spp. [N=1]), resulting in 92% sensitivity (95% confidence interval [CI]: 82-97%). There were no false positives (100% specificity; 95% CI: 16-100%; Table 2).

Conclusion
To our knowledge, this is the first assessment of the MucorGenius® assay with fixed tissue specimens in trauma-related IFI. When compared with sequencing in those with histopathologically proven fungal infections, the MucorGenius® assay was sensitive and specific. The assay also successfully amplified DNA of three genera that were not targeted by the panel kit (i.e., Apophysomyces, Actinomucor and Saksenaea). The potential for fast results with the MucorGenius® assay offers promise for rapid diagnosis of IFI. Further assessment of performance should be conducted using fresh and fixed specimens with suspicion of trauma-related IFI.

Disclosures
Ralf Bialek, n/a, InfectoPharm: Advisor/Consultant|InfectoPharm: Honoraria|InfectoPharm: podcasts|Sanofi-Adventis Deutschland GmbH: Advisor/Consultant|Sanofi-Adventis Deutschland GmbH: Honoraria|Sanofi-Adventis Deutschland GmbH: podcasts David Tribble, MD, DrPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response
P-2127. Frequency, Interval, and Patient Factors Associated With Recurrence of Disseminated Cutaneous Coccidioidomycosis
Authors: Chow Nathan , Blair Janis E 
Published: January 2025

Abstract

Background
Coccidioidomycosis (cocci) is a fungal infection caused by Coccidioides and a common cause of community acquired pneumonia in endemic regions. Disseminated cocci occurs in ≤ 1% of persons with cocci, and among these, disseminated cutaneous coccidioidomycosis (DCC) is estimated to occur in 15 to 67% of cases, however little data exists to describe its frequency and timing of recurrence. Limited small studies show recurrence rates from 17 to 50% and often do not distinguish skin dissemination from other soft tissues. Our aim was to determine the frequency, timeframe and risk factors for relapsed DCC.

Methods
Potential cases of disseminated cocci were identified by ICD-10 codes 38.3, 38.7, 38.9 (& ICD-9 equivalents) and keyword-based search of pathology reports from 1/1/2008 - 3/31/2024. We included patients with proven or probable DCC. We excluded patients with primary cutaneous cocci or reactive rash. We performed a retrospective review to identify episodes of recurrence, comorbidities, and antifungal regimen.

Results
We identified 44 proven and 3 probable cases of DCC (33 males, 14 females), median age 48 years, 66.0% white, 21.3% black, 5.4% Hispanic. 18 (38.3%) were immunosuppressed and 6 (13.6%) had diabetes mellitus. Median follow-up duration was 68 months; 12 (25.5%) patients had ≥1 recurrence, 7 (14.9%) of whom relapsed ≥2 times. Median interval off of antifungals until recurrence was 14 months (range: 1 - 96). 3 (6.4%) patients had recurrence within three months of diagnosis, and 6 (13.0%) and 11 (23.9%) had a recurrence by the 1st and 5th follow-up year, respectively. 21 (87.5%) recurrences were at the same site as a prior occurrence, 4 (18.2%) occurred on antifungal therapy. There were no significant differences in recurrence rates by race or diabetes. Of the 18 immunosuppressed cases, there was 1 (5.6%) recurrence, though 14 (77.8%) continued antifungal therapy throughout follow-up.

Conclusion
Once antifungal treatment was discontinued, recurrence of disseminated cutaneous cocci was common, and among those whose DCC relapsed, multiple relapses were noted. Longer follow up is needed to better characterize the risk of long-term recurrence.

Disclosures
All Authors: No reported disclosures
P-2158. A Single Center's Utilization of Cell Free Microbial DNA Testing
Authors: Shaffer Alexander , Orner Erika , Thwe Phyu , Conway-Pearson Liam S , Szymczak Wendy , McCort Margaret E 
Published: January 2025

Abstract

Background
Metagenomic next generation sequencing techniques, either through targeted (tMGS) or shotgun sequencing (sMGS), have been shown to improve the odds of identifying a causative pathogen in a variety of disease states compared to conventional microbiologic testing. However, the high cost and unfamiliarity with MGS have led to questions on when and how these should best be used. We aimed to characterize the utilization of sMGS at a large urban academic hospital system, specifically the use of the commercial Karius test, a cell free microbial DNA (cfDNA) assay.
* conditions not mutually exclusive

