Viral Load in Blood Is Correlated with Disease Severity of Neonatal Coxsackievirus B3 Infection: Early Diagnosis and Predicting Disease Severity Is Possible in Severe Neonatal Enterovirus Infection

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.

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Adenovirus viremia may predict adenovirus pneumonia severity in immunocompetent children

BMC Infectious Diseases ◽

10.1186/s12879-021-05903-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ruimu Zhang ◽

Hongmei Wang ◽

Shufeng Tian ◽

Jikui Deng

Keyword(s):

Risk Factors ◽

Viral Load ◽

Disease Severity ◽

Mycoplasma Pneumoniae ◽

Quantitative Polymerase Chain Reaction ◽

Univariate Analysis ◽

Clinical Manifestations ◽

Pneumonia Severity ◽

Adenovirus Pneumonia ◽

Blood Viral Load

Abstract Background Previous studies have demonstrated an association between adenovirus viremia and disease severity in immunocompromised children. However, few studies have focused on this association in immunocompetent children. This study explored the association between adenovirus viremia and adenovirus pneumonia severity in immunocompetent children. Methods We performed a retrospective, observational study of immunocompetent children with adenovirus pneumonia admitted to Shenzhen Children’s Hospital in Shenzhen, China. Pneumonia was classified as severe or mild based on the Chinese guideline for the classification of pneumonia severity. Serum samples from all the children included in the study were tested for adenovirus DNA with a quantitative polymerase chain reaction. Clinical manifestations, laboratory examinations, and disease severity were compared between children with severe and mild pneumonia. Results A total of 111 immunocompetent children with adenovirus pneumonia (60 severe, 51 mild) were included. The median age was 40 months, and 64 patients were male. Five patients were admitted to the intensive care unit, and two underwent endotracheal intubation. All patients were discharged after recovery or improvement. Univariate analysis and binary logistic regression analysis showed that leukocytosis (OR = 1.1; 95% CI: 1.0 to 1.2; P = 0.033), co-infection with Mycoplasma pneumoniae (OR = 5.0; 95% CI: 2.1 to 12.3; P < 0.001), and high blood viral load (OR = 1.5; 95% CI: 1.2 to 2.0; P = 0.001) may be risk factors for severe adenovirus pneumonia. Conclusions Leukocytosis, co-infection with Mycoplasma pneumoniae, and high blood viral load may be risk factors for severe adenovirus pneumonia in immunocompetent children. Blood viral load may predict pneumonia severity.

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Viral Load Dynamics and Clinical Disease Severity in Infants With Respiratory Syncytial Virus Infection

The Journal of Infectious Diseases ◽

10.1093/infdis/jiy655 ◽

2018 ◽

Vol 219 (8) ◽

pp. 1207-1215 ◽

Cited By ~ 23

Author(s):

Cristina Garcia-Mauriño ◽

Melissa Moore-Clingenpeel ◽

Jessica Thomas ◽

Sara Mertz ◽

Daniel M Cohen ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Virus Infection ◽

Disease Severity ◽

Respiratory Syncytial Virus Infection ◽

Clinical Disease ◽

Syncytial Virus

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The Characterization of Disease Severity Associated IgG Subclasses Response in COVID-19 Patients

Frontiers in Immunology ◽

10.3389/fimmu.2021.632814 ◽

2021 ◽

Vol 12 ◽

Author(s):

Huanle Luo ◽

Tingting Jia ◽

Jiamin Chen ◽

Shike Zeng ◽

Zengzhao Qiu ◽

...

Keyword(s):

Viral Load ◽

Disease Severity ◽

Young Patients ◽

Neutralizing Antibody ◽

Igg Subclasses ◽

Nasopharyngeal Swab ◽

Obvious Effect ◽

Old Patients ◽

Biological Sex ◽

Specific Igg

Increasing evidence suggests that dysregulated immune responses are associated with the clinical outcome of coronavirus disease 2019 (COVID-19). Nucleocapsid protein (NP)-, spike (S)-, receptor binding domain (RBD)- specific immunoglobulin (Ig) isotypes, IgG subclasses and neutralizing antibody (NAb) were analyzed in 123 serum from 63 hospitalized patients with severe, moderate, mild or asymptomatic COVID-19. Mild to modest correlations were found between disease severity and antigen specific IgG subclasses in serum, of which IgG1 and IgG3 were negatively associated with viral load in nasopharyngeal swab. Multiple cytokines were significantly related with antigen-specific Ig isotypes and IgG subclasses, and IL-1β was positively correlated with most antibodies. Furthermore, the old patients (≥ 60 years old) had higher levels of chemokines, increased NAb activities and SARS-CoV-2 specific IgG1, and IgG3 responses and compromised T cell responses compared to the young patients (≤ 18 years old), which are related with more severe cases. Higher IgG1 and IgG3 were found in COVID-19 patients with comorbidities while biological sex had no effect on IgG subclasses. Overall, we have identified diseases severity was related to higher antibodies, of which IgG subclasses had weakly negative correlation with viral load, and cytokines were significantly associated with antibody response. Further, advancing age and comorbidities had obvious effect on IgG1 and IgG3.

