scholarly journals A Large-Scale Clinical Validation Study Using nCapp Cloud Plus Terminal by Frontline Doctors for the Rapid Diagnosis of COVID-19 and COVID-19 pneumonia in China

2020 ◽  
Author(s):  
Dawei Yang ◽  
Tao Xu ◽  
Xun Wang ◽  
Deng Chen ◽  
Ziqiang Zhang ◽  
...  
Keyword(s):  
False Negative ◽  
Risk Groups ◽  
Ct Scans ◽  
Training Dataset ◽  
Validation Dataset ◽  
Test Results ◽  
Rt Pcr ◽  
Cutoff Value ◽  
Asymptomatic Patients ◽  
Pcr Test

Background The outbreak of coronavirus disease 2019 (COVID-19) has become a global pandemic acute infectious disease, especially with the features of possible asymptomatic carriers and high contagiousness. It causes acute respiratory distress syndrome and results in a high mortality rate if pneumonia is involved. Currently, it is difficult to quickly identify asymptomatic cases or COVID-19 patients with pneumonia due to limited access to reverse transcription-polymerase chain reaction (RT-PCR) nucleic acid tests and CT scans, which facilitates the spread of the disease at the community level, and contributes to the overwhelming of medical resources in intensive care units. Goal This study aimed to develop a scientific and rigorous clinical diagnostic tool for the rapid prediction of COVID-19 cases based on a COVID-19 clinical case database in China, and to assist global frontline doctors to efficiently and precisely diagnose asymptomatic COVID-19 patients and cases who had a false-negative RT-PCR test result. Methods With online consent, and the approval of the ethics committee of Zhongshan Hospital Fudan Unversity (approval number B2020-032R) to ensure that patient privacy is protected, clinical information has been uploaded in real-time through the New Coronavirus Intelligent Auto-diagnostic Assistant Application of cloud plus terminal (nCapp) by doctors from different cities (Wuhan, Shanghai, Harbin, Dalian, Wuxi, Qingdao, Rizhao, and Bengbu) during the COVID-19 outbreak in China. By quality control and data anonymization on the platform, a total of 3,249 cases from COVID-19 high-risk groups were collected. These patients had SARS-CoV-2 RT-PCR test results and chest CT scans, both of which were used as the gold standard for the diagnosis of COVID-19 and COVID-19 pneumonia. In particular, the dataset included 137 indeterminate cases who initially did not have RT-PCR tests and subsequently had positive RT-PCR results, 62 suspected cases who initially had false-negative RT-PCR test results and subsequently had positive RT-PCR results, and 122 asymptomatic cases who had positive RT-PCR test results, amongst whom 31 cases were diagnosed. We also integrated the function of a survey in nCapp to collect user feedback from frontline doctors. Findings We applied the statistical method of a multi-factor regression model to the training dataset (1,624 cases) and developed a prediction model for COVID-19 with 9 clinical indicators that are fast and accessible: 'Residing or visiting history in epidemic regions', 'Exposure history to COVID-19 patient', 'Dry cough', 'Fatigue', 'Breathlessness', 'No body temperature decrease after antibiotic treatment', 'Fingertip blood oxygen saturation<=93%', 'Lymphopenia', and 'C-reactive protein (CRP) increased'. The area under the receiver operating characteristic (ROC) curve (AUC) for the model was 0.88 (95% CI: 0.86, 0.89) in the training dataset and 0.84 (95% CI: 0.82, 0.86) in the validation dataset (1,625 cases). To ensure the sensitivity of the model, we used a cutoff value of 0.09. The sensitivity and specificity of the model were 98.0% (95% CI: 96.9%, 99.1%) and 17.3% (95% CI: 15.0%, 19.6%), respectively, in the training dataset, and 96.5% (95% CI: 95.1%, 98.0%) and 18.8% (95% CI: 16.4%, 21.2%), respectively, in the validation dataset. In the subset of the 137 indeterminate cases who initially did not have RT-PCR tests and subsequently had positive RT-PCR results, the model predicted 132 cases, accounting for 96.4% (95% CI: 91.7%, 98.8%) of the cases. In the subset of the 62 suspected cases who initially had false-negative RT-PCR test results and subsequently had positive RT-PCR results, the model predicted 59 cases, accounting for 95.2% (95% CI: 86.5%, 99.0%) of the cases. Considering the specificity of the model, we used a cutoff value of 0.32. The sensitivity and specificity of the model were 83.5% (95% CI: 80.5%, 86.4%) and 83.2% (95% CI: 80.9%, 85.5%), respectively, in the training dataset, and 79.6% (95% CI: 76.4%, 82.8%) and 81.3% (95% CI: 78.9%, 83.7%), respectively, in the validation dataset, which is very close to the published AI model. The results of the online survey 'Questionnaire Star' showed that 90.9% of nCapp users in WeChat mini programs were 'satisfied' or 'very satisfied' with the tool. The WeChat mini program received a significantly higher satisfaction rate than other platforms, especially for 'availability and sharing convenience of the App' and 'fast speed of log-in and data entry'. Discussion With the assistance of nCapp, a mobile-based diagnostic tool developed from a large database that we collected from COVID-19 high-risk groups in China, frontline doctors can rapidly identify asymptomatic patients and avoid misdiagnoses of cases with false-negative RT-PCR results. These patients require timely isolation or close medical supervision. By applying the model, medical resources can be allocated more reasonably, and missed diagnoses can be reduced. In addition, further education and interaction among medical professionals can improve the diagnostic efficiency for COVID-19, thus avoiding the transmission of the disease from asymptomatic patients at the community level.

