Association of Viral Load With Disease Severity in Outpatient Children With Respiratory Syncytial Virus Infection

2020 ◽  
Vol 222 (2) ◽  
pp. 298-304 ◽  
Author(s):  
Erika Uusitupa ◽  
Matti Waris ◽  
Terho Heikkinen

Abstract Background There are scarce data on whether viral load affects the severity of respiratory syncytial virus (RSV) disease in outpatient children. Methods We analyzed the association between viral load and disease severity among children who participated in a prospective cohort study of respiratory infections. The children were examined and nasal swabs for the detection of RSV were obtained during each respiratory illness. Quantification of RSV load was based on the cycle threshold (Ct) value. For the primary analysis, the children were divided into 2 groups: higher (Ct < 27) and lower viral load (Ct ≥ 27). Results Among 201 episodes of RSV infection, children with higher viral load had significantly longer median durations of rhinitis (8 vs 6 days; P = .0008), cough (8 vs 6 days; P = .034), fever (2 vs 1 days; P = .018), and any symptom (10 vs 8 days; P = .024) than those with lower viral load. There were statistically significant negative correlations between the Ct values and durations of all measured symptoms. Conclusions Our findings support the concept that viral load drives the severity of RSV disease in children. Reducing the viral load by RSV antivirals might provide substantial benefits to outpatient children.

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
John DeVincenzo ◽  
Dereck Tait ◽  
John Efthimiou ◽  
Julie Mori ◽  
Young-In Kim ◽  
...  

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.)


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S843-S843
Author(s):  
Cynthia Lucero-Obusan ◽  
Patricia Schirmer ◽  
Gina Oda ◽  
Mark Holodniy

Abstract Background Respiratory Syncytial Virus (RSV) is an increasingly recognized cause of acute respiratory illness in older adults, leading to an estimated 177,000 hospitalizations and 14,000 deaths each year in the US. In adult populations, diagnostic testing for RSV has historically been underutilized. Herein, we examine national trends in RSV testing and infection across the Veterans Affairs (VA) healthcare system. Methods Electronic RSV laboratory testing results, ICD-coded hospitalizations and outpatient encounters were obtained from VA’s Praedico Surveillance System (1/1/2010-12/31/2018). Patients were reviewed for positive results, repeat testing, and demographics. Antibody tests were excluded. Results A total of 102,251 RSV results were included. Overall, 4,372 (4.3%) specimens from 4,263 unique individuals were positive with a median age of 67 years (range 0-101) and 90% were male. 1,511 individuals (35.4%) also had an RSV-coded hospitalization. RSV type was specified for only 7.8% of positives (Table). During 2010-2018 there were 2,522 RSV-coded hospitalizations (median length of stay = 4 days) among 2,444 unique individuals, which included 413 ICU stays (16.4%) and 98 deaths (3.9%) during the RSV-coded hospitalization. Approximately 78% of RSV-coded hospitalizations within VA (excluding all non-VA hospitalizations) had a documented positive test result. A greater than 15-fold increase in RSV tests performed, hospitalizations and outpatient encounters was observed from 2010-2018, although the percent testing positive remained relatively stable (Figure, Table). Figure. Testing for Respiratory Syncytial Virus (RSV), Department of Veterans Affairs, 2010-2018. Table. Select RSV Surveillance Metrics, Department of Veterans Affairs, 2010-2018 Conclusion RSV testing and identification of patients with RSV infection increased dramatically during the time period analyzed, likely due to increased availability of PCR-based multi-pathogen panels and duplex assays. While the percentage of tests positive for RSV remained relatively stable, the rise in coded hospitalizations may be due to increased testing for RSV among hospitalized Veterans with severe respiratory infections. These surveillance data may allow for further characterization of RSV disease burden estimates which can help inform clinical management and development of interventions for adults, such as vaccines and antiviral therapies. Disclosures All Authors: No reported disclosures


Author(s):  
Ian Mitchell ◽  
Abby Li ◽  
Candice L. Bjornson ◽  
Krista L. Lanctot ◽  
Bosco A. Paes ◽  
...  

