scholarly journals Accuracy of Healthcare Professionals’ Nasopharyngeal Swab Technique in SARS-CoV-2 Specimen Collection

2020 ◽  
Author(s):  
Robbie S. R. Woods ◽  
Kellie Nwaokorie ◽  
Jana Crowley ◽  
Michael Walsh ◽  
Eoghan de Barra ◽  
...  
Keyword(s):  
Healthcare Professionals ◽  
False Negative ◽  
Three Dimensional ◽  
False Negative Rate ◽  
Nasopharyngeal Swab ◽  
Three Dimensional Model ◽  
Tertiary Referral Centre ◽  
Specimen Collection ◽  
A Prospective Study ◽  
Novel Design

AbstractBackgroundThe COVID-19 pandemic has caused huge pressure on healthcare systems worldwide. Public health measures to control the virus are reliant on testing, including appropriate collection of specimens for analysis.MethodsA prospective study of nasopharyngeal swab technique by staff in an academic tertiary referral centre was carried out. Nasopharyngeal swab technique was evaluated by a novel design of a navigated swab on a three-dimensional model head.ResultsSwab technique of 228 participants was assessed. Technique was poor, with a success rate of nasopharyngeal swabbing at 38.6%. Angle and length of insertion were significantly different between those with successful and unsuccessful technique. Doctors were significantly more accurate than nurses and non-healthcare professionals (p<0.01).ConclusionInaccurate specimen collection from poor swab technique could contribute to a false negative rate of testing for SARS-CoV-2. Specific training in nasopharyngeal anatomy and swab technique may improve the accuracy of nasopharyngeal swabbing.

scholarly journals Three-dimensional camera anthropometry to assess risk of cephalopelvic disproportion-related obstructed labour in Ethiopia

2019 ◽  
Vol 9 (5) ◽  
pp. 20190036 ◽  
Author(s):  
Lorenzo Tolentino ◽  
Mahlet Yigeremu ◽  
Sisay Teklu ◽  
Shehab Attia ◽  
Michael Weiler ◽  
...  
Keyword(s):  
False Negative ◽  
Three Dimensional ◽  
False Negative Rate ◽  
Detection Rates ◽  
Cephalopelvic Disproportion ◽  
Obstructed Labour ◽  
Tape Measure ◽  
Negative Rate ◽  
Positive Rate ◽  
Tape Measurement

Cephalopelvic disproportion (CPD)-related obstructed labour requires delivery via Caesarean section (C/S); however, in low-resource settings around the world, facilities with C/S capabilities are often far away. This paper reports three low-cost tools to assess the risk of CPD, well before labour, to provide adequate time for referral and planning for delivery. We performed tape measurement- and three-dimensional (3D) camera-based anthropometry, using two 3D cameras (Kinect and Structure) on primigravida, gestational age ≥ 36 weeks, from Addis Ababa, Ethiopia. Novel risk scores were developed and tested to identify models with the highest predicted area under the receiver-operator characteristic curve (AUC), detection rate (true positive rate at a 5% false-positive rate, FPR) and triage rate (true negative rate at a 0% false-negative rate). For tape measure, Kinect and Structure, the detection rates were 53%, 61% and 64% (at 5% FPR), the triage rates were 30%, 56% and 63%, and the AUCs were 0.871, 0.908 and 0.918, respectively. Detection rates were 77%, 80% and 84% at the maximum J -statistic, which corresponded to FPRs of 10%, 15% and 11%, respectively, for tape measure, Kinect and Structure. Thus, tape measurement anthropometry was a very good predictor and Kinect and Structure anthropometry were excellent predictors of CPD risk.

scholarly journals One-Year Update on Salivary Diagnostic of COVID-19

2021 ◽  
Vol 9 ◽  
Author(s):  
Douglas Carvalho Caixeta ◽  
Stephanie Wutke Oliveira ◽  
Leia Cardoso-Sousa ◽  
Thulio Marquez Cunha ◽  
Luiz Ricardo Goulart ◽  
...  
Keyword(s):  
Healthcare Professionals ◽  
Close Contact ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Frontline Workers ◽  
Non Invasive ◽  
Negative Results ◽  
False Negative Results ◽  
One Year ◽  
Frontline Healthcare Workers

