ABSTRACT
The efforts to prevent respiratory syncytial virus (RSV) infection in infants span over half a century. RSV vaccine development began in the 1960s, and it confronted a significant disappointment after testing a formalin-inactivated RSV (FI RSV) vaccine candidate. This inactivated RSV vaccine was not protective. A large number of the vaccinated RSV-naive children, when subsequently exposed to natural RSV infection from wild-type virus in the community, developed severe lung inflammation termed enhanced respiratory disease. This resulted in a halt in RSV vaccine development. In the 1990s, attention turned to the potential for passive protection against severe RSV disease with immunoglobulin administration. This led to studies on using standard intravenous immunoglobulins in high-risk infants, followed by high-titer RSV immunoglobulin preparation and, subsequently, the development of RSV monoclonal antibodies. Over the past 25 years, palivizumab has been recognized as a safe and effective monoclonal antibody as a prevention strategy for RSV in high-risk children. Its high cost and need for monthly administration, however, has hindered its use to ~2% of the birth cohort, neglecting the vast majority of newborns, including healthy full-term infants who comprise the largest portion of RSV hospitalizations and the greatest part of the burden of RSV disease. Still these efforts, helped pave the way for the present advances in RSV prevention that hold promise for mitigating severe RSV disease for all infants.
Subject(s)
Immunization, Passive , Palivizumab , Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus Vaccines , Respiratory Syncytial Virus Infections/prevention & control , Respiratory Syncytial Virus Infections/history , Humans , Respiratory Syncytial Virus Vaccines/immunology , Respiratory Syncytial Virus Vaccines/therapeutic use , Respiratory Syncytial Virus Vaccines/administration & dosage , History, 20th Century , Immunization, Passive/methods , Palivizumab/therapeutic use , History, 21st Century , Infant , Respiratory Syncytial Virus, Human/immunology , Vaccines, Inactivated/immunology , Vaccine Development , Antiviral Agents/therapeutic use , Antiviral Agents/administration & dosage , Immunoglobulins, Intravenous/therapeutic use , Antibodies, Monoclonal/therapeutic useSubject(s)
Respiratory Syncytial Virus Infections/prevention & control , Respiratory Syncytial Virus Vaccines , Respiratory Syncytial Virus, Human/immunology , Vaccine Development , Aged , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/isolation & purification , Clinical Trials as Topic/history , History, 20th Century , History, 21st Century , Humans , Infant , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus Infections/mortality , Respiratory Syncytial Virus Vaccines/adverse effects , Respiratory Syncytial Virus Vaccines/history , United States/epidemiology , Vaccine Development/history , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/immunology , Viral Proteins/chemistry , Viral Proteins/immunology , Viral Proteins/ultrastructureABSTRACT
Two main mechanisms contribute to the continuous evolution of influenza viruses: accumulation of mutations in the hemagglutinin and neuraminidase genes (antigenic drift) and genetic re-assortments (antigenic shift). Epidemiological surveillance is important in identifying new genetic variants of influenza viruses with potentially increased pathogenicity and transmissibility. In order to characterize the 2019/20 influenza epidemic in Romania, 1042 respiratory samples were collected from consecutive patients hospitalized with acute respiratory infections in the National Institute for Infectious Diseases "Prof. Dr. Matei BalÈ", Bucharest Romania and tested for influenza A virus, influenza B virus and respiratory syncytial virus (RSV) by real-time PCR. Out of them, 516 cases were positive for influenza, with relatively equal distribution of influenza A and B. Two patients had influenza A and B co-infection and 8 patients had influenza-RSV co-infection. The most severe cases, requiring supplemental oxygen administration or intensive care, and the most deaths were reported in patients aged 65 years and over. Subtyping showed the predominance of A(H3N2) compared to A(H1N1)pdm09 pdm09 (60.4% and 39.6% of all subtyped influenza A isolates, respectively), and the circulation of Victoria B lineage only. Influenza B started to circulate first (week 47/2019), with influenza A appearing slightly later (week 50/2019), followed by continued co-circulation of A and B viruses throughout the season. Sixty-eight samples, selected to cover the entire influenza season and all circulating viral types, were analysed by next generation sequencing (NGS). All A(H1N1)pdm09 sequences identified during this season in Romania were clustered in the 6b1.A clade (sub-clades: 6b1.A.183P -5a and 6b1.A.187A). For most A(H1N1)pdm09 sequences, the dominant epitope was Sb (pepitope = 0.25), reducing the vaccine efficacy by approximately 60%. According to phylogenetic analysis, influenza A(H3N2) strains circulating in this season belonged predominantly to clade 3C.3A, with only few sequences in clade 3C.2A1b. These 3C.2A1b sequences, two of which belonged to vaccinated patients, harbored mutations in antigenic sites leading to potential reduction of vaccine efficacy. Phylogenetic analysis of influenza B, lineage Victoria, sequences showed that the circulating strains belonged to clade V1A3. As compared to the other viral types, fewer mutations were observed in B/Victoria strains, with limited impact on vaccine efficiency based on estimations.
