scholarly journals Genomic epidemiology and evolutionary dynamics of respiratory syncytial virus group B in Kilifi, Kenya, 2015–17

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Everlyn Kamau ◽  
James R Otieno ◽  
Nickson Murunga ◽  
John W Oketch ◽  
Joyce M Ngoi ◽  
...  

Abstract Respiratory syncytial virus (RSV) circulates worldwide, occurring seasonally in communities, and is a leading cause of acute respiratory illness in young children. There is paucity of genomic data from purposively sampled populations by which to investigate evolutionary dynamics and transmission patterns of RSV. Here we present an analysis of 295 RSV group B (RSVB) genomes from Kilifi, coastal Kenya, sampled from individuals seeking outpatient care in nine health facilities across a defined geographical area (∼890 km2), over two RSV epidemics between 2015 and 2017. RSVB diversity was characterized by multiple virus introductions into the area and co-circulation of distinct genetic clusters, which transmitted and diversified locally with varying frequency. Increase in relative genetic diversity paralleled seasonal virus incidence. Importantly, we identified a cluster of viruses that emerged in the 2016/17 epidemic, carrying distinct amino-acid signatures including a novel nonsynonymous change (K68Q) in antigenic site ∅ in the Fusion protein. RSVB diversity was additionally marked by signature nonsynonymous substitutions that were unique to particular genomic clusters, some under diversifying selection. Our findings provide insights into recent evolutionary and epidemiological behaviors of RSVB, and highlight possible emergence of a novel antigenic variant, which has implications on current prophylactic strategies in development.

2020 ◽  
Author(s):  
Everlyn Kamau ◽  
James R. Otieno ◽  
Nickson Murunga ◽  
John W. Oketch ◽  
Joyce M. Ngoi ◽  
...  

AbstractRespiratory syncytial virus (RSV) circulates worldwide and is a leading cause of acute respiratory illness in young children. There is paucity of genomic data from purposively sampled populations by which to investigate evolutionary dynamics and transmission patterns of RSV. Here we present an analysis of 295 RSV group B genomes from Kilifi, coastal Kenya, sampled from individuals seeking outpatient care in 9 health facilities across a defined geographical area (890 km2), over 2 RSV epidemics between 2015 and 2017. RSVB diversity was characterized by multiple viral introductions into the area and co-circulation of distinct genetic groups or clusters, which transmitted and diversified locally but with varying frequency. Bayesian analyses indicated a strong spatially and temporally structured viral population suggesting extensive within-epidemic virus transmission. Phylogeographic analysis provided a strong support for epidemiological linkage from one central health facility to other facilities. Increase in relative diversity paralleled increase in seasonal viral incidence. Importantly, we identified a cluster of viruses (n=91) that emerged in the 2016/17 epidemic, carrying distinct amino-acid signatures including a novel non-synonymous change (K68Q) in antigenic site Ø in the Fusion gene. A different non-synonymous change K68N was recently associated with escape from a potent neutralizing monoclonal antibody (MEDI8897). RSVB diversity was additionally marked by signature non-synonymous substitutions that were unique to particular genomic clusters, some of which were under diversifying selection. Our findings provide insights into recent evolutionary and epidemiologic behaviors of RSV group B, and highlight possible emergence of a novel antigenic variant, which has implications on current prophylactic development strategies.


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


2001 ◽  
Vol 43 (3) ◽  
pp. 125-131 ◽  
Author(s):  
Sandra E. VIEIRA ◽  
Klaus E. STEWIEN ◽  
Divina A. O. QUEIROZ ◽  
Edison L. DURIGON ◽  
Thomas J. TÖRÖK ◽  
...  

The respiratory viruses are recognized as the most frequent lower respiratory tract pathogens for infants and young children in developed countries but less is known for developing populations. The authors conducted a prospective study to evaluate the occurrence, clinical patterns, and seasonal trends of viral infections among hospitalized children with lower respiratory tract disease (Group A). The presence of respiratory viruses in children's nasopharyngeal was assessed at admission in a pediatric ward. Cell cultures and immunofluorescence assays were used for viral identification. Complementary tests included blood and pleural cultures conducted for bacterial investigation. Clinical data and radiological exams were recorded at admission and throughout the hospitalization period. To better evaluate the results, a non- respiratory group of patients (Group B) was also constituted for comparison. Starting in February 1995, during a period of 18 months, 414 children were included- 239 in Group A and 175 in Group B. In Group A, 111 children (46.4%) had 114 viruses detected while only 5 children (2.9%) presented viruses in Group B. Respiratory Syncytial Virus was detected in 100 children from Group A (41.8%), Adenovirus in 11 (4.6%), Influenza A virus in 2 (0.8%), and Parainfluenza virus in one child (0.4%). In Group A, aerobic bacteria were found in 14 cases (5.8%). Respiratory Syncytial Virus was associated to other viruses and/or bacteria in six cases. There were two seasonal trends for Respiratory Syncytial Virus cases, which peaked in May and June. All children affected by the virus were younger than 3 years of age, mostly less than one year old. Episodic diffuse bronchial commitment and/or focal alveolar condensation were the clinical patterns more often associated to Respiratory Syncytial Virus cases. All children from Group A survived. In conclusion, it was observed that Respiratory Syncytial Virus was the most frequent pathogen found in hospitalized children admitted for severe respiratory diseases. Affected children were predominantly infants and boys presenting bronchiolitis and focal pneumonias. Similarly to what occurs in other subtropical regions, the virus outbreaks peak in the fall and their occurrence extends to the winter, which parallels an increase in hospital admissions due to respiratory diseases.


2009 ◽  
Vol 182 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Hans Fransén ◽  
Göran Sterner ◽  
Marianne Forsgren ◽  
Zdenka Heigl ◽  
Sigvard Wolontis ◽  
...  

2020 ◽  
pp. 2000714
Author(s):  
Steven J. Frey ◽  
Chad Varner ◽  
Ammar Arsiwala ◽  
Michael G. Currier ◽  
Martin L. Moore ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Gilberto González-Parra ◽  
Hana M. Dobrovolny

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age in the United States. Moreover, RSV is being recognized more often as a significant cause of respiratory illness in older adults. Although RSV has been studied both clinically and in vitro, a quantitative understanding of the infection dynamics is still lacking. In this paper, we study the effect of uncertainty in the main parameters of a viral kinetics model of RSV. We first characterize the RSV replication cycle and extract parameter values by fitting the mathematical model to in vivo data from eight human subjects. We then use Monte Carlo numerical simulations to determine how uncertainty in the parameter values will affect model predictions. We find that uncertainty in the infection rate, eclipse phase duration, and infectious lifespan most affect the predicted dynamics of RSV. This study provides the first estimate of in vivo RSV infection parameters, helping to quantify RSV dynamics. Our assessment of the effect of uncertainty will help guide future experimental design to obtain more precise parameter values.


2018 ◽  
Vol 6 (16) ◽  
pp. e00316-18 ◽  
Author(s):  
Amani Ezzeddine ◽  
Nadia Soudani ◽  
Chun Kiat Lee ◽  
Ghassan Dbaibo ◽  
Husni Elbahesh ◽  
...  

ABSTRACT We report here the complete genome sequence of a human respiratory syncytial virus (HRSV) strain obtained from an infant who presented to the emergency room with an acute respiratory illness during the 2014/2015 HRSV season in Lebanon. Analysis revealed that this virus belongs to the ON1 genotype that has recently emerged worldwide.


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