Background: Coronavirus disease 2019 (COVID-19) is a global health problem, which is challenging healthcare worldwide. In this critical review, we discussed the advantages and limitations in the implementation of salivary diagnostic platforms of COVID-19. The diagnostic test of COVID-19 by invasive nasopharyngeal collection is uncomfortable for patients and requires specialized training of healthcare professionals in order to obtain an appropriate collection of samples. Additionally, these professionals are in close contact with infected patients or suspected cases of COVID-19, leading to an increased contamination risk for frontline healthcare workers. Although there is a colossal demand for novel diagnostic platforms with non-invasive and self-collection samples of COVID-19, the implementation of the salivary platforms has not been implemented for extensive scale testing. Up to date, several cross-section and clinical trial studies published in the last 12 months support the potential of detecting SARS-CoV-2 RNA in saliva as a biomarker for COVID-19, providing a self-collection, non-invasive, safe, and comfortable procedure. Therefore, the salivary diagnosis is suitable to protect healthcare professionals and other frontline workers and may encourage patients to get tested due to its advantages over the current invasive methods. The detection of SARS-CoV-2 in saliva was substantial also in patients with a negative nasopharyngeal swab, indicating the presence of false negative results. Furthermore, we expect that salivary diagnostic devices for COVID-19 will continue to be used with austerity without excluding traditional gold standard specimens to detect SARS-CoV-2.

scholarly journals Comparing routine versus selective use of intraoperative cerebral angiography in aneurysm surgery: a prospective study

2014 ◽  
Vol 8 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Chad W Washington ◽  
Colin P Derdeyn ◽  
Michael R Chicoine ◽  
DeWitte T Cross ◽  
Ralph G Dacey ◽  
...  
Keyword(s):  
False Negative ◽  
False Negative Rate ◽  
Preoperative Assessment ◽  
Aneurysm Surgery ◽  
Intraoperative Angiography ◽  
Aneurysm Clipping ◽  
Intraoperative Assessment ◽  
Negative Rate ◽  
Clip Application ◽  
A Prospective Study

IntroductionWhile the use of intraoperative angiography (IA) has been shown to be a useful adjunct in aneurysm surgery, its routine use remains controversial.ObjectiveWe wished to determine if IA is required in all patients undergoing aneurysm surgery (ie, routine IA) or if intraoperative assessment can reliably predict the need for IA (ie, select IA).MethodsWe prospectively evaluated all patients undergoing craniotomy for aneurysm clipping. In these patients, the treating surgeons were asked to record whether they felt IA was required at two time points: (1) prior to surgery and (2) immediately after clip application but before IA. All patients underwent IA as per the institutional protocol. IA results and the need for post-IA clip adjustments were recorded.ResultsOf the 200 patients enrolled, 197 were included for analysis. IA was deemed necessary on preoperative assessment in 144 cases (73%) and on post-clip assessment in 116 cases (59%). Post-clip IA demonstrated 47 (24%) positive findings and post-IA clip adjustments were made in 19 of 198 cases (10%). On preoperative assessment, there were four cases where IA was deemed unnecessary, yet post-IA clip adjustment was required, resulting in a sensitivity of 79% and false negative rate of 8%. Regarding post-clip assessment, there were five cases where IA was thought to be unnecessary and clip adjustment was required, resulting in a sensitivity of 73% and false negative rate of 6%.ConclusionsThe accuracy of a strategy of select IA was not improved by assessing the need for IA immediately after aneurysm clipping versus prior to surgery onset. This suggests that intraoperative assessment regarding the adequacy of aneurysm clip application should be viewed with caution.