Methods
We conducted a retrospective observational study through detailed chart review of the Karius tests sent from our hospital system from June 13, 2020, through April 10, 2024. Charts were reviewed for demographic, clinical and outcome information. Statistical analysis was performed using chi-square analyses.Figure 1:Pathogens with clinical additive diagnostic value (ADV)

Results
110 Karius tests from 104 unique patients have been sent from our institution since 2020. Most patients were immunocompromised (72.7%); see Table 1 for demographics. Patients received on average 13.4 days of antimicrobials before cfDNA testing was sent. An average of 6.5 blood cultures were sent, and in 69 cases, invasive procedures were performed before Karius testing was sought.
A pathogen was detected by Karius in 62 cases (56%). Results led to a change in antimicrobial management in 23% of cases. Karius had clinical additive diagnostic value (ADV) in 17 cases (15.6%), as defined by the detection of a causative pathogen that was not detected on conventional testing. Pathogens with clinical ADV are shown in Figure 1. There was no statistically significant difference between ADV, pathogen detection, or test concordance with conventional testing (p=0.71, p=0.64, and p=0.50 respectively) for cfDNA use in immunocompetent versus immunocompromised patients.

Conclusion
sMGS testing can provide clinically impactful results, although the optimal patient population and clinical scenario in which to employ these tests remains undetermined. Despite significant antimicrobial exposure prior to cfDNA testing, the Karius assay detected several fastidious pathogens that may not have been detected by conventional methods. Further research into ideal diagnostic utilization and stewardship of these tools is needed.

Disclosures
Wendy Szymczak, PhD, Quidel: Advisor/Consultant
P-2176. Validation of Air Sampling and Real-Time Quantitative Polymerase Chain Reaction for Measles Virus Surveillance: A Single-Center, Preliminary Assessment
Authors: Fricchione Marielle J , Nash Colleen B , Nguyen David , Barbian Hannah , Hayden Mary K 
Published: January 2025

Abstract

Background
During the early months of Chicago’s 2024 measles outbreak, many patients were admitted to local hospitals due to a lack of isolation housing in congregate settings. While the infection control potential of air sampling for viral pathogens is well described for viruses such as SARS-CoV-2, its utility for measles virus response is less clear. Here, we report a single center assessment of inpatient air sampling from airborne isolation rooms of patients with and without PCR-confirmed measles infection.Figure.Mean Measles Genome Copies in Four Rooms by Air Sampling Time

Methods
Aerosolsense samplers (ThermoFisher) were placed in 3 occupied and 1 unoccupied (negative control) airborne isolation rooms under negative pressure conditions. Air samples were collected at varying timeframes (30 minutes – 20 hours). Total nucleic acids were extracted from air samples within 24 hours of collection. Quantitative reverse transcription PCR (qRT-PCR) was performed to detect wildtype measles virus and genotype A (vaccine strain) measles virus; a gBlock DNA standard was included to estimate viral copy numbers. N450 amplification and Sanger sequencing were performed on selected positive samples to determine measles genotype.Table:Inpatient Measles Air Sampling Data at Different Time Intervals*per 5 μl cartridge nucleic acid extract, viral copies approximated using measles N1 DNA gBlock, ND: not done, UD: undetermined, NA: not applicable

Results
Air sampling methods were successful, with measles PCR positivity only in rooms with a measles. Measles patients were 2-3 days post rash onset. The air samples collected between 0.5 – 5 hours showed linearly-increasing measles viral load from 950-10,550 genome copies. [Figure] Samples collected at 20 hours did not show increased virus load compared to 2 hours, with mean 10,000 viral copies, indicating possible saturation over extended air sampling. Sequences derived from air samples were determined to be wildtype measles virus genotype D8 (the circulating genotype in Chicago at the time). [Table]

Conclusion
Air sampling in patient rooms allowed genotyping of measles virus in real-time and shows promise for describing the dynamics of measles viral load and potential for transmissibility. The utility of air sampling as a tool for measles surveillance and outbreak management warrants further testing in healthcare and congregate settings.

Disclosures
All Authors: No reported disclosures
P-2184. Antiviral Use among Immigrants with Chronic Hepatitis B (HBV) in Metropolitan-DC
Authors: Lin Christine , Dang Huong , Tang Lydia 
Published: January 2025

Abstract

Background
Globally, 296 million people are infected with chronic hepatitis B (HBV) and at risk for cirrhosis and hepatocellular carcinoma. In the Metropolitan-DC area, chronic hepatitis B infection (HBV) is 10 times more common in Asian, African, and Latin American communities (5% prevalence) than non-immigrants communities. Therefore, HBV-related liver disease, including cancer, is a major health disparity for immigrants. Antivirals reduce cancer risk but require long-term adherence. Immigrants face barriers to HBV antiviral adherence, including language, high cost of antivirals, and establishing care for HBV management. We examine antiviral use in a cohort of people with HBV.

