bluuebunny/crossref_metadata_2025 huggingface dataset:
P-1902. Routine Anti-Nuclear Antibody (ANA) Testing in Patients Experiencing Long COVID: Worth it?
Authors: Ghorbani Abigail , Strong Nora , Keller MaryJane , Ostrosky-Zeichner Luis
Published: January 2025

Background

Patients with long COVID are often tested for ANA as part of their routine work-up (Son et al., 2023). However, it is unclear if this testing leads to a rheumatological diagnosis or is actionable. This project assessed the frequency of ANA-positivity in patients experiencing long COVID and the outcomes of rheumatic disease diagnosis and treatment.

Methods

Electronic medical records (EMR) from January 2022 through May 2023 at the UT Physicians COVID Center of Excellence were reviewed. The population included those experiencing long COVID and presenting with symptoms. Symptoms, personal and family history of rheumatic disease, last known COVID date, ANA test results, referral to rheumatology, diagnoses, and treatment, if any, were recorded. Data was analyzed using Microsoft Excel PivotTables and JavaStat, with right-tailed Fisher Exact Tests.

Results

The 117-patient sample was 76.92% female, with an average age of 49.21+/-15.09 SD years, with last known COVID between March 2020 and February 2023. 17.95% had a previous rheumatic diagnosis, and 22.22% had a family history of rheumatic disease. The symptoms reported were: fever (6.84%), arthralgia (43.59%), arthritis (22.22%), rash (23.08%), and fatigue (79.49%). 75.21% of patients received an ANA test, of which 43.18% were positive. The mode titer was 1:80, and the most common pattern was nuclear. 48.72% of the patients with a positive test were referred to rheumatology, but only 21.05% received a rheumatological diagnosis. Only 11.97% received any treatment for their symptoms, and most treatments were for symptom control or an anti-inflammatory. On the last visit, only 2.56% had resolution of long COVID symptoms. None of the symptoms were predictive of a positive ANA test.

Conclusion

The majority of patients experiencing long COVID presenting to our clinic received an ANA test, and almost half had a positive result. Few received any rheumatological diagnosis and most had ongoing symptoms by their latest visit. Although this study is limited by sample size, bias in ANA ordering, and its retrospective nature, these data suggest that routine ANA testing and rheumatology referrals may not be cost-effective in patients experiencing long COVID.

Disclosures

Luis Ostrosky-Zeichner, MD, FACP, FIDSA, FSHEA, FECMM, CMQ, Cidara: Advisor/Consultant|Enanta: Advisor/Consultant|F2G: Advisor/Consultant|Gilead: Advisor/Consultant|GSK: Advisor/Consultant|Melinta: Advisor/Consultant|Octapharma: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pulmocide: Grant/Research Support|Scynexis: Grant/Research Support|Viracor: Advisor/Consultant
646. Clinical and microbiological outcomes of omadacycline for pulmonary Mycobacterium abscessus complex
Authors: Al Musawa Mohammed , Vemula Raaga , Mammadova Mehriban , Wadle Carly , Muscarella Anahit , Cimino Christo , Zeuli John , Howard Catessa A , Butt Saira , Mejia-Chew Carlos , Hamad Yasir , Ong Aaron , Cohen Keira A , Kaip Emily A , Tupayachi-Ortiz Maria G , Fiske Christina T , Judd Chloe , Caniff Kaylee E , Rybak Michael J
Published: January 2025

Background

Mycobacterium abscessus complex (MABC) is a difficult-to-treat infection due to antibiotic resistance. Our study aimed to assess omadacycline’s (OMC) clinical and microbiological outcomes for the treatment of pulmonary MABC.

Methods

A retrospective study was carried out across 12 US medical institutions from 1/2018-4/2023 to examine the clinical outcomes, and tolerability of OMC treatment for pulmonary MABC. Patients aged ≥ 18 years who were treated with OMC for ≥ 3 months were included. The primary outcome was clinical success at 3, 6, and 12 months. The secondary outcomes were sputum culture conversion rate, adverse effects, and clinical success by subspecies and macrolide susceptibility.

Results

Thirty-five patients were included in this analysis. Most patients were female (74.3%) and Caucasian (74.3%), with a median (IQR) age of 61 years (51–70). Subspeciation was performed for 22 isolates with predominant M. abscessus subspecies (77.3%). Moreover, coinfection with other NTM species was present in 28.6% of cases where Mycobacterium avium complex was present in 8 cultures. Sixty-eight percent of the MABC isolates were confirmed to be macrolide resistance; half (12/24, 50.0%) were evident by the presence of functional erm gene, while the other half by antimicrobial susceptibility (Table 3). Of the remaining isolates, 14% were macrolide-susceptible, while no information was reported in 17%. The median (IQR) treatment duration of OMC was 8 months (3.9 – 15.7). The most commonly co-administered antibiotics were intravenous amikacin, imipenem/cilastatin, inhaled amikacin and clofazimine with the same percentage (42.9%) (Table 1). Overall, MABC clinical success was observed in 71.4%, 89.7%, and 90.9% in 3-, 6- and 12 months, respectively (Table 3). Adverse effects reported in 34.3%. The most common side effects were gastrointestinal intolerance (25.7%) and hepatoxicity (11.4%), which led to drug discontinuation in 22.9%.

Conclusion

OMC treatment showed clinical success in > 70% of patients with pulmonary MABC including patients with macrolide resistant strains for more than 3 months. However, larger studies are needed to validate the outcomes beyond 12 months.

