scholarly journals Lower nasopharyngeal viral load during the latest phase of COVID-19 pandemic in a Northern Italy University Hospital

2020 ◽  
Vol 58 (9) ◽  
pp. 1573-1577 ◽  
Author(s):  
Nicola Clementi ◽  
Roberto Ferrarese ◽  
Marco Tonelli ◽  
Virginia Amato ◽  
Sara Racca ◽  
...  
Keyword(s):  
Viral Load ◽  
Pilot Study ◽  
Pcr Amplification ◽  
Clinical Severity ◽  
University Hospital ◽  
Rt Pcr ◽  
Viral Loads ◽  
Viral Load Data ◽  
The Mean ◽  
Polymerase Chain

AbstractObjectivesA milder clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been anecdotally reported over the latest phase of COVID-19 pandemic in Italy. Several factors may contribute to this observation, including the effect of lockdown, social distancing, lower humidity, lower air pollution, and potential changes in the intrinsic pathogenicity of the virus. In this regard, the clinical severity of COVID-19 could be attenuated by mutations in SARS-CoV-2 genome that decrease its virulence, as well as by lower virus inocula.MethodsIn this pilot study, we compared the reverse transcription polymerase chain reaction (RT-PCR) amplification profile of 100 nasopharyngeal swabs consecutively collected in April, during the peak of SARS-CoV-2 epidemic, to that of 100 swabs collected using the same procedure in May.ResultsThe mean Ct value of positive samples collected in May was significantly higher than that of samples collected in the previous period (ORF 1a/b gene: 31.85 ± 0.32 vs. 28.37 ± 0.5, p<0.001; E gene: 33.76 ± 0.38 vs. 29.79 ± 0.63, p<0.001), suggesting a lower viral load at the time of sampling. No significant differences were observed between male and females in the two periods, whilst higher viral loads were found in (i) patients over 60-years old, and (ii) patients that experienced severe COVID-19 during the early stages of the pandemic.ConclusionsThis pilot study prompts further investigation on the correlation between SARS-CoV-2 load and different clinical manifestation of COVID-19 during different phases of the pandemic. Laboratories should consider reporting quantitative viral load data in the molecular diagnosis of SARS-CoV-2 infection.

Detecting SARS-CoV-2 by Realtime RT-PCR in clinical samples collected in the North of Vietnam

2021 ◽  
Vol 30 (9) ◽  
pp. 11-17
Author(s):  
Hoang Vu Mai Phuong ◽  
Ung Thi Hong Trang ◽  
Nguyen Vu Son ◽  
Le Thi Thanh ◽  
Nguyen Le Khanh Hang ◽  
...  
Keyword(s):  
Viral Load ◽  
Average Rate ◽  
Clinical Samples ◽  
Viet Nam ◽  
Rt Pcr ◽  
Ct Value ◽  
The North ◽  
Viral Load Data ◽  
The Mean ◽  
High Level

From January to August 2020, Northern Viet Nam faced a COVID-19 outbreak, up to September 2020, there were 1122 confrmed cases of SARS-CoV-2, of which 465 cases were imported from Europe, America and Asia, 657 cases were identifed domestically. A total of 30,686 samples were collected during the SARS-CoV-2 outbreak in Northern Viet Nam and examined by Real-time RT-PCR using primers and probe from Charite - Berlin protocol. This study showed the initial results of SARS-CoV-2 detection and RNA quantitative in positive samples. The positive rate was 0.8%, ranging from 0.4 to 3.5% according to collection sites. Out of 251 positive samples, the mean Ct value was 28 (IQR: 22.3-32; range 14 - 38). The positive samples had a Ct value below 30 was 68.5%, there was no signifcant difference between the Ct value of the group ≤ 30 and > 30. The mean of the RNA copies/µl was 8.4.107, (IQR: 2.29.106 - 1.83.109 RNA copies/µl, range: 1.95.103 – 4.95.1011). In the group of imported COVID-19 cases, the rate of virus at low level was 29%, an average was 56% and at high level was 15%. In the community groups, the viral load data showed that the average rate at low, intermediate and high level were 20%, 63% and 17% respectively. The proportion of high-level viral load may raise an alert to start the quarantine process to reduce the transmission of SARS-CoV-2

scholarly journals Potential Use of Antigen-Based Rapid Test for SARS-CoV-2 in Respiratory Specimens in Low-Resource Settings in Egypt for Symptomatic Patients and High-Risk Contacts

2020 ◽  
Author(s):  
Abeer Mohamed Abdelrazik ◽  
Shahira Morsy Elshafie ◽  
Hossam M Abdelaziz
Keyword(s):  
Test Performance ◽  
Healthcare Professionals ◽  
Rapid Test ◽  
University Hospital ◽  
Antigen Test ◽  
Rt Pcr ◽  
Viral Loads ◽  
Viral Transport Medium ◽  
Public Health Challenges ◽  
Polymerase Chain