Subject(s)
Epidemics , Hospitalization , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H3N2 Subtype/genetics , Influenza B virus/genetics , Influenza, Human/epidemiology , Influenza, Human/history , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Viruses/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Coinfection , Female , History, 21st Century , Humans , Infant , Infant, Newborn , Influenza Vaccines/therapeutic use , Influenza, Human/prevention & control , Influenza, Human/virology , Male , Middle Aged , Phylogeny , RNA, Viral/genetics , Respiratory Syncytial Virus Infections/virology , Romania/epidemiology , Vaccine Efficacy , Young AdultABSTRACT
Respiratory syncytial virus (RSV) causes seasonal respiratory infection, with hospitalization rates of up to 50% in high-risk infants. Palivizumab provides safe and effective, yet costly, immunoprophylaxis. The American Academy of Pediatrics (AAP) recommends palivizumab only for high-risk infants and only during the RSV season. Outside of Florida, the current guidelines do not recommend regional adjustments to the timing of the immunoprophylaxis regimen. Our hypothesis is that adjusting the RSV prophylaxis regimen in Connecticut based on spatial variation in the timing of RSV incidence can reduce the disease burden compared to the current AAP-recommended prophylaxis regimen. We obtained weekly RSV-associated hospital admissions by ZIP-code in Connecticut between July 1996 and June 2013. We estimated the fraction of all Connecticut RSV cases occurring during the period of protection offered by immunoprophylaxis ("preventable fraction") under the AAP guidelines. We then used the same model to estimate protection conferred by immunoprophylaxis regimens with alternate start dates, but unchanged duration. The fraction of RSV hospitalizations preventable by the AAP guidelines varies by county because of variations in epidemic timing. Prophylaxis regimens adjusted for state- or county-level variation in the timing of RSV seasons are superior to the AAP-recommended regimen. The best alternative strategy yielded a preventable fraction of 95.1% (95% CI 94.7-95.4%), compared to 94.1% (95% CI 93.7-94.5%) for the AAP recommendation. In Connecticut, county-level recommendations would provide only a minimal additional benefit while adding complexity. Initiating RSV prophylaxis based on state-level data may improve protection compared with the AAP recommendations.
Subject(s)
Public Health Surveillance , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/prevention & control , Respiratory Syncytial Virus, Human , Connecticut/epidemiology , Geography, Medical , History, 20th Century , History, 21st Century , Humans , Incidence , Practice Guidelines as Topic , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus Infections/virology , SeasonsABSTRACT
Human respiratory syncytial virus (RSV) is the most common cause of upper and lower respiratory tract infections in infants and young children. It is actively evolving under environmental and herd immunity influences. This work presents, for the first time, sequence variability analysis of RSV G gene and G protein using St. Petersburg (Russia) isolates. Viruses were isolated in a cell culture from the clinical samples of 61 children hospitalized (January-April 2014) with laboratory-confirmed RSV infection. Real-time RT-PCR data showed that 56 isolates (91.8%) belonged to RSV-A and 5 isolates (8.2%) belonged to RSV-B. The G genes were sequenced for 27 RSV-A isolates and all of them belonged to genotype ON1/GA2. Of these RSV-A, 77.8% belonged to the ON1(1.1) genetic sub-cluster, and 14.8% belonged to the ON1(1.2) sub-cluster. The ON1(1.3) sub-cluster constituted a minor group (3.7%). Many single-amino acid substitutions were identified in the G proteins of St. Petersburg isolates, compared with the Canadian ON1/GA2 reference virus (ON67-1210A). Most of the amino acid replacements were found in immunodominant B- and T-cell antigenic determinants of G protein. These may affect the antigenic characteristics of RSV and influence the host antiviral immune response to currently circulating viruses.