Disclosures

Kaylee E. Caniff, PharmD, BCIDP, T2Biosystems: Honoraria Michael J. Rybak, PharmD, PhD, MPH, Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Advisor/Consultant|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Grant/Research Support|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Speaker
P-1958. Impact of COVID-19 on Acute Diverticulitis: Evidence of United States Hospitals in 2020
Authors: Suenghataiphorn Thanathip , Lohawatcharagul Tuntanut , Danpanichkul Pojsakorn , Thongpiya Jerapas , Polpichai Natchaya , Kulthamrongsri Narathorn , Tangsirisatian Ponphisudti , Sasipong Nuttarak , Wattanachayakul Phuuwadith
Published: January 2025

Background

Acute diverticulitis, a prevalent gastrointestinal condition, frequently necessitates hospitalization and is associated with potential adverse in-hospital outcomes. Recent data showed the detrimental effects of COVID-19 infection on acute diverticulitis, particularly in patients with severe COVID-19 infections. However, limited information exists on the specific impacts of COVID-19 infection in patients hospitalized for acute diverticulitis.

Methods

We analyzed the 2020 U.S. National Inpatient Sample (NIS) to investigate the effects of COVID-19 infection on cases primarily admitted due to acute diverticulitis. Participants aged 18 and above were identified using relevant ICD-10 CM codes. Adjusted odds ratios (aORs) for specified outcomes were calculated through multivariable logistic and linear regression analyses. The primary outcome was inpatient mortality, with secondary outcomes including system-based complications. Statistical significance was established at a P value of 0.05.

Results

We identified 167,170 patients with a primary discharge diagnosis of acute pancreatitis. The mean age was 60.1 years; 56.8% were female. Caucasians accounted for the majority, followed by Hispanics. Of these, 0.90% (1,504/167,170) had a concurrent diagnosis of COVID-19 infection.

In a survey multivariable logistic and linear regression model adjusting for patient and hospital factors, COVID-19 infection was associated with higher in-hospital mortality (aOR 8.43; 95% CI 4.32, 16.42, P < 0.001), prolonged length of stay (β LOS 2.02; 95% CI 1.27, 2.77, P < 0.001) and increased hospitalization charge ( β charge 17,813.27; 95% CI 4,080, 31,546, P < 0.001), We observed non-significant, but increased, risks of shock, acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), and mechanical ventilation in COVID-19 positive patients.

Conclusion

In conclusion, our study revealed that COVID-19 infection is associated with higher in-hospital mortality, prolonged hospital stays, and increased hospitalization charges in patients diagnosed with acute diverticulitis. Future longitudinal studies are warranted to comprehensively assess the long-term health sequelae in this population.

Disclosures

All Authors: No reported disclosures
P-1961. Epidemiologic analysis of an alpha variant COVID-19 nosocomial cluster that occurred after completed vaccination of healthcare workers
Authors: Kawamura Hideki , Nakano Koji , Hanada Norihisa , Sameshima Koji
Published: January 2025

Background

In a field where few reports have been made on the efficacy of SARS-CoV-2 vaccines in healthcare settings. We experienced an outbreak of an alpha variant in a medical institution cluster after healthcare workers were vaccinated, providing a novel perspective on the topic.Figure 1.Epidemic curve based on the day of positive SARS-CoV-2 PCR test (A) or on the symptom onset day (B) during this COVID-19 outbreak

The index case was a patient admitted to the hospital on 24 May. The last positive case was detected ten days after the first detection, but 42 patients, including five asymptomatics and three healthcare workers, including an asymptomatic, were infected.

Methods

We conducted descriptive epidemiology from case detection in the cluster of medical institutions with the alpha variant in June 2021. We also compared the relationship between vaccination status and infection using the Fisher exact test for healthcare workers in the same period.Figure 2.Diagram of hospital room layouts for patients infected in the first wave (through June 1)

We confirmed infected inpatients in a wide range of hospital rooms.

Results

We identified one healthcare worker as a first test-positive case on 4 Jun 2021, and 21 positive patients were identified by screening on the day of detection and the following day. Based on the descriptive epidemiological analysis, the index case was a patient admitted to the hospital on 24 May with pneumonia treated with NPPV in an independently air-conditioned negative pressure room from the third day of admission. The last positive case was detected 10 days after first detection, but 42 patients and three healthcare workers were infected (Figure 1).

Forty-two of 88 hospitalized patients (53.7%) and 3 of 38 healthcare workers (7.9%) were infected. There were no cases of infection among the 30 healthcare workers who had completed the 2-dose vaccination, and the infection rate was significantly lower than that of the staff members who had not completed the vaccination (0% (0/30) vs. 37.5% (3/8), p=0.008). No hospitalized patients had completed the 2-dose vaccination, including infected and uninfected cases. Aerosol transmission from initial cases, the patient-to-patient droplet route, and the hospital ward contact route were considered factors in the spread of the disease (Figure 2 and Figure 3).Figure 3.Links within the cluster

Aerosol transmission from initial cases, the patient-to-patient droplet route, and the hospital ward contact route were considered factors in the spread of the disease.

Conclusion

Our study not only underscores the importance of strict adherence to standard precautions, early detection of infected cases, and implementation of route-specific prophylaxis but also highlights the crucial role of vaccination in preventing the outbreak and spread of COVID-19 clusters in medical institutions.

Disclosures

All Authors: No reported disclosures
P-1990. Out-of-Hospital Care Setting in a Febrile Emergency Unit of Suspected Covid 19 Patients
Authors: Guglielmo María Cecilia , Aprea Valeria , Guedes Veronica , Debaisi Gustavo , Puleio Liliana Yazde , Miño Laura
Published: January 2025

Background

In 2019, a new infection was reported in China. This coronavirus was named SARS-COV-2, causative of the 21st-century pandemic, COVID-19. Health systems adopted different strategies to cope with it.

