bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-245 Reagent Lot Variation—When should I be Concerned?
Authors: Vincini G , Dimech W 
Published: September 2023

Abstract

Background
Reagent lot variation is often considered a major source of concern for infectious disease serology testing. Regular review of quality control testing data for specific assays confirms that, when using traditional statistical methods, such as using small datasets to establish mean/SD and then applying Westgard rules, reagent lot variation is the most common cause of variation observed. To investigate every incident is time consuming, costly and likely unnecessary in the majority of cases. But how do we create an alternative to monitoring QC data that accepts normal reagent lot variation yet highlight unacceptable variation? Applying the results from two assays using the same multimarker QC sample to traditional and an alternative QC monitoring method such as QConnect highlights when we should be concerned with lot variation and when the variation is normal.

Methods
QC testing data from 14 lots of the multimarker QC “Optitrol Blue” over a three year period tested on two assays—Abbott ARCHITECT Anti-HCV (n = 54 102) and Abbott ARCHITECT HIV AgAb Combo (n = 62 682) were reviewed for lot variation using traditional and alternative QC monitoring methods.

Results
Numerous examples of lot variation were identified from the two assays over the three-year period. Applying traditional QC methods resulted in frequent recalculation of mean/SD to accommodate the lot variation, effectively making the lot variation part of the routine, negating its importance, and making the clinical significance of reagent lot variation difficult to ascertain. Using an alternative QC monitoring method such as QConnect, which incorporated normal lot in calculations to create a constant acceptance range, removed the uncertainty and highlighted instances where variation was outside ‘normal’, triggering further investigation by using meaningful QC ranges. A clear example was observed where two similar looking Levey-Jennings charts (one for ARCHITECT HCV and one for ARCHITECT HIV) demonstrated reagent lot variation that was detected as an outlier whereas Traditional methods identified all reagent lots as being outliers.

Conclusion
In infectious disease serology testing, reagent lot variation is frequent, normal, and rarely a cause for concern. However, it is difficult to determine how much variation is acceptable when using traditional QC methods, because most lot changes are flagged as “rejections”. QC processes that incorporate normal reagent lot variation, derived from historical data, allows for rapid identification of unacceptable variation, saving money and time (particularly when all reagent lot variation identified as outliers need unnecessary investigation), while reducing risk of poor results.
A-248 Evaluation of NextGene™ MTB/NTM Detection Kit for Detection of Mycobacterium tuberculosis Complex and Nontuberculous Mycobacteria in Sputum and Culture Specimens
Authors: Ahn J , Kim D , Lee W 
Published: September 2023

Abstract

Background
Tuberculosis, an infectious disease, is a major cause of deteriorating health, and, until SARS-CoV-2 (COVID-19) became a pandemic disease, a major cause of death worldwide. The recently developed NextGene™ MTB/NTM Detection Kit is designed for detection of Mycobacterium tuberculosis complex (MTB) using IS6110 genes and MPB64 genes, and for detection of nontuberculous mycobacteria (NTM) using 16S rRNA genes for resolution of false positive and false negative results, and for development of more sensitive and specific real-time PCR products. The purpose of this study is to examine the clinical sensitivity and specificity of the NextGene™ MTB/NTM Detection Kit in order to verify its clinical efficacy.

Methods
A total of 446 residual clinical specimens were obtained from 274 sputum and 172 culture samples collected from July to August 2021. Diagnostic tests were performed in order to confirm that these residual samples were positive and negative; 344 specimens were positive for MTB or NTM, and 102 specimens were confirmed as negative for both MTB and NTM. Measurement of positive/negative percent agreement values and kappa coefficients was performed for comparison of diagnostic performance between the NextGene™ and Advansure assays. Positive and negative controls were included in each run.

Results
Of the 446 samples (274 sputum and 172 culture samples), 344 specimens showed a positive result and 102 specimens showed a negative result. Results of the comparison tests were all consistent for detection of MTB and NTM. Both MTB and NTM met the criterion for evaluation of target validity of kappa value 0.8 or higher in sputum and culture samples. Results of the evaluation of clinical sensitivity and specificity were consistent with both clinical diagnoses.