Subject(s)
Genetic Variation , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/physiology , Viral Envelope Proteins/genetics , Genotype , History, 21st Century , Humans , Phylogeny , Public Health Surveillance , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/isolation & purification , Russia/epidemiology , Sequence Analysis, DNA , Viral Envelope Proteins/metabolismSubject(s)
Bronchiolitis/history , Critical Care/history , Pulmonary Medicine/history , Bronchiolitis/virology , Female , History, 20th Century , History, 21st Century , Humans , Infant , Infant, Newborn , Male , Respiratory Syncytial Virus Infections/complications , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial VirusesABSTRACT
Respiratory Syncytial Virus (RSV) is the most common cause of respiratory tract infection in infants and children and shows increasing trend among elderly people worldwide. In many developing country settings, population and household structures have gone through some significant changes in the past decades, namely fewer births, more elderly population, and smaller household size but more RSV high-risk individuals. These dynamics have been captured in a mathematical model with RSV transmission dynamics to predict the disease burden on the detailed population for future targeted interventions. The population and disease dynamics model was constructed and tested against the hospitalization data for Acute Lower Respiratory Tract Infection due to RSV in rural Thai settings between 2005 and 2011. The proportion of extended families is predicted to increase by about 10% from 2005 to 2020, especially for those with elderly population, while the classic nuclear family type (with adults and children) will decline by about 10%. For RSV, infections from extended family type (approximately 60% of all household types) have majorly contributed to the force of infection (FOI). While the model predicted the increase of FOI from the extended family by 15% from 2005 to 2020, the FOI contributed by other household types would be either stable or decrease in the same time period. RSV incidence rate is predominantly high among babies (92.2%) and has been predicted to decrease slightly over time (from 940 to 864 cases per 100,000 population by 2020), while the incidence rates among children and elderly people may remain steadily low over the same period. However, the estimated incidence rates among elderly people were twice than those in children. The model predicts that approximately 60% of FOI for RSV will come from members of the extended family type. The incidence rate of RSV among children and elderly in extended families was about 20 times lower than that in infants and the trend is steady. Targeted intervention strategies, such as health education in some specific groups and targeted vaccination, may be considered, with the focus on extended family type. Target interventions on babies can lessen the transmission to children and elderly especially when transmission within households of extended family type is high.
Subject(s)
Models, Theoretical , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus, Human , Adolescent , Adult , Child , Child, Preschool , Female , History, 21st Century , Hospitalization , Humans , Incidence , Male , Middle Aged , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus Infections/transmission , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/physiology , Seasons , Thailand/epidemiology , Young AdultABSTRACT
During July 2007-June 2015, we enrolled 4,225 hospitalized children with pneumonia in a study to determine the seasonality of respiratory syncytial virus (RSV) infection in Beijing, China. We defined season as the period during which >10% of total PCRs performed each week were RSV positive. We identified 8 distinctive RSV seasons. On average, the season onset occurred at week 41 (mid-October) and lasted 33 weeks, through week 20 of the next year (mid-May); 97% of all RSV-positive cases occurred during the season. RSV seasons occurred 3-5 weeks earlier and lasted ≈6 weeks longer in RSV subgroup A-dominant years than in RSV subgroup B-dominant years. Our analysis indicates that monitoring such RSV subgroup shifts might provide better estimates for the onset of RSV transmission. PCR-based tests could be a flexible or complementary way of determining RSV seasonality in locations where RSV surveillance is less well-established, such as local hospitals throughout China.
Subject(s)
Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human , Seasons , Adolescent , Adult , Beijing/epidemiology , Child , Child, Preschool , Female , History, 21st Century , Hospitalization , Humans , Infant , Infant, Newborn , Male , Middle Aged , Patient Outcome Assessment , Population Surveillance , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/isolation & purification , Risk Factors , Young AdultABSTRACT
From 2011 through 2016, we conducted surveillance for severe respiratory illness in infants. Human immunodeficiency virus exposure significantly increased the risk of respiratory syncytial virus (RSV)-associated hospitalization in infants aged <5 months. More than 60% of RSV-associated hospitalizations occurred in the first 4 months of life and may be preventable through maternal vaccination or birth-dose monoclonal antibody.
