Point of care testing using rapid automated antigen testing for SARS-COV-2 in care homes – an exploratory safety, usability and diagnostic agreement evaluation

Introduction Successful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of the contextual and usability factors that affect test results and minimise biosafety risks. This paper presents a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes. Methods A mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was conducted to explore biosafety issues. Results The agreement analysis was conducted on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI:1.3%−98.7%) positive agreement and 96% (95% CI: 92.5%−98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857−0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%−99.6%) positive agreement and 100% (95% CI: 63.1%−100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549−1). The dry run highlighted four main sources of contamination that led to the modification of the standard operating procedures. Simulation post-modification showed no further evidence of contamination. Conclusion Careful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

462. Differences in the Humoral Response to SARS-CoV-2 Infection in Children vs. Adult

Background One of the most striking observations of the COVID-19 pandemic has been the difference in infection among children vs. adults. Overall, children with SARS-CoV-2 infection generally had milder disease compared to adults, though the cause is not clear. The objective of this study was to compare the humoral response to infection in children vs. adults of a same family. Methods We performed a prospective cohort study at Sainte-Justine University Health Center in Montreal, Canada from July 2020 to March 2021. Children with a positive SARS-CoV-2 PCR were recruited from the COVID-19 clinic (index case), enrollment was offered to all household members. Serum IgG against SARS-CoV-2 native S1/S2 spike proteins was measured using the Diasorin (Liaison XL) assay, 4-6 months following a positive PCR. A mean antibody threshold of 15 Arbitrary unit per ml (AU/ml) was considered seropositive, with 94.4% positive agreement to plaque reduction neutralization tests (PRNT90) at a 1:40 ratio. Antibody titer was compared between children and adults. Results 111 participants (52 adults and 59 children) were recruited from 50 separate families. Characteristic of participants and their clinical symptoms are described in Table 1. Among all participants, 76.3% children were SARS-CoV-2 seropositive vs. 51.9% of adults (p=0.007). Median antibody titer was significantly higher in children vs. adults (82.8 AU, [IQR: 18.4-130], vs 17.0 AU, [IQR: 6.8-77.8], p=0.006); findings were similar among SARS-CoV-2 PCR positive participants only. Overall, 13 participants were PCR positive but seronegative, 7 were PCR negative and seropositive, while 61 were both PCR positive and seropositive. Older participants and those with any comorbidity. Among the PCR positive group, the seropositive participants were younger (median age 31±17 vs 19±17 years, p=0.003) and more likely to have comorbidity (69% vs 29%, p=0.007). Conclusion These results suggest that children have a stronger antibody response to SARS-CoV-2 infection than adults, and that older age and presence of comorbidity are associated with a less robust humoral response. Further work on the differences in response between children and adults may help elucidate mechanisms underlying the severity of disease Disclosures Olivier Drouin, MDCM MsC MPH, Covis Pharma (Research Grant or Support)

Comparison of Saliva and Nasopharyngeal Swabs for SARS-CoV-2 Detection in an Emergency Department and Ambulatory Testing Locations

Introduction/Objective Nasopharyngeal (NP) swabs have been the traditional specimen source used for testing for respiratory viruses. However, at the start of the COVID-19 pandemic, several studies suggested that saliva could also be used as a specimen source for testing for SARS-CoV-2. Despite potential benefits, there was limited data on the characteristics of this specimen type and few commercial assays with FDA emergency use authorization allowed saliva as a specimen source. In order to explore the feasibility and validate using saliva as a specimen source for ambulatory and emergency department patients we designed a study to compare saliva to NP swabs for SARS-CoV-2 testing. Methods/Case Report Specimens were collected in the emergency department and ambulatory testing sites between May 6, 2020-July 7, 2020. Nasopharyngeal swabs were collected as part of routine clinical practice and patients were given written instructions to self-collect 1mL of saliva into a sterile specimen cup with or without a straw. SARS-CoV-2 testing was performed in parallel with both specimen types using the TaqPath COVID-19 Combo Kit (Thermo Fisher Waltham, MA). Saliva was diluted 1:1 in saline prior to testing. Specimens were transported to the lab at 4C and frozen at -80C prior to testing. Results (if a Case Study enter NA) Seventy-four patients had both an NP swab and saliva tested in this study. Thirty of the 74 patients (41%) were unable to produce the full 1mL of saliva requested, but all samples had sufficient volume for testing after dilution. There were 34 positive samples obtained with an 82% positive agreement between the NP swabs and saliva. In 6 cases, the NP swab was positive, and the paired saliva was negative. In 1 case, only the saliva was positive. The average Ct of the positive NP swabs with a paired negative saliva sample was 39.6. There was only a single invalid test for one of the saliva samples. Conclusion Saliva was a straightforward sample to collect and test for SARS-CoV-2. Challenges included obtaining sufficient sample and a less predictable matrix that required dilution to ensure proper pipeting. In this study, NP swabs were more sensitive for detection of SARS-CoV-2. Paired saliva was more often negative in patients shedding small amounts of SARS-CoV-2 based on a high Ct of the positive NP sample.

