Detection of high-grade cervical neoplasia using extended genotyping: Performance data from the longitudinal phase of the Onclarity trial.

OBJECTIVES: The Onclarity cervical cancer screening trial was designed to establish the clinical validity of the Onclarity HPV assay for extended genotyping (xGT) during detection of high-grade cervical neoplasia grades 2 or 3 (≥CIN2 or ≥CIN3). Here, three-year follow up data is presented to evaluate the overall efficacy of these screening strategies, compared to the baseline data. METHODS: At baseline 29,513 women, ≥25 years, had evaluable cytology and valid high-risk HPV results. Women with atypical squamous cells-undetermined significance or worse cytology or a positive HPV test were referred for colposcopy/biopsy. Participants that did not reach the study end point (treatment for ≥CIN2) continued into the longitudinal phase that included the same protocol as baseline. RESULTS: The three-year cumulative incident risk (CIR) for ≥CIN3 in HPV-negative women was 0.15% [95%CI: 0.06, 0.26] and for HPV- and cytology-negative women was 0.12% [95% CI: 0.03,0.23]. HPV16 carried the highest baseline and three-year ≥CIN3 CIR, followed by HPV31 and HPV18. At least one year of genotype-specific persistence increased ≥CIN3 risk for xGT results compared to genotype non-persistence, HPV clearance, or new infection over the same time period. Risk-based screening with immediate colposcopy for HPV16/18/31 and further xGT triage resulted in better ≥CIN3 sensitivity (79.2% versus 72.3%; relative difference of 6.9 [95%CI: 3.3, 10.4]) and a lower colposcopy/≥CIN3 ratio (9.2 versus 11.2; relative difference of -1.9 [95%CI: -2.6, -1.3]) when compared to primary HPV16/18-based screening. CONCLUSIONS: An HPV-negative result offers the same assurance of no disease over three years of follow up as that offered by a negative co-testing result. xGT facilitates risk-based screening and persistence tracking and can help optimize disease detection during screening without excessive colposcopic procedures.

A pragmatic approach for dynamically incorporating predicate device data in prospective diagnostic test studies.

Clinical studies are generally required to characterize the accuracy of new diagnostic tests. In some cases, historical data are available from a predicate device, which is directly relevant to the new test. If this data can be appropriately incorporated into the new test study design, there is an opportunity to reduce the sample size and trial duration for the new test. One approach to achieve this is the Bayesian power prior method, which allows for the historical information to be down-weighted via a power parameter. We propose a dynamic method to calculate the power parameter based on first comparing the data between the historical and new data sources using a one-sided comparison, and second mapping the comparison probability through a scaled-Weibull discount function to tune the effective sample size borrowed. This pragmatic and conservative approach is embedded in an adaptive trial framework allowing for the trial to stop early for success. An example is presented for a new test developed to detect Methicillin-resistant Staphylococcus aureus present in the nasal carriage.

Antigen-Based Testing but Not Real-Time Polymerase Chain Reaction Correlates With Severe Acute Respiratory Syndrome Coronavirus 2 Viral Culture.

BACKGROUND: Individuals can test positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by molecular assays following the resolution of their clinical disease. Recent studies indicate that SARS-CoV-2 antigen-based tests are likely to be positive early in the disease course, when there is an increased likelihood of high levels of infectious virus. METHODS: Upper respiratory specimens from 251 participants with coronavirus disease 2019 symptoms (≤7 days from symptom onset) were prospectively collected and tested with a lateral flow antigen test and a real-time polymerase chain reaction (rt-PCR) assay for detection of SARS-CoV-2. Specimens from a subset of the study specimens were utilized to determine the presence of infectious virus in the VeroE6TMPRSS2 cell culture model. RESULTS: The antigen test demonstrated a higher positive predictive value (90%) than rt-PCR (70%) when compared to culture-positive results. The positive percentage agreement for detection of infectious virus for the antigen test was similar to rt-PCR when compared to culture results. CONCLUSIONS: The correlation between SARS-CoV-2 antigen and SARS-CoV-2 culture positivity represents a significant advancement in determining the risk for potential transmissibility beyond that which can be achieved by detection of SARS-CoV-2 genomic RNA. SARS-CoV-2 antigen testing can facilitate low-cost, scalable, and rapid time-to-result, while providing good risk determination of those who are likely harboring infectious virus, compared to rt-PCR.