Conclusion
This study was conducted in order to examine the clinical sensitivity and specificity of the NextGene™ MTB/NTM Detection Kit in order to verify its clinical validity. Residual samples from sputum and culture specimens from patients who were suspected being infected that were confirmed positive or negative for MTB and NTM were used in this study with the goal of establishing the already commercially available licensed product as a control reagent for comparative analysis of the clinical performance of the NextGene™ MTB/NTM Detection Kit. Compared to existing kits that are widely used, consistent results from comparison of the NextGene™ MTB/NTM Detection Kit have been reported with comparable clinical sensitivity and specificity, thus it is regarded as showing the same performance.
A-256 Clinical Performance of Presepsin for Sepsis in the Emergency Department Patients in a Tertiary Hospital in Korea
Authors: Ji E , Lee S 
Published: September 2023

Abstract

Background
Sepsis is a life-threatening condition that requires prompt recognition and treatment. Presepsin is a new diagnostic biomarker of sepsis that has been implemented as a selective reimbursement in Korea and was introduced in our hospital in October 2022. This study aimed to evaluate the clinical performance of the Presepsin Assay (Sysmex, Kobe, Japan) on the Sysmex HISCL-5000 system in the southeast population in Korea.

Methods
The study is a retrospective study that included emergency department (ED) and ED-based intensive care unit (EICU) patients tested for presepsin from August 18, 2022, to February 11, 2023. We calculated the patients’ sepsis-related organ failure assessment (SOFA) score at the time of blood collection for presepsin from the electronic medical record. Presepsin, procalcitonin, and high-sensitivity C-reactive protein (hsCRP) were also investigated. The sepsis markers for sepsis prediction were evaluated using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC).

Results
A total of 81 patients, including 66 ED and 15 EICU patients, were tested for presepsin. The presepsin results ranged from 101 to 8788 pg/mL (Mean 1,005.9 pg/mL, Standard deviation 1,509.4). In ROC curve analysis, three biomarkers—presepsin, procalcitonin, and hsCRP generated an area under the curve (AUC) value of 0.698, 0.670, and 0.694 for predicting sepsis, respectively, for the threshold ≥7 of SOFA score to screen the risk of sepsis.

Conclusion
The clinical performance of presepsin in the ED-based setting in Korea was found to be comparable in detecting the risk of sepsis. Further research is needed to determine the optimal use of presepsin in the other clinical areas of the hospital, such as intensive care units, and to assess its impact on patient outcomes.
A-264 Comparison of the ZEUS Scientific Lyme Assays to the DiaSorin Liaison Lyme Assays Using a Modified Two-Tiered Testing Algorithm for Lyme Disease
Authors: Walsh M E , Sietsma D J , Martin I W , Brunelle L A 
Published: September 2023

Abstract

Background
Lyme borreliosis is the most common vector-borne disease in the United States. Modified two-tiered testing (MTTT) strategies have recently been developed that use enzyme immunoassays as the second tier test in place of an immunoblot. We directly compared two sets of MTTT assays with samples obtained from the northeastern United States, a Lyme disease endemic area.

Methods
Remnant specimens from 120 patients initially tested by the ZEUS Scientific Lyme ELISAs in accordance with an MTTT algorithm were analyzed with the DiaSorin Lyme chemiluminescent immunoassays. The ZEUS assays were performed on a DYNEX DS2 and the DiaSorin assays were performed on the DiaSorin Liaison XL. Analytical concordance was evaluated.

Results
Of the 25 samples that were negative by the ZEUS VlsE1/pepC10 IgG/IgM assay, 100% (25/25) were negative by the DiaSorin Lyme Total Antibody Plus assay. Of the 95 samples that were presumptive positive or equivocal by the ZEUS IgG/IgM assay, 64% (61/95) were presumptive positive or equivocal and 36% (34/95) were negative by the DiaSorin Lyme Total assay. Samples that tested presumptive positive or equivocal on the ZEUS IgG/IgM or DiaSorin Lyme Total were evaluated by the respective IgG and IgM assays. Positive IgG results and negative IgM results demonstrated &gt;90% agreement between the ZEUS and DiaSorin assays (Table 1). Overall clinical interpretation was concordant between the ZEUS and DiaSorin MTTTs in 57% (54/95) of patients who tested presumptive positive or equivocal on the ZEUS IgG/IgM. Twenty-four samples that tested positive for IgM by the ZEUS assay tested negative for DiaSorin Lyme Total or IgM assays.

