scholarly journals Simple Concentration Method Enables the Use of Gargle and Mouthwash Instead of Nasopharyngeal Swab Sampling for the Diagnosis of Covid19 by PCR

2021 ◽  
Author(s):  
Tanil Kocagoz ◽  
Ozge Can ◽  
Neval Yurttutan Uyar ◽  
Ece Aksoy ◽  
Tuba Polat ◽  
...  
Keyword(s):  
Sampling Procedure ◽  
New Method ◽  
Healthcare Personnel ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Rt Pcr ◽  
Painful Procedure ◽  
Concentration Method ◽  
Before And After ◽  
Mouth Wash

Abstract Purpose Since its emergence in December 2019, SARS-CoV-2 is causing one of the most devastating pandemics in human history. Currently, the most important method for definitive diagnosis of COVID-19 is identification of SARS-CoV-2 RNA in nasopharyngeal swab samples by RT-PCR. Nasopharyngeal swab sampling is a discomforting procedure sometimes with adverse effects, which also poses a risk for infection for the personnel performing the sampling. We have developed a new method for concentrating biological samples, which enabled us to use gargle and mouth-wash samples to be used in RT-PCR, for the diagnosis of COVID-19, as an alternative to nasopharyngeal swab samples.Methods We have analyzed nasopharyngeal and gargle and mouthwash samples, before and after concentration, of 363 patients by RT-PCR for the presence of SARS-CoV-2.Results Among 114 patients in which SARS-CoV-2 was identified in at least one of their samples, the virus was identified in 76 (66.7%), 67 (58.8%) and 101 (88.6%) of nasopharyngeal swab, gargle and mouth-wash samples before and after concentration, respectively.Conclusion When concentrated by our new method, gargle and mouthwash samples can be used instead of nasopharyngeal samples in identification of SARS-CoV-2 by RT-PCR, with the same or better sensitivity. Eliminating the need for nasopharyngeal sampling, will save the patients from an invasive and painful procedure and will lower the risk of infection for the healthcare personnel taking the sample. This easy sampling procedure may decrease the workload of hospitals, shorten the turn-around time of obtaining test results and thus enable rapid isolation of infected patients.

scholarly journals Comparison of SARS-CoV-2 RT-PCR on a high-throughput molecular diagnostic platform and the cobas SARS-CoV-2 test for the diagnostic of COVID-19 on various clinical samples

2020 ◽  
Vol 78 (8) ◽  
Author(s):  
Onya Opota ◽  
René Brouillet ◽  
Gilbert Greub ◽  
Katia Jaton
Keyword(s):  
High Throughput ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Rt Pcr ◽  
Clinical Specimens ◽  
Rapid Spread ◽  
Bronchial Aspirate ◽  
Very High

ABSTRACT Objectives:In order to cope with the rapid spread of the COVID-19 pandemic, we introduced on our in-house high-throughput molecular diagnostic platform (MDx Platform) a real-time reverse transcriptase PCR (RT-PCR) to detect the SARS-CoV-2 from any clinical specimens. The aim of this study was to compare the RT-PCR results obtain with the MDx Platform and the commercial assay cobas SARS-CoV-2 (Roche) on nasopharyngeal swab and other clinical specimens including sputum, bronchial aspirate, bronchoalveolar lavage and anal swabs. Methods: Samples received in our laboratory from patients suspected of COVID-19 (n = 262) were tested in parallel with our MDx platform SARS-CoV-2 PCR and with the cobas SARS-CoV-2 test. Results: The overall agreement between the two tests for all samples tested was 99.24% (260/262), which corresponded to agreements of 100% (178/178) on nasopharyngeal swabs, 95.45% (42/44) on lower respiratory tract specimen with discordant resultS obtained for very high cycle threshold (Ct) value and 100% (40/40) on anorectal swabs. The Ct values for nasopharyngeal swabs displayed an excellent correlation (R2 > 96%) between both tests. Conclusions: The high agreements between the cobas SARS-CoV-2 test and the MDx platform supports the use of both methods for the diagnostic of COVID-19 on various clinical samples. Very few discrepant results may occur at very low viral load.