Performance Evaluation of the BD SARS-CoV-2 Reagents for the BD MAX System.

Nucleic acid amplification testing (NAAT) for SARS-CoV-2 is the standard approach for confirming COVID-19 cases. This study compared results between two emergency use authorization (EUA) NAATs, with two additional EUA NAATs utilized for discrepant testing. The limits of detection (LOD) for the BD SARS-CoV-2 reagents for the BD MAX system (MAX SARS-CoV-2 assay), the bioMérieux BioFire respiratory panel 2.1 (BioFire SARS-CoV-2 assay), the Roche cobas SARS-CoV-2 assay (cobas SARS-CoV-2 assay), and the Hologic Aptima SARS-CoV-2 assay Panther (Aptima SARS-CoV-2 assay) NAAT systems were determined using a total of 84 contrived nasopharyngeal specimens with 7 target levels for each comparator. The positive and negative percent agreement (PPA and NPA, respectively) of the MAX SARS-CoV-2 assay, compared to the Aptima SARS-CoV-2 assay, was evaluated in a postmarket clinical study utilizing 708 nasopharyngeal specimens collected from suspected COVID-19 cases. Discordant testing was achieved using the cobas and BioFire SARS-CoV-2 NAATs. In this study, the measured LOD for the MAX SARS-CoV-2 assay (251 copies/ml; 95% confidence interval [CI], 186 to 427) was comparable to the cobas SARS-CoV-2 assay (298 copies/ml; 95% CI, 225 to 509) and the BioFire SARS-CoV-2 assay (302 copies/ml; 95% CI, 219 to 565); the Aptima SARS-CoV-2 assay had an LOD of 612 copies/ml (95% CI, 474 to 918). The MAX SARS-CoV-2 assay had a PPA of 100% (95% CI, 97.3% to 100.0%) and an NPA of 96.7% (95% CI, 94.9% to 97.9%) compared to the Aptima SARS-CoV-2 assay. The clinical performance of the MAX SARS-CoV-2 assay agreed with another sensitive EUA assay.

Clinical Performance of the BD CTGCTV2 Assay for the BD MAX System for Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis Infections.

BACKGROUND: Diagnostic options to combat the increasing rates of sexually transmitted infections recorded throughout the world increasingly include multiplex assays. Here we describe the estimated sensitivity and specificity of a triplex molecular assay that simultaneously detects Chlamydia trachomatis (CT), Neisseria gonorrhoeae (or gonococci [GC]), and Trichomonas vaginalis (TV). METHODS: Participants (2547 women and 1159 men) were recruited from 12 clinics in the United States. BD CTGCTV2 for BD MAX System assay (CTGCTV2) results were obtained from vaginal and endocervical swabs, endocervical samples in cytology medium, and female and male urine. Results were compared with infection standards that were sample type and pathogen dependent. RESULTS: Female specimen sensitivity estimates ranged from 92.7% to 98.4%, 92.9% to 100%, and 86.6% to 100% for CT, GC and TV, respectively. Male urine sensitivity estimates were 96.7%, 99.2%, and 97.9% for CT, GC, and TV, respectively. Specificity estimates were >98.7% for all sample types. CONCLUSIONS: BD CTGCTV2 performed well using a variety of sample types. As a true triplex assay, performed using a benchtop instrument, BD CTGCTV2 may be useful in settings where no testing is currently performed and in settings, such as reference laboratories, where testing turnaround time may be several days. Use of this assay at local laboratories may result in greater access to testing and a shorter time to result, which are important steps for improving our ability to combat sexually transmitted infections.

Multicenter Study of the Accuracy of the BD MAX Multidrug-resistant Tuberculosis Assay for Detection of Mycobacterium tuberculosis Complex and Mutations Associated With Resistance to Rifampin and Isoniazid.