Objective

to describe the clinical-epidemiological characteristics of COVID-19 in children seen at an Emergency Febril Unit (UFU). Demographic and epidemiological characteristics of children treated at EFU of Pedro de Elizalde Children's Hospital (n = 952)

Methods

Cross-sectional study in patients under 18 years of age tested for SARS-COV-2 between April 1 and June 30, 2020. All epidemiological records made at the time of consultation and the result of the Polymerase Chain Reaction (PCR) test of these patients, either by suspicion of COVID-19 or epidemiological isolation criteria, were included. Patients whose samples had been taken for SARS-COV-2 determination outside the initial time of consultation or whose epidemiological records were incomplete or did not meet the established inclusion criteria were excluded. The diagnosis of COVID-19 was made using the PCR technique for SARS-COV-2 in nasopharyngeal secretions obtained by nasopharyngeal swab or aspirate. The following variables were recorded: age, gender, place of residence, history of close contact, history of history of close contacts, travel history and comorbidities, history of institutionalization and PCR result.

Presentation of symptoms: Frequency

Results

1,104 patients were admitted to the UFU and tested due to suspected COVID-19. 152 patients had to be excluded due to insufficient data. Of the 952 patients tested, 22.6% had a detectable result, and 71.2% of them reported close contact with confirmed cases. The mean age was 5.9 years. The 55.4% were male and 99.3% lived in the Metropolitan Area of Buenos Aires. 72.8% of the patients tested had symptoms. The time of delay in consultation was 2.17 days. 25% of the children had comorbidities.

Conclusion

The availability of the UFU facilitated access and optimized the care circuit in response to demand. Children with a history of close contact and those symptomatic showed more frequently a detectable result for SARS-COV-2.

Disclosures

All Authors: No reported disclosures
P-1994. Rapid COVID-19 Transmission and Multi-layered Interventions in a High-rise Detention Center from January to March 2022 in South Korea
Authors: Song Jin Su , Choe Pyoeng Gyun , Park Wan Beom , Lee Shin Young , Yi Seonju
Published: January 2025

Background

Correctional and detention facilities face significant challenges in controlling the spread of highly infectious pathogens such as SARS-CoV-2 due to overcrowded conditions, inadequate ventilation, and shared facilities. Despite reports on COVID-19 outbreaks in various correctional settings worldwide, investigations into outbreaks in metropolitan high-rise prisons remain scarce, warranting detailed examination.

Diagnosed cases of coronavirus diseases 2019 (COVID-19) in detention center (blue) and South Korea (yellow), January through March 2022

Methods

The detention center, which covers an area of 41,658 mm2, can accommodate 2,070 individuals and housed 1,977 inmates and 674 correctional officers at the time of outbreak detection. The facility comprises five buildings, including one 10-story and four 12-story buildings, with 47 wards. Each building is connected with the following building through a common hallway located at the distal end of each building. Descriptive analyses were conducted on demographic characteristics, symptom onset dates, comorbidities, vaccination status, and exposure history of confirmed COVID-19 cases. Vaccine effectiveness was estimated using logistic regression models.

Epidemic curve of SARS-CoV-2 case-patients by building and floor(vertical axis), South Korea, 2022

Results

From January 25 to March 2, 2022, 492 people, including 474 (30.0%) of 1,977 incarcerated persons (cumulative attack rate of 24%) and 18 (2.7%) of 674 staff members at the detention center, were confirmed with SARS-CoV-2 infection. High-rise facility characteristics contributed to rapid transmission, with the index case identified on January 25, 2022. However, the implementation of physical distancing, decarceration, limiting movement, and conducting serial and mass testing, despite being complex and requiring substantial resources, effectively slowed the spread of the Omicron variant amidst persistent community transmission. Vaccine effectiveness against infection was estimated at 52.7% (95% confidence interval, 37.2% to 64.4%) for three doses.

Characteristics of coronavirus disease 2019 case-patients in a detention center, South Korea, 2022

Conclusion

The findings underscore the vulnerability of high-rise detention centers to COVID-19 outbreaks and emphasize the effectiveness of multi-layered interventions in curbing transmission. Swift and comprehensive measures are crucial for controlling outbreaks in high-density, enclosed settings, informing future pandemic response efforts and policy development.

Disclosures

All Authors: No reported disclosures
P-2053. Clinical Outcomes and Severity of Hospitalized COVID-19 Patients Among Partially and Fully Vaccinated Patients in Louisville, Kentucky
Authors: Shahnawaz Waqas , Ali T’shura , Shafique Nouman , Wakeel Jafir , Sheikh Daniya , Salunkhe Vidyulata , Gootee Steven , Arnold Forest W
Published: January 2025

Background

Despite COVID-19 vaccine availability, reducing disease severity and hospitalizations remains crucial. Persistent vaccine hesitancy necessitates studies comparing outcomes between partially and fully vaccinated individuals. Our study aims to evaluate clinical outcomes among hospitalized COVID-19 patients, distinguishing between partial and full vaccination.

Multivariable logistic regression analysis for ICU admission among fully and partially vaccinated patients with COVID-19 CAP

Methods

We conducted a retrospective cohort study among hospitalized COVID-19 patients with community-acquired pneumonia (CAP) in Louisville, Kentucky. Clinical outcomes, including in-hospital mortality, cardiac events, ICU admission, and use of mechanical intubation and ventilation, were assessed. Statistical analyses included univariate and multivariable logistic regression to compare outcomes between vaccination statuses.