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Saliva viral load is a dynamic unifying correlate of COVID-19 severity and mortality

10.1101/2021.01.04.21249236 ◽

2021 ◽

Author(s):

Julio Silva ◽

Carolina Lucas ◽

Maria Sundaram ◽

Benjamin Israelow ◽

Patrick Wong ◽

...

Keyword(s):

Viral Load ◽

Disease Severity ◽

T Cell Subsets ◽

Temporal Association ◽

Strongly Correlated ◽

Immunological Parameters ◽

Viral Loads ◽

Patient Demographics ◽

Over Time

While several clinical and immunological parameters correlate with disease severity and mortality in SARS-CoV-2 infection, work remains in identifying unifying correlates of coronavirus disease 2019 (COVID-19) that can be used to guide clinical practice. Here, we examine saliva and nasopharyngeal (NP) viral load over time and correlate them with patient demographics, and cellular and immune profiling. We found that saliva viral load was significantly higher in those with COVID-19 risk factors; that it correlated with increasing levels of disease severity and showed a superior ability over nasopharyngeal viral load as a predictor of mortality over time (AUC=0.90). A comprehensive analysis of immune factors and cell subsets revealed strong predictors of high and low saliva viral load, which were associated with increased disease severity or better overall outcomes, respectively. Saliva viral load was positively associated with many known COVID-19 inflammatory markers such as IL-6, IL-18, IL-10, and CXCL10, as well as type 1 immune response cytokines. Higher saliva viral loads strongly correlated with the progressive depletion of platelets, lymphocytes, and effector T cell subsets including circulating follicular CD4 T cells (cTfh). Anti-spike (S) and anti-receptor binding domain (RBD) IgG levels were negatively correlated with saliva viral load showing a strong temporal association that could help distinguish severity and mortality in COVID-19. Finally, patients with fatal COVID-19 exhibited higher viral loads, which correlated with the depletion of cTfh cells, and lower production of anti-RBD and anti-S IgG levels. Together these results demonstrated that viral load – as measured by saliva but not nasopharyngeal — is a dynamic unifying correlate of disease presentation, severity, and mortality over time.

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A Randomized, Placebo-Controlled, Respiratory Syncytial Virus Human Challenge Study of the Antiviral Efficacy, Safety, and Pharmacokinetics of RV521, an Inhibitor of the RSV-F Protein

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01884-19 ◽

2019 ◽

Vol 64 (2) ◽

Cited By ~ 9

Author(s):

John DeVincenzo ◽

Dereck Tait ◽

John Efthimiou ◽

Julie Mori ◽

Young-In Kim ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Adverse Events ◽

Disease Severity ◽

Controlled Trial ◽

Primary Analysis ◽

Double Blind ◽

Challenge Virus ◽

F Protein ◽

Syncytial Virus

ABSTRACT Effective treatments for respiratory syncytial virus (RSV) infection are lacking. Here, we report a human proof-of-concept study for RV521, a small-molecule antiviral inhibitor of the RSV-F protein. In this randomized, double-blind, placebo-controlled trial, healthy adults were challenged with RSV-A Memphis-37b. After infection was confirmed (or 5 days after challenge virus inoculation), subjects received RV521 (350 mg or 200 mg) or placebo orally every 12 h for 5 days. The primary endpoint was area under the curve (AUC) for viral load, as assessed by reverse transcriptase quantitative PCR (RT-qPCR) of nasal wash samples. The primary efficacy analysis set included subjects successfully infected with RSV who received ≥1 dose of study drug. A total of 66 subjects were enrolled (n = 22 per group); 53 were included in the primary analysis set (RV521 350 mg: n = 16; 200 mg: n = 18; placebo: n = 19). The mean AUC of RT-qPCR-assessed RSV viral load (log10 PFU equivalents [PFUe]/ml · h) was significantly lower with RV521 350 mg (185.26; standard error [SE], 31.17; P = 0.002) and 200 mg (224.35; SE, 37.60; P = 0.007) versus placebo (501.39; SE, 86.57). Disease severity improved with RV521 350 mg and 200 mg versus placebo (P = 0.002 and P = 0.009, respectively, for AUC total symptom score [score × hours]). Daily nasal mucus weight was significantly reduced (P = 0.010 and P = 0.038 for RV521 350 mg and 200 mg, respectively, versus placebo). All treatment-emergent adverse events were grade 1 or 2. No subjects discontinued due to adverse events. There was no evidence of clinically significant viral resistance, and only three variants were detected. RV521 effectively reduced RSV viral load and disease severity in humans and was well tolerated. (This study has been registered at ClinicalTrials.gov under registration no. NCT03258502.)