scholarly journals Head-to-head comparison of SARS-CoV-2 antigen-detecting rapid test with self-collected anterior nasal swab versus professional-collected nasopharyngeal swab

2020 ◽  
Author(s):  
Andreas K. Lindner ◽  
Olga Nikolai ◽  
Franka Kausch ◽  
Mia Wintel ◽  
Franziska Hommes ◽  
...  
Keyword(s):  
Point Of Care ◽  
Rapid Test ◽  
High Viral Load ◽  
Ease Of Use ◽  
Healthcare Personnel ◽  
Nasopharyngeal Swab ◽  
Swab Sample ◽  
Rt Pcr ◽  
Percent Agreement ◽  
Accuracy Study

AbstractBackgroundTwo antigen-detecting rapid diagnostic tests (Ag-RDTs) are now approved through the WHO Emergency Use Listing procedure and can be performed at the point-of-care. However, both tests use nasopharyngeal (NP) swab samples. NP swab samples must be collected by trained healthcare personnel with protective equipment and are frequently perceived as uncomfortable by patients.MethodsThis was a manufacturer-independent, prospective diagnostic accuracy study with comparison of a supervised, self-collected anterior nose (AN) swab sample with a professional-collected NP swab sample, using a WHO-listed SARS-CoV-2 Ag-RDT, STANDARD Q COVID-19 Ag Test (SD Biosensor), which is also being distributed by Roche. The reference standard was RT-PCR from an oro-/nasopharyngeal swab sample. Percent positive and negative agreement as well as sensitivity and specificity were calculated.ResultsAmong the 289 participants, 39 (13.5%) tested positive for SARS-CoV-2 by RT-PCR. The positive percent agreement of the two different sampling techniques for the Ag-RDT was 90.6% (CI 75.8-96.8). The negative percent agreement was 99.2% (CI 97.2-99.8). The Ag-RDT with AN sampling showed a sensitivity of 74.4% (29/39 PCR positives detected; CI 58.9-85.4) and specificity of 99.2% (CI 97.1-99.8) compared to RT-PCR. The sensitivity with NP sampling was 79.5% (31/39 PCR positives detected; CI 64.5-89.2) and specificity was 99.6% (CI 97.8-100). In patients with high viral load (>7.0 log 10 RNA SARS-CoV2/swab), the sensitivity of the Ag-RDT with AN sampling was 96% and 100% with NP sampling.ConclusionSupervised self-sampling from the anterior nose is a reliable alternative to professional nasopharyngeal sampling using a WHO-listed SARS-CoV-2 Ag-RDT. Considering the ease-of-use of Ag-RDTs, self-sampling and potentially patient self-testing at home may be a future use case.

SARS-CoV2 infection rate in patients and health care personnel in a chemoradiotherapy unit: A prospective cohort in Mexico.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e22521-e22521
Author(s):  
Mónica Isabel Meneses Medina ◽  
Jorge Humberto Hernandez-Felix ◽  
Vanessa Rosas Rosas Camargo ◽  
Ana Karen Valenzuela ◽  
Alberto Cedro-Tanda ◽  
...  
Keyword(s):  
Mexico City ◽  
Infection Rate ◽  
Median Number ◽  
Severe Form ◽  
Healthcare Personnel ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Inform Consent ◽  
Receive Treatment