Multivariable logistic regression analysis for Mechanical intubation and ventilation use among fully and partially vaccinated patients with COVID-19 CAP

Results

Of 142 eligible patients, 87% were fully vaccinated, with 13% partially vaccinated. The fully vaccinated group had less patients with a CURB-65 score >3 compared to the partially vaccinated group (63% vs. 53%, P=0.55). In addition, partially vaccinated patients exhibited increased rates of ARDS (6% vs 1%, P=0.61), septic shock (11% vs 3%, P=0.37), intubation (16% vs 8%, P=0.20) and mortality (21% vs 7%, P=0.09). Fully vaccinated patients exhibited lower rates of ICU admission compared to partially vaccinated patients (40% vs 15%, P=0.04). After adjusting for confounders, fully vaccinated patients had significantly lower odds of ICU admission (OR: 0.28, 95%CI: 0.15, 0.56) and intubation (OR: 0.22, 95%CI: 0.06, 0.81). However, fully vaccinated individuals had more in-hospital cardiac events (12% vs. 1%, P=0.61) and a lower odds of in-hospital mortality (OR: 0.18, 95%CI: 0.02, 1.66), but these were not statistically significant.

Multivariable logistic regression analysis for in-hospital mortality among fully and partially vaccinated patients with COVID-19 CAP

Conclusion

This study highlights full vaccination's importance in reducing COVID-19 severity among hospitalized patients. Male gender and cancer were associated with higher mortality rates. Fully vaccinated patients had lower odds of ICU admission and intubation compared to partially vaccinated counterparts. Being fully vaccinated was not found to be associated with less cardiac events or mortality. These findings emphasize the need for comprehensive vaccination strategies and targeted public health initiatives.

Disclosures

All Authors: No reported disclosures
P-2078. Performance of Anyplex and Xpert for the Detection of Mycobacterium tuberculosis complex in Respiratory and Non-Respiratory Samples
Authors: Gaxiola-Castro Alina , Flores-Treviño Samantha , Ibarías Paola Bocanegra , Camacho-Ortiz Adrian
Published: January 2025

Background

Tuberculosis diagnosis requires rapid and sensitive diagnostic methods. The aim was to evaluate the performance of Anyplex MTB/NTM and Xpert MTB/RIF assays for the detection of Mycobacterium tuberculosis complex (MTC) in respiratory and non-respiratory samples from patients suspected of having tuberculosis in a third-level hospital in Mexico.

Methods

Samples (n=436) from January 2020 to December 2023 in a hospital from Monterrey, Mexico underwent paired microbiological (MGIT or Lowenstein-Jensen culture) and molecular assays (Anyplex™ MTB/NTM Real-time Detection or Xpert MTB/RIF™) for mycobacterial detection.

Results

Of the 279 (63.8%) respiratory samples (bronchoalveolar lavage 71.3%, sputum 20.7% and tracheal aspirate 7.8%), positive culture and detected PCR were found in 26/201 samples by Anyplex and in 20/78 samples by Xpert whereas negative culture and detected PCR were found in 32 and 7 samples, respectively. Anyplex showed 65% sensitivity, 80.1% specificity, 26.5% positive predictive value (PPV), and 90.2% negative predictive value (NPV) whereas Xpert showed 100% sensitivity, 87.9% specificity, 74% PPV and 100% NPV. Of the 157 (36.1%) non-respiratory samples (cerebrospinal fluid 37.3%, soft tissues 21.5%, pleural 22.1%, lymph nodes 11.3%, and synovial 7.5%), positive culture and detected PCR were found in 14/118 samples by Anyplex and in 4/39 by Xpert whereas negative culture and detected PCR were found in 17 and 4 samples, respectively. Anyplex showed 73.6% sensitivity, 82.8% specificity, 45.1% PPV, 94.2% NPV whereas Xpert showed 66.6% sensitivity, 87.8% specificity, 50% PPV and 93.5% NPV.

Conclusion

Xpert assays showed higher sensitivity than Anyplex for the detection of MTC in respiratory samples and showed higher specificity compared to Anyplex in both respiratory and non- respiratory samples. Xpert showed higher PPV for respiratory samples, indicating its superiority disregarding true positive cases.

Disclosures

All Authors: No reported disclosures
P-2080. Impact of the Implementation of Multiplex Gastrointestinal PCR Panel on Antimicrobial Use for Infectious Diarrhea
Authors: Mangum Blake R , Smith Richard D , Sandruck Matthew , Kristie Johnson J , Luethy Paul , Claeys Kimberly C
Published: January 2025

Background

Rapid molecular methods, such as BioFire FilmArray™ Gastrointestinal (GI) Panel, have become common in clinical practice. The GI Panel identifies 22 GI pathogens in approximately 1 hour. We evaluated antimicrobial prescribing before and after the implementation of the GI Panel to see the impact on appropriate prescribing for infectious diarrhea and to identify quality improvement areas for antimicrobial stewardship moving forward.Figure 2:Percent Type of Antibiotic Change After Result of Diagnostic Testing

Methods

This retrospective cohort analysis compared antimicrobial prescribing practices for infectious diarrhea one year before and after the implementation of the BioFire GI Panel at the University of Maryland Medical Center (UMMC) in August 2021. Prior to GI Panel implementation at UMMC, the major diagnostic tests for infectious diarrhea were stool culture, ova and parasite smear, and a parasite PCR. Cases were randomly selected with an even distribution from each month from August 2019 to August 2022. Appropriateness of empiric and definitive management was assessed based on diarrhea type (bloody, acute, or prolonged), the patient's immune status, travel history, clinical presentation, and antibiotic selection.

