bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-2070. SARS-CoV-2 Vaccination Rates Among a Cohort of Pediatric Solid Organ Transplant Recipients
Authors: Reis Christopher , Ristagno Elizabeth H , Madigan Theresa 
Published: January 2025

Abstract

Background
SARS-CoV-2 vaccination has been shown to prevent severe disease and subsequent secondary infections in immunocompromised patients. This study assessed the rate of SARS-CoV-2 vaccinations among pediatric solid organ transplant (SOT) recipients at a single transplant center.Figure 1.SARS-CoV-2 vaccination status among pediatric solid organ transplant recipients for all ages and by age group.

Methods
We retrospectively reviewed medical records of pediatric recipients of heart, kidney, and liver transplants at Mayo Clinic, Rochester, MN between January 2011 and December 2023. All SARS-CoV-2 vaccine doses administered on or before April 1, 2024 were recorded. Up-to-date (UTD) status was based on current CDC recommendations for immunocompromised patients for each age group. Deceased patients, those no longer following at Mayo Clinic and whose vaccine records were unavailable were excluded. We also assessed whether patients had been seen by an ID physician in the year prior to collection stop date.

Results
The study included 136 patients: 48 kidney, 58 heart and 30 liver transplant recipients; 52.9% were male. Two patients subsequently received organs of a different type. Mean age was 16.1 years. Since authorization in 2020, 90 patients (66.2%) received at least one SARS-CoV-2 vaccine. This varied by age group, with 72.8% of &gt; =12 year olds, 40.0% of 5-11 year olds and 62.5% of under 5 year olds (p = 0.007 [Figure 1]). Seventy-three patients (53.7%) completed at least three doses. Based on current recommendations that include the 2023-2024 formulation, 30 patients (22.0%) were UTD. This did not differ between age groups (p = 0.717) or by transplanted organ type (p = 0.21). Patients that saw ID were significantly more likely to be UTD (p = 0.001). Among partially immunized patients, 95% (n = 57) needed one additional dose to be UTD.

Conclusion
Despite simplified guidelines with fewer doses needed, a third of pediatric SOT recipients remain unvaccinated against SARS-CoV-2 and only 22% are UTD based on current recommendations. The proportion of unvaccinated patients was highest in the 5-11 year old age group and lowest in the oldest. Those that recently saw ID were significantly more likely to be UTD. Our data suggest that continued care provided by ID physicians may increase vaccine uptake, but reasons for undervaccination and strategies to counteract this should be further explored within this vulnerable population.

Disclosures
All Authors: No reported disclosures
P-2074. Evaluation of Adherence and Access to Booster COVID-19 Vaccination in Persons with HIV
Authors: Krishna Tara , Swaminathan Shobha 
Published: January 2025

Abstract

Background
COVID-19 disproportionately effects minority communities. Completion of the primary COVID-19 vaccination series (≥ 2 doses) is recommended for all American adults by the Centers for Disease Control and Prevention. A population with high mortality and morbidity related to COVID-19 is persons with HIV (PWH). The Infectious Diseases Practice (IDP) at University Hospital (UH) has been providing care to PWH for over 30 years, and it was one of the designated COVID-19 vaccination centers early in the pandemic. We compared rates of PWH who receive COVID-19 vaccine (incomplete: &lt; 2, complete: ≥ 2) amongst different demographic factors to better understand subgroups that can benefit from additional messaging to promote vaccine uptake.

Methods
A retrospective chart review study was conducted at the IDP at UH, Newark. Adult PWH (18-88 years old) who had an office visit to the clinic between January 2021-December 2022 were included. Demographic variables and COVID vaccine count were collected.

Results
The IDP identified PWH (mean age 52, 75.4% Black, 20.4% Hispanic, 39.5% women) who had either complete (n=1085) or incomplete (n=815) primary vaccine schedules for COVID-19. The most common HIV risk factors were heterosexual contact (52.8%), homosexual contact (28.16%), and injection drug use (8.58%). 54% of patients had a CD4+ count &gt; 499, 87.08% of patients had an HbA1c &lt; 6.4, and 72.68% of patients had an HIV viral load that was undetectable.
Notably, PWH who completed the primary vaccination series were more likely to be undetectable (80.6%) years compared to PWH who did not complete their vaccination series (62.1%). Furthermore, PWH who completed the primary vaccination series were more likely to have an HbA1c&lt; 6.4 (83.1%) compared to PWH who did not complete their vaccination series (77.9%). PWH who completed the primary vaccination series were more likely to have a CD4 count &gt; 499 (54.4%) compared to PWH who did not complete their vaccination series (44.4%).

