scholarly journals Duration of Viral Clearance in IDF Soldiers with Mild COVID-19

2020 ◽  
Author(s):  
Tomer Talmy ◽  
Adili Tsur ◽  
Or Shabtay
Keyword(s):  
Healthy Adult ◽  
Young Patients ◽  
Rehabilitation Center ◽  
Rt Pcr ◽  
Mild Disease ◽  
Serial Testing ◽  
Study Population ◽  
Israel Defense Forces ◽  
Isolation Period ◽  
Pcr Test

Policies determining the duration of quarantine and return to work for confirmed COVID-19 patients still lack evidence. We report our findings regarding the duration of viral RNA positivity among a cohort of young patients with mild disease. Between March 20th, 2020, and May 10th, 2020, 219 soldiers were admitted to the Israel Defense Forces Medical Corps (IDF-MC) COVID-19 rehabilitation center following a positive RT-PCR test for SARS-CoV-2. 119 of these patients, 84 (70.6%) males, 35 (29.4%) females with a median age of 21 (IQR 19-25) were classified as having mild disease and had two consecutive negative RT-PCR tests by May 10th, 2020. The median time for SARS-CoV-2 positivity in nasopharyngeal or oropharyngeal swabs in the study population was 21 days (IQR 15-27) from symptom onset, with a range of 4 to 45 days. The results of this study suggest that in young and healthy adult patients with COVID-19, the median duration of viral positivity is around three weeks. This duration is higher than previously reported in other populations. Young and healthy adults comprise much of the population workforce, and the results of this study may assist in determining the isolation period for symptomatic adults and confirmed COVID-19 patients with mild symptoms. Further studies on this topic should look to expand and determine the intervals of serial testing for confirmed patients and determine the duration of SARS-CoV-2 positivity in other populations.

scholarly journals Comparative analyses of all FDA EUA-approved rapid antigen tests and RT-PCR for COVID-19 quarantine and surveillance-based isolation

2021 ◽  
Author(s):  
Chad R. Wells ◽  
Abhishek Pandey ◽  
Seyed M. Moghadas ◽  
Burton H. Singer ◽  
Gary Krieger ◽  
...  
Keyword(s):  
Relative Effectiveness ◽  
Policy Decision ◽  
Turnaround Time ◽  
Reproductive Number ◽  
Rt Pcr ◽  
Serial Testing ◽  
Test Specificity ◽  
Tool Set ◽  
Antigen Tests ◽  
Pcr Test

AbstractRapid antigen (RA) tests are being increasingly employed to detect COVID-19 infections in quarantine and surveillance. We conducted a comparative analysis of quarantine durations, testing frequencies, and false-positive rates for all of the 18 RA tests with emergency use authorization (EUA) from the FDA, and an RT-PCR test. For each test, we employed a mathematical model of imminent infections to calculate the effective reproductive number in the context of the test used for quarantine or serial testing. We informed the model with data on test specificity, temporal diagnostic sensitivity, and COVID-19 infectiousness. Our results demonstrate that the relative effectiveness of RA and RT-PCR tests in reducing post-quarantine transmission depends on the quarantine duration and the turnaround time of testing results. For quarantines shorter than five days, RA test on entry to and on exit from quarantine reduced onward transmission more than a single RT-PCR test conducted upon exit. Conducting surveillance via serial RT-PCR testing with a 24-h turnaround time, the minimum testing frequency paired with isolation of positives that is required to suppress the effective reproduction number (RE) below one was found to be every six days. RA tests reduce RE below one when conducted at a minimum frequency that ranges from every six days to every eight days. Our analysis also highlights that the risk of onward transmission during serial testing increases with the delay in obtaining the results. These RA test-specific results are an important component of the tool set for policy decision-making, and demonstrate that judicious selection of an appropriate RA test can supply a viable alternative to RT-PCR in efforts to control the spread of disease.

scholarly journals The long-quarantined case of COVID-19 with prolonged viral shedding and intermittent fever for more than 70 days