scholarly journals Artificial intelligence-enabled rapid diagnosis of COVID-19 patients

2020 ◽  
Author(s):  
Xueyan Mei ◽  
Hao-Chih Lee ◽  
Kai-yue Diao ◽  
Mingqian Huang ◽  
Bin Lin ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Clinical Symptoms ◽  
False Negative ◽  
Clinical History ◽  
Alternative Methods ◽  
Ct Scans ◽  
Rt Pcr ◽  
Negative Results ◽  
Radiologic Findings ◽  
Pcr Test

AbstractFor diagnosis of COVID-19, a SARS-CoV-2 virus-specific reverse transcriptase polymerase chain reaction (RT-PCR) test is routinely used. However, this test can take up to two days to complete, serial testing may be required to rule out the possibility of false negative results, and there is currently a shortage of RT-PCR test kits, underscoring the urgent need for alternative methods for rapid and accurate diagnosis of COVID-19 patients. Chest computed tomography (CT) is a valuable component in the evaluation of patients with suspected SARS-CoV-2 infection. Nevertheless, CT alone may have limited negative predictive value for ruling out SARS-CoV-2 infection, as some patients may have normal radiologic findings at early stages of the disease. In this study, we used artificial intelligence (AI) algorithms to integrate chest CT findings with clinical symptoms, exposure history, and laboratory testing to rapidly diagnose COVID-19 positive patients. Among a total of 905 patients tested by real-time RT-PCR assay and next-generation sequencing RT-PCR, 419 (46.3%) tested positive for SARSCoV-2. In a test set of 279 patients, the AI system achieved an AUC of 0.92 and had equal sensitivity as compared to a senior thoracic radiologist. The AI system also improved the detection of RT-PCR positive COVID-19 patients who presented with normal CT scans, correctly identifying 17 of 25 (68%) patients, whereas radiologists classified all of these patients as COVID-19 negative. When CT scans and associated clinical history are available, the proposed AI system can help to rapidly diagnose COVID-19 patients.

scholarly journals Coronavirus Disease 2019 (COVID-19) Candidate Chest CT Features: A Systematic Review of Extracted Imaging Features from 7571 Individuals

2020 ◽  
Author(s):  
Javad Zahiri ◽  
Mohammad Hossein Afsharinia ◽  
Zhaleh Hekmati ◽  
Mohsen Khodarahmi ◽  
Shahrzad Hekmati ◽  
...  
Keyword(s):  
False Negative ◽  
Ct Imaging ◽  
Response To Therapy ◽  
Imaging Features ◽  
Lung Involvement ◽  
Test Results ◽  
Rt Pcr ◽  
Pubmed Database ◽  
Bilateral Lung ◽  
Pcr Test