e22521 Background: Cancer treatment during the COVID-19 pandemic represents a challenge. Increased hospital visits to receive treatment as well as interaction with healthcare personnel (HCP), represent a potential risk factor for acquiring COVID-19. Our objective was to analyze the SARS-CoV-2 infection rate in patients (pts) with cancer and HCP of a chemoradiotherapy unit localized in a center designated as a COVID-19 priority facility in Mexico City. Methods: We invited HCP and pts with solid tumors attending the chemoradiotherapy unit to participate in a prospective follow-up cohort to early detect asymptomatic COVID-19 infection. Only participants who gave informed consent were included. A RT-PCR test for SARS-COV-2 from nasopharyngeal swab samples was performed every 2 weeks, and daily electronic clinical questionnaires were sent. Recruitment started on June 12, 2020. Participants entered the study in different moments and they were followed until a positive test for COVID-19 was found, or pts finished treatment or, HCP changed work area or, withdrawal of inform consent, or follow up completion, which ever occurred first. The last day of follow up was September 30, 2020. The general infection rate during all the period of follow-up was calculated, as well as the infection rate per month. Results: We included 130 asymptomatic participants, 44.6% (n = 58) were HCP and 55.4% (n = 72) were cancer pts, 45.9% (n = 61) were men, and 54.1% (n = 72) were women. During a median follow-up of 85 days (IQR 48-103) we performed 634 nasopharyngeal swabs for SARS-CoV-2 RT-PCR, with a median number per participant of 5 (IQR 3-7). Within this period, 18 (13.5%) participants tested positive for SARS-CoV-2 infection. 12 were asymptomatic and 6 developed symptoms. None of them had a severe form of COVID-19 and we did not register any death associated to COVID-19. Table shows the infection rate per month. Conclusions: In our center, during the time period of follow up, the overall rate of COVID-19 infection was higher than that reported in a study from asymptomatic HCP and office workers in Mexico City (13.5 vs 8.4%). We also observed a monthly variation that was consistent with the months with the highest number of cases detected in Mexico City during the first wave. With careful implementation, it is feasible to continue to safely deliver systemic oncologic treatments during the COVID-19 pandemic.[Table: see text]

scholarly journals Concentration of the cellular material in the nasopharyngeal swabs increases the clinical sensitivity of SARS-CoV2 RT-PCR

2020 ◽  
Author(s):  
Priya Kannian ◽  
Pasuvaraj Mahanathi ◽  
Veeraraghavan Ashwini
Keyword(s):  
Direct Method ◽  
Rna Extraction ◽  
Direct Methods ◽  
N Gene ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Clinical Sensitivity ◽  
Concentration Method ◽  
Viral Transport Medium ◽  
Analytical Variable

SummarySevere acute respiratory syndrome - coronavirus 2 (SARS-CoV2) is detected by a highly sensitive molecular method, reverse transcriptase-polymerase chain reaction (RT-PCR) from nasopharyngeal swab (NPS) samples collected in 2-3ml of viral transport medium (VTM). Unlike body fluids, NPS samples are undermined by high variability in the amount of cells that get suspended into the VTM. Hence, the cell density used for RNA extraction becomes an important analytical variable that contributes to the overall sensitivity of the RT-PCR. In this study, we compared the sensitivity of SARS-CoV2 RT-PCR in 50 NPS samples collected from in-patients of the COVID wards using the concentration and direct methods. The concentration method detected the viral RNA in all 50 samples, while the direct method was positive in only 41 (82%) samples (p=0.003). Additionally, the Ct values were lower in the direct method compared to concentration method among the 41 positive samples (p=0.03 for N gene and p=0.04 for RdRp gene). The mean CV% was also ≥10%. Thus, the concentration of the cells prior to RNA extraction drastically improves the sensitivity of detection of SARS-CoV2 in NPS samples.

New Basket-Based Method for Testing Coarse Aggregate Saturated Surface-Dry Mass

2014 ◽  
Vol 971-973 ◽  
pp. 2191-2197
Author(s):  
Feng Han Liu ◽  
Xiao Ling Chen
Keyword(s):  
Coarse Aggregate ◽  
Current Method ◽  
Dry Mass ◽  
New Method ◽  
Test Results ◽  
Before And After ◽  
Real Value ◽  
The Difference ◽  
Current Code ◽  
Saturated Surface

This paper introduces a new method to get the saturated-surface-dry mass of coarse aggregate based on basket method, by testing the difference of the aggregate mass before and after being immersed in water for 24 hours. It also describes the design of test process. By comparing the different test results of the new method and the method in current code, it shows significant advantages of the new method and removes the shortcoming of the current method, the result is more close to the real value of material properties.

scholarly journals Comparison of Rapid Antibody Test and Thorax Computed Tomography Results in Patients who Underwent RT-PCR with the Pre-Diagnosis of COVID-19