Conclusion
Comparison of the DiaSorin Lyme assays to the ZEUS Lyme assays using an MTTT algorithm suggests that the DiaSorin assays would result in fewer positive screening tests, decreasing unnecessary secondary testing, and may result in fewer patients treated with antibiotics.
A-265 Disparities Among SARS-CoV-2 Antibody Positivity in Healthcare Workers
Authors: Mullins K E , Christenson R 
Published: September 2023

Abstract

Background
Early in the COVID-19 pandemic disparities in hospitalizations and mortality rates were seen between race/ethnicities. Currently, the CDC reports that there is a 2.1× and 1.6× increase in risk of hospitalizations and deaths, respectively, for Black non-Hispanic (NH) persons when compared to White NH persons. Additionally, studies have found that Black and Hispanic individuals are more likely to test positive for SARS-CoV-2 as compared to other ethnicities/races. Many socioeconomic factors have been associated with increased risk, however, few if any, studies have investigated the disparities in SARS-CoV-2 exposure for healthcare workers.

Methods
To gain a better understanding of the risk of SARS-CoV-2 exposure in healthcare workers, EDTA plasma samples were collected from healthcare workers associated with the University of Maryland Medical System between June 1st, 2020, and August 31st, 2020. Plasma samples were tested for Anti-SARS-CoV-2 Spike Ig/M/A Antibodies using an in-house developed Enzyme-linked Immunoassay and the Ortho Vitros COVID-19 Total Antibody assay.

Results
7850 healthcare workers were enrolled (82.3% female). 26.7% were Black NH and 75.3% were White NH individuals. No differences were seen between age or sex between the two groups. Overall, the positivity rate for Anti-SARS-CoV-2 antibodies was 3.5%, however, when stratified by race/ethnicity 6.7% of Black NH individuals and 2.4% of White NH individuals were positive for Anti-SARS-CoV-2 antibodies. When stratified by sex there were no statistically significant differences.

Conclusion
These findings suggest that Black NH healthcare workers were 2.6 times more likely to have been exposed to SARS-CoV-2 when compared to White NH individuals, irrespective of sex. Further understanding of the geographic and socioeconomic factors that play a role in these findings is needed. However, these findings suggest that heath disparities are prevalent and need to be addressed not only in the communities that our healthcare workers treat, but within our healthcare worker communities themselves.
A-275 Clinical Evaluation of SMARTCHEK® SARS-CoV-2 Detection Kit and SMARTCHEK® SARS-CoV-2 Fast Detection Kit for Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Nasopharyngeal Swabs
Authors: Ahn J , Lee W , Yoon S , Cho S 
Published: September 2023

Abstract

Background
Rapid and accurate diagnosis of COVID-19 is very important in our daily lives. SMARTCHEK® SARS-CoV-2 Detection Kit (Genesystem, Daejeon, Korea) and SMARTCHEK® SARS-CoV-2 Fast Detection Kit (Genesystem) are rapid PCR kits for SARS-CoV-2 using a microfluidic chip-based PCR method. These two kits can provide results in 40 min and 20 min, respectively, enabling rapid point-of-care diagnostics. In this study, the diagnostic performance of SMARTCHEK® SARS-CoV-2 Detection Kit and SMARTCHEK® SARS-CoV-2 Fast Detection Kit using UF-340 Four-in-One Real-time PCR System (Genesystem) were compared to STANDARD M nCoV Real-Time Detection kit (SD Biosensor, Korea) using CFX96 Dx System (Bio-Rad, USA) in nasopharyngeal swabs.

Methods
Nasopharyngeal swabs were collected and frozen (at ≤−70°C) using 500ul of the residual samples of 64 patients who underwent COVID-19 PCR at Ajou University Hospital. After thawing, RNA was extracted with TANBead OptiPure Nucleic Acid Auto Plate (Taiwan Advanced Nanotech Inc., Taoyuan, Taiwan) using SLA-E13200 (Taiwan Advanced Nanotech Inc.), and real time PCR was performed according to the manufacturer’s instructions. For correlation evaluation, positive, negative, and overall concordance rates were calculated.