BACKGROUND: Tuberculosis (TB) control is hindered by absence of rapid tests to identify Mycobacterium tuberculosis (MTB) and detect isoniazid (INH) and rifampin (RIF) resistance. We evaluated the accuracy of the BD MAX multidrug-resistant (MDR)-TB assay (BD MAX) in South Africa, Uganda, India, and Peru. METHODS: Outpatient adults with signs/symptoms of pulmonary TB were prospectively enrolled. Sputum smear microscopy and BD MAX were performed on a single raw sputum, which was then processed for culture and phenotypic drug susceptibility testing (DST), BD MAX, and Xpert MTB/RIF (Xpert). RESULTS: 1053 participants with presumptive TB were enrolled (47% female; 32% with human immunodeficiency virus). In patients with confirmed TB, BD MAX sensitivity was 93% (262/282 [95% CI, 89-95%]); specificity was 97% (593/610 [96-98%]) among participants with negative cultures on raw sputa. BD MAX sensitivity was 100% (175/175 [98-100%]) for smear-positive samples (fluorescence microscopy), and 81% (87/107 [73-88%]) in smear-negative samples. Among participants with both BD MAX and Xpert, sensitivity was 91% (249/274 [87-94%]) for BD MAX and 90% (246/274 [86-93%]) for Xpert on processed sputa. Sensitivity and specificity for RIF resistance compared with phenotypic DST were 90% (9/10 [60-98%]) and 95% (211/222 [91-97%]), respectively. Sensitivity and specificity for detection of INH resistance were 82% (22/27 [63-92%]) and 100% (205/205 [98-100%]), respectively. CONCLUSIONS: The BD MAX MDR-TB assay had high sensitivity and specificity for detection of MTB and RIF and INH drug resistance and may be an important tool for rapid detection of TB and MDR-TB globally.

Clinical Evaluation of BD Veritor SARS-CoV-2 Point-of-Care Test Performance Compared to PCR-Based Testing and versus the Sofia 2 SARS Antigen Point-of-Care Test.

The clinical performance of the BD Veritor System for Rapid Detection of SARS-CoV-2 nucleocapsid antigen (Veritor), a chromatographic immunoassay used for SARS-CoV-2 point-of-care testing, was evaluated using nasal specimens from individuals with COVID-19 symptoms. Two studies were completed to determine clinical performance. In the first study, nasal specimens and either nasopharyngeal or oropharyngeal specimens from 251 participants with COVID-19 symptoms (≤7 days from symptom onset [DSO], ≥18 years of age) were utilized to compare Veritor with the Lyra SARS-CoV-2 PCR assay (Lyra). In the second study, nasal specimens from 361 participants with COVID-19 symptoms (≤5 DSO, ≥18 years of age) were utilized to compare performance of Veritor to that of the Sofia 2 SARS Antigen FIA test (Sofia 2). The positive, negative, and overall percent agreement (PPA, NPA, and OPA, respectively) were the primary outcomes. In study 1, the PPA for Veritor, compared to Lyra, ranged from 81.8 to 87.5% across the 0 to 1 and 0 to 6 DSO ranges. In study 2, Veritor had PPA, NPA, and OPA values of 97.4, 98.1, and 98.1%, respectively, with Sofia 2. Discordant analysis showed one Lyra positive missed by Veritor and five Lyra positives missed by Sofia 2; one Veritor positive result was negative by Lyra. Veritor met FDA emergency use authorization (EUA) acceptance criteria for SARS-CoV-2 antigen testing for the 0 to 5 and 0 to 6 DSO ranges (PPA values of 83.9% and 82.4%, respectively). Veritor and Sofia 2 showed a high degree of agreement for SARS-CoV-2 detection. The Veritor test allows for more rapid COVID-19 testing utilizing easy-to-collect nasal swabs but demonstrated <100% PPA compared to PCR.

Analytical and Clinical Sample Performance Characteristics of the Onclarity Assay for the Detection of Human Papillomavirus.

