scholarly journals Relationships between Viral Load and the Clinical Course of COVID-19

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 304
Author(s):  
Hiroyuki Tsukagoshi ◽  
Daisuke Shinoda ◽  
Mariko Saito ◽  
Kaori Okayama ◽  
Mitsuru Sada ◽  
...  
Keyword(s):  
Viral Load ◽  
Early Stage ◽  
Fatal Case ◽  
Epidemiological Data ◽  
High Viral Load ◽  
Viral Loads ◽  
Severe Stage ◽  
Asymptomatic Patients ◽  
Positive Rate

To predict the clinical outcome of coronavirus disease-2019 (COVID-19), we examined relationships among epidemiological data, viral load, and disease severity. We examined viral loads of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in fatal (15 cases), symptomatic/survived (133 cases), and asymptomatic cases (138 cases) using reverse transcription quantitative real-time PCR (RT-qPCR). We examined 5768 nasopharyngeal swabs (NPS) and attempted to detect the SARS-CoV-2 genome using RT-qPCR. Among them, the viral genome was detected using the method for the 370 NPS samples with a positive rate of 6.4%. A comparison of each age showed that the fatal case was higher than the survived case and asymptomatic patients. Survived cases were older than asymptomatic patients. Notably, the viral load in the fatal cases was significantly higher than in symptomatic or asymptomatic cases (p < 0.05). These results suggested that a high viral load of the SARS-CoV-2 in elderly patients at an early stage of the disease results in a poor outcome. We should, therefore, intervene early to prevent a severe stage of the disease in such cases.

Detection of SARs CoV-2 during initial phase of pandemic from population of banas kantha district of Gujarat-India with special emphasis on pooled samples

2021 ◽  
Vol 7 (4) ◽  
pp. 295-299
Author(s):  
Hiren Patel ◽  
Parijat N Goswami
Keyword(s):  
Viral Load ◽  
Age Groups ◽  
High Viral Load ◽  
Rt Pcr ◽  
Viral Loads ◽  
Corona Virus ◽  
Asymptomatic Patients ◽  
Care Workers ◽  
Pcr Method ◽  
Pharynx Swab

Corona virus (SARs CoV-2) has caused immense effect on morbidity and mortality of the population globally. We undertook this study as we are a part of one of the network laboratories of ICMR to test the patient’s sample by RT PCR for the ORF 1 ab gene of corona virus. : For a period of one and half months (14 April to 31 May 2020) we tested the nasopharynx and oro-pharynx swab samples sent to us in VTM from the assigned districts of Gujarat. All the samples were subjected to RT PCR method by following standard methods. Total of 9.04%(256/2833) population was positive and 4.73%(139/2833) belonged to age groups 21-40 and 2.33% (66/2833) to 41-60yrs. Above the age of 60yrs there were only 0.95% (22/2833) cases which were positive. It was advantageous to pool the samples. Out of the number of pools prepared, we reported around 80% negative and rest were positive in pools. The study also included association of viral load and infectivity. We found that 12% of the asymptomatic people and 5.1% of symptomatic individuals had high viral load. : It is seen that the incidence of Novel corona virus -19 detection by RT PCR is a reliable method and the establishment of the Ct value and infectivity of the patient to the health care workers and relatives needs to be taken care of. Also, the study presents asymptomatic patients having high viral loads being highly infective.

scholarly journals Interface Hepatitis over Grade 2 May Differentiate Chronic Inflammation Associated with CHB from NAFLD in the Early Stage

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yong-fen Zhu ◽  
Jin Wang ◽  
Jia-zhui Fang ◽  
Qiao Yang ◽  
Fang-fang Lv
Keyword(s):  
Viral Load ◽  
Chronic Inflammation ◽  
Early Stage ◽  
Antiviral Treatment ◽  
High Viral Load ◽  
Nonalcoholic Fatty Liver ◽  
Viral Loads ◽  
Pathological Characteristics ◽  
Significant Difference ◽  
Lobular Inflammation

Background. Patients with chronic hepatitis B (CHB) concomitant with nonalcoholic fatty liver disease (NAFLD) are increasing. Objectives. To identify pathological features that can be used to differentiate between chronic inflammation caused by CHB and that caused by NAFLD. Methods. Patients with CHB (n=31) needing antiviral treatment, NAFLD (n=50), or CHB-NAFLD (n=51) who underwent biopsy were retrospectively enrolled. Pathological characteristics of chronic inflammation were evaluated using the METAVIR scoring system. The rates of three pathological characteristics were first compared in patients with NAFLD and those with CHB, then compared after fibrosis matching, and were finally compared in CHB-NAFLD patients with different viral loads. Results. The rates of interface hepatitis over grade 2 and fibrosis over grade 2 were significantly higher in the CHB group than in the NAFLD group (100% vs. 4% and 80.6% vs. 22%; both P<0.0001), while no significant difference was observed in the rate of lobular inflammation over grade 2 between the two groups. After fibrosis matching, in patients with F0–2 fibrosis, the rate of interface hepatitis over grade 2 in CHB was significantly higher than that in NAFLD (100% vs. 0%; P<0.0001). In CHB-NAFLD patients with F0–2 fibrosis, the rate of interface hepatitis over grade 2 in cases with a high viral load was significantly higher than cases with a low viral load (66.6% vs. 0%; P<0.0001). The rate of lobular inflammation showed no difference between groups. Conclusion. Interface hepatitis over grade 2 can be used for the differential diagnosis of chronic inflammation associated with CHB or NAFLD in the early stage.