Results

353 patients were included: 179 pre-GI panel implementation and 174 post-implementation. Empiric antibiotic therapy for infectious diarrhea was started in 47/179 (26.3%) of the pre-panel group and 50/174 (28.7%) of the post-panel (P = 0.601). The diagnostic tests resulted in positive organism identification in 10% of patients in the pre-group, while positive identification increased to 19.4% post-group (P = 0.012). When an organism was identified, 12/33 (66.7%) of the post-panel group received antibiotic therapy, while only 6/18 (33.3%) of the pre-panel group received antibiotics (P = 0.83)

Conclusion

Our analysis showed that many patients did not have antimicrobial therapy for infectious diarrhea, which was impacted by the diagnostic test. The increased sensitivity to detect organisms in the GI Panel may account for the increased utilization of definitive antimicrobials in the post-implementation cohort.

Disclosures

J Kristie Johnson, PhD, D (ABMM), biomerieux: has given presentations/speeches for the company listed above Kimberly C. Claeys, PharmD, PhD, bioMérieux: Advisor/Consultant|bioMérieux: Honoraria
P-2090. Using MRSA Nares PCR to Predict MRSA Purulent Skin and Soft Tissue Infections
Authors: Greene William , Aslam Sadaf
Published: January 2025

Background

Skin and soft tissue infections (SSTI) are divided into purulent vs non-purulent with the former necessitating the need for methicillin resistant staph aureus MRSA antimicrobial coverage per IDSA guidelines for management of SSTI. MRSA nares PCR screening for MRSA pneumonia has demonstrated high negative predictive value (NPV) (98.1%) for MRSA associated community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Studies evaluating MRSA nares PCR to predict MRSA infection involving other anatomical sites including skin/soft tissue have shown mixed results. This retrospective cohort study seeks to further evaluate the utility of MRSA nares PCR in predicting MRSA associated purulent SSTI including in relation to anatomical site of the skin infection (above the waist line vs below the waist line).

Methods

We performed a retrospective medical record review of patients admitted to the hospital or evaluated in the emergency department with SSTI between 1/1/2015-11/30/2022. Patients 18 years or older with a diagnosis of purulent cellulitis were included if they had a MRSA nares PCR result and a positive culture for staph aureus from either a purulent wound culture swab or an abscess incision/drainage culture. Medical records were reviewed to confirm a diagnosis of purulent cellulitis including physician documentation and pictures of associated skin infections when available. The anatomic site of the SSTI were recorded.

Results

85 patients were included in the final analysis. MRSA nares PCR for MRSA SSTI had a negative predictive value (NPV) of 66.7% and positive predictive value (PPV) of 96.8%. The sensitivity and specificity of MRSA nares PCR for MRSA SSTI was 62.5% and 97.3% respectively. The NPV of MRSA nares PCR for MRSA SSTI above the waist was 71% vs 63% below the waist.

Conclusion

Our results are consistent with other studies showing high specificity and low sensitivity for MRSA nares PCR in predicting MRSA SSTI. However, the NPV was much lower in this cohort compared to other studies. These results do not support the use of MRSA nares PCR to rule out MRSA SSTI. Clinicians should continue to use clinical exam (purulent vs non-purulent) and microbiologic data when available to guide antimicrobial coverage of MRSA when treating patients with SSTI.

Disclosures

All Authors: No reported disclosures
P-2098. Clinical culture rates among hospitalized patients in the United States, 2012-2021
Authors: Wolford Hannah , McCarthy Natalie , Baggs James , Reddy Sujan , Lutgring Joseph D
Published: January 2025

Background

Microbial cultures are used in clinical care and to track trends in infectious diseases. Changes in culturing practices may affect these trends but have not been thoroughly explored. This analysis examines temporal and facility variability of clinical cultures among a cohort of acute care hospitals in the U.S. from 2012-2021.

Methods

We used microbiology data from a dynamic cohort of hospitals reporting data to the PINC-AI Healthcare Database from 2012-2021. Surveillance cultures and hospitals with outlier hospital-months were excluded. We defined admission cultures as those collected on or before calendar day 3 of hospitalization and post-admission cultures as those collected after calendar day 3. Admission culture rates were calculated per 1,000 discharges. Post-admission culture rates were calculated per 1,000 patient days. We calculated overall rates as well as rates stratified by specimen source (blood, respiratory, urine, other sterile sites, and other non-sterile sites). To account for multiple blood culture sets, only the first blood culture per patient per day was counted in this analysis.

Results

From 2012-2021, 361 hospitals were included in our cohort. Admission culture rates remained stable from 2012 through 2019. Admission culturing rates and facility variability increased in 2020 and 2021 (Fig. 1). Post-admission culture rates decreased from 2012 to 2016 and then plateaued; increases in rates and facility variability were noted in 2020 and 2021 (Fig. 2). Admission blood cultures increased over time and admission urine cultures decreased; respiratory and other non-sterile site cultures increased in 2020 and 2021 (Fig. 3). Most types of post-admission cultures declined from 2012-2016; post-admission blood cultures increased between 2016-2021 (Fig. 4).

Conclusion

Both admission and post-admission cultures increased during the early years of the COVID-19 pandemic, and these increases were driven by respiratory, other non-sterile, and blood cultures (which increased since 2016). Prior to 2020, culturing trends differed by specimen type and timing of culture. Assessing factors that contribute to testing tends and facility variability can inform diagnostic stewardship efforts and increase understanding of how testing changes may impact infection rates.