The objective of this study was to determine the result reproducibility and performance of the BD Onclarity human papillomavirus (HPV) assay (Onclarity) on the BD Viper LT platform using both contrived and clinical specimens. Reproducibility was assessed in BD SurePath liquid-based cytology (LBC) medium (SurePath) using contrived panels (HPV genotype 16 [HPV16] positive, HPV18 positive, or HPV45 positive) or clinical specimens (HPV16, -18, -31, -33/58, -45, or -52 positive or HPV negative). In addition, specimens from 3,879 individuals from the Onclarity trial were aliquoted prior to or following cytology processing and tested for HPV. Finally, specimens were collected using either the Cervex-Brush or Cytobrush (or Cytobrush/spatula) for comparison of HPV results. Contrived specimens showed >95% concordance with the expected results, and pooled clinical specimens had standard deviations and coefficients of variation ranging from 0.87 to 1.86 and 2.9% to 5.6%, respectively. For precytology and postcytology aliquot analyses, specimens showed >98.0% overall agreement and mean differences in cycle threshold (CT ) scores for HPV ranging from -0.07 to 0.31. Positivity rates were close between the Cervex-Brush and Cytobrush/spatula for all age groups tested. Onclarity results are reproducible and reliable, regardless of sample collection before or after cytology aliquoting. Onclarity performs well regardless of the method of specimen collection (Cervex-Brush or Cytobrush/spatula) for cervical cancer screening.

Molecular-based Testing for Sexually Transmitted Infections Using Samples Previously Collected for Vaginitis Diagnosis.

Background: Vaginal symptoms are a leading cause of primary care visits for women. Individuals exhibiting symptoms often receive laboratory testing based on clinic-specific standards of care. Thus, women seen at a family practice clinic might only receive a vaginitis workup, whereas those seen at a sexually transmitted diseases clinic could be more likely to receive only sexually transmitted infection (STI) testing. Methods: The likelihood of STIs was assessed in women from whom samples were tested for vaginitis using a molecular diagnostic assay. Positivity rates for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis DNA, detected using the BD MAX CT/GC/TV assay, were calculated. Concordance between the BD MAX Vaginal Panel and the BD MAX CT/GC/TV assay for detection of T. vaginalis was determined. Results: Women with bacterial vaginosis alone or with concurrent Candida spp infections had high rates of coinfection with sexually transmitted infections (24.4%-25.7%); samples from women who were negative for vaginitis had significantly lower positivity rates (7.9%; P < .001). Trichomonas vaginalis results were concordant between the BD MAX Vaginal Panel and the BD MAX CT/GC/TV assay in 559 of 560 samples tested. Conclusions: These data suggest, as have other studies, that women with vaginitis symptoms may be at risk for an STI. Molecular testing could provide broad diagnostic coverage for symptomatic women and improve patient management, regardless of the type of clinic in which patients are treated.

Stratified risk of high-grade cervical disease using onclarity HPV extended genotyping in women, ≥25 years of age, with NILM cytology.

OBJECTIVES: Increasing evidence suggests that extended human papillomavirus (HPV) genotyping (beyond 16/18) is effective for risk stratification in women with normal cytology. This report provides extended genotyping results, using the BD Onclarity HPV Assay, for individual genotypes HPV16, 18, 31, 45, 51, and 52 ̶ and three pooled genotype results for HPV33/58, 35/39/68, and 56/59/66. METHODS: 27,037 women with normal cytology, ≥25 years, were enrolled into the Onclarity HPV trial during routine screening. Women positive for any HPV genotype were referred to colposcopy/biopsy. Hierarchical-ranked prevalence and risk values, associated with cervical intraepithelial neoplasia, grade 2 or worse (≥CIN2) or ≥CIN3, were calculated based on extended genotyping results. RESULTS: HPV 16 and 31 carried the highest risk for ≥CIN2 (11.6% and 12.1%, respectively) and ≥CIN3 (8.1% and 7.5%, respectively); these genotypes were the most prevalent in both ≥CIN2 (29.6% and 19.3%, respectively) and ≥CIN3 (43.7% and 22.5%, respectively). Of the other 12 genotypes, HPV 18, 33/58, and 52 comprised an intermediate risk band (≥CIN2 risk range: 4.9-6.8%; ≥CIN3 risk range: 3.9-5.0%). Genotypes 45, 51, 35/39/68, and 56/59/66 constituted the lowest risk band for both disease grades (≥CIN2 value risk range: 1.7-3.0%; ≥CIN3 value risk range: 1.2-3.6%). CONCLUSIONS: Extended genotyping stratifies risk for ≥CIN2/3 in the ≥25 year-old, normal cytology population. While baseline HPV 16/31 values exceeded the risk threshold for colposcopy referral, the management of women with normal cytology who were positive for the intermediate- or lower-risk genotypes may evolve based on refined risk estimates as well as clinical factors.