2021 ◽  
Vol 16 (2) ◽  
pp. 79-84
Author(s):  
Eijiro Yamada ◽  
Emi Ishida ◽  
Yasuyo Nakajima ◽  
Kazuhiko Horiguchi ◽  
Shunichi Matsumoto ◽  
...  
Keyword(s):  
Japanese Woman ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Intermittent Fever ◽  
Laboratory Findings ◽  
Inflammatory Reactions ◽  
Mild Disease ◽  
Viral Shedding ◽  
Reverse Transcription Pcr ◽  
Pcr Test

A 79-year old Japanese woman was diagnosed with coronavirus disease (COVID-19), caused by SARS coronavirus 2 (SARS-CoV-2), based on a positive reverse transcription-PCR (RT-PCR) test result. Chest computed tomography revealed mild interstitial pneumonia. She had intermittent persistent inflammatory reactions with fever. Laboratory findings and RT-PCR test results showed SARS-CoV-2 positivity for more than 70 days. To the best of our knowledge, this relatively mild case has the longest duration of viral shedding recorded, as confirmed by RT-PCR analysis. This case demonstrates that the viral shedding in COVID-19 can be prolonged, even in mild disease, and highlights the difficulties in distinguishing viral shedding from SARS-CoV-2 infectivity.

A Case Series of SARS-CoV-2 RT-PCR-Positive Hospitalized Infants 60 Days of Age or Younger From 2 New York City Pediatric Emergency Departments

2021 ◽  
Vol 60 (4-5) ◽  
pp. 247-251
Author(s):  
Ameer Hassoun ◽  
Nessy Dahan ◽  
Christopher Kelly
Keyword(s):  
New York ◽  
Case Reports ◽  
Severe Disease ◽  
Case Series ◽  
Pediatric Emergency ◽  
Rt Pcr ◽  
Vulnerable Group ◽  
Mild Disease ◽  
Young Infants ◽  
Novel Coronavirus

The emergence of novel coronavirus disease-2019 poses an unprecedented challenge to pediatricians. While the majority of children experience mild disease, initial case reports on young infants are conflicting. We present a case series of 8 hospitalized infants 60 days of age or younger with coronavirus disease-2019. A quarter of these patients had coinfections (viral or bacterial). None of these infants had severe disease. Continued vigilance in testing this vulnerable group of infants is warranted.

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 The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikram rao Bollineni ◽  
Koenraad Hans Nieboer ◽  
Seema Döring ◽  
Nico Buls ◽  
Johan de Mey
Keyword(s):  
Ct Scan ◽  
Predictive Value ◽  
Ct Imaging ◽  
Chest Ct ◽  
University Hospital ◽  
Rt Pcr ◽  
Ct Findings ◽  
Epidemic Area ◽  
Chest Ct Scan ◽  
Pcr Test

Abstract Background To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. Methods From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. Results Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97–100%, 144/240), 28% (95% CI: 19–38%, 27/240), 68% (95% CI: 65–70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65–77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. Conclusion Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

scholarly journals Incorporating false negative tests in epidemiological models for SARS-CoV-2 transmission and reconciling with seroprevalence estimates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rupam Bhattacharyya ◽  
Ritoban Kundu ◽  
Ritwik Bhaduri ◽  
Debashree Ray ◽  
Lauren J. Beesley ◽  
...  
Keyword(s):  
False Negative ◽  
Population Based ◽  
Training Data ◽  
Epidemiological Models ◽  
Rt Pcr ◽  
Antibody Prevalence ◽  
Igg Antibody ◽  
False Negatives ◽  
Seir Model ◽  
Study Population