Disclosures

All Authors: No reported disclosures
P-2118. False-positive Aspergillus Galactomannan Test in Multiple Myeloma
Authors: Nakamura Shingen , Maeda Yusaku , Sumitani Ryohei , Oura Masahiro , Sogabe Kimiko , Yagi Hikaru , Fujii Shiro , Harada Takeshi , Miki Hirokazu
Published: January 2025

Background

Invasive pulmonary aspergillosis (IA) is a common infectious disease in patients with hematological diseases. The prevention, early detection, and establishment of treatment strategies for IA are important clinical issues. One of the mycological tests for IA is the serum galactomannan antigen (GM), which is included in the European Organization for Research and Treatment of Cancer-Invasive Fungal Infections Cooperative Group/National Institute of Allergy and Infectious Diseases Mycosis Study Group (EORTC/MSG) mycological criteria and is widely used because of its high sensitivity and specificity. However, whether this method is useful for all diseases and situations is unclear.

Methods

We retrospectively analyzed the results of all GM tests performed in our department between April 2003 and January 2012.

Results

Of 330 cases and 2155 samples, 540 (25%) were positive (0.5≦). The positivity rates for underlying diseases were 10.1%, 6.6%, 4.8%, 20%, 21.2%, and 61.3% for acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, myelodysplastic syndrome, lymphoma, and multiple myeloma, respectively, with the highest positivity rate for myeloma. By type, IgG, IgA, Bence Jones protein, and IgD were 71.7%, 33.3%, 57.1%, and 34.6%, respectively, and the positivity rate of IgG type was high. All 18 IgG-positive cases at the time of diagnosis of MM were false positives according to the 2019 EORTC/MSG criteria. There was no direct correlation between the IgG and GM values. Of the 18 false-positive cases, 12 patients received antifungal prophylaxis, two of whom developed IA during treatment with steroids, and five who did not receive prophylaxis did not develop IA. When the Aspergillus antigen was measured using the serum from which IgG-type monoclonal protein in some patients with IgG-type myeloma was purified and extracted using protein G, the Aspergillus antigen values decreased.

Conclusion

Although it is possible that the GM test for myeloma captures subclinical IA, the GM antigen test may be prone to false positives in IgG-type myeloma, and the results should be interpreted with caution.

Disclosures

All Authors: No reported disclosures
P-2119. Development of a Machine-Learning-Based Prediction Model for Candidemia Diagnosis
Authors: Lee Chaeryoung , Wang Da Woon , Hong Sung Kwan , Han Hyun Wook , Kim Jong Hun
Published: January 2025

Background

Early recognition and prompt initiation of antifungal therapy for candidemia substantially reduce morbidity and mortality. However, differentiating candidemia from bacteremia remains a clinical challenge and often results in delays in antifungal treatment. This study aimed to develop a machine-learning-based prediction model for candidemia.Figure 1.Receiver Operating Characteristic (ROC) Curves for Machine-Learning-Based Prediction Models for Candidemia

Methods

We conducted a single-center retrospective cohort study involving adult patients diagnosed with candidemia from 2014 to 2021, who were included as cases. Control patients, defined as adults with bacteremia, were randomly selected during the same timeframe. Patients with concurrent bacterial and candida infections were excluded. The event time was defined as the moment of blood culture collection for diagnosing each case of candidemia and bacteremia. Clinical data collected at the event time included vital signs (systolic blood pressure and heart rate), epidemiologic, and laboratory data. In total, 55 types of clinical variables were collected. Nine different machine learning algorithms—XGBoost, Random Forest, Logistic Regression, Support Vector Machine, Multinomial Naive Bayes, K-Nearest Neighbors, AdaBoost, CatBoost, and an ensemble incorporating CatBoost and AdaBoost—were utilized to develop a machine-learning-based prediction model for candidemia. The model demonstrating the highest area under the receiver operating characteristic curve (AUROC) was selected for further analysis. Model performance was assessed based on accuracy, precision, recall, and F1 score.

Results

The cohort included 261 patients with candidemia and 522 with bacteremia, with a median age of 68 years. The AUROC for the models varied from 0.439 to 0.895. The ensemble model achieved the highest AUROC of 0.895 (Figure 1). For this ensemble model, the F1 score was 0.853, recall was 0.849, precision was 0.862, and accuracy was 0.849.

Conclusion

A machine-learning-based prediction model could be a useful tool for identifying high-risk patients for the early diagnosis of candidemia.

Disclosures

All Authors: No reported disclosures
P-2180. Linkage to Care, Treatment Initiation, and Outcomes in Individuals with Hepatitis B Virus Infection With and Without Cirrhosis
Authors: Butt Adeel A , Yan Peng , Shaikh Obaid , Bedimo Roger
Published: January 2025

Background

Screening for hepatitis B virus (HBV) is far from ideal. Linkage to care is also poor. While traditional models suggest a progression of liver disease from fibrosis to cirrhosis to hepatic decompensation and hepatocellular carcinoma (HCC), emerging evidence suggest that terminal outcomes can occur without preceding cirrhosis. Our aim was to define the cascade of care for HBV and clinical outcomes in HBV infected individuals with and without cirrhosis in the US VA healthcare system.

Annual numbers of individuals with newly diagnosed hepatitis B virus infection and numbers initiated on treatment.

Methods

Within the Veterans Health Administration (VA) national databases, we identified all individuals with a positive HBsAg, HBeAg, or HBV DNA between 2002-2023. We tabulated the number of new infections per year and numbers initiated on treatment. We also calculated the incidence rates for development of cirrhosis, hepatic decompensation (HD), hepatocellular carcinoma (HCC), and death among HBV+ individuals.

Outcomes in individuals with hepatitis B virus infection who were free of cirrhosis at baseline.