Coherence in intersectoral collaboration between psychiatric centres and community mental healthcare: A critical discourse analysis

2020 ◽  
Vol 40 (3) ◽  
pp. 130-141 ◽  
Author(s):  
Kim Jørgensen ◽  
Mette Bonde Dahl ◽  
Jesper Frederiksen
Keyword(s):  
Discourse Analysis ◽  
Critical Discourse Analysis ◽  
Healthcare Professionals ◽  
Three Dimensional ◽  
Mental Healthcare ◽  
Intersectoral Collaboration ◽  
Three Dimensional Model ◽  
Healthcare Data ◽  
Group Interviews ◽  
The Right

There is scarce research studying healthcare professionals’ and users’ perceptions in relation to creating coherence in intersectoral collaboration between psychiatric centres and community mental healthcare. Drawing on the discourse analysis framework of Fairclough, this study aimed to explore how healthcare professionals and users could perceive coherence in intersectoral collaboration between psychiatric centres and community mental healthcare. But also to explore their perception of how coherence could be maintained through an intersectoral journey, and what discourses manifested themselves within the field of mental healthcare. Data were collected through 11 focus group interviews, five of which with healthcare professionals ( n = 20) and six with users ( n = 18). Fairclough’s three-dimensional model for the studying of discourse was used to analyse the transcribed texts. This study is reported in accordance with the COREQ checklist. Coherence in intersectoral collaboration was interpreted to exist in tension between being predominantly steered by the healthcare professionals while the users had a desire to be more involved in decisions regarding their own intersectoral journey. The users were subjected to a paternalistic steering, expressed by the power of the healthcare professionals to select the right efforts as well as the purpose of the users’ journeys. The findings showed that coherence in intersectoral collaboration in general was articulated from an overall discourse of neoliberal governance, with its embedded discourses of rationality and structure, and discourses of linearity, objectivity, paternalism, biomedicine and evidence have a controlling influence on how users should guide themselves based on the discourse of self-care.

scholarly journals Evaluation of saliva molecular point of care for detection of SARS-CoV-2 in ambulatory care

2021 ◽  
Author(s):  
Jerome Le Goff ◽  
Solen Kerneis ◽  
Caroline Elie ◽  
Severine Mercier Delarue ◽  
Nabil Gastli ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Lamp Assay ◽  
Rapid Identification ◽  
Ambulatory Setting ◽  
Nasopharyngeal Swab ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
A Prospective Study ◽  
Antigen Testing

Background: The rapid identification of SARS-CoV-2 infected individuals is a cornerstone in strategies for the control of virus spread. The sensitivity of SARS-CoV-2 RNA detection by RT-PCR is similar in saliva and nasopharyngeal swab. Rapid molecular point-of-care tests in saliva could facilitate, broaden and speed up the diagnosis. Objectives and methods: We conducted a prospective study in two community COVID-19 screening centers to evaluate the performances of a CE-marked RT-LAMP assay (EasyCoV) specifically designed for the detection of SARS-CoV-2 RNA from fresh saliva samples, compared to nasopharyngeal RT-PCR as reference test, saliva RT-PCR and nasopharyngeal antigen testing. Results: Overall, 117 of the 1718 participants (7%) were tested positive with nasopharyngeal RT-PCR. Sensitivities of saliva RT-PCR and nasopharyngeal antigen test were 93% (95% Confidence Interval (95%CI): 86-97) and 85% (95%CI: 77-91), respectively. The sensitivity and specificity of the RT-LAMP assay in saliva were 34% (95%CI: 26-44) and 97% (95%CI: 96-98). The performance was similar in symptomatic and asymptomatic participants and whatever the reference standard considered. Ct values of nasopharyngeal RT-PCR were significantly lower in the 40 true positive subjects with saliva RT-LAMP (Ct 25.9) than in the 48 false negative subjects with saliva RT-LAMP (Ct 28.4) (p=0.028). Conclusion: In the ambulatory setting, the detection of SARS-CoV-2 from crude saliva samples with the RT-LAMP assay had a lower sensitivity than nasopharyngeal RT-PCR, saliva RT-PCR and nasopharyngeal antigen testing.