AbstractSusceptible-Exposed-Infected-Removed (SEIR)-type epidemiologic models, modeling unascertained infections latently, can predict unreported cases and deaths assuming perfect testing. We apply a method we developed to account for the high false negative rates of diagnostic RT-PCR tests for detecting an active SARS-CoV-2 infection in a classic SEIR model. The number of unascertained cases and false negatives being unobservable in a real study, population-based serosurveys can help validate model projections. Applying our method to training data from Delhi, India, during March 15–June 30, 2020, we estimate the underreporting factor for cases at 34–53 (deaths: 8–13) on July 10, 2020, largely consistent with the findings of the first round of serosurveys for Delhi (done during June 27–July 10, 2020) with an estimated 22.86% IgG antibody prevalence, yielding estimated underreporting factors of 30–42 for cases. Together, these imply approximately 96–98% cases in Delhi remained unreported (July 10, 2020). Updated calculations using training data during March 15-December 31, 2020 yield estimated underreporting factor for cases at 13–22 (deaths: 3–7) on January 23, 2021, which are again consistent with the latest (fifth) round of serosurveys for Delhi (done during January 15–23, 2021) with an estimated 56.13% IgG antibody prevalence, yielding an estimated range for the underreporting factor for cases at 17–21. Together, these updated estimates imply approximately 92–96% cases in Delhi remained unreported (January 23, 2021). Such model-based estimates, updated with latest data, provide a viable alternative to repeated resource-intensive serosurveys for tracking unreported cases and deaths and gauging the true extent of the pandemic.

scholarly journals Delayed pulmonary embolism after COVID-19 pneumonia: a case report

2020 ◽  
Author(s):  
Mohamad Kanso ◽  
Thomas Cardi ◽  
Halim Marzak ◽  
Alexandre Schatz ◽  
Loïc Faucher ◽  
...  
Keyword(s):  
Risk Factors ◽  
Intensive Care Unit ◽  
Pulmonary Embolism ◽  
Acute Pulmonary Embolism ◽  
Index Hospitalization ◽  
Rt Pcr ◽  
Moderate Severity ◽  
Respiratory Status ◽  
Case Summary ◽  
Pcr Test

Abstract Background  Since the onset of the COVID-19 pandemic, several cardiovascular manifestations have been described. Among them, venous thromboembolism (VTE) seems to be one of the most frequent, particularly in intensive care unit patients. We report two cases of COVID-19 patients developing acute pulmonary embolism (PE) after discharge from a first hospitalization for pneumonia of moderate severity. Case summary  Two patients with positive RT-PCR test were initially hospitalized for non-severe COVID-19. Both received standard thromboprophylaxis during the index hospitalization and had no strong predisposing risk factors for VTE. Few days after discharge, they were both readmitted for worsening dyspnoea due to PE. One patient was positive for lupus anticoagulant. Discussion  Worsening respiratory status in COVID-19 patients must encourage physicians to search for PE since SARS-CoV-2 infection may act as a precipitant risk factor for VTE. Patients may thus require more aggressive and longer thromboprophylaxis after COVID-19 related hospitalization.

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.

THE RELEVANCE OF RT-PCR TEST TO THE INFECTION WITH SARS-COV-2 VIRUS.

2021 ◽  
pp. 2-4
Author(s):  
Sujan Narayan Agrawal
Keyword(s):  
Rna Virus ◽  
High Sensitivity ◽  
Standard Test ◽  
Laboratory Method ◽  
Global Public Health ◽  
Rt Pcr ◽  
Mild Disease ◽  
Pathogenic Virus ◽  
Appropriate Treatment ◽  
Tract Infections

It is now a fact that the disease COVID-19 is caused by the virus SARC-CoV-2. This virus is a member of the Coronavridae family and Coronavirinae subfamily. It is an RNA virus. The outer surface of the virus has characteristic projections which are club-shaped or spiked. This gives virion a typical look like the solar corona hence the name coronavirus. These viruses primarily cause respiratory tract infections which may range from mild disease to lethal one. The recent outbreak caused by this virus has posed a great threat to global public health and is now declared a pandemic. It is of vital importance to have a rapid and accurate identication of the pathogenic virus. This will help in selecting appropriate treatment, saving people’s lives, and preventing its spread. The RT-PCR is regarded as the gold standard test for the molecular diagnosis of this viral infection. It has got high sensitivity and specicity. This review summarises the characteristics of the virus and the laboratory method of its detection by RT-PCR.

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.

Sign in / Sign up

Export Citation Format

Share Document