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 Differential Kinetics of Cycle Threshold Values during Admission by Symptoms among Patients with Mild COVID-19: A Prospective Cohort Study

2021 ◽  
Vol 18 (15) ◽  
pp. 8181
Author(s):  
Teppei Sakano ◽  
Mitsuyoshi Urashima ◽  
Hiroyuki Takao ◽  
Kohei Takeshita ◽  
Hiroe Kobashi ◽  
...  
Keyword(s):  
Cohort Study ◽  
Viral Load ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Polymerase Chain Reaction Test ◽  
Cycle Threshold ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Individuals ◽  
Chain Reaction Test

In the coronavirus disease 2019 (COVID-19) pandemic, more than half of the cases of transmission may occur via asymptomatic individuals, which makes it difficult to contain. However, whether viral load in the throat during admission is different between asymptomatic and symptomatic patients is not well known. By conducting a prospective cohort study of patients with asymptomatic or mild COVID-19, cycle threshold (Ct) values of the polymerase chain reaction test for COVID-19 were examined every other day during admission. The Ct values during admission increased more steadily in symptomatic patients and febrile patients than in asymptomatic patients, with significance (p = 0.01 and p = 0.004, respectively), although the Ct values as a whole were not significantly different between the two groups. Moreover, the Ct values as a whole were higher in patients with dysosmia/dysgeusia than in those without it (p = 0.02), whereas they were lower in patients with a headache than those without (p = 0.01). Patients who were IgG-positive at discharge maintained higher Ct values, e.g., more than 35, during admission than those with IgG-negative (p = 0.03). Assuming that viral load and Ct values are negatively associated, the viral loads as a whole and their changes by time may be different by symptoms and immune reaction, i.e., IgG-positive at discharge.

scholarly journals SARS-CoV-2 Persistence in Immunocompromised Children

2021 ◽  
Author(s):  
Susan Dolan ◽  
Jean Mulcahy Levy ◽  
Angla Moss ◽  
Kelly Pearce ◽  
Samuel Dominguez ◽  
...  
Keyword(s):  
Viral Load ◽  
Median Time ◽  
Immunosuppressive Treatment ◽  
Viral Persistence ◽  
High Viral Load ◽  
Viral Loads ◽  
Mild Disease ◽  
Kaplan Meier ◽  
Diagnostic Panel ◽  
Event Times

Introduction/Objectives: We evaluated the length of time immunocompromised children (ICC) remain positive for SARS-CoV-2, identified factors associated with viral persistence and determined cycle threshold (CT) values of children with viral persistence as a surrogate of viral load. Methods: We conducted a retrospective cohort study of ICC at a pediatric hospital from March 2020-2021. Immunocompromised status was defined as primary, secondary or acquired due to medical comorbidities/immunosuppressive treatment. The primary outcome was time to first-of-two consecutive negative SARS-CoV-2 Polymerase chain reaction (PCR) tests at least 24 hours apart. Testing of sequential clinical specimens from the same subject was conducted using the Centers for Disease Control (CDC) 2019-nCoV Real-Time RT-PCR Diagnostic Panel assay. Descriptive statistics, Kaplan-Meier curve median event times and log-rank-sum tests were used to compare outcomes between groups. Results: Ninety-one children met inclusion criteria. Median age was 15.5 years (IQR 8-18 yrs), 64% were male, 58% were white, and 43% were Hispanic/Latinx. Most (67%) were tested in outpatient settings and 58% were asymptomatic. The median time to two negative tests was 42 days (IQR 25.0,55.0), with no differences in median time by illness presentation or level of immunosuppression. Seven children had >1 sample available for repeat testing, and 5/7 (71%) children had initial CT values of <30, (moderate to high viral load); 4 children had CT values of <30 3-4 weeks later, suggesting persistent moderate to high viral loads. Conclusions: Most ICC with SARS-CoV-2 infection had mild disease, with prolonged viral persistence >6 weeks and moderate to high viral load.

scholarly journals Evaluation of saliva sampling procedures for SARS-CoV-2 diagnostics reveals differential sensitivity and association with viral load