HPV infections and cytologic abnormalities in vaccinated women 21-34 years of age: Results from the baseline phase of the Onclarity trial.

OBJECTIVES: Countries with school-based human papillomavirus (HPV) vaccination have seen significant reductions in vaccine-targeted HPV infections, cytologic abnormalities, and high-grade cervical intraepithelial neoplasia (≥CIN2). However, the impact of HPV vaccination in the United States (where vaccination is largely opportunistic) may be less due to lower coverage rates and vaccination in patients at ages beyond the recommended routine vaccination age. METHODS: The Onclarity trial enrolled 33,858 subjects ≥21 years who were screened with cytology and the BD Onclarity HPV Assay. HPV positive women or those with cytologic abnormalities underwent colposcopy and biopsy. The prevalence of HPV, cytologic abnormalities, and ≥CIN2 was compared in a subset of 14,153, vaccinated and unvaccinated women, 21-34 years. Results were compared by vaccination status; Mantel-Haenszel analysis was performed to determine the association between vaccination status and prevalence, adjusting for age. RESULTS: The prevalence of overall HPV, HPV16, 18, 31, and 33/58 were all lower in vaccinated women for each age group; a significant difference (p < 0.001) was observed in vaccinated women for all ages combined. Cytologic low-grade squamous intraepithelial lesion (LSIL) or worse was lower in vaccinated women (p = 0.021), as was ≥CIN2 prevalence associated with HPV 16 or 18 (p = 0.011). CONCLUSIONS: Women with a prior history of HPV vaccination have a lower prevalence of any high-risk HPV, HPV 16, 18, 31, and 33/58; a cytology result of ≥LSIL, and ≥CIN2 associated with HPV 16/18 compared to unvaccinated women. A lower HPV prevalence in older, vaccinated women suggests that "catch-up" vaccination provides benefit.

Diagnostic Performance of a Molecular Test versus Clinician Assessment of Vaginitis.

Vaginitis is a common complaint, diagnosed either empirically or using Amsel's criteria and wet mount microscopy. This study sought to determine characteristics of an investigational test (a molecular test for vaginitis), compared to reference, for detection of bacterial vaginosis, Candida spp., and Trichomonas vaginalis Vaginal specimens from a cross-sectional study were obtained from 1,740 women (≥18 years old), with vaginitis symptoms, during routine clinic visits (across 10 sites in the United States). Specimens were analyzed using a commercial PCR/fluorogenic probe-based investigational test that detects bacterial vaginosis, Candida spp., and Trichomonas vaginalis Clinician diagnosis and in-clinic testing (Amsel's test, potassium hydroxide preparation, and wet mount) were also employed to detect the three vaginitis causes. All testing methods were compared to the respective reference methods (Nugent Gram stain for bacterial vaginosis, detection of the Candida gene its2, and Trichomonas vaginalis culture). The investigational test, clinician diagnosis, and in-clinic testing were compared to reference methods for bacterial vaginosis, Candida spp., and Trichomonas vaginalis The investigational test resulted in significantly higher sensitivity and negative predictive value than clinician diagnosis or in-clinic testing. In addition, the investigational test showed a statistically higher overall percent agreement with each of the three reference methods than did clinician diagnosis or in-clinic testing. The investigational test showed significantly higher sensitivity for detecting vaginitis, involving more than one cause, than did clinician diagnosis. Taken together, these results suggest that a molecular investigational test can facilitate accurate detection of vaginitis.

The Onclarity Human Papillomavirus Trial: Design, methods, and baseline results.