Conclusion
Patients most at risk of not completing the primary COVID-19 vaccine schedule include PWH who are virally uncontrolled, persons with diabetes, or have a low CD4+ count. This indicates medical adherence should be targeted in such populations to improve their healthcare outcomes.

Disclosures
Shobha Swaminathan, MD, Viiv Healthcare: Advisor/Consultant
P-2077. Carbapenemase Resistance Detection by Direct Xpert Carba-R Assay on Flagged Blood Cultures
Authors: Didwania Akansha , Bhatt Manasvini , Kodan Parul , Singh Binit Kumar , Perumalla Sowjanya , Mohapatra Sarita , Wig Naveet , Soneja Manish 
Published: January 2025

Abstract

Background
Early detection of carbapenem-resistant gram negative bacilli(CR-GNB) is critical in patients with sepsis. Delay in diagnosis leads to higher mortality. We evaluated the performance of the Xpert® Carba-R assay (Cepheid, Sunnyvale, CA, USA) directly on flagged blood culture samples in patients with sepsis.Fig 1:Workflow

Methods
Patients with suspected sepsis with GNB on flagged blood culture were recruited. Xpert® Carba-R assay was performed directly on the positive sample. Their diagnostic performance was compared with culture and drug susceptibility testing (DST)(VITEK-2) and time to results were noted and compared.Table 1:Organism profile of patients with sepsis (n=57)

Results
In the study, 57 patients were included; Stenotrophomonas maltophila (n=17; 29.8%) was found to be the predominant isolate, which was excluded from analysis (being intrinsically resistant to carbapenems). This was followed by Klebsiella pneumoniae (n=14 ; 24.5%), Acinetobacter baumannii (n=10 ;17.5%), Escherichia coli (n=6;10.5%), Pseudomonas mendonica (n=3; 5.2%), Pseudomonas aeruginosa (n=2;3.5%) and 1 each of Salmonella typhi, Serratia sp., Enterobacter cloacae, Acinetobacter dendrificans, and Enterobacter sp. Xpert® Carba-R positivity was seen in 23/40 isolates (57.5%), and CR GNB was found in 25/40 isolates (62.5%) on routine DST. Discordant results were seen in 6/40 isolates (15%). Overall sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of Xpert® Carba-R compared to routine DST (Disk diffusion method and VITEK-2) were 84%, 86.6% , 91.3%, 76.47 %, 6.30 and 0.18 respectively. On genomic analysis, most common CR gene expression was co-expression of NDM and OXA-48 [10/23 (43.5%)], followed by NDM [9/23 (39.1%)] and OXA-48 [4/23 (17.4%)]. The median time to obtain Carba-R result was 44 hours compared to 97 hours for detection of carbapenem resistance in routine DST, giving a 53-hour lead time.Table 2:Comparison of direct Xpert® Carba-R and DST ( disc diffusion method and Vitek-2) in various organisms

Conclusion
Xpert® Carba-R was found to have a good diagnostic performance for detection of carbapenem resistance when performed directly on positive blood culture samples with substantial time advantage over conventional methods.Fig 2:Distribution of Carbapenem resistant genes*Two discordant sampleCRO- Carbapenem resistant organismCSO- Carbapenem sensitive organism

Disclosures
All Authors: No reported disclosures
P-2079. A Retrospective Analysis of the Reproducibility of Discordant Fourth-Generation Quantiferon Tests
Authors: Burra Arun , Graber Christopher J , Goetz Matthew B , Ikuta Kevin 
Published: January 2025

Abstract

Background
Interferon-gamma release assays (IGRAs) are used for tuberculosis (TB) screening. The Quantiferon-TB Gold Plus (QFT-Plus) assesses T-cell reactivity to two distinct sets of TB antigens; the test is considered positive if either assay returns positive. Many studies suggest retesting patients with low level positivity prior to proceeding with TB treatment given high rates of reversion in this group. The significance and reproducibility of when TB antigen minus nil (TB Ag-Nil) in one assay is positive and the other is negative (i.e., a discordant result) is unknown.

Methods
We reviewed 26,474 QFT-Plus tests completed for any purpose between 2018 and 2024 at an academic VA medical center. Excluding indeterminate tests, we noted the frequency and (where follow-up tests were available) reproducibility of discordant results. Based on a literature review on the reproducibility of prior generation tests, we defined levels of positivity: “low+” TB Ag-Nil as 0.35-0.69 IU/mL, “mid+” 0.7-0.99 IU/mL, and ”high+” ≥1 IU/mL. For statistical analysis, we performed univariate logistic regression assessing the probability of follow up QFT testing returning negative (reversion) in a discordant result compared to a concordant low+ result.