2020 ◽  
Author(s):  
Pieter Mestdagh ◽  
Michel Gillard ◽  
Marc Arbyn ◽  
Jean-Paul Pirnay ◽  
Jeroen Poels ◽  
...  
Keyword(s):  
Viral Load ◽  
High Risk ◽  
Health Professionals ◽  
High Viral Load ◽  
Sampling Procedure ◽  
Differential Sensitivity ◽  
Collection Method ◽  
Viral Loads ◽  
Saliva Collection ◽  
Sampling Procedures

AbstractNasopharyngeal sampling has been the preferential collection method for SARS-CoV-2 diagnostics. Alternative sampling procedures that are less invasive and do not require a healthcare professional would be more preferable for patients and health professionals. Saliva collection has been proposed as such a possible alternative sampling procedure. We evaluated the sensitivity of SARS-CoV-2 testing on two different saliva collection devices (spitting versus swabbing) compared to nasopharyngeal swabs in over 2500 individuals that were either symptomatic or had high-risk contacts with infected individuals. We observed an overall poor sensitivity in saliva for SARS-CoV-2 detection (30.8% and 22.4% for spitting and swabbing, respectively). However, when focusing on individuals with medium to high viral load, sensitivity increased substantially (97.0% and 76.7% for spitting and swabbing, respectively), irrespective of symptomatic status. Our results suggest that saliva cannot readily replace nasopharyngeal sampling for SARS-CoV-2 diagnostics but may enable identification of cases with medium to high viral loads.

scholarly journals High Resolution Analysis of Respiratory Syncytial Virus Infection In Vivo

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 926 ◽  
Author(s):  
Waleed Aljabr ◽  
Stuart Armstrong ◽  
Natasha Y. Rickett ◽  
Georgios Pollakis ◽  
Olivier Touzelet ◽  
...  
Keyword(s):  
Viral Load ◽  
Respiratory Syncytial Virus ◽  
The Elderly ◽  
High Viral Load ◽  
Label Free ◽  
Respiratory Problems ◽  
Viral Loads ◽  
High Resolution Analysis ◽  
Syncytial Virus

Human respiratory syncytial virus (HRSV) is a major cause of pediatric infection and also causes disease in the elderly and those with underlying respiratory problems. There is no vaccine for HRSV and anti-viral therapeutics are not broadly applicable. To investigate the effect of HRSV biology in children, nasopharyngeal aspirates were taken from children with different viral loads and a combined high throughput RNAseq and label free quantitative proteomics approach was used to characterize the nucleic acid and proteins in these samples. HRSV proteins were identified in the nasopharyngeal aspirates from infected children, and their abundance correlated with viral load (Ct value), confirming HRSV infection. Analysis of the HRSV genome indicated that the children were infected with sub-group A virus and that minor variants in nucleotide frequency occurred in discrete clusters along the HRSV genome, and within a patient clustered distinctly within the glycoprotein gene. Data from the samples were binned into four groups; no-HRSV infection (control), high viral load (Ct < 20), medium viral load (Ct = 20–25), and low viral load (Ct > 25). Cellular proteins associated with the anti-viral response (e.g., ISG15) were identified in the nasopharyngeal aspirates and their abundance was correlated with viral load. These combined approaches have not been used before to study HRSV biology in vivo and can be readily applied to the study the variation of virus host interactions.

scholarly journals Feasibility and Effectiveness Assessment of SARS-CoV-2 Antigenic Tests in Mass Screening of a Pediatric Population and Correlation with the Kinetics of Viral Loads

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2071
Author(s):  
Marcello Lanari ◽  
Giovanni Battista Biserni ◽  
Matteo Pavoni ◽  
Eva Caterina Borgatti ◽  
Marta Leone ◽  
...  
Keyword(s):  
Viral Load ◽  
Mass Screening ◽  
Point Of Care ◽  
Pediatric Population ◽  
Late Phase ◽  
High Viral Load ◽  
Pediatric Emergency ◽  
Nucleic Acid Amplification ◽  
Baseline Sensitivity ◽  
Viral Loads