scholarly journals Microfluidic nano-scale qPCR enables ultra-sensitive detection of SARS-CoV-2

2020 ◽  
Author(s):  
Xin Xie ◽  
Tamara Gjorgjieva ◽  
Zaynoun Attieh ◽  
Mame Massar Dieng ◽  
Marc Arnoux ◽  
...  
Keyword(s):  
Viral Infections ◽  
Limit Of Detection ◽  
False Negative ◽  
False Negative Rate ◽  
Clinical Samples ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Viral Loads ◽  
Nano Scale ◽  
Negative Rate

Background: A major challenge in controlling the COVID-19 pandemic is the high false-negative rate of the commonly used standard RT-PCR methods for SARS-CoV-2 detection in clinical samples. Accurate detection is particularly challenging in samples with low viral loads that are below the limit of detection (LoD) of standard one- or two-step RT-PCR methods. Methods: We implement a three-step approach for SARS-CoV-2 detection and quantification that employs reverse transcription, targeted cDNA preamplification and nano-scale qPCR based on the Fluidigm 192.24 microfluidic chip. We validate the method using both positive controls and nasopharyngeal swab samples. Results: Using SARS-CoV-2 synthetic RNA and plasmid controls, we demonstrate that the addition of a preamplification step enhances the LoD of the Fluidigm method by 1,000-fold, enabling detection below 1 copy/μl. We applied this method to analyze 182 clinical NP swab samples previously diagnosed using a standard RT-qPCR protocol (91 positive, 91 negative) and demonstrate reproducible detection of SARS-CoV-2 over five orders of magnitude (< 1 to 106 viral copies/μl). Crucially, we detect SARS-CoV-2 with relatively low viral load estimates (<1 to 40 viral copies/μl) in 17 samples with negative clinical diagnosis, indicating a potential false negative rate of 18.7% by clinical diagnostic procedures. Conclusion: The three-step nano-scale RT-qPCR method can robustly detect SARS-CoV-2 in samples with relatively low viral loads (< 1 viral copy/μl) and has the potential to reduce the false negative rate of standard RT-PCR-based diagnostic tests for SARS-CoV-2 and other viral infections.

scholarly journals Comparison of the Accula SARS-CoV-2 Test with a Laboratory-Developed Assay for Detection of SARS-CoV-2 RNA in Clinical Nasopharyngeal Specimens

2020 ◽  
Vol 58 (8) ◽  
Author(s):  
Catherine A. Hogan ◽  
Natasha Garamani ◽  
Andrew S. Lee ◽  
Jack K. Tung ◽  
Malaya K. Sahoo ◽  
...  
Keyword(s):  
Viral Load ◽  
Test Performance ◽  
Point Of Care ◽  
False Negative ◽  
False Negative Rate ◽  
Kappa Coefficient ◽  
Performance Characteristics ◽  
Nasopharyngeal Swab ◽  
Percent Agreement ◽  
Gene Assay

ABSTRACT Several point-of-care (POC) molecular tests have received emergency use authorization (EUA) from the Food and Drug Administration (FDA) for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The test performance characteristics of the Accula (Mesa Biotech) SARS-CoV-2 POC test need to be evaluated to inform its optimal use. The aim of this study was to assess the test performance of the Accula SARS-CoV-2 test. The performance of the Accula test was assessed by comparing results of 100 nasopharyngeal swab samples previously characterized by the Stanford Health Care EUA laboratory-developed test (SHC-LDT), targeting the envelope (E) gene. Assay concordance was assessed by overall percent agreement, positive percent agreement (PPA), negative percent agreement (NPA), and Cohen’s kappa coefficient. Overall percent agreement between the assays was 84.0% (95% confidence interval [CI], 75.3 to 90.6%), PPA was 68.0% (95% CI, 53.3 to 80.5%), and the kappa coefficient was 0.68 (95% CI, 0.54 to 0.82). Sixteen specimens detected by the SHC-LDT were not detected by the Accula test and showed low viral load burden, with a median cycle threshold value of 37.7. NPA was 100% (95% CI, 94.2 to 100%). Compared to the SHC-LDT, the Accula SARS-CoV-2 test showed excellent negative agreement. However, positive agreement was low for samples with low viral load. The false-negative rate of the Accula POC test calls for a more thorough evaluation of POC test performance characteristics in clinical settings and for confirmatory testing in individuals with moderate to high pretest probability of SARS-CoV-2 who test negative on Accula.