Results

Of the 44,951 individuals with HBV, 62.9% were referred to gastroenterology, hepatology, or infectious disease specialist. Only 14.5% were initiated on an approved HBV treatment regimen. The mean time to treatment initiation was 34.1 months. Among 38,472 individuals without baseline cirrhosis, the incidence rates/100 person years (95% CI) for cirrhosis, HD, HCC, and death were 0.60 (0.58,0.63), 0.72 (0.69,0.75), 0.49 (0.47,0.52), and 4.29 (4.22,4.35) respectively.

Conclusion

While the incidence rates for liver related complications and death are high among those with HBV infection, large gaps remain in linkage to care and treatment initiation. Terminal events, e.g. hepatic decompensation and HCC, can occur without antecedent cirrhosis, highlighting the need for early screening, diagnosis and treatment. Focused interventions are required to bridge these gaps in care.

Disclosures

Adeel A. Butt, MD, MS, Gilead Sciences: Grant/Research Support
P-2216. The characteristics of human microbiome and fecal resistome in patients with recurrent urinary tract infection
Authors: Kim Bongyoung , Kim Yerin , Na Yeseul , Kim Jeoungyeon , Jang Wooyoung , Go Ji Won , Kim Jinnam , Park Se Yoon , Lee Yangsoon , Pai Hyunjoo , Rho Mina
Published: January 2025

Background

While uropathogenic E. coli (UPEC) is recognized as a primary causative agent of recurrent urinary tract infections (rUTIs), the factors contributing to its colonization remain poorly understood. The study aims to elucidate the characteristics of the human microbiome in patients with rUTI.

Bacterial proportion in genus level: PCoA (distance: Bray-Curtis dissimilarity)

Methods

A prospective study was conducted at a tertiary-care hospital (850 beds) in Korea from August 2021 to November 2023. All female adults (aged ≥19 years) hospitalized with upper UTI were screened daily for inclusion if they met the following criteria: i) E. coli was confirmed as causative pathogen, ii) no structural abnormalities in the urinary tract were present, and iii) patients agreed to participate in the study. Individuals diagnosed with UTI after 48 hours of admission or those transferred from other hospitals were excluded. Fresh stool samples were collected after 28 days of completion of antibiotic treatment, and whole metagenome sequences were obtained using Illumina HiSeq sequencing. Patients with a history of UTI within the past year were defined as having rUTI. We analyzed the characteristics of the microbiome in rUTI patients compared with those in non-rUTI patients as well as the healthy population (n=214), which had already been analyzed in other studies.

Bacterial proportion in genus level: Top 7 genera in each dataset

Results

A total of 51 cases were initially enrolled, but three samples failed to pass the quality check. Consequently, 48 cases (including 13 with rUTI) were included in the final analysis. Among UTI patients, the dominant genera observed were Blautia (7.7%), Bacteroides (7.6%), Faecalibacterium (4.3%), and Bifidobacterium (3.5%). Principal coordinates analysis (PCoA) revealed that the overall distribution of the microbiome in rUTI patients exhibited a distinct pattern compared to non-rUTI patients. Additionally, the proportion of Faecalibacterium and Prevotella was lower in rUTI patients compared to non-rUTI patients and the healthy population. Regarding antibiotic resistance genes (ARGs), rUTI patients showed a lower proportion of ACI and CatS compared to non-rUTI patients and the healthy population.

ARG abundance (RPKM) in gene family level: PCoA (distance: Bray-Curtis dissimilarity)

Conclusion

Some differences observed in the distribution of microbiome and resistome between patients with rUTI and non-rUTI or healthy population.

ARG abundance (RPKM) in gene family level

Disclosures

All Authors: No reported disclosures
P-41. Effectiveness of recombinant zoster vaccine against postherpetic neuralgia in a real-world setting
Authors: Zerbo Ousseny , Bartlett Joan , Fireman Bruce , Goddard Kristin , Duffy Jonathan , Glanz Jason , Naleway Allison L , Donahue James , Anderson Tara C , Klein Nicola P
Published: January 2025

Background

Recombinant zoster vaccine (RZV) is highly effective in preventing herpes zoster (HZ). Effectiveness against postherpetic neuralgia (PHN) was nearly 90% in clinical trials but has not been extensively evaluated in real-world settings. The objective of this study was to evaluate real-world RZV effectiveness against PHN overall, by time-since-vaccination, by age, by corticosteroid use, and by time between the two doses.

Methods

\We conducted a prospective cohort study from January 1, 2018 through December 2022 in persons aged ≥ 50 years at 4 healthcare systems in the Vaccine Safety Datalink (VSD) in the US. Using diagnosis codes, we identified PHN cases between 90 and 365 days after an incident HZ episode. We used Cox regression to compare the hazard of PHN in fully (≥30 days after dose 2) and partially (≥30 days after dose 1) vaccinated persons with unvaccinated persons, adjusted for demographics, comorbidities, prior receipt of zoster vaccine live, VSD site and calendar time. Vaccine effectiveness (VE) was calculated as one minus the adjusted hazard ratio.

Results

Of the 45333 incident HZ cases, 2922 (6.4%) were diagnosed with PHN, of which 2775 were unvaccinated. The unadjusted incidence of PHN per 100000 person years was 43.2 among unvaccinated, 17.4 among partially vaccinated, and 7.8 among fully vaccinated persons. After adjustment, VE against PHN of partial vaccination was 68.9% (95% confidence interval [CI] 59.3% – 76.2%) and VE of full vaccination was 87.1% (CI 83.2% - 90.0%). VE of full vaccination was 91.1% during the first year, 89.8% during the second year, and 77.0% after the second year. Among fully vaccinated persons, VE was 93.1% among persons who received their first dose at ages 50-64 years and 85.9% among those who received their first dose at ages ≥65 years; VE was 74.9% in persons who had received corticosteroids within 90 days of vaccination compared to 88.3% in persons who had not. VE was 86.0% in persons who received their second dose within the recommended 6 months after their first dose compared with 91.4% in persons who received their second dose > 6 months.

