scholarly journals SARS-CoV-2 RT-PCR test results across symptomatic COVID-19 cases in Auckland, New Zealand, February–June 2020

2021 ◽  
Vol 45 ◽  
Author(s):  
Kevin Howe ◽  
Michael Hale ◽  
Gary Edwin Reynolds
Keyword(s):  
New Zealand ◽  
Symptom Onset ◽  
Detection Rate ◽  
Test Results ◽  
Rt Pcr ◽  
Negative Results ◽  
Positive Detection Rate ◽  
Auckland Region ◽  
Pcr Test

During the first wave of COVID-19 transmission in New Zealand, a review of RT-PCR testing in all symptomatic cases reported in the Auckland Region found 74% of test results to have been positive. Detection rate was superior for nasopharyngeal swabs than for oropharyngeal samples, and highest one week after symptom onset. Certain symptom presentations may associate with these cases returning negative results, with dyspnoea reported by a greater proportion of cases who tested negative.

scholarly journals Persistent infection with SARS-CoV-2 – first direct evidence

2020 ◽  
Author(s):  
Tao Liu ◽  
Huangheng Tao ◽  
Jianping Peng ◽  
Fuling Zhou ◽  
Tongzu Liu ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Persistent Infection ◽  
Direct Evidence ◽  
Test Results ◽  
Rt Pcr ◽  
Persistent Infections ◽  
Pcr Test

Abstract Whether persistent infections with SARS-CoV-2 exist is still unknown. This study reported a case with COVID-19 who still got positive RT-PCR test results for SARS-CoV-2 in his throat swabs about 4 months post symptom onset. This case is potentially the first direct evidence of persistent infection with SARS-CoV-2.

scholarly journals Positive RT-PCR test results after consecutively negative results in patients with COVID-19

2020 ◽  
Vol 52 (7) ◽  
pp. 517-519 ◽  
Author(s):  
Chao Liang ◽  
JiaTian Cao ◽  
Zilong Liu ◽  
Feng Ge ◽  
Jing Cang ◽  
...  
Keyword(s):  
Test Results ◽  
Rt Pcr ◽  
Negative Results ◽  
Pcr Test

scholarly journals Clinical characteristics and viral load dynamics of COVID-19 in a mildly or moderately symptomatic outpatient sample

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258970
Author(s):  
Amanda Caplan ◽  
Kelly W. Bates ◽  
Carla Brioni ◽  
Aileen Santos ◽  
Linda M. Sabatini ◽  
...  
Keyword(s):  
Viral Load ◽  
Symptom Onset ◽  
Clinical Characteristics ◽  
Symptom Duration ◽  
Test Results ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Antibody Tests ◽  
Pcr Test

Background Studies of outpatients with mild or moderate COVID-19 are uncommon. We studied: 1) association of symptoms with reverse transcriptase polymerase chain reaction (RT-PCR) test results; and 2) association of initial RT-PCR cycle threshold (Ct) in relation to duration of RT-PCR positivity in outpatients with mild or moderate COVID-19. Methods This was a cohort study of outpatients with confirmed COVID-19 and at least one symptom. Participants had repeat nasopharyngeal swabs and symptom checklists every 3–5 days until two consecutive RT-PCR tests were negative. RT-PCR tests were used to assess viral load. Antibody tests for COVID-19 were performed at 2 weeks, 4 weeks, and 8 weeks after symptom onset. Results Twenty-five patients (nine females) were enrolled, ranging in age from 19–58 (median age 28 years). All patients reported at least one symptom, with a median of six symptoms per patient. Symptoms persisted for 6–67 days (median duration 18 days). In all 25 patients, blood samples collected a median of 13 days after symptom onset were positive for SARS-CoV-2 antibodies in 15 (60%). After a median of 28 days following symptom onset, 23/23 patients with available samples tested positive for antibodies. The longest duration of positive RT-PCR test was 49 days from first positive PCR test (Mean = 27.4, SD = 12.5, Median = 24). Initial Ct was significantly associated with longer duration (β = -1.3, SE = 0.3, p<0.01 per 1 cycle higher) of RT-PCR positivity. Conclusions In mildly or moderately ill COVID-19 outpatients, RT-PCT tests remained positive for as long as 49 days and test positivity and symptom duration correlated with initial viral load.