Results
During the study period, 449 QFT-Plus test results were discordant, representing 26% of all positive QFT-Plus tests (Table 1). Among all discordant tests with follow-up available, 70% (103/148) reverted to negative while 49% (43/88) of repeated concordant low+ tests reverted. Discordant tests were more likely to revert than were concordant low+ tests (OR 2.40, 95% CI 1.39-4.15, p=0.002). 71% (79/111), 58% (11/19), and 72% (13/18) of repeat tests were negative with an initial discordant test that was low+, mid+, or high+, respectively (Table 1). Most discordant results were low+ (Figure 1).

Conclusion
Upon retesting, discordant QFT-Plus tests most often revert. The level of positivity in discordant tests does not appear to correspond with the likelihood of reversion. We found that the rates of reversion for discordant tests were significantly higher than for concordant lowly positive tests, suggesting a role for retesting patients with discordant results — regardless of the actual test values — prior to decision making around TB treatment in some settings.

Disclosures
All Authors: No reported disclosures
P-2083. Validation of the Modified Rapid Test for detection of the Cefazolin Inoculum Effect (CzIE) in bloodstream isolates of Methicillin-Susceptible Staphylococcus aureus (MSSA) from North and Latin America
Authors: Carvajal Lina Paola , Rincon Sandra , Panesso Diana , Gomez Villegas Sara I , Singh Kavindra , Jacques-Palaz Karen , Malikzad Husna , Dziadula Jacob , Dingle Tanis C , Butler-Wu Susan , Miller William R , Arias Cesar A , Reyes Jinnethe 
Published: January 2025

Abstract

Background
S. aureus is a major human pathogen and a leading cause of bloodstream infections (BSI). Cefazolin is frequently used for severe deep-seated MSSA infections, as in general it displays similar efficacy and a more favorable side effect profile as compared to isoxazolyl-penicillins. In some studies, the CzIE has been associated with therapeutic failures and mortality in MSSA BSI treated with cefazolin, however, current laboratory testing methods are unable to detect the CzIE. The aim of this study was to conduct a blinded evaluation of a modified colorimetric rapid test to detect the CzIE in MSSA isolated from BSI in North and Latin-America.

Methods
99 MSSA recovered from BSI in North America (2019; n=69) and Latin-America (2011-2019; n=30), and previously characterized for the presence of the CzIE (71 CzIE + and 28 CzIE -) using gold-standard broth microdilution at high inoculum (breakpoint &gt;= 16 ug/mL) were included. In a central laboratory in Colombia, a modified rapid colorimetric test (rCT) was performed according to a published protocol with modification that included the use of ampicillin (AMP) discs placed in 1 mL of BHI-broth for induction of β-lactamase expression. The researchers were blinded to the results of the gold standard test to detect CzIE. Diagnostic performance metrics were calculated and typing of BlaZ was performed using whole genome sequence data.

Results
Compared to the gold standard, the modified test showed a sensitivity and specificity of 97% and 86%, respectively, and overall accuracy of 94%. The predominant BlaZ β-lactamase types in the 99 MSSA were type C (70%) and type A (27%). When analyzing the performance of the rCT by BlaZ type, in isolates with type C enzyme the modified rapid test had a sensitivity of 96% and specificity of 82% with an accuracy of 91%. In isolates with BlaZ type A, the sensitivity and specificity of the rCT were 100%.

Conclusion
The modified rapid colorimetric test detected the CzIE in bloodstream MSSA from different geographic areas with a global accuracy of 94%. Notably, the accuracy of the test for BlaZ type A isolates was 100% and for BlaZ type C isolates was 91%. Further, the use of AMP discs proved to be a practical, time-saving modification that did not impair accuracy of the test.

Disclosures
William R. Miller, M.D., Merck: Grant/Research Support|UptoDate: Royalties
P-2084. Construction of dominant peptide librarys of Mycobacterium tuberculosis-specific antigens and validation of their immunogenicity
Authors: Li Yuanchun , Ge Qiping , Gao Mengqiu , Liu Xiaoqing , Zhang Lifan 
Published: January 2025

Abstract

Background
Current immunological methods cannot accurately distinguish active tuberculosis (ATB) and latent tuberculosis infection (LTBI). The combination of latency-associated antigens with virulence antigens of Mtb enhances the discriminatory diagnostic ability. This study aims to screen and integrate dominant peptide segments of virulence factors and latency-associated antigens, verify their immunogenicity.