Objective This study aimed to evaluate palivizumab (PVZ) use, trends in indications, and outcomes of respiratory illness hospitalizations (RIH) and respiratory syncytial virus hospitalizations (RSVH). Study Design It involves a large, Canadian prospective (2005–2017) observational multicenter study of children at high risk for RSV infection. Results A total of 25,003 infants (56.3% male) were enrolled at 32 sites; 109,579 PVZ injections were administered. Indications included: prematurity (63.3%); “miscellaneous” (17.8%); hemodynamically significant congenital heart disease (10.5%); bronchopulmonary dysplasia/chronic lung disease (8.4%). The “miscellaneous” group increased over time (4.4% in 2005–2006 to 22.5% in 2016–2017) and included: trisomy 21, airway anomalies, pulmonary disorders, cystic fibrosis, neurological impairments, immunocompromised, cardiac aged >2 years, multiple conditions, and a residual “unclassified” group. Adherence measured by expected versus actual doses plus correct interdose interval was 64.7%. A total of 2,054 RIH occurred (6.9%); 198 (9.6%) required intubation. Three hundred thirty-seven hospitalized children were RSV-positive (overall RSVH 1.6%). Risk factors for RSVH included having siblings, attending daycare, family history of atopy, smoking exposure, and crowded household. Infants with 5 risk factors were 9.0 times (95% CI or confidence interval 4.4–18.2; p < 0.0005) more likely to have RSVH than infants without risk factors. Three adverse events occurred; none were fatal. Conclusion Results are relevant to both clinicians and decision-makers. We confirmed the safety of PVZ. Use of PVZ increased steadily for children with miscellaneous conditions and medical complexity. Medical and social factors pose a risk for severe RIH and RSVH with accompanying burden of illness. A vaccine that protects against RSV is urgently required. Key Points


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abate Yeshidinber Weldetsadik ◽  
Frank Riedel

Abstract Background Respiratory Syncytial Virus (RSV) is the commonest cause of acute lower respiratory infections (ALRI) in infants. However, the burden of RSV is unknown in Ethiopia. We aimed to determine the prevalence, seasonality and predictors of RSV infection in young infants with ALRI for the first time in Ethiopia. Methods We performed RSV immuno-chromatographic assay from nasopharyngeal swabs of infants, 29 days to 6 months of age. We included the first 10 eligible infants in each month from June 2018 to May 2019 admitted in a tertiary pediatric center. Clinical, laboratory and imaging data were also collected, and chi-square test and regression were used to assess associated factors with RSV infection. Results Among a total of 117 study children, 65% were male and mean age was 3 months. Bronchiolitis was the commonest diagnosis (49%). RSV was isolated from 26 subjects (22.2%) of all ALRI, 37% of bronchiolitis and 11% of pneumonia patients. Although RSV infection occurred year round, highest rate extended from June to November. No clinical or laboratory parameter predicted RSV infection and only rainy season (Adjusted Odds Ratio (AOR) 10.46 [95%. C.I. 1.95, 56.18]) was independent predictor of RSV infection. Conclusions RSV was isolated in a fifth of young infants with severe ALRI, mostly in the rainy season. Diagnosis of RSV infection in our setting require specific tests as no clinical parameter predicted RSV infection. Since RSV caused less than a quarter of ALRI in our setting, the other causes should be looked for in future studies.


2009 ◽  
Vol 16 (6) ◽  
pp. 816-823 ◽  
Author(s):  
Carolina Scagnolari ◽  
Fabio Midulla ◽  
Alessandra Pierangeli ◽  
Corrado Moretti ◽  
Enea Bonci ◽  
...  

ABSTRACT Given the critical role of pattern recognition receptors (PRRs) in acid nucleic recognition in the initiation of innate immunity and the orchestration of adaptive immunity, the aim of this study was to determine whether any heterogeneity of PRR expression in the airway tracts of infants with respiratory syncytial virus (RSV) infection might explain the broad clinical spectrum of RSV-associated bronchiolitis in infants. For this purpose, the levels of melanoma differentiation-associated protein-5 (MDA-5), retinoic acid inducible gene-1 (RIG-1), and Toll-like receptor 3 (TLR-3), TLR-7, TLR-8, and TLR-9 mRNAs were evaluated, using TaqMan quantitative reverse transcription-PCR, in cells from nasopharyngeal washes collected from 157 infants suffering from acute bronchiolitis whether or not they were associated with respiratory viruses. High interindividual variability was observed in both virus-positive and -negative infants; however, the relative gene expression levels of MDA-5, RIG-1, TLR-7, and TLR-8 were significantly higher in the virus-infected group, whereas the expression levels of TLR-3 and TLR-9 were not significantly different. The differences in the gene expression of MDA-5, RIG-1, TLR-7, and TLR-8 were more evident in infants with RSV infection than in those with bocavirus or rhinovirus infection. In RSV-infected infants, PRR-mRNA levels also were analyzed in relation to interferon protein levels, viral load, clinical severity, days of hospitalization, age, and body weight. A significant positive correlation was observed only between RSV viral load and RIG-1 mRNA levels. These findings provide the first direct evidence that, in infants with respiratory virus-associated bronchiolitis, especially RSV, there are substantial changes in PRR gene expression; this likely is an important determinant of the clinical outcome of bronchiolitis.


2018 ◽  
Vol 219 (8) ◽  
pp. 1207-1215 ◽  
Author(s):  
Cristina Garcia-Mauriño ◽  
Melissa Moore-Clingenpeel ◽  
Jessica Thomas ◽  
Sara Mertz ◽  
Daniel M Cohen ◽  
...  