scholarly journals Comparative study of tubal patency by sonosalpingogram hysterosalpingography and diagnostic laparoscopy

2019 ◽  
Vol 8 (9) ◽  
pp. 3435
Author(s):  
Spoorthy Reddy ◽  
M. Padma
Keyword(s):  
Diagnostic Laparoscopy ◽  
False Negative ◽  
False Negative Rate ◽  
Radiation Hazard ◽  
First Line ◽  
Diagnostic Efficacy ◽  
Tubal Patency ◽  
Negative Rate ◽  
Unilateral Block ◽  
A Prospective Study

Background: Sonosalpingography has been suggested as the first-line method to study tubal patency. This study is to bring into focus the value of pelvic sonogram in accessing tubal patency in order to overcome the radiation hazard associated with hysterosalpingogram reduce the cost of examination and encourage it at first-line office. Objective of this study was to compare the diagnostic efficacy of sonosalpingogram, hysterosalpingography and diagnostic laparoscopy for tubal patency as a cause for female infertility.Methods: It is a prospective study in 100 patients attending for evaluation of infertility for a period of 2 years were chosen for this study. All cases with primary and secondary infertility who have attended infertility clinic for tubal causes.Results: 68 cases were found to have bilateral patency as per SSG while 58 cases had bilateral patency as HSG. Similarly 24 cases had bilateral block as per SSG while 28 cases had bilateral block as per HSG. 8 cases had unilateral block as per SSG while 14 cases had unilateral block as per HSG.  This difference in observations may probably attribute to tubal spasm in HSG. Bilateral patency was observed in 68 cases as against 64 cases in laparoscopy.  Out of these 68 cases 9 cases were false positive as bilaterally patent.  However bilateral blocks were shown to be 24 in both methods. Out of 12 cases of unilateral block as per laparoscopy 8 cases were detected by SSG. There was false negative rate of 5%. There was false negative rate of 10% for tubal patency with HSG.Conclusions: For low risk subjects for tubal factors in infertility, sonosalpingogram can be employed as a screening test of choice and for high risk subjects HSG and laparoscopy can be used.

scholarly journals Greedy 3-Point Search (G3PS)—A Novel Algorithm for Pharmacophore Alignment

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7201
Author(s):  
Christian Permann ◽  
Thomas Seidel ◽  
Thierry Langer
Keyword(s):  
Virtual Screening ◽  
False Negative ◽  
Three Dimensional ◽  
False Negative Rate ◽  
Alignment Algorithm ◽  
Screening Experiments ◽  
Point Search ◽  
Optimal Alignments ◽  
Pharmacophore Models ◽  
Feature Pattern

Chemical features of small molecules can be abstracted to 3D pharmacophore models, which are easy to generate, interpret, and adapt by medicinal chemists. Three-dimensional pharmacophores can be used to efficiently match and align molecules according to their chemical feature pattern, which facilitates the virtual screening of even large compound databases. Existing alignment methods, used in computational drug discovery and bio-activity prediction, are often not suitable for finding matches between pharmacophores accurately as they purely aim to minimize RMSD or maximize volume overlap, when the actual goal is to match as many features as possible within the positional tolerances of the pharmacophore features. As a consequence, the obtained alignment results are often suboptimal in terms of the number of geometrically matched feature pairs, which increases the false-negative rate, thus negatively affecting the outcome of virtual screening experiments. We addressed this issue by introducing a new alignment algorithm, Greedy 3-Point Search (G3PS), which aims at finding optimal alignments by using a matching-feature-pair maximizing search strategy while at the same time being faster than competing methods.

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