Methods
ATB patients and LTBI healthy healthcare workers were enrolled, and PBMCs were isolated. Peptide pools of ESAT-6, CFP-10, Rv1733c and Rv2028c were used as stimuli. The frequencies of total IFN-γ secretion, total IL-2 secretion, and dual secretion of IFN-γ and IL-2 were measured using the FluoroSpot assay. Dominant peptide segments for library construction were screened based on the cytokine secretion characteristics of ATB and LTBI. Clinical T-SPOT.TB-positive patients were included for the verification of the immunogenicity of the newly combined peptide library.

Results
Significant differences were found in the frequencies of specific T cells secreting IFN-γ, secreting IL-2, and dual-secreting IFN-γ and IL-2 between the ATB group and the LTBI group (p&lt; 0.05) after stimulation with peptide pools from ESAT-6 and CFP-10, integrating six dominant peptide pools into the virulence antigen dominant peptide library. Similarly, six peptide pools from Rv1733c and Rv2028c were integrated into another dominant peptide library. The newly constructed library showed no significant differences (p &gt;0.05) in the frequencies of total IFN-γ secretion, total IL-2 secretion, and dual secretion of IFN-γ and IL-2 compared to ESAT-6 combined with CFP-10, and the correlation coefficients were 0.947, 0.763, and 0.993, respectively. Similarly, the newly constructed latency-associated antigen library also showed no significant differences (p &gt;0.05) in the frequencies of total IFN-γ secretion, total IL-2 secretion, and dual secretion of IFN-γ and IL-2 compared to Rv1733c combined with Rv2028c, and the correlation coefficients were 0.674, 0.562, and 0.692, respectively.

Conclusion
The newly constructed librarys retain good immunogenicity and can be further used clinically to evaluate the accuracy of ATB and LTBI differential diagnosis.

Disclosures
All Authors: No reported disclosures
P-2088. Correlation of pediatric blood culture transport time and time-to-positivity since microbiology service centralization
Authors: Yeung Eugene 
Published: January 2025

Abstract

Background
Guidance from Clinical & Laboratory Standards Institute (CLSI) and Infectious Diseases Society of America (IDSA) both recommend that transport of blood culture specimens from collection to laboratory accession should take less than 2 hours to preserve the specimen quality, such as positivity rate and time-to-positivity (TTP). This recommendation could be impractical in Canada as many diagnostic microbiology laboratories are moving towards centralization, in which microbiology services are relocated from individual laboratories to regional sites, where resources and personnel are consolidated. This is especially crucial for the pediatric population as different published guidelines are available on the required pediatric blood culture volume, which could affect their positivity rate and TTP.

Methods
The current study investigated the blood culture transport time and TTP for Children’s Hospital of Eastern Ontario (CHEO), a tertiary pediatric hospital, situated about 700 meters away from Eastern Ontario Regional Laboratory Association (EORLA) microbiology laboratory, which has consolidated the microbiology services for 18 hospitals in Eastern Ontario since 2010’s. All first positive blood cultures from patients at CHEO from 1 November 2019 to 31 October 2020 were included. TTP was defined as the time from collection to a positive signal from the automated incubators. Two-tailed Spearman’s correlation was used to determine the association between transport time and TTP.

Results
A mean transport time of 2.95 hours and a mean TTP of 31.8 hours were calculated from the 268 episodes of first positive blood culture from patients in a year (mean patient age 6.27 years). Only 82 specimens were transported to the laboratory in less than 2 hours. A weak but statistically significant correlation (rs = 0.17, p = 0.0047.) was observed between transport time and TTP.

Conclusion
Even for a hospital within walking distance of a regional microbiology laboratory, the blood culture transport time was unable to meet the guidance recommendation, associated with delay in TTP. Centralization of microbiology services could affect the quality of critical clinical specimens. Remedial actions, such as molecular testing, could be considered to salvage specimens if they are crucial for diagnoses.