Abstract Objective Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. Methods The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. Results Three hundred ten specimens from 3 categories—patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals—were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. Conclusion Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.

scholarly journals Clinical importance of reporting SARS-CoV-2 viral loads across the different stages of the COVID-19 pandemic

2020 ◽  
Author(s):  
Milo Moraz ◽  
Damien Jacot ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Laurence Senn ◽  
Gilbert Greub ◽  
...  
Keyword(s):  
Viral Load ◽  
Universal Screening ◽  
Clinical Importance ◽  
Screening Strategy ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Admission Screening ◽  
Polymerase Chain

On April 25th, corresponding to the first deconfinement phase after the end of the lockdown in Switzerland, a universal admission screening strategy for COVID-19 was introduced in our hospital. All patients, including asymptomatic patients were tested for SARS-CoV-2 by quantitative reverse transcription polymerase chain reaction (RT-PCR). In addition to a qualitative answer, providing viral load values to the RT-PCR results not only helped the clinician to evaluate the stage of the infection but addressed patient contagiousness and guided infection control decisions. Here, we discuss the importance of reporting viral load values when a shift from a symptomatic to a universal screening strategy was performed.

scholarly journals Comparison of SARS-CoV-2 viral load in saliva samples in symptomatic and asymptomatic cases

2021 ◽  
Author(s):  
Anuja Bhatta ◽  
Rebecca Henkhaus ◽  
Heather L. Fehling
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Reverse Transcription ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Gene Target ◽  
Viral Loads ◽  
Ct Value ◽  
Polymerase Chain

AbstractSARS-CoV-2 infections can be symptomatic as well as asymptomatic. In this study, we analyzed 460,814 saliva samples collected from July 2020 to January 2021 for a SARS-CoV-2-specific gene target using the FDA EUA test, CRL Rapid Response™, based on reverse transcription polymerase chain reaction (RT-PCR). We measured SARS-CoV-2 viral loads using cycle threshold (Ct) values. A total of 17,813 samples tested positive for COVID-19 using self-collected saliva samples. The Ct values ranged from 11 to 40, 91.3% distributed between 22 to 38 Ct. We then compared Ct values for symptomatic and asymptomatic cases for all positive saliva samples. A total of 8,706 cases were symptomatic with an average Ct value of 29.24, and 9,107 cases were asymptomatic with an average Ct value of 30.99. Hence, SARS-CoV-2 viral loads (Ct) in saliva samples for both symptomatic and asymptomatic cases are similar.

scholarly journals Implementing SARS-CoV-2 Rapid Antigen Testing in the Emergency Ward of a Swiss University Hospital: The INCREASE Study

2021 ◽  
Vol 9 (4) ◽  
pp. 798
Author(s):  
Giorgia Caruana ◽  
Antony Croxatto ◽  
Eleftheria Kampouri ◽  
Antonios Kritikos ◽  
Onya Opota ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
University Hospital ◽  
Lower Sensitivity ◽  
Clinical Settings ◽  
Rt Pcr ◽  
Emergency Ward ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Subjects ◽  
Antigen Testing

Following the Swiss Federal Office of Public Health (FOPH) authorization of the rapid antigen test (RAT), we implemented the use of the RAT in the emergency ward of our university hospital for patients’ cohorting. RAT triaging in association with RT-PCR allowed us to promptly isolate positive patients and save resources. Among 532 patients, overall sensitivities were 48.3% for Exdia and 41.2% for Standard Q®, PanbioTM and BD Veritor™. All RATs exhibited specificity above 99%. Sensitivity increased to 74.6%, 66.2%, 66.2% and 64.8% for Exdia, Standard Q®, PanbioTM and BD Veritor™, respectively, for viral loads above 105 copies/mL, to 100%, 97.8%, 96.6% and 95.6% for viral loads above 106 copies/mL and 100% for viral loads above 107 copies/mL. Sensitivity was significantly higher for patients with symptoms onset within four days (74.3%, 69.2%, 69.2% and 64%, respectively) versus patients with the evolution of symptoms longer than four days (36.8%, 21.1%, 21.1% and 23.7%, respectively). Among COVID-19 asymptomatic patients, sensitivity was 33%. All Immunoglobulin-A-positive patients resulted negative for RAT. The RAT might represent a useful resource in selected clinical settings as a complementary tool in RT-PCR for rapid patient triaging, but the lower sensitivity, especially in late presenters and COVID-19 asymptomatic subjects, must be taken into account.

scholarly journals Performance of the Innova SARS-CoV-2 antigen rapid lateral flow test in the Liverpool asymptomatic testing pilot: population based cohort study