Results
Among 64 samples, results from STANDARD M nCoV Real-Time Detection kit showed 49 negative (77%) and 15 positive (23%) results. Ct value exceeding 30 was observed in 4 samples (27% of positive samples). The positive, negative, and overall concordance rates of the STANDARD M nCoV Real-Time Detection Kit and SMARTCHEK® SARS-CoV-2 Detection Kit were all 100%. One positive sample with the STANDARD M nCoV Real-Time Detection Kit (Ct value: E gene 34.5, RdRp gene 35.5) was excluded from the analysis because the results could not be determined even after repeated testing with SMARTCHEK® SARS-CoV-2 Detection Kit. The positive, negative, and overall concordance rate of the STANDARD M nCoV Real-Time Detection Kit and SMARTCHEK® SARS-CoV-2 Fast Detection Kit were 87%, 100%, and 97%, respectively. Both of the two discrepant samples had a Ct value close to 35.

Conclusion
SMARTCHEK® SARS-CoV-2 Detection Kit and SMARTCHEK® SARS-CoV-2 Fast Detection Kit can quickly and accurately diagnose COVID-19 in nasopharyngeal swabs and is especially useful in small to medium-sized laboratories or areas where space or equipment is limited.
A-285 Performance Evaluation of LIAISON® QuantiFERON®-TB Gold Plus Assay and Its Use in Long-Term Care Facilities
Authors: Khoury R , Gandhi A , Gudaitis D , Gudaitis P 
Published: September 2023

Abstract

Background
Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis with 7860 cases reported in 2021 in the United State and estimated 13 million people are living with Latent TB infection (LTBI); Early detection of TB infection is crucial to prevent the spread of the disease; there are two types of tests for TB and LTBI: Tuberculin Skin Test (TST) and Interferon-Gamma Release Assay (IGRA). Although TST has good sensitivity but false-negative reactions occur in certain population and the specificity of is decreased among persons with prior Bacillus Calmette-Guérin (BCG) vaccination, especially those vaccinated post-infancy and those with repeat vaccination. Similarly, persons living in areas where nontuberculous mycobacteria are common are at increased risk of having false-positive TST reactions. IGRA is blood-based laboratory test that measures responses to TB-specific peptide antigens in whole blood. Like the tuberculin skin test (TST), it is an indirect test for M. tuberculosis infection, but is more specific than TST and is unaffected by prior BCG vaccination and most environmental mycobacterial infections.

Methods
The LIAISON® QuantiFERON®-TB Gold Plus assay is an in vitro diagnostic test for the detection of interferon-γ (IFN-γ) in human lithium heparin plasma by chemiluminescence immunoassay (CLIA) using the LIAISON ® XL Analyzer. The clinical specificity and sensitivity were 96.9% and 84.4% respectively. Clinical studies have shown Positive Percent Agreement (PPA) of 97.4% and Negative Percent Agreement (NPA) of 98.6%. We evaluated the precision, reproducibility, and correlated patient results to our reference lab results. 452 samples collected from Long-Term Care facilities resident were run over 9 months. Statistical analyses were done using Analyse-it.

Results
The percentage agreement for precision, reproducibility, and accuracy were 100%. The correlation with the reference laboratory was 100% agreement. We found 14.8% of samples tested were positive, 83.2% were negative and 2.0% were indeterminate.

Conclusion
The LIAISON® QuantiFERON®-TB Gold Plus assay offers the benefit of a fully automated with high sensitivity and specificity. The faster turnaround will aid the physician in the diagnosing M. tuberculosis, eliminates the need for two-step testing, and is preferred in patients who received BCG vaccination. In addition, with the growing geriatric population, the availability of this test will give the physician the opportunity to follow the 2016 American Thoracic Society (ATS)/Infectious Disease Society of America (IDSA)/CDC clinical practice guidelines for using IGRAs in older patients.
A-286 Performance Evaluation of Molecular Clostridium Difficile Assay using BD MaxTM System
Authors: Khoury R , Patel P , Gandhi A , Gudaitis D , Gudaitis P 
Published: September 2023