OBJECTIVES: The baseline phase of the Onclarity trial was conducted to determine the screening performance of the Onclarity human papillomavirus (HPV) assay for detecting cervical cancer and precancer (≥CIN2) during triage of women ≥21 years with ASC-US cytology, as an adjunct test in women ≥30 years with normal cytology and for primary screening (HPV alone) in women ≥25 years. METHODS: 33,858 women ≥21 years were enrolled during routine clinic visits. All women with abnormal cytology, women ≥25 years that were high-risk HPV positive, and a random subset of women ≥25 years, negative by cytology and for HPV, were referred for colposcopy and cervical biopsy. Verification bias adjustment with 95% confidence intervals was applied. RESULTS: ASC-US prevalence was 5.8%. The overall HPV prevalence was 14.7%; for HPV 16, 18, and the 12 other HPV types it was 2.7%, 0.8%, and 11.2%, respectively. The prevalence of ASC-US and HPV was inversely proportional with age. The verification bias adjusted prevalence of ≥CIN2 and ≥CIN3 was 1.8% and 0.8%, respectively. Overall, five cases of cervical cancer were identified (all were HPV positive). The odds ratios associated with any HPV positive genotype, or with individual genotypes HPV 16, HPV 18, and HPV 31, for ≥CIN3, were statistically significant when compared to negative histology (p < 0.0001 for all). CONCLUSIONS: This report provides demographic information, cytology findings, HPV genotype information, and histopathology for participants in the baseline phase of this trial and offers further evidence to support genotype-specific screening for cervical cancer and precancer. Clinical Trial Registry URL:https://clinicaltrials.gov/ct2/show/NCT01944722.

Clinical Evaluation of BD Veritor SARS-CoV-2 and Flu A+B Assay for Point-Of-Care System.

Differential diagnosis of COVID-19 and/or influenza (flu) at point of care is critical for efficient patient management and treatment of both these diseases. The study presented here characterizes the BD Veritor System for Rapid Detection of SARS-CoV-2 and Flu A+B ("Veritor SARS-CoV-2/Flu") triplex assay. The performance for SARS-CoV-2 detection was determined using 298 specimens from patients reporting COVID-19 symptoms within 7 days from symptom onset (DSO) in comparison with the Lyra SARS-CoV-2 RT-PCR (reverse transcriptase PCR) assay ("Lyra SARS-CoV-2") as the reference. The performance for flu A and flu B detection was determined using 75 influenza-positive and 40 influenza-negative retrospective specimens in comparison with the previously FDA-cleared BD Veritor System for Rapid Detection of Flu A+B assay ("Veritor Flu") as the reference. The Veritor SARS-CoV-2/Flu assay met the FDA EUA acceptance criteria (86.7%; 95% confidence interval [95% CI]: 75.8 to 93.1) for SARS-CoV-2 testing compared to Lyra SARS-CoV-2. The Veritor SARS-CoV-2/Flu assay also demonstrated 100% agreement with the Veritor Flu for Flu A+B assay. For flu A detection, the lower bound of the 95% CI was 91.2%; for flu B detection, the lower bound was 90.0%. The dual detection capability of Veritor SARS-CoV-2/Flu for the etiologic agents causing COVID-19 and flu will allow efficient differentiation between the two illnesses, inform disease management, and facilitate optimal treatment. IMPORTANCE COVID-19 and flu are two respiratory illnesses which share similar clinical symptoms. The BD Veritor SARS-CoV-2/Flu assay has high sensitivity and specificity for detecting the SARS-CoV-2 and influenza A/B, the two etiologic agents causing COVID-19 and flu, respectively. This dual detection capability is critical when overlap occurs between the COVID-19 pandemic and the flu season. This triplex assay will allow efficient differentiation between the two respiratory illnesses and support a point-of-care physician diagnosis to facilitate the proper treatment and disease management for patients exhibiting overlapping symptoms.

Large-Scale SARS-CoV-2 Antigen Testing With Real-World Specimens.