AbstractSince the outbreak of Coronavirus Disease 2019 (COVID-19) causing novel coronavirus (2019-nCoV)-infected pneumonia (NCIP), over 45 million affected cases have been reported worldwide. Many patients with COVID-19 have involvement of their respiratory system. According to studies in the radiology literature, chest computed tomography (CT) is recommended in suspected cases for initial detection, evaluating the disease progression and monitoring the response to therapy. The aim of this article is to review the most frequently reported imaging features in COVID-19 patients in order to provide a reliable insight into expected CT imaging manifestations in patients with positive reverse-transcription polymerase chain reaction (RT-PCR) test results, and also for the initial detection of patients with suspicious clinical presentation whose RT-PCR test results are false negative. A total of 60 out of 173 initial COVID-19 studies, comprising 7571 individuals, were identified by searching PubMed database for articles published between the months of January and June 2020. The data of these studies were related to patients from China, Japan, Italy, USA, Iran and Singapore. Among 40 reported features, presence of ground glass opacities (GGO), consolidation, bilateral lung involvement and peripheral distribution are the most frequently observed ones, reported in 100%, 91.7%, 85%, and 83.3% of articles, respectively. In a similar way, we extracted CT imaging studies of similar pulmonary syndromes outbreaks caused by other strains of coronavirus family: Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). For MERS and SARS, 2 out of 21 and 5 out of 153 initially retrieved studies had CT findings, respectively. Herein, we have indicated the most common coronavirus family related and COVID-19 specific features. Presence of GGO, consolidation, bilateral lung involvement and peripheral distribution were the features reported in at least 83% of COVID-19 articles, while air bronchogram, multi-lobe involvement and linear opacity were the three potential COVID-19 specific CT imaging findings. This is necessary to recognize the most promising imaging features for diagnosis and follow-up of patients with COVID-19. Furthermore, we identified co-existed CT imaging features.

scholarly journals How Did Radiologists’ Diagnostic Accuracy Have Changed in Covid-19 Pneumonia; a Single Centre Retrospective Study

2021 ◽  
Author(s):  
Ali Murat Koc ◽  
Levent Altın ◽  
Türker Acar ◽  
Alpay Arı ◽  
Zehra Hilal Adıbelli
Keyword(s):  
Chest Ct ◽  
Ct Scans ◽  
Test Results ◽  
Rt Pcr ◽  
Educational Activities ◽  
Admission Rates ◽  
Interpretation Errors ◽  
Concomitant Factors ◽  
Level Of Experience ◽  
Pcr Test

Aims Delay and false positivity in PCR test results have necessitated accurate chest CT reporting for management of patients with COVID-19 suspected symptoms. Pandemic related workload and level of experience on covid-dedicated chest CT scans might have effected diagnostic performance of on-call radiologists. The aim of this study is to reveal the interpretation errors in chest-CT reports of COVID-19 suspected patients admitted to the ER. Methods COVID-19 dedicated chest-CT scans which were performed between March and June 2020 were re-evaluated and compared with the former reports of these scans and PCR test results. CT scan results were classified into four groups. Parenchymal involvement ratios, radiology departments’ workload, COVID-19 related educational activities have examined. Results Out of 5721 Chest-CT scans, 783 CTs belonging to 664 patients (340 female, 324 male) were included to this study. RT-PCR test was positive in 398; negative in 385 cases. PCR positivity was found to be highest in “normal” and “typical for covid” groups whereas lowest in “atypical for covid” and “not covid” groups. 5-25% parenchymal involvement ratio was found in 84.2% of the cases. Regarding number of chest CT scans performed, radiologists’ workload have found to be increased six-folds compared to the same months of the former year. With the re-evaluation, a total of 145 IEs (18.5%) have been found. IEs were mostly precipitated in the first two months (88.3%) and mostly in “not covid” class (60%) regardless of PCR positivity. COVID-19 and radiology entitled educational activities along with the ER admission rates within the first two months of pandemic have seem to be related with the decline of IEs within time. Conclusion COVID-19 pandemic made a great impact on radiology departments with an inevitable burden of daily chest-CT reporting. This workload and concomitant factors have possible effects on diagnostic challenges in COVID-19 pneumonia.

scholarly journals Multicentre comparison of quantitative PCR-based assays to detect SARS-CoV-2, Germany, March 2020

2020 ◽  
Vol 25 (24) ◽  
Author(s):  
Maximilian Muenchhoff ◽  
Helga Mairhofer ◽  
Hans Nitschko ◽  
Natascha Grzimek-Koschewa ◽  
Dieter Hoffmann ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Quantitative Pcr ◽  
Clinical Management ◽  
False Negative ◽  
Test Results ◽  
Rt Pcr ◽  
Diagnostic Pcr ◽  
Pcr Assays ◽  
Pcr Test ◽  
False Negative Test

Containment strategies and clinical management of coronavirus disease (COVID-19) patients during the current pandemic depend on reliable diagnostic PCR assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we compare 11 different RT-PCR test systems used in seven diagnostic laboratories in Germany in March 2020. While most assays performed well, we identified detection problems in a commonly used assay that may have resulted in false-negative test results during the first weeks of the pandemic.