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A41 Deep sequencing of respiratory syncytial virus links viral diversity to disease severity

Virus Evolution ◽

10.1093/ve/vez002.040 ◽

2019 ◽

Vol 5 (Supplement_1) ◽

Author(s):

Inne Nauwelaers ◽

Tiina Talts ◽

Monica Galiano ◽

Peter Openshaw

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Disease Severity ◽

Illumina Sequencing ◽

Likelihood Method ◽

Evolutionary Analysis ◽

Viral Loads ◽

Ct Value ◽

A Genome ◽

Syncytial Virus

Abstract Respiratory syncytial virus (RSV) is a common virus that can cause bronchiolitis in infants and pneumonia in immunocompromised and elderly people. RSV belongs to the Pneumoviridae family and consists of a genome of 15 kb. Its genome contains ten genes that code for eleven proteins, with M2 coding for two different proteins in overlapping open reading frames. It is unclear why some infected children have severe disease and others have mild or asymptomatic disease. In this project, methods for complete genome sequencing of RSV via Sanger and Illumina MiSeq platforms were optimized. One hundred and twenty-four community samples (59 RSV A and 65 RSV B) from 2014 to 2018 were collected (in collaboration with the Royal College of General Practitioners) and sequenced. Samples were selected based on viral load (e.g. Ct values had to be < 30). The genotype of each sample was determined by constructing phylogenetic trees with reference sequences from all genotypes. Trees were reconstructed using the maximum likelihood method. Furthermore, Illumina sequencing was used to deep sequence seven community samples and four hospital samples that were spatiotemporally matched (obtained via Imperial College NHS Trust hospitals). Variants were studied to investigate if certain variants influence disease severity (e.g. cause mild (community samples) or severe infection (hospital samples)). Analysis so far showed that ON1 (with a seventy-two nucleotide duplication in attachment protein G) is the most common genotype in both community and hospitalized samples (90% and 75% of samples, respectively), with GA2 (without duplication) as the next most common genotype for RSV A subtypes (7% and 25%). Three per cent of community samples were of the GA5 genotype. Samples from the RSV B subgroup all belong to the BA genotypes with a 60-nucleotide duplication in G. Samples that were selected for Illumina sequencing had a Ct value between 19.0 and 29.1, while hospital samples had a Ct value of 18.3 to 29.1. Viral load, therefore, did not explain disease severity in these selected samples. The Shannon entropy from Illumina sequenced samples averaged at 22.78 in community samples (ranges from 15 to 28) and 38.78 in hospitalized samples (ranges from 31 to 57). This indicated that diversity of the virus pool might influence disease severity; however, more samples need to be analyzed. There are no specific variants that could explain disease severity. Diversity of the virus pool could explain the link between higher viral loads and disease severity, which is sometimes found but cannot always be confirmed. Higher viral loads can harbor more diverse viral particles compared to lower viral loads. Future work will focus on more in-depth variation and diversity analysis and on evolutionary analysis of both community and hospital samples. We will also investigate intra-host evolution of RSV in acute infections using consecutive samples and its possible implications on the host response.

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Correlation of Cytomegalovirus (CMV) Disease Severity and Mortality With CMV Viral Burden in CMV-Seropositive Donor and CMV-Seronegative Solid Organ Transplant Recipients

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz003 ◽

2019 ◽

Vol 6 (2) ◽

Cited By ~ 11

Author(s):

Jacqueline M McBride ◽

Daniel Sheinson ◽

Jenny Jiang ◽

Nicholas Lewin-Koh ◽

Barbara G Werner ◽

...

Keyword(s):

Viral Load ◽

Disease Severity ◽

Quantitative Polymerase Chain Reaction ◽

Solid Organ Transplantation ◽

Area Under The Curve ◽

World Health ◽

Solid Organ ◽

Transplant Recipients ◽

Viral Burden ◽

Cmv Disease

Abstract Background The rate of cytomegalovirus (CMV) viral load increase and peak viral loads are associated with CMV disease in kidney and liver transplant recipients, but relationships to disease severity or mortality have not been shown. Methods Using stored serial serum specimens from renal (n = 59) and liver (n = 35) transplant recipients (D+R-; CMV-seropositive donors, CMV-seronegative recipients) from 2 prospective, randomized, controlled, interventional prophylaxis trials of CMV immune globulin (CMVIG), CMV viral load was measured using the COBAS quantitative polymerase chain reaction assay and the World Health Organization CMV standard. Patients with severe CMV-associated disease were classified according to trial definitions. Pairwise comparisons of mean viral load among deceased, surviving diseased, and nondiseased patients were analyzed by 2-way analysis of variance. To determine if viral load could predict mortality, receiver operating characteristic (ROC) curves were constructed using area under the curve (AUC) of the viral load and peak viral concentration (Vmax). Results Viral load (mean log10 [AUC], peak viral load [Vmax]) for patients with severe CMV disease was significantly higher compared with nondiseased patients (P < .001). Similarly, higher viral burden was significantly associated with mortality (P < .001). Viral load AUC and Vmax AUROCs for predicting mortality were 0.796 and 0.824, respectively, for renal patients, and 0.769 and 0.807, respectively, for liver patients. Conclusions Using specimens from studies preceding the antiviral prophylaxis era, CMV viral load was associated with severe CMV disease and death, supporting CMV viral load quantification as a proxy for CMV disease severity and disease-associated mortality end points in solid organ transplantation.

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