Disclosures
All Authors: No reported disclosures
P-17. Worldwide Impact of Increased Recombinant Zoster Vaccine Coverage on the Burden of Herpes Zoster, based on 11-year Clinical Trial Follow-up Data, in Adults Aged ≥50 Years
Authors: Curran Desmond , Matthews Sean , Giannelos Nikolaos 
Published: January 2025

Abstract

Background
Herpes zoster (HZ) is a viral disease impacting patients quality of life due to pain and rash. It is a vaccine-preventable disease with approximately 15 million cases observed annually in individuals ≥50 years of age (YOA) worldwide. Recombinant zoster vaccine (RZV) has proven effective in protecting against HZ infection. This is the first study evaluating the potential increased (incremental) public health benefits - in terms of HZ cases averted - of vaccinating adults ≥50 YOA worldwide with RZV.Table 1:Number of Herpes Zoster cases avoided by region as a function of increasing vaccine coverage and second dose completion levels*Incremental coverage: impact observed due to increased coverage of X%

Methods
A previously published static multi-cohort Markov model with an annual cycle length, and a lifetime horizon was used, which incorporated the following inputs : population estimates, and age-gender specific mortality rates from the latest (2022) United Nations data, depicting populations on December 31, 2023; HZ incidence rates from a recent (2021) meta-regression analysis of HZ burden across the globe (Asia, Europe, Northern America, and Oceania); RZV efficacy modelled based on 11-year clinical trial follow-up data [NCT02723773].Table 2:Number needed to vaccinate to prevent Herpes Zoster cases by age and region as a function of increasing vaccine second dose completion levelsYOA, years of age.

Results
Assuming a 70% second-dose completion rate in the general population ≥50 YOA worldwide, absolute increases in uptake of RZV by 5% would reduce the number of expected cases by &gt;10 million over the remaining lifetime of vaccinated individuals (see Table 1). Numbers needed to vaccinate (NNV) to avert 1 HZ case by age group worldwide varied from 9 in 50-59 YOA to 18 in ≥80 YOA, and 10 overall in ≥50 YOA (see Table 2). Variations observed by region and age reflected varying inputs, i.e. population demographics, HZ incidence rates, life expectancy and vaccine efficacy.

Conclusion
Even with a relatively modest increase of coverage rates worldwide, RZV is projected to prevent millions of HZ cases due to the long term protection it affords. Lower NNVs are observed in younger vaccinated cohorts, irrespective of region, outlining the relative merits of age of vaccination.
Funding: GSK

Disclosures
Desmond Curran, PhD, GSK: employee|GSK: Stocks/Bonds (Public Company) Sean Matthews, MSc, GSK: Advisor/Consultant Nikolaos Giannelos, PhD, GSK: Employee|GSK: Stocks/Bonds (Private Company)
P-2096. Reverse Blot Hybridization Assay for Simultaneous Multi-drug Resistance Detection of Helicobacter pylori
Authors: Lee Kyoung Hwa , Lee Eun Hwa , Han Sang Hoon , Song Young Goo , Lee Hye Young 
Published: January 2025

Abstract

Background
Helicobacter pylori (H. pylori) the eradication is important for cancer prevention. Amoxicillin and clarithromycin, the initial treatments of H. pylori, have been shown increasing resistance, suggesting alternative levofloxacin or tetracycline based treatment option. However, theses resistance rate is also increasing by nearly 18-37%, thus, early recognition of multi-drug resistance is critical for efficient treatment success.

Methods
The novel diagnostic kit is needed that can simultaneously detect multi-drug resistance (Table 1). A total of 311 clinical H. pylori isolates were obtained from the gastric endoscopic biopsy in Gangnam Severance Hospital, Seoul, Republic of Korea. The phenotypic drug susceptibility test (pDST) was performed (Table 2), compared with the reverse blot hybridization assay (REBA) tests, and whole genome sequencing was done for the inconsistency.

Results
The overall sensitivity about clarithromycin, tetracycline, and levofloxacin are 95.5%, 16.7%, and 55.8%, respectively. The specificity showed much improved detection rate, 96.3%, 92.7%, and 81.8%, respectively (Table 3). Clarithromycin resistance was not significantly different from the performance of the other previously developed kits, and no specific novel mutation sites were discovered other than already known resistance genes. However, novel mutations at A926G, A926T, A926C, A928C, and A934G of tetracycline resistance were discovered. Tetracycline-susceptible clinical H. pylori isolates (n = 100) were sequenced at the target region, and these novel mutations were not present. A926G, A926T, A926C showed low-level resistance, with MIC range from 0.36 µg/mL to 1 µg/mL, and the A928C mutation was found in high-level tetracycline resistance (MIC &gt; 2 µg/mL). Among 102 quinolone-resistant H. pylori isolates, 45 H. pylori isolates showed mismatched with REBA, they had specific sequence (Table 4).

Conclusion
Detection of resistance against H. pylori is important in selecting treatment options, therefore, we found novel mutation of tetracycline which can be new target lesion. By simultaneously targeting and detecting various resistance genes, efficiency in antibiotic selection, shortened treatment duration, and reduced medical costs can be expected.

Disclosures
All Authors: No reported disclosures