scholarly journals Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 730
Author(s):  
Magda Rybicka ◽  
Ewa Miłosz ◽  
Krzysztof Piotr Bielawski
Keyword(s):  
Mass Spectrometry ◽  
Gold Standard ◽  
Viral Genome ◽  
False Negative ◽  
Rt Pcr ◽  
Rna Detection ◽  
Maldi Tof ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Test

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

scholarly journals Performance of Unobserved Self-Collected Nasal Swabs for Detection of SARS-CoV-2 by RT-PCR Utilizing a Remote Specimen Collection Strategy

2021 ◽  
Author(s):  
Ron M Kagan ◽  
Amy A Rogers ◽  
Gwynngelle A Borillo ◽  
Nigel J Clarke ◽  
Elizabeth M Marlowe
Keyword(s):  
Return To Work ◽  
Screening Program ◽  
False Negative ◽  
N Gene ◽  
Rt Pcr ◽  
Pooled Testing ◽  
Specimen Collection ◽  
Asymptomatic Patients ◽  
Nasal Swabs ◽  
The Impact

Abstract Background The use of a remote specimen collection strategy employing a kit designed for unobserved self-collection for SARS-CoV-2 RT-PCR can decrease the use of PPE and exposure risk. To assess the impact of unobserved specimen self-collection on test performance, we examined results from a SARS-CoV-2 qualitative RT-PCR test for self-collected specimens from participants in a return-to-work screening program and assessed the impact of a pooled testing strategy in this cohort. Methods Self-collected anterior nasal swabs from employee return to work programs were tested using the Quest Diagnostics SARS-CoV-2 RT-PCR EUA. The Ct values for the N1 and N3 N-gene targets and a human RNase P (RP) gene control target were tabulated. For comparison, we utilized Ct values from a cohort of HCP-collected specimens from patients with and without COVID-19 symptoms. Results Among 47,923 participants, 1.8% were positive. RP failed to amplify for 13/115,435 (0.011%) specimens. The median (IQR) Cts were 32.7 (25.0-35.7) for N1 and 31.3 (23.8-34.2) for N3. Median Ct values in the self-collected cohort were significantly higher than those of symptomatic, but not asymptomatic patients. Based on Ct values, pooled testing with 4 specimens would have yielded inconclusive results in 67/1,268 (5.2%) specimens but only a single false-negative result. Conclusions Unobserved self-collection of nasal swabs provides adequate sampling for SARS-CoV-2 RT-PCR testing. These findings alleviate concerns of increased false negatives in this context. Specimen pooling could be used for this population as the likelihood of false negative results is very low due when using a sensitive, dual-target methodology.

Death and COVID-19 Anxiety in Home-Quarantined Individuals Aged 65 and Over During the Pandemic

2021 ◽  
pp. 003022282110598
Author(s):  
Hümeyra Aslaner ◽  
Betül Özen ◽  
Zeliha K. Erten ◽  
Mebrure Beyza Gökçek
Keyword(s):  
Polymerase Chain Reaction ◽  
Death Anxiety ◽  
Short Form ◽  
Anxiety Score ◽  
Test Results ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Test Result ◽  
Pcr Test

Urgent measures were taken for those at the age of 65 and over who were at the risk group all over the world due to the COVID-19 pandemic. It is known that many individuals at the age of 65 and over have experienced anxiety due to the uncertainties. This study aimed to determine the anxiety and death anxiety in individuals aged 65 and over who were isolation at home due to being diagnosed with COVID-19 or being in contact during the pandemic process. The study is descriptive and cross-sectional. It was performed with 656 home-quarantined individuals aged between 65–80 years with positive or negative real-time polymerase chain reaction (RT-PCR) test result. A form including questions about the death anxiety and the Coronavirus Anxiety Scale Short Form prepared by the researchers were administered to the individuals by phone call. Of the participants, 49.5% were male. Median COVID-19 anxiety score was 4 (0–18). Anxiety scores of the male and female participants were similar. Participants with negative polymerase chain reaction (PCR) results and those with death anxiety had higher COVID anxiety scores. Death anxiety has increased by 1.661 times in male gender, 1.983 times in RT-PCR positivity and 0.146 times in the presence of symptoms. Individuals with positive COVID-19 test results or those aged 65 and over who had death anxiety and negative COVID-19 test result but who were in home-isolation due to being a contact had higher anxiety score. For this reason, those with death anxiety can be supported in line with their religious beliefs to reduce anxiety. Those with negative PCR test results in quarantine can be adequately informed about the COVID-19.