Abstract

Background
Clostridium difficile (C.Diff) is a gram positive anaerobe producing Enterotoxin and Cytotoxin (toxin A and B respectively); toxin B has been reported to be essential for its virulence. It is estimated that C. Diff will cause over half a million infection yearly and one in 11 people over the age of 65 diagnosed with healthcare-associated C.Diff infection die within one month. It is the most common cause of acute diarrhea; residents in Long-Term Care Facilities (LTCF) are more prone to have C. Diff infection (CDI) because of their age, the frequent use of antibiotics, fragilities, co-morbidity, and living environment. Diagnosing CDI is based on clinical signs and symptoms as well as laboratory tests. Several tests available for diagnosing the infection which include: enzyme immunoassays, tissue culture cytotoxicity, anaerobic culture, glutamate dehydrogenase antigen and nucleic acid amplification. The BD MAX™ System is a PCR based assay that provides the sensitivity, specificity and faster turnaround.

Methods
The MAX™ System is an automated in vitro diagnostic test for the direct qualitative detection of the C. difficile toxin B gene (tcdB) in human liquid or soft stool specimens from patients suspected of having Clostridium difficile Infection (CDI).The test is performed directly on the specimen, utilizing real-time polymerase chain reaction (PCR) for the amplification of C. difficile toxin B gene (tcdB). The test utilizes fluorogenic sequence-specific hybridization probes for detection of the amplified DNA. The test was validated for accuracy, precision, and patient correlation to enzyme-immunoassay using Premier Toxins A & B is an enzyme immunoassay for the direct detection of Clostridium difficile toxin A and toxin B in stool samples. Statistical analyses were done using Analyse-it.

Results
The percentage agreement for precision, reproducibility, and accuracy were 100%. We had 100% agreement for positive patients on EIA and 85% for negative patients on EIA; however, upon investigation we found the discrepancies were due to false negative EIA results.

Conclusion
The BD Max gave the benefit of a fully automated with high sensitivity and specificity for the presence of toxin B producing C. Diff. The faster turnaround gives the physician the ability to diagnose CDI and prevent spreading of the disease to other patients. It is very important to remember that C.diff infection can be prevented with appropriate use of antibiotics and implementing antibiotic stewardship and infection control plan to prevent and stop spreading of the infection.
A-305 Evaluation of the Analytical Performance of Rapid Tests to Detect Arboviruses Antibodies Intended for Point-of-Care Screening
Authors: Domingues R S , Martins L A , Zauli D A , de Lima A B , Silva J D 
Published: September 2023

Abstract

Background
Arboviruses are recognized as a group of RNA viruses that can transmit diseases by different sucking arthropods vectors, especially Aedes Aegypti, a mosquito that can transmit several viral diseases including Dengue (DENV) and Chikungunya (CHIKV). The re-emergence and spread of these diseases are considered a concern in global health and Latin American countries, such as Brazil. Therefore, it's necessary to offer efficient, simpler, and faster diagnosis tools for accurate case identification and help promote adequate treatment. Rapid tests (RTs) can be used as one of these tools for qualitative detection and it's important mainly in point-of-care (POC) testing places. Thus, this work aimed to evaluate RTs to identify antibodies (IgG and IgM) of DENV and CHIKV.

Methods
Serum samples were previously selected as positive, negative, or inconclusive results based on ELISA method or RTs confirmation. It was used the immunofluorescence-based ECO Diagnostica RTs kits (ECO-F Dengue IgG/IgM and ECO-F ChikV IgG/IgM). The samples were diluted in proper buffer and incubated for 15 minutes. The results were read in ECO Reader F200 equipment that uses the Cut-Off value for results. Cut-Off values &gt;1.00 are considered positives, while Cut-off values &lt;1.00 are considered negatives.

Results
The results are presented in Tabela 1.

Conclusion
Both RTs showed specificity that surpasses 88%. The sensibility obtained was 57,14% and 33,3% for DENV and CHIKV tests respectively. All samples that obtained inconclusive results by other methodologies showed negative results in the RTs assessed. The NPV was 64% and 86,96% for DENV and CHIKV tests respectively. Although RTs can be used to help in the initial screening of diseases caused by arboviruses, it is necessary to carry out molecular tests for confirmation, especially in negative cases.