2021 ◽  
Author(s):  
İlker Kızıloglu ◽  
Aslı Şener ◽  
Neslihan Siliv
Keyword(s):  
Computed Tomography ◽  
Emergency Department ◽  
Predictive Value ◽  
Antibody Test ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Rt Pcr ◽  
Hospital Data ◽  
Thorax Ct ◽  
Rapid Antibody

Introduction: In this study, it is planned to compare the RT-PCR test, which is the gold standard in the diagnosis of COVID-19, with Thorax computed tomography (CT) and rapid antibody test results. Methods: Patients who were admitted to the emergency service of İzmir Çiğli Training and Research Hospital between 01.04.2020 and 31.05.2020 and who were suspected of having COVID-19 infection were included in the study. The medical records of the patients were retrospectively analyzed through the hospital data processing database. Age, gender, hospitalization, status of home quarantine, real-time reverse transcription-polymerase chain reaction (RT-PCR), thorax CT and rapid antibody test results of the patients were examined. The relationship between RT-PCR, thorax CT and rapid antibody test results were compared statistically. Results: A total of 181 patients, 115 (63.5%) male and 66 (36.5%) female, with an average age of 56.4 ± 18.06 years were included in the study. The nasopharyngeal swab PCR result obtained at the first admission of the patients to the emergency department was positive in 71 (39.2%) patients. Thorax CT was performed in 173 (95.6%) patients who applied to the emergency department, and 112 (64.7%) of them had findings that could be compatible with COVID-19. According to the thorax CT findings in patients, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting COVID-19 infection were respectively; 76.1%, 43.1%, 48.2% and 72.1% (ĸ: 0.176, p <0.001). In our study, the mortality rate for COVID-19 was found to be 2.8%. Conclusion: Rapid antibody test and thorax CT examinations were found to have low diagnostic value in patients who admitted to the emergency department of our hospital and whose first RT-PCR SARS-CoV-2 test was positive. Studies involving larger patient groups are needed for their use alone in diagnosis and screening.

scholarly journals Salivary molecular testing for SARS-CoV-2: simplifying the diagnosis without losing accuracy

2021 ◽  
Author(s):  
Francesca Saluzzo ◽  
Paola Mantegani ◽  
Valeria Poletti de Chaurand ◽  
Federica Cugnata ◽  
Patrizia Rovere-Querini ◽  
...  
Keyword(s):  
Public Health ◽  
Health Care Workers ◽  
Point Of Care ◽  
Nasopharyngeal Swab ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Care Workers ◽  
Before And After ◽  
Overall Performance ◽  
The Stability

Background Quantitative RT-PCR on NasoPharyngeal Swab (NPS) is still considered the standard for the diagnosis of SARS-CoV-2 infection, even if saliva has been evaluated in several studies as a possible alternative. The use of point of care (POC) platforms, providing highly specific results performed on saliva could simplify the diagnosis of COVID-19 and contribute to contain the spreading of SARS-CoV-2. Methods We assess the sensitivity and specificity of molecular testing performed on saliva in comparison to NPS using two different POC platforms (DiaSorin Simplexa ™ and Cepheid Xpert ®). NPS and saliva were collected prospectically from asymptomatic health care workers and mildly symptomatic patients. Moreover, the stability of saliva samples after storage at -80 C ° for up to 45 days was tested. Results The obtained results in comparison to NPS demonstrated for both DiaSorin Simplexa ™ and Xpert ® Xpress a specificity of 100% and a sensitivity of 90.24%. The overall agreement between the tests performed on saliva was 98%. A positive correlation in Ct values detected on saliva and on NPS was identified for all the targets shared by the tests in analysis (Orf1ab, E and N2). Both S Ct values and Orf1ab Ct values were not significantly different before and after the freezing in the tested saliva samples. Conclusion The obtained results demonstrated an overall performance of saliva comparable to NPS, confirming that RT-PCR performed using POCs on saliva could represent a valid public health solution for controlling SARS-CoV-2 pandemic.

scholarly journals Less Exposure for Health Care Workers, More Comfort for Patients During COVID-19 Swab Testing