Methods
HOPE is a natural history study at the University of Maryland, Baltimore. HOPE enrolls adults with HBV and includes TEMUL, a sub-study providing free tenofovir alafenamide (TAF) for 2 years. After completing 2 years of TEMUL, participants are transitioned to receiving antivirals through their non-study healthcare providers. We describe antiviral use while on TEMUL and at a 2-year follow-up.

Results
From May 2017 to March 2024, 92 people received TAF through TEMUL. Eighty-four were foreign-born (78 born in Asia and 6 born in Africa). Most (67%) had mild liver fibrosis at baseline. Eleven were withdrawn (3 lost to follow-up, 3 moved out of state, 5 voluntarily withdrew). Eighty-one completed TEMUL with sustained adherence to TAF. Fifty-eight completed a 2-year follow-up. At follow-up, 36 of 58 (62%) remained on TAF without interruption. Twelve (21%) switched antivirals because of insurance coverage. This caused lapses in antiviral use ranging from 1 month to 2 years in 5 (9%). Ten (17%) stopped antivirals due to loss of health insurance, high copay, and inability to follow-up with a healthcare provider. All 10 were foreign-born, Asian, and non-English speaking. Of these 10, 9 were viremic at follow-up and resumption of antivirals was clinically indicated in all.

Conclusion
Language and inadequate health insurance coverage hinder antiviral adherence in immigrants with HBV. Foreign-born, non-English speaking patients may be especially vulnerable to lapses in antiviral use. Interventions to improve access to antivirals tailored to this patient group are needed.

Disclosures
Lydia Tang, MBChB, Arbutus Biopharma: Grant/Research Support|Gilead Sciences: Grant/Research Support
P-2185. Community Health Worker-Led Intervention to Increase Hepatitis D Virus Screening among Immigrants in the Metropolitan-DC Area
Authors: Lin Christine , Nguyen Angeline , Byambaa Chooson , Galdamez Jennifer , Le Hai Chi , Ashford Sandra , Tang Lydia 
Published: January 2025

Abstract

Background
Hepatitis delta virus (HDV) is the most aggressive form of human viral hepatitis and coinfects people with chronic hepatitis B (HBV), increasing the risk of liver cancer. But HDV screening is not routinely done for people with HBV. In Metropolitan-DC, 5% of Asian, African, and Latino immigrants have HBV (10x the national rate). Therefore, these communities are at risk of HDV and would benefit from increased HDV awareness and screening. Health Betterment Initiative (HBI, an immigrant advocacy group) community health workers (CHWs) routinely assist immigrants with HBV and are well situated to deliver HDV education. However, little is known about the efficacy of CHW-led education interventions in these communities. We seek to evaluate an HDV education intervention aimed at increasing HDV screening in adults with HBV.

Methods
We developed an education intervention with HBI CHWs including educational programming, counseling, and printed materials. The post-intervention group (diagnosed from May 2023-May 2024) received the intervention and were surveyed 3-6 months after to assess HDV screening, knowledge, and usage of materials. We surveyed the pre-intervention group (diagnosed from April 2022-April 2023) to determine baseline HDV screening rate. Our primary outcome will be change in HDV screening from pre- to post-intervention. We present our lessons learnt so far.

Results
Since May 2023, HBI screened 2012 people and diagnosed 22 with HBV. All were from immigrant communities. So far, 18 pre- and 9 post-intervention surveys have been completed. Most were completed in Mongolian and Vietnamese. 20 were born in an Asian country, 6 in an African country, and 1 in El Salvador. Of the pre-intervention group, 4 (22%) reported HDV testing. All in the post-intervention group consulted doctors for HBV, and 1 reported HDV testing. Three recalled receiving our printed materials, but none used them at their doctor’s appointments.

Conclusion
Preliminary findings indicate good linkage-to-care for HBV, but low HDV screening and usage of our educational materials. More work is needed to customize education interventions for immigrant communities. We will use these lessons to consult with stakeholders to refine our intervention to improve engagement.

Disclosures
Lydia Tang, MBChB, Arbutus Biopharma: Grant/Research Support|Gilead Sciences: Grant/Research Support