Accuracy of Computed Tomography for Detection of COVID-19 among Suspected Patients

2021 ◽  
Vol 15 (9) ◽  
pp. 2474-2476
Author(s):  
Maham Munir Awan ◽  
Afshan Noreen ◽  
Farah Kalsoom ◽  
Muhammad Tahir ◽  
Umaima Majeed ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Predictive Value ◽  
Gold Standard ◽  
Radiology Department ◽  
True Positive ◽  
Test Results ◽  
Rt Pcr ◽  
Radiological Society ◽  
Medical University ◽  
Pcr Test

Objective: To determine the accuracy of CT chest in diagnosis of COVID-19 taking RT-PCR-testing as gold standard. Materials and Methods: A total of 150 patients of suspicion of COVID-19 who were referred for CT Chest in Radiology Department of Nishtar Medical University Multan from June-2020 to May-2021 were included. In all patients, two RT-PCR test results were obtained with 7 days of admission in hospital. Presence of any of these positive was labelled as COVID-19 infection. CT chest was performed in all patients within 2 days of admission in hospital using 128 slices CT scan machine. The diagnosis of COVID-19 infection was made according to the recommendations by Radiological Society of North America (RSNA) protocol. Results: Mean age was 51.3±14.7 years. 78 (52%) patients were male and 72 (48%) patients were female. RTPCR test was positive in 89 (59.3%) patients. While the CT chest findings were suggestive of COVID-19 infection in 130 (86.7%) patients. The sensitivity of CT chest was 95.5%, specificity 26.2%, PPV wad 65.4% and NPV was 80.0%. Conclusion: CT chest has a very good sensitivity for detection of COVID-19, it can be used as a rapid diagnostic tool especially in areas of pandemic. However, the specificity of CT chest is low, that can limit its use in low COVID-19 affected areas. Keywords: COVID-19, Computed tomography, False Positive, True Positive, Positive Predictive Value, Negative Predictive Value.

DIAGNOSTIC ROLE OF CHEST CT USING CO-RADS CATEGORIZATION IN SARS-COV-2 INFECTION WITH EMPHASIS ON IMPACT OF CT IN PATIENTS WITH DELAYED OR NEGATIVE INITIAL RTPCR TEST

2021 ◽  
pp. 51-52
Author(s):  
Tharani Putta ◽  
Kaushik Deconda
Keyword(s):  
Diagnostic Performance ◽  
Virus Disease ◽  
Vital Role ◽  
Chest Ct ◽  
Lung Involvement ◽  
Test Results ◽  
Rt Pcr ◽  
Diagnostic Role ◽  
Pcr Test

BACKGROUND AND OBJECTIVE: Role of chest CT in diagnosis of corona virus disease 2019 (COVID-19) has been controversial. The purpose of this study is to evaluate the diagnostic performance of chest CT when utilizing COVID-19 Reporting and Data System (CO-RADS). METHODOLOGY: Retrospective study including consecutive patients with positive SARS-CoV-2 RT-PCR test (initial or repeat test) and chest CT done in our institute between June and September 2020. Spectrum of CT ndings, CO-RADS score and 25 point CT severity score (CTSS) were recorded. RESULTS: A total of 300 consecutive patients with SARS-CoV-2 infection were included in the analysis. Out of the 168 patients who underwent CT prior to positive RT-PCR result, 125 (74.4%) had CO-RADS 3, 4 or 5 score on chest CT. 32 study patients (10.6%) had initial negative RT-PCR of which 24 (75%) had CO-RADS 4 or 5 score. Of the total patients with CO-RADS 3 to 5 score (227), 20 (8.8%) had severe lung involvement (CTSS 18-25), 83 (36.6%) had moderate lung involvement (CTSS 8-17) and 124 (54.6%) had mild lung involvement (CTSS 1-7). The mean CTSS was 7.9 with mean lobar score being higher in lower lobes (RLL=1.82, LLL=1.78) compared to the upper and middle lobes (RUL=1.61, RML=1.19, LUL=1.53). CONCLUSION:CT using CO-RADS scoring system has good diagnostic performance. In addition to assessing disease severity, it plays a vital role in triage of patients with suspected COVID-19 especially when there is limited availability of SARS-CoV-2 RT-PCR tests, delay in RT-PCR test results or in negative RT-PCR cases when there is high index of clinical suspicion.

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