2021 ◽  
pp. 216507992110453
Author(s):  
Adeviyye Karaca ◽  
Mehmet Akçimen ◽  
Hatice Özen
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Tertiary Care ◽  
Care Hospital ◽  
Test Results ◽  
Rt Pcr ◽  
Exposure Risk ◽  
Care Workers ◽  
Before And After ◽  
Pcr Test

Background Nasopharyngeal (NP) and oropharyngeal (OP) swab sampling for coronavirus disease 2019 (COVID-19) diagnosis may lead to droplet and/or airborne particle transmission and increase the exposure risk for health care workers (HCWs). However, there is limited evidence for effective methods to reduce occupational exposure from NP and OP swab sampling. This study aimed to reduce droplet-forming responses (DFRs) and the related exposure risk of NP and OP swab sampling by administering 10% lidocaine spray (LS) to the NP and OP areas prior to conducting swab tests. Methods This quasi-experimental study was conducted with 100 patients who presented to our tertiary care hospital with symptoms of COVID-19 between December 1 and 15, 2020. First, NP and OP swabbings were performed on each patient. Thereafter, LS was applied to the OP and NP regions, and the swab samples were taken once again. Frequency of DFRs and real-time polymerase chain reaction (RT-PCR) test results before and after LS application were recorded for comparison. In addition, the cycle threshold (Ct) was used as a proxy indicator for SARS-CoV-2 viral load in COVID-19 positive cases. Findings Significant differences in OP DFR frequencies before and after LS intervention were found (37% and 9%, respectively), as well as before and after NP DFR (31% and 18%, respectively). The mean Ct values for the positive samples did not differ before and after applying LS. Conclusion Our results suggest that applying LS to the OP and NP area prior to swab testing reduces DFR frequencies without affecting (RT-PCR) test results for SARS-CoV-2 and may increase patient and practitioner comfort.

scholarly journals Detection of SARS-CoV-2 infection by rapid antigen test in comparison with RT-PCR in a public setting

2021 ◽  
Author(s):  
Kathrine Kronberg Jakobsen ◽  
Jakob Schmidt Jensen ◽  
Tobias Todsen ◽  
Freddy Lippert ◽  
Cyril Jean-Marie Martel ◽  
...  
Keyword(s):  
False Negative ◽  
Pcr Analysis ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Antigen Test ◽  
Rt Pcr ◽  
Predictive Values ◽  
Public Setting ◽  
Antigen Tests ◽  
Sensitivity Specificity

AbstractBackgroundRapid and accurate detection of SARS-CoV-2 infection is essential in limiting the spread of infection during the ongoing COVID-19 pandemic. The aim of this study was to determine the accuracy of the STANDARD Q COVID-19 Ag test (SD BIOSENSOR) by comparison with RT-PCR in a public setting.MethodIndividuals aged 18 years or older who had booked an appointment for a RT-PCR test on December 26-31, 2020 at a public test center in Copenhagen, Denmark, were invited to participate. An oropharyngeal swab was collected for RT-PCR analysis, immediately followed by a nasopharyngeal swab examined by the STANDARD Q COVID-19 Ag test (SD BIOSENSOR). Sensitivity, specificity, positive and negative predictive values of the antigen test were calculated with test results from RT-PCR as reference.ResultsOverall, 4697 individuals were included (female n=2456, 53.3%; mean age: 44.7 years, SD: 16.9 years); 196 individuals were tested twice or more. Among 4811 paired conclusive test results from the RT-PCR and antigen tests, 221 (4.6%) RT-PCR tests were positive. The overall sensitivity and specificity of the antigen test were 69.7% and 99.5%, the positive and negative predictive values were 87.0% and 98.5%. Ct values were significantly higher among individuals with false negative antigen tests compared to true positives.ConclusionThe sensitivity, specificity, and predictive values found indicate that the STANDARD Q COVID-19 Ag is a good supplement to RT-PCR testing.

The Plasmin Inhibitors of Plasma

1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon
Keyword(s):  
Human Plasma ◽  
New Method ◽  
Normal Amount ◽  
Caseinolytic Activity ◽  
Before And After ◽  
Plasmin Inhibitors

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.

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