The gold standard for diagnosis of SARS-CoV-2 infection has been nucleic acid amplification tests (NAAT). However, rapid antigen detection kits (Ag-RDTs), may offer advantages over NAAT in mass screening, generating results in minutes, both as laboratory-based test or point-of-care (POC) use for clinicians, at a lower cost. We assessed two different POC Ag-RDTs in mass screening versus NAAT for SARS-CoV-2 in a cohort of pediatric patients admitted to the Pediatric Emergency Unit of IRCCS—Polyclinic of Sant’Orsola, Bologna (from November 2020 to April 2021). All patients were screened with nasopharyngeal swabs for the detection of SARS-CoV-2-RNA and for antigen tests. Results were obtained from 1146 patients. The COVID-19 Ag FIA kit showed a baseline sensitivity of 53.8% (CI 35.4–71.4%), baseline specificity 99.7% (CI 98.4–100%) and overall accuracy of 80% (95% CI 0.68–0.91); the AFIAS COVID-19 Ag kit, baseline sensitivity of 86.4% (CI 75.0–93.9%), baseline specificity 98.3% (CI 97.1–99.1%) and overall accuracy of 95.3% (95% CI 0.92–0.99). In both tests, some samples showed very low viral load and negative Ag-RDT. This disagreement may reflect the positive inability of Ag-RDTs of detecting antigen in late phase of infection. Among all cases with positive molecular test and negative antigen test, none showed viral loads > 106 copies/mL. Finally, we found one false Ag-RDTs negative result (low cycle thresholds; 9 × 105 copies/mL). Our results suggest that both Ag-RDTs showed good performances in detection of high viral load samples, making it a feasible and effective tool for mass screening in actively infected children.

scholarly journals Viral Load of SARS-CoV-2 in Respiratory Aerosols Emitted by COVID-19 Patients while Breathing, Talking, and Singing

2021 ◽  
Author(s):  
Kristen K. Coleman ◽  
Douglas Jie Wen Tay ◽  
Kai Sen Tan ◽  
Sean Wei Xiang Ong ◽  
Than The Son ◽  
...  
Keyword(s):  
Viral Load ◽  
Significant Role ◽  
N Gene ◽  
Exhaled Breath ◽  
Indoor Environments ◽  
Future Studies ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Gene Copies ◽  
Study Participants

Background: Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. However, the detailed roles of coarse (>5μm) and fine (≤5μm) respiratory aerosols produced when breathing, talking, and singing are not well-understood. Methods: Using a G-II exhaled breath collector, we measured viral RNA in coarse and fine respiratory aerosols emitted by COVID-19 patients during 30 minutes of breathing, 15 minutes of talking, and 15 minutes of singing. Results: Among the 22 study participants, 13 (59%) emitted detectable levels of SARS-CoV-2 RNA in respiratory aerosols, including 3 asymptomatic patients and 1 presymptomatic patient. Viral loads ranged from 63 - 5,821 N gene copies per expiratory activity. Patients earlier in illness were more likely to emit detectable RNA, and loads differed significantly between breathing, talking, and singing. The largest proportion of SARS-CoV-2 RNA copies was emitted by singing (53%), followed by talking (41%) and breathing (6%). Overall, fine aerosols constituted 85% of the viral load detected in our study. Virus cultures were negative. Conclusions: Fine aerosols produced by talking and singing contain more SARS-CoV-2 copies than coarse aerosols and may play a significant role in the transmission of SARS-CoV-2. Exposure to fine aerosols should be mitigated, especially in indoor environments where airborne transmission of SARS-CoV-2 is likely to occur. Isolating viable SARS-CoV-2 from respiratory aerosol samples remains challenging, and whether this can be more easily accomplished for emerging SARS-CoV-2 variants is an important enquiry for future studies.

scholarly journals SARS-CoV-2 Viral RNA Load Dynamics in the Nasopharynx of Infected Children

2020 ◽  
Author(s):  
Kai-qian Kam ◽  
Koh Cheng Thoon ◽  
Matthias Maiwald ◽  
Chia Yin Chong ◽  
Han Yang Soong ◽  
...  
Keyword(s):  
Viral Load ◽  
Early Stage ◽  
Transmission Potential ◽  
Cycle Threshold ◽  
Viral Loads ◽  
Viral Shedding ◽  
Asymptomatic Children ◽  
Peak Viral Load ◽  
Epidemiological Risk ◽  
Mean Cycle

It is important to understand the temporal trend of pediatric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load to estimate the transmission potential of children in schools and communities. We determined differences in SARS-CoV-2 viral load dynamics between nasopharyngeal samples of infected asymptomatic and symptomatic children. The daily cycle threshold values of SARS-CoV-2 in the nasopharynx of a cohort of infected children were collected for analysis. Among 17 infected children, 10 (58.8%) were symptomatic. Symptomatic children, when compared to asymptomatic children, had higher viral load (mean cycle threshold on day 7 of illness 28.6 versus 36.7, p = 0.02). Peak SARS-CoV-2 viral loads occured around days 2-3 of illness/days of diagnosis in infected children. After adjusting for the estimated date of infection, the higher SARS-CoV-2 viral loads in symptomatic children remained. We postulate that symptomatic SARS-CoV-2-infected children may have higher transmissibility than asymptomatic children. As peak viral load in infected children occurred in the early stage of illness, viral shedding and transmission in the pre-symptomatic phase probable. Our study highlights the importance of screening for SARS-CoV-2 in children with epidemiological risk factors, even when they are asymptomatic in order to improve containment of the virus in the community, including educational settings.

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