Real-world data are needed to establish SARS-CoV-2 rapid antigen testing (RAT) as an effective and reliable approach for SARS-CoV-2 screening. This study included 1,952,931 individuals who provided upper respiratory specimens during SARS-CoV-2 screening at CityMD urgent care locations in the New York metropolitan area from October 2020 to March 2021. Positive and negative results, as determined by the BD Veritor™ System for Rapid Detection of SARS-CoV-2 antigen (Veritor), were obtained for all individuals, with reflex reverse transcriptase-polymerase chain reaction (RT-PCR) testing performed on a case-by-case basis, per standard of care. Using verification bias adjustment, two alternative model assumptions were utilized for RAT results with missing reflex RT-PCR results. The worst antigen diagnostic performance estimates asserted that missing RT-PCR results would show a distribution similar to those RT-PCR results actually obtained, based on symptom category. The best antigen diagnostic performance estimates asserted that individuals without RT-PCR results had a clinical presentation consistent with RAT results, and, therefore, missing RT-PCR results would agree with RAT results. For patients with symptoms or high-risk exposure, 25.3% (n = 86,811/343,253) of RAT results were positive; vs. 3.4% (n = 53,046/1,559,733) positive for asymptomatic individuals without high-risk exposure. Reflex RT-PCR results were obtained from 46.3% (n = 158,836/343,253) and 13.8% (n = 215,708/1,559,733) of symptomatic and asymptomatic individuals, respectively. RT-PCR confirmed 94.4% (4,265/4,518) of positive and 90.6% (139,759/154,318) of negative RAT results in symptomatic individuals; and confirmed 83.4% (6,693/8,024) of positive and 95.3% (197,955/207,684) of negative RAT results in asymptomatic individuals. Applied assumptions for missing reflex RT-PCR results led to worst performance sensitivity estimates of 77.2 and 38.5% in the symptomatic and asymptomatic populations, respectively; assumptions for best performance estimates led to sensitivity values of 85.6 and 84.2%, respectively. Specificity values, regardless of assumptions or symptom category, ranged from 97.9-99.9%. At 10% SARS-CoV-2 prevalence, RAT positive predictive value was 86.9 and 99.0% for worst and best performance estimates across the total population, respectively; negative predictive values were >95% regardless of the applied assumption. Veritor test performance was consistent with that listed in the manufacturer instructions for use for symptomatic individuals. Real-world evidence should be gathered on RATs to support their efficacy as SARS-CoV-2 persists.

Validation of a New High-Throughput BD COR System Using the BD CTGCTV2 Assay.

This study determined the precision and reproducibility of results for the BD CTGCTV2 (CTGCTV2) assay on the BD COR System (COR). The clinical performance of the CTGCTV2 assay conducted on COR was compared with its performance on the BD MAX System (MAX) for detecting Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis. The multiday precision and multisite reproducibility studies were conducted using contrived panels of positive and negative urine and PreservCyt specimens. A total of 433 panel members, generated from remnant clinical specimens, were tested in the clinical comparison study. Each panel member was tested three times on MAX and three times on COR. The results in the same testing group were compared for agreement by target. The cycle threshold scores from MAX and COR were analyzed by paired t-test and Deming regression. The CTGCTV2 assay on COR showed high reproducibility in the multiday and multisite precision analysis. The point estimates of positive percent agreement and negative percent agreement in the clinical comparison study for all three targets were greater than 95%, with all corresponding lower bounds of two-sided 95% CIs greater than 90%. Cycle threshold score comparison showed no systematic difference between the two systems. The results of this study show equivalent performance of the CTGCTV2 assay on the MAX and COR systems.

Clinical evaluation of the molecular-based BD SARS-CoV-2/Flu for the BD MAX™ system.

BACKGROUND: COVID-19 and influenza (flu) share similar clinical symptoms. Therefore, differential detection of these viruses during the respiratory virus season will be an important component for proper patient triage, management, and treatment. OBJECTIVES: Establish the diagnostic performance related to SARS-CoV-2 and Flu A/B detection for the BD SARS-CoV-2/Flu for BD MAX™ System ("MAX SARS-CoV-2/Flu") multiplex assay. MATERIALS AND METHODS: Two hundred and thirty-five (235) retrospective nasopharyngeal specimens were obtained from external vendors. The BD BioGx SARS-CoV-2 Reagents for BD MAX™ System ("BioGx SARS-CoV-2″) and the Cepheid Xpert® Xpress Flu/RSV ("Xpert Flu/RSV") were utilized as reference methods. RESULTS: By reference methods, 52 specimens were SARS-CoV-2-positive, 59 were Flu A-positive, and 60 were Flu B-positive. MAX SARS-CoV-2/Flu had positive percent agreement (PPA) and negative percent agreement (NPA) values for SARS-CoV-2 detection of 96.2% ([95%CI]:87.0-98.9) and 100% [95%CI:88.7-100], respectively; PPA values for Flu A and Flu B of 100% [95%CI:93.9-100] and 98.3% [95%CI:91.1-99.7], respectively, and NPA values for Flu A and Flu B of 98.9% [95%CI:94.0-99.8] and 100% [95%CI:95.9-100], respectively. CONCLUSIONS: The MAX SARS-CoV-2/Flu assay met FDA-EUA performance criteria for SARS-CoV-2 (≥95% for PPA and NPA) and FDA clearance criteria for Flu A/B (PPA ≥90%; lower bound of the 95%CI ≥80% and NPA ≥95%; lower bound of the 95%CI ≥90%).