Conclusion

Two-dose VE against PHN was 87%, which was similar to that of clinical trials. One-dose VE was 69%, underscoring the importance of the second dose. Two-dose VE may have waned after 2 years.

Disclosures

Jason Glanz, PhD, Hillevax: Grant/Research Support Nicola P. Klein, MD, PhD, CSL Seqirus: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Grant/Research Support
P-2334. Clesrovimab Binding Site Conservation on the RSV F Protein: An Evaluation of RSV Molecular Sequencing Data from 2019-2023 and GenBank Sequence Analysis
Authors: Fridman Arthur , Love-Gregory Latisha , Railkar Radha , Levitan Diane , Strizki Julie , Vora Kalpit A
Published: January 2025

Background

Clesrovimab is a half-life extended RSV-neutralizing antibody targeting site IV of the RSV fusion protein, that is currently in phase 3 development for the prevention of RSV in infants. As viral sequences drift over time, the possibility for the emergence of viral resistance exists, and the conduct of contemporary global RSV surveillance is important.

Methods

Here, we report the frequency of naturally occurring RSV F gene polymorphisms in the clesrovimab binding site [amino acids (a.a) 426-447] using two approaches. First, a total of 15,527 RSV F protein sequences with a complete extracellular domain were obtained from GenBank (accessed April 2024) for analysis. Sequences were aligned using MUSCLE multiple sequence alignment program. The a.a. frequency at each position was determined as well as the frequency of variants in the clesrovimab binding site. Secondly, we collected RSV positive samples in 2019 through 2023 from individuals of any age in a total of 8 countries (in the northern and southern hemisphere). Next generation sequencing was performed of the RSV F gene and data were analyzed for sequence changes in the clesrovimab binding site.

Results

A total of 15,495 of 15,527 (99.8%) of sequences analyzed from GenBank were 100% conserved at the clesrovimab binding site. Thirteen clesrovimab epitope variants were found, 7 of which occurred in 2 or more sequences. The most frequent variant occurred in < 0.04% of GenBank sequences. Additionally, a total of 555 RSV viruses (300 RSV A [54%], 255 RSV B [46%]) were analyzed from the molecular surveillance. There were no variants identified in the clesrovimab binding site that met the prespecified study criteria (prevalence over 5% AND a variant allele fraction of >10%).

Conclusion

These data demonstrate that the clesrovimab binding epitope on site IV of the RSV fusion protein is highly conserved. These findings are in line with previous reports on the conserved nature of site IV and support the continued development of clesrovimab for the prevention of RSV disease in infants.

Disclosures

Arthur Fridman, PhD, Merck & Co., Inc.: employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Latisha Love-Gregory, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Radha Railkar, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Diane Levitan, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Julie Strizki, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Kalpit A. Vora, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company)
P-2335. Comparison of Adverse Drug Effects and Incidence of CMV Infection Between Different Dosing Regimens for Valganciclovir in the Pediatric Solid Organ Transplant Population
Authors: Al Zubaidi Khaled , Huppler Anna R , Jastrow Jena , Groth Shay , Dasgupta Mahua , Yan Ke , Waggoner Winfield S
Published: January 2025

Background

Valganciclovir has become widely used for the prevention of (CMV) infection in solid organ transplant (SOT) patients in both adult and pediatric populations. However, there is no consensus about the optimum dosing regimen in pediatric patients. Our study aims to compare the frequency of side effects and rate of CMV between two commonly used dosing regimens.

Methods

In August 2020, as part of quality improvement initiative our internal SOT guideline for Valganciclovir dosing switched from weight-based (15-25 mg/kg/dose) to the manufacturer recommended dosing based on body surface area and estimated glomerular filtration rate (BSA/eGFR). We retrospectively reviewed medical records of pediatric patients (0-20 years) who underwent SOT (including liver, heart, and kidney) from 2/2015 to 2/2024. The collected data include age, transplanted organ, occurrence of abnormal liver functions (LFT) and neutropenia, and number of episodes of CMV infection during prophylaxis and 6 months post-prophylaxis. Moderate and severe neutropenia were defined as absolute neutrophil count (ANC) 500-1000 and ANC < 500, respectively.

Results

116 pediatric SOT recipients were distributed almost equally between heart (32%), kidney (34%), and liver (34%) transplants. 28/116 (24%) received BSA/eGFR-based dosing. The median duration of prophylaxis was 3.9 months (IQR 2.9-6). The frequency of abnormal LFTs were similar in both dosing groups (64% in the BSA/eGFR group vs 65% in the weight-based group). Moderate neutropenia was more frequent in the BSA/eGFR group (36%) compared to the weight-based group (17%) and severe neutropenia occurred in 11% and 18%, respectively. However, these differences were not significantly different(P=0.11). CMV infection occurred in 27% of total population of patients with no significant difference in breakthrough infection on prophylaxis between the two groups (4% vs 10%, P=0.45).

Conclusion

In pediatric SOT recipients, valganciclovir prophylaxis dosed based on BSA/eGFR or weight had a similar side effect profile for liver toxicity and severe neutropenia. In addition, there was no significant difference in the occurrence of CMV infections between the dosing regimens.

Disclosures

All Authors: No reported disclosures