Subject(s)
Coinfection , HIV Infections/epidemiology , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human , Female , HIV Infections/virology , History, 21st Century , Hospitalization , Humans , Infant , Infant, Newborn , Male , Mass Screening , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus Infections/history , Severity of Illness Index , South Africa/epidemiologyABSTRACT
A study was conducted to investigate the circulation of HRSV subgroup B (HRSVB) in China in recent years. HRSVB sequences from 365 samples collected in 1991, 2004 and 2008-2014 in China, together with 332 Chinese HRSVB sequences obtained from GenBank were analyzed to determine the geographic and yearly distribution of HRSVB. Phylogenetic analysis revealed these HRSVB sequences clustered into 4 genotypes with different frequencies: BA (83%), CB1 (11%), SAB (3.0%) and GB3 (0.7%). Between 2005 and 2013, there was a co-circulation of BA and non-BA genotypes in China. Genotypes BA9 and BA10 were two of the main BA genotypes detected in this study. Genotype BA9 was first detected in China in 2006 and became the predominant HRSVB genotype circulating in China from 2008 to 2014. Three different lineages were detected for both genotypes BA9 and BA10. Time to the most recent common ancestor for genotypes BA9 and BA10 was estimated for years 1997 and 1996, respectively. Results of this study not only contribute to the understanding of the circulation pattern, but also the phylogenetic pattern and evolution of HRSVB in China from 1991 to 2014.
Subject(s)
Genetic Variation , Genotype , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , China/epidemiology , Evolution, Molecular , Geography , History, 21st Century , Humans , Phylogeny , Phylogeography , Respiratory Syncytial Virus Infections/history , Sequence Analysis, RNAABSTRACT
In February 2012, the novel respiratory syncytial virus (RSV) group A, genotype ON1, was detected in Kilifi County, coastal Kenya. ON1 is characterized by a 72-nt duplication within the highly variable G gene (encoding the immunogenic attachment surface protein). Cases were diagnosed through surveillance of pneumonia in children at the county hospital. Analysis of epidemiologic, clinical, and sequence data of RSV-A viruses detected over 5 RSV seasons (2010/2011 to 2014/2015) indicated the following: 1) replacement of previously circulating genotype GA2 ON1, 2) an abrupt expansion in the number of ON1 variants detected in the 2014/2015 epidemic, 3) recently accumulation of amino acid substitutions within the ON1 duplicated sequence, and 4) no clear evidence of altered pathogenicity relative to GA2. The study demonstrates the public health importance of molecular surveillance in defining the spread, clinical effects, and evolution of novel respiratory virus variants.
Subject(s)
Evolution, Molecular , Genotype , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Amino Acid Substitution , Child, Preschool , Female , Genetic Variation , History, 21st Century , Humans , Infant , Infant, Newborn , Kenya/epidemiology , Male , Odds Ratio , Phylogeny , Public Health Surveillance , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/classification , Sequence Analysis, DNA , Viral Envelope Proteins/geneticsABSTRACT
We studied the molecular evolution of the fusion protein (F) gene in the human respiratory syncytial virus subgroup A (HRSV-A). We performed time-scaled phylogenetic analyses using the Bayesian Markov chain Monte Carlo (MCMC) method. We also conducted genetic distance (p-distance), positive/negative selection, and Bayesian skyline plot analyses. Furthermore, we mapped the amino acid substitutions of the protein. The MCMC-constructed tree indicated that the HRSV F gene diverged from the bovine RSV (BRSV) gene approximately 550years ago and had a relatively low substitution rate (7.59×10(-4) substitutions/site/year). Moreover, a common ancestor of HRSV-A and -B diverged approximately 280years ago, which has since formed four distinct clusters. The present HRSV-A strains were assigned six genotypes based on F gene sequences and attachment glycoprotein gene sequences. The present strains exhibited high F gene sequence similarity values and low genetic divergence. No positive selection sites were identified; however, 50 negative selection sites were identified. F protein amino acid substitutions at 17 sites were distributed in the F protein. The effective population size of the gene has remained relatively constant, but the population size of the prevalent genotype (GA2) has increased in the last 10years. These results suggest that the HRSV-AF gene has evolved independently and formed some genotypes.