Comparison of antigen- and RT-PCR-based testing strategies for detection of SARS-CoV-2 in two high-exposure settings.

Surveillance testing for infectious disease is an important tool to combat disease transmission at the population level. During the SARS-CoV-2 pandemic, RT-PCR tests have been considered the gold standard due to their high sensitivity and specificity. However, RT-PCR tests for SARS-CoV-2 have been shown to return positive results when performed to individuals who are past the infectious stage of the disease. Meanwhile, antigen-based tests are often treated as a less accurate substitute for RT-PCR, however, new evidence suggests they may better reflect infectiousness. Consequently, the two test types may each be most optimally deployed in different settings. Here, we present an epidemiological model with surveillance testing and coordinated isolation in two congregate living settings (a nursing home and a university dormitory system) that considers test metrics with respect to viral culture, a proxy for infectiousness. Simulations show that antigen-based surveillance testing coupled with isolation greatly reduces disease burden and carries a lower economic cost than RT-PCR-based strategies. Antigen and RT-PCR tests perform different functions toward the goal of reducing infectious disease burden and should be used accordingly.

Factors that Influence the Reported Sensitivity of Rapid Antigen Testing for SARS-CoV-2.

Tests that detect the presence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen in clinical specimens from the upper respiratory tract can provide a rapid means of coronavirus disease 2019 (COVID-19) diagnosis and help identify individuals who may be infectious and should isolate to prevent SARS-CoV-2 transmission. This systematic review assesses the diagnostic accuracy of SARS-CoV-2 antigen detection in COVID-19 symptomatic and asymptomatic individuals compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) and summarizes antigen test sensitivity using meta-regression. In total, 83 studies were included that compared SARS-CoV-2 rapid antigen-based lateral flow testing (RALFT) to RT-qPCR for SARS-CoV-2. Generally, the quality of the evaluated studies was inconsistent; nevertheless, the overall sensitivity for RALFT was determined to be 75.0% (95% confidence interval: 71.0-78.0). Additionally, RALFT sensitivity was found to be higher for symptomatic vs. asymptomatic individuals and was higher for a symptomatic population within 7 days from symptom onset compared to a population with extended days of symptoms. Viral load was found to be the most important factor for determining SARS-CoV-2 antigen test sensitivity. Other design factors, such as specimen storage and anatomical collection type, also affect the performance of RALFT. RALFT and RT-qPCR testing both achieve high sensitivity when compared to SARS-CoV-2 viral culture.

Detection of Cervical Neoplasia by Human Papillomavirus Testing in an Atypical Squamous Cells-Undetermined Significance Population: Results of the Becton Dickinson Onclarity Trial.

Objectives: To determine clinical utility of Onclarity human papillomavirus (HPV) assay for atypical squamous cells-undetermined significance (ASC-US) triage, and the value of HPV genotyping within ASC-US. Methods: Women (n = 33,858; 21 years or older) had HPV testing using Onclarity and Hybrid Capture 2 (HC2). ASC-US individuals (n = 1,960, 5.8%) were referred to colposcopy. Results: Of ASC-US, 39.1% were HPV positive by Onclarity; HPV 16 was the most prevalent genotype (7.4%). Cervical intraepithelial neoplasia grade 2 (CIN 2) and CIN 3+ prevalences were 4.4% and 2.2%, respectively. Onclarity had sensitivity for CIN 2+ (85.7%) and CIN 3+ (91.4%), and specificities for CIN 2+ (64.1%) and CIN 3+ (62.0%), similar to HC2. Risks for CIN 3+ were 16.1%, 2.8%, 2.5%, and 2.7% with HPV 16, 18, 45, and 11 other genotypes, respectively. Conclusions: Onclarity is clinically validated for ASC-US triage. Through risk stratification, genotyping could help identify women at highest risk for CIN 3+.