Author(s):  
Giovanni Rossi ◽  
Stefania Ballarini ◽  
Michela Silvestri ◽  
Oliviero Sacco ◽  
Andrew Colin

The immunopathology of respiratory syncytial virus (RSV) infection, the most common cause of lower respiratory tract infections (LRTI) in the pediatric population, with severe disease being the exception. The variability of the clinical presentation is incompletely explained by host, viral and environmental factors but, in infants and young children, disease severity is certainly linked to the physiological immune immaturity. There is evidence that the maturation of the host immune response is, at least in part, promoted by the composition of the nasopharyngeal microbiome that, modulating excessive inflammation, can counteract the predisposition to develop viral respiratory infections and lower the risk of disease severity. However, interaction between the nasopharyngeal microbiota and respiratory viruses can be bidirectional. Microbial dysbiosis can drive disease pathogenesis but may also represents a reflection of the disease-induced alterations of the local milieu. Moreover, viruses like RSV, can also increase the virulence of potential pathogens in nasopharynx, which is a main reservoir of bacteria, and therefore promote their spread to the lower airways causing superinfection. Negative changes in microbial community composition in early life may constitute a heightened risk towards severe RSV respiratory infection and bacterial superinfection, whilst specific groups of microorganisms can be associated with protection. A better understanding into the potential negative and positive role of the different nasopharyngeal bacterial species in disease prevention as well as into the possible benefits of microbiome therapeutic manipulation, may improve patient outcomes.


Author(s):  
Alex Grier ◽  
Ann L Gill ◽  
Haeja A Kessler ◽  
Anthony Corbett ◽  
Sanjukta Bandyopadhyay ◽  
...  

Abstract Rationale Respiratory Syncytial Virus (RSV) is a leading cause of infant respiratory disease. Infant airway microbiota has been associated with respiratory disease risk and severity. The extent to which interactions between RSV and microbiota occur in the airway, and their impact on respiratory disease susceptibility and severity, are unknown. Objectives Characterize temporal associations between microbiota and RSV infection before, during, and after infants’ first respiratory illness. Methods 16S rRNA microbiota profiling of two infant cohorts in the first year of life: 1) a cross-sectional cohort of 89 RSV infected infants sampled during illness and 102 matched healthy controls, and 2) a matched longitudinal cohort of 12 infants who developed RSV infection and 12 who did not, sampled before, during, and after infection. Results We identified 12 taxa significantly associated with RSV infection. All 12 taxa were differentially abundant during infection, with 8 associated with disease severity. Nasal microbiota composition was more discriminative of healthy vs. infected than of disease severity. Conclusions Our findings elucidate the chronology of nasal microbiota dysbiosis and suggest an altered developmental trajectory associated with RSV infection. Microbial temporal dynamics reveal indicators of disease risk, correlates of illness and severity, and impact of RSV infection on microbiota composition.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S305-S306
Author(s):  
Li-Juan Jiang ◽  
Lisha Xu ◽  
Meng Huang ◽  
Shucha Zhang ◽  
Yang Li ◽  
...  

Abstract Background Respiratory syncytial virus (RSV) infection presents a significant health challenge in young children, elderly and immunocompromised patients. To date, there are no effective treatments available. EDP-938 was designed to meet this unmet medical need and is currently in Phase 2 clinical trials. Herein we report its preclinical pharmacokinetic (PK) and pharmacodynamic (PD) properties. Methods The pharmacokinetics of EDP-938 following single intravenous and oral doses were determined in mice, rats, dogs, and monkeys. In vitro cellular permeability and metabolic stability were assayed using Caco-2 cells and human liver microsomes, respectively. In vivo pharmacodynamic efficacy of EDP-938 was conducted in the African green monkey model, in which animals experimentally challenged with RSV were orally dosed twice daily with 100 mg/kg EDP-938 for 6 days starting 24 hours prior to infection. Results EDP-938 was well absorbed in the preclinical species with oral bioavailability values ranging from 27.1% in dogs, 35.4% in mice, 35.7% in rats, and 39.5% in monkeys, after a single oral dose when formulated in 0.5% methylcellulose. EDP-938 showed a moderate in vitro permeability of 3.6 x 10–6 cm/sec in Caco-2 cells. Based on the outcome of these absorption studies, EDP-938 was projected to have good oral absorption in humans. EDP-938 had low intrinsic clearance of 5 mL/minute/mg in human liver microsomes. Moreover, EDP-938 demonstrated potent antiviral efficacy in an African green monkey model of RSV infection. In untreated monkeys the RSV RNA viral load in the bronchoalveolar lavage fluid peaked at 106 copies/mL on day 5 post-infection, by comparison in animals treated with EDP-938 the viral load was below the limit of detection by day 3 post-infection. The PK/PD modeling suggested that plasma trough concentrations ≥10 × EC90 led to &gt;4-log viral load reduction in EDP-938 treated monkeys. Conclusion The favorable preclinical PK and PD properties of EDP-938 support its further clinical development as a novel treatment for RSV infection. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Inne Nauwelaers ◽  
Tiina Talts ◽  
Monica Galiano ◽  
Peter Openshaw

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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