Comparative Evaluation of Three Serologic Assays for the Identification of SARS-CoV-2 Antibodies

Serologic assays for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies continue to be developed and approved rapidly with limited external validation. Accurate diagnostics are an essential component of pandemic management and public health. Residual serum samples (N=113) from patients who were evaluated for SARS-CoV-2 infection status by polymerase chain reaction (PCR) were retrospectively tested in parallel across three automated SARS-CoV-2 serologic assays: Liaison SARS-CoV-2 S1/S2 IgG, Elecsys anti-SARS-CoV-2 total antibody, and Access SARS-CoV-2 IgG. Testing of 51 PCR-positive and 62 PCR-negative patients demonstrated qualitative inter-test agreement of 96% overall, 100% in PCR-negative patients, 88% in early positive samples (0-13 days post positive PCR), and 100% in convalescent samples (14+ days post positive PCR). Calculated kappa values for paired inter-test agreement ranged 0.93-0.96. Compared to PCR, overall percent positive agreement ranged from 82-86% (100% for convalescent samples) and percent negative agreement was 100% for each assay. This study demonstrates high diagnostic accuracy and inter-test agreement for three automated SARS-CoV-2 serologic assays. External validation of serologic assays is critical to ensure diagnostic accuracy and appropriate utilization of critical resources.

Real-Time Fluorometric Isothermal LAMP Assay for Detection of Chlamydia pecorum in Rapidly Processed Ovine Abortion Samples: A Veterinary Practitioner’s Perspective

Traditional methods of detecting Chlamydia pecorum in tissue samples such as polymerase chain reaction or cell culture are laborious and costly. We evaluated the use of a previously developed C. pecorum LAMP assay using minimally processed ovine samples. Cotyledon (n = 16), foetal liver (n = 22), foetal lung (n = 2), and vaginal (n = 6) swabs, in addition to cotyledon (n = 6) and foetal liver (n = 8) tissue samples, were rapidly processed and used for LAMP testing without DNA extraction. Overall, LAMP test results were highly congruent with the in-house reference qPCR, with 80.43% (37/46; 72.73% positive agreement (PA); 84.75% negative agreement (NA)) overall agreeance for swab samples, and 85.71% (12/14; 80% PA; 88.89% NA) overall agreeance for tissue samples. Out of the 11 total discrepant results, discrepancy was mainly observed in samples (n = 10) with less than 100 copies/µL C. pecorum DNA. While sensitivity could be improved, the simplicity, low cost, and accuracy of detection makes this test amenable for use at point-of-care for detecting C. pecorum in sheep.

The CAI as seen from Spain: a positive agreement with uncertain implementation

Spanish elite’s perceptions of the European Union-China Comprehensive Agreement on Investment (CAI) are positive given its economic and normative prospects and its compatibility with Spain’s policy objectives. Spanish Ministry officials and business representatives welcome the potential progress on market access, level-playing field, and sustainable development, as it would offer economic opportunities in the Chinese market and bilateral investment, without precluding increased monitoring of Chinese economic activities. The agreement is in line with their willingness to increase bilateral ties under a normative framework that defends Spanish interests and values. Spanish elites consider that it is compliant with Spain’s and the European Union’s strategies and characterization of China as a partner, competitor, rival, which acknowledges that China is a key economic and multilateral partner, but also promotes a unified European China strategy, European strategic autonomy, and initiatives that tackle China’s challenges related with human rights, or investments in strategic sectors. Hence, Spanish political parties supported the resolution of the European Parliament freezing an eventual ratification of the CAI whilst Chinese sactions against European stakeholders are in place. Spanish elites also value that the agreement does not prevent greater cooperation with the United States, a key ally and more significant partner than China. Some political and private groups have expressed their opposition to the agreement, but their impact is likely to be limited. Finally, the practical implications—and reception—of the agreement will depend of its implementation.