BMJ ◽  
2021 ◽  
pp. n1637 ◽  
Author(s):  
Marta García-Fiñana ◽  
David M Hughes ◽  
Christopher P Cheyne ◽  
Girvan Burnside ◽  
Mark Stockbridge ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Predictive Value ◽  
High Viral Load ◽  
Test Results ◽  
Chain Reaction ◽  
Viral Loads ◽  
Flow Test ◽  
Polymerase Chain ◽  
Lateral Flow Test

Abstract Objective To assess the performance of the SARS-CoV-2 antigen rapid lateral flow test (LFT) versus polymerase chain reaction testing in the asymptomatic general population attending testing centres. Design Observational cohort study. Setting Community LFT pilot at covid-19 testing sites in Liverpool, UK. Participants 5869 asymptomatic adults (≥18 years) voluntarily attending one of 48 testing sites during 6-29 November 2020. Interventions Participants were tested using both an Innova LFT and a quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) test based on supervised self-administered swabbing at testing sites. Main outcome measures Sensitivity, specificity, and predictive values of LFT compared with RT-qPCR in an epidemic steady state of covid-19 among adults with no classic symptoms of the disease. Results Of 5869 test results, 22 (0.4%) LFT results and 343 (5.8%) RT-qPCR results were void (that is, when the control line fails to appear within 30 minutes). Excluding the void results, the LFT versus RT-qPCR showed a sensitivity of 40.0% (95% confidence interval 28.5% to 52.4%; 28/70), specificity of 99.9% (99.8% to 99.99%; 5431/5434), positive predictive value of 90.3% (74.2% to 98.0%; 28/31), and negative predictive value of 99.2% (99.0% to 99.4%; 5431/5473). When the void samples were assumed to be negative, a sensitivity was observed for LFT of 37.8% (26.8% to 49.9%; 28/74), specificity of 99.6% (99.4% to 99.8%; 5431/5452), positive predictive value of 84.8% (68.1% to 94.9%; 28/33), and negative predictive value of 93.4% (92.7% to 94.0%; 5431/5814). The sensitivity in participants with an RT-qPCR cycle threshold (Ct) of <18.3 (approximate viral loads >10 6 RNA copies/mL) was 90.9% (58.7% to 99.8%; 10/11), a Ct of <24.4 (>10 4 RNA copies/mL) was 69.4% (51.9% to 83.7%; 25/36), and a Ct of >24.4 (<10 4 RNA copies/mL) was 9.7% (1.9% to 23.7%; 3/34). LFT is likely to detect at least three fifths and at most 998 in every 1000 people with a positive RT-qPCR test result with high viral load. Conclusions The Innova LFT can be useful for identifying infections among adults who report no symptoms of covid-19, particularly those with high viral load who are more likely to infect others. The number of asymptomatic adults with lower Ct (indicating higher viral load) missed by LFT, although small, should be considered when using single LFT in high consequence settings. Clear and accurate communication with the public about how to interpret test results is important, given the chance of missing some cases, even at high viral loads. Further research is needed to understand how infectiousness is reflected in the viral antigen shedding detected by LFT versus the viral loads approximated by RT-qPCR.

scholarly journals A prospective clinical pilot study on the effects of a hydrogen peroxide mouthrinse on the intraoral viral load of SARS-CoV-2

2020 ◽  
Vol 24 (10) ◽  
pp. 3707-3713
Author(s):  
Maximilian J. Gottsauner ◽  
Ioannis Michaelides ◽  
Barbara Schmidt ◽  
Konstantin J. Scholz ◽  
Wolfgang Buchalla ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Clinical Trials ◽  
Viral Load ◽  
Pilot Study ◽  
High Risk ◽  
Infection Prevention ◽  
Healthcare Professionals ◽  
Patient Contact ◽  
Rt Pcr ◽  
Virus Culture

Abstract Objectives SARS-CoV-2 is mainly transmitted by inhalation of droplets and aerosols. This puts healthcare professionals from specialties with close patient contact at high risk of nosocomial infections with SARS-CoV-2. In this context, preprocedural mouthrinses with hydrogen peroxide have been recommended before conducting intraoral procedures. Therefore, the aim of this study was to investigate the effects of a 1% hydrogen peroxide mouthrinse on reducing the intraoral SARS-CoV-2 load. Methods Twelve out of 98 initially screened hospitalized SARS-CoV-2-positive patients were included in this study. Intraoral viral load was determined by RT-PCR at baseline, whereupon patients had to gargle mouth and throat with 20 mL of 1% hydrogen peroxide for 30 s. After 30 min, a second examination of intraoral viral load was performed by RT-PCR. Furthermore, virus culture was performed for specimens exhibiting viral load of at least 103 RNA copies/mL at baseline. Results Ten out of the 12 initially included SARS-CoV-2-positive patients completed the study. The hydrogen peroxide mouthrinse led to no significant reduction of intraoral viral load. Replicating virus could only be determined from one baseline specimen. Conclusion A 1% hydrogen peroxide mouthrinse does not reduce the intraoral viral load in SARS-CoV-2-positive subjects. However, virus culture did not yield any indication on the effects of the mouthrinse on the infectivity of the detected RNA copies. Clinical relevance The recommendation of a preprocedural mouthrinse with hydrogen peroxide before intraoral procedures is questionable and thus should not be supported any longer, but strict infection prevention regimens are of paramount importance. Trial registration German Clinical Trials Register (ref. DRKS00022484)