scholarly journals The Issue of Recurrently Positive Patients Who Recovered From COVID-19 According to the Current Discharge Criteria: Investigation of Patients from Multiple Medical Institutions in Wuhan, China

2020 ◽  
Vol 222 (11) ◽  
pp. 1784-1788 ◽  
Author(s):  
You Zou ◽  
Bin-Ru Wang ◽  
Liu Sun ◽  
Shan Xu ◽  
Yong-Gang Kong ◽  
...  
Keyword(s):  
Test Results ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Current Discharge ◽  
Negative Results ◽  
Medical Institutions ◽  
Polymerase Chain ◽  
Discharge Criteria ◽  
Test Result ◽  
Pcr Test

Abstract The current discharge criteria for COVID-19 require that patients have 2 consecutive negative results for reverse transcription polymerase chain reaction (RT-PCR) detection. Here, we observed that recurrent positive RT-PCR test results in patients with 3 consecutive negative results (5.4%) were significantly decreased compared with those in patients with 2 consecutive negative results (20.6%); such patients reported positive RT-PCR test results within 1 to 12 days after meeting the discharge criteria. These results confirmed that many recovered patients could show a positive RT-PCR test result, and most of these patients could be identified by an additional RT-PCR test prior to discharge.

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.

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.

scholarly journals Reducing False Negative PCR Test for COVID-19

2020 ◽  
Vol 9 (3) ◽  
pp. 408-410
Author(s):  
Fatemeh Bahreini ◽  
Rezvan Najafi ◽  
Razieh Amini ◽  
Salman Khazaei ◽  
Saeid Bashirian
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
False Negative ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Creative Commons ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Test

As the SARS-CoV-2 (COVID-19) pandemic spreads rapidly, there is need for a diagnostic test with high accuracy to detect infected individuals especially those without symptoms. Real-time polymerase chain reaction (RT-PCR) is a common molecular test for diagnosing SARS-CoV-2. If some factors are not taken into consideration when performing this test, it can have a relatively large number of false negative results. In this article, we discuss important considerations that could lead to false negative test reduction. Key words: • SARS-CoV-2 • COVID-19 • Real time polymerase chain reaction • RT-PCR test • Diagnosis • False negatives • Genetics • Emerging disease   Copyright © 2020 Bahreini et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.

scholarly journals Assessing the effects of exposure to a SARS-CoV-2 re-positive patient in healthcare personnel

2020 ◽  
Author(s):  
Yoshihiko Ogawa ◽  
Koji Nishida ◽  
Iwao Gohma ◽  
Kei Kasahara ◽  
Hisakazu Yano
Keyword(s):  
Medical Center ◽  
Ethics Committee ◽  
Healthcare Personnel ◽  
Test Results ◽  
Negative Results ◽  
Active Isolation ◽  
Aerosol Exposure ◽  
Contact Exposure ◽  
Pcr Test

Abstract Objective: To evaluate whether patients with COVID-19 who have tested re-positive with the PCR test for the SARS-CoV-2 virus are infectious is a challenge in the current circumstances. A follow-up survey was conducted with healthcare personnel (HCP) who were exposed to a patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative PCR results.Results: We studied a total of 15 HCP who had contact exposures (15/15) and aerosol exposures (7/15). None of them tested positive for IgG against SARS-CoV-2 on blood examination. None of them had any symptoms during 10 days of active isolation. All PCR tests conducted using the nasopharyngeal swabs collected from the HCP on day 10 were negative. No apparent infection was found in any of the HCP who had contact exposure with and/or aerosol exposure from the patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative results of PCR tests for SARS-CoV-2.Trial Registration: No. 170, approved June 10th, 2020 by the ethics committee of Sakai City Medical Center.

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