Assessment of Factor Affecting the Customization Process In Real Estate Sector

In construction industry, real estate sector in northern India (specially Lucknow Uttar Pradesh) has been on peak point recently and maximizing the productivity of project delivery and provide a Customization has been a attraction point around the circle of real estate sector. Customization is defined as a customer integrated process for providing a product design, manufacturing, marketing and delivery service, and this one has become a main competitive factor. In real estate industry construction and customization of housing being a remarkable example of providing a amenity has various key concern which a interpoint factors on together. Any gap break between the time of construction of housing destroys and customer satisfaction get affected. The strange and genuine problem of connection communication gap has been observed between the customer and developer, which causes many obstacles or hurdle at the time of delivery of project. The paper presents customization of housing in the field of real estate sector at the time of delivery on the basis of customer needs after the positive agreement of developer and find a way to obstacles or hurdles of communication gap between the customer and developer.

Clinical Performance of Two Methods for Detecting Anti SARS-CoV-2 Antibodies

Evaluating the clinical performance of available methods to detect antibodies against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has become a primordial issue in clinical laboratories. The aim of this study was to evaluate the clinical performance of two methods for SARS-CoV-2 antibodies detection, an automated Chemiluminescent Immunoassay (CLIA) and an immunochromatographic Lateral-Flow Assay (LFA) in patients with positive reverse transcription polymerase chain reaction (RT-PCR). Performance for CLIA method was Positive Agreement (PA) 56.6% and Negative Agreement (NA) 96,6% for IgM and PA 85.8%/NA 90,2% for IgG. Performance for LFA method was PA 56.2% and NA 100% for IgM and PA 95.5% and NA 100 % for IgG. LFA general agreement IgG was better than CLIA. In both methods, significant differences in Kappa index are observed when IgG and IgM are compared. When evaluating the data from a clinical perspective, we found that both method performance for IgM detection may not meet the expected requirements for their clinical utility and could lead to an inappropriate medical decision. The findings of this study show that both immunoassay methods might be reliable for assessing immunological response in COVID-19 patients. Our results also confirm that IgG measurement could be helpful, especially for epidemiological studies in our population. These results provide evidence to justify epidemiological studies in our population.

Point of Care Testing using rapid automated Antigen Testing for SARS-COV-2 in Care Homes – an exploratory safety, usability and diagnostic agreement evaluation

IntroductionSuccessful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of contextual and usability factors that affect test results and minimise biosafety risks. This paper presents findings from a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes.MethodsA mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was carried out to explore biosafety issues.ResultsThe agreement analysis was carried out on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI: 1.3%-98.7%) positive agreement and 96% (95% CI: 92.5%-98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857-0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 100% (95% CI: 63.1%-100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549-1).The dry run showed four main sources of contamination that led to the modification of the standard operating procedures. Simulation after modification showed no further evidence of contamination.ConclusionCareful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

Is Point-of-Care testing feasible and safe in care homes in England? An exploratory usability and accuracy evaluation of a Point-of-Care Polymerase Chain Reaction test for SARS-COV-2

Introduction Reliable rapid testing for COVID-19 is needed in care homes to reduce the risk of outbreaks and enable timely care. This study aimed to examine the usability and test performance of a point of care polymerase chain reaction (PCR) test for detection of SARS-COV2 (POCKITTM Central) in care homes. Methods POCKITTM Central was evaluated in a purposeful sample of four UK care homes. Test agreement with laboratory real-time PCR and usability and use errors were assessed. Results No significant usability-related hazards emerged, and the sources of error identified were found to be amendable with minor changes in training or test workflow. POCKITTM Central has acceptable sensitivity and specificity based on RT-PCR as the reference standard, especially for symptomatic cases. Asymptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 98.7% negative agreement (95% CI: 96.2%-99.7%), with overall prevalence and bias-adjusted kappa (PABAK) of 0.965 (95% CI: 0.932– 0.999). Symptomatic specimens showed 100% (95% CI: 2.5%-100%) positive agreement and 100% negative agreement (95% CI: 85.8%-100%), with overall PABAK of 1. Recommendations are provided to mitigate the frequency of occurrence of the residual use errors observed. Integration pathways were discussed to identify opportunities and limitations of adopting POCKIT™ Central for screening and diagnostic testing purposes. Conclusion Point-of-care PCR testing in care homes can be considered with appropriate preparatory steps and safeguards. Further diagnostic accuracy evaluations and in-service evaluation studies should be conducted, if the test is to be implemented more widely, to build greater certainty on this initial exploratory analysis.