Subject(s)
Evolution, Molecular , Mutation Rate , Phylogeny , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/genetics , Viral Fusion Proteins/genetics , Amino Acid Substitution , Animals , Bayes Theorem , Cattle , Gene Expression , Genetic Variation , Genotype , History, 16th Century , History, 18th Century , Humans , Markov Chains , Models, Molecular , Molecular Epidemiology , Monte Carlo Method , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/classificationABSTRACT
Human respiratory syncytial virus (HRSV) is the most common viral pathogen causing lower respiratory infections in infants and young children worldwide. HRSV ON1 genotype in subgroup A with a characteristic of a 72 nucleotide duplication in the second highly variable region of attachment glycoprotein gene, has been reported in some countries since it was first detected in clinical samples collected in Canada in 2010. In this study, 557 HRSV antigen-positive nasopharyngeal aspirates were randomly selected during 2012/2013 to 2013/2014 HRSV seasons in Beijing for subgroup typing and for ON1 genotype screening by using a PCR based method developed for easily identifying genotype ON1 out of strains of subtype A. It was found that subgroup B was dominant in the 2012/2013 season and sudden shift of subgroup dominance from B to A and rapid replacement of previously prevailing NA1 genotype by ON1 genotype occurred in the 2013/2014 season. Reversible amino acid replacement in the G protein gene was found in a new branch of ON1 genotype. The evolutionary rate of the 351 global ON1 sequences was estimated to 7.34 × 10(-3) nucleotide substitutions per site per year (95% highest probability density intervals, HPD, 5.71 × 10(-3) to 9.04 × 10(-3)), with the time of most recent common ancestor dating back to June 2009.
Subject(s)
Genotype , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Amino Acid Sequence , Beijing/epidemiology , Evolution, Molecular , History, 21st Century , Humans , Molecular Sequence Data , Phylogeny , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/classification , Seasons , Sequence Alignment , Sequence Analysis, DNA , Viral Envelope Proteins/geneticsABSTRACT
We estimated deaths attributable to influenza and respiratory syncytial virus (RSV) among persons >5 years of age in South Africa during 1998-2009 by applying regression models to monthly deaths and laboratory surveillance data. Rates were expressed per 100,000 person-years. The mean annual number of seasonal influenza-associated deaths was 9,093 (rate 21.6). Persons >65 years of age and HIV-positive persons accounted for 50% (n = 4,552) and 28% (n = 2,564) of overall seasonal influenza-associated deaths, respectively. In 2009, we estimated 4,113 (rate 9.2) influenza A(H1N1)pdm09-associated deaths. The mean of annual RSV-associated deaths during the study period was 511 (rate 1.2); no RSV-associated deaths were estimated in persons >45 years of age. Our findings support the recommendation for influenza vaccination of older persons and HIV-positive persons. Surveillance for RSV should be strengthened to clarify the public health implications and severity of illness associated with RSV infection in South Africa.
Subject(s)
HIV Infections/epidemiology , Influenza, Human/epidemiology , Respiratory Syncytial Virus Infections/epidemiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Child , Child, Preschool , Coinfection , Female , HIV Infections/history , History, 20th Century , History, 21st Century , Humans , Infant , Infant, Newborn , Influenza, Human/history , Influenza, Human/mortality , Male , Middle Aged , Mortality , Orthomyxoviridae , Population Surveillance , Prevalence , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus Infections/mortality , Respiratory Syncytial Virus, Human , Risk , South Africa/epidemiology , Young AdultABSTRACT
Human respiratory syncytial virus (HRSV) of genus Pneumovirus is one of the most common pathogens causing severe acute lower respiratory tract infection in infants and children. No information on the genotype distribution of HRSV is available in East China (e.g. Shanghai). From August 2009 to December 2012, 2407 nasopharyngeal swabs were collected from outpatient children with fever and respiratory symptoms in Shanghai. HRSV infection was determined using a multiplex RT-PCR assay. The second hypervariable region (HVR2) of G protein gene of HRSV was amplified and sequenced from HRSV positive samples. Genotypes were characterized by phylogenetic analyses. Of 2407 nasopharyngeal samples, 184 (7.6%) were tested as HRSV positive. From 160 positive subjects with sufficient nasopharyngeal samples, 69 HVR2 sequences were