scholarly journals Olfactory and Gustatory Dysfunctions as a Clinical Manifestation of Coronavirus Disease 2019 in a Malaysian Tertiary Center

2020 ◽  
pp. 000348942096316 ◽  
Author(s):  
Kuganathan Ramasamy ◽  
Jeyasakthy Saniasiaya ◽  
Norhaslinda Abdul Gani
Keyword(s):  
Nasal Obstruction ◽  
Telephone Interview ◽  
Complete Recovery ◽  
Sudden Onset ◽  
Olfactory Dysfunction ◽  
Rt Pcr ◽  
Younger Age ◽  
Tertiary Center ◽  
The Mean ◽  
Polymerase Chain

Objective: To investigate the prevalence of olfactory and gustatory dysfunction among patients with COVID-19 infection and the recovery rate. Methods: Adult patients (≥18 years) tested positive for COVID-19 via reverse transcription-polymerase chain reaction (RT-PCR) and admitted in Hospital Tuanku Ja’afar Seremban, Malaysia, were recruited in this study. Patients completed a questionnaire via telephone interview comprising the following details: age, sex, ethnicity, comorbidities, general and otorhinolaryngological symptoms, onset and duration of olfactory and gustatory dysfunction. Patients with persistent olfactory and gustatory dysfunction at the time of the initial interview were followed-up every 3 to 5 days till resolution. Results: A total of 145 patients were included in our study. The mean age of patients was 43.0 ± 17.7 (range: 18-86). Fever (44.1%) and cough (39.3%) were the most prevalent general symptoms. Thirty-one patients (21.4%) reported olfactory dysfunction and 34 (23.4%) reported dysgeusia. There was a significant association between both olfactory and gustatory dysfunction ( P < .001). Altered sense of smell or taste occurred before other symptoms in 7 (15.9%); concomitant in 16 (36.4%) and after in 15 (34.1%). Six patients (13.6%) reported isolated sudden-onset anosmia. The median duration of olfactory and gustatory dysfunctions was 7 days. Complete recovery was achieved for 70.5% of the patients within 7 days of symptom onset. Only 6 (19.4%) of the 31 patients with olfactory dysfunction experienced nasal obstruction or rhinorrhea. Olfactory dysfunction was not significantly associated with nasal obstruction or rhinorrhea. Olfactory dysfunction was significantly associated with younger age ( P = .002), female ( P = .011), and hyperlipidemia ( P = .012). Gustatory dysfunction was significantly associated with fever ( P = .019) and cough ( P = .039). Conclusion: Olfactory and gustatory dysfunction is a pertinent manifestation of COVID-19. Most of the affected patients achieve rapid and complete recovery. Sudden onset of olfactory and gustatory dysfunction should be recognized as a major symptom of COVID-19 as we implore to contain this pandemic.

scholarly journals Persistent Detection and Infectious Potential of SARS-CoV-2 Virus in Clinical Specimens from COVID-19 Patients

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1384
Author(s):  
Michael Zapor
Keyword(s):  
Pcr Amplification ◽  
World Health ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Distinctive Features ◽  
Clinical Specimens ◽  
Polymerase Chain ◽  
Health Organization ◽  
Infectious Potential ◽  
Infective Potential

The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) that emerged in December 2019 as the causative agent of Coronavirus 2019 (COVID-19) and was declared a pandemic by the World Health Organization in March 2020 has several distinctive features, including extensive multiorgan involvement with a robust systemic inflammatory response, significant associated morbidity and mortality, and prolonged persistence of viral RNA in the clinical specimens of infected individuals as detected by Reverse Transcription Polymerase Chain Reaction (RT-PCR) amplification. This review begins with an overview of SARS-CoV-2 morphology and replication and summarizes what is known to date about the detection of the virus in nasal, oropharyngeal, and fecal specimens of patients who have recovered from COVID-19, with a focus on the factors thought to contribute to prolonged detection. This review also provides a discussion on the infective potential of this material from asymptomatic, pre-symptomatic, and convalescing individuals, to include a discussion of the relative persistence and infectious potential of virus in clinical specimens recovered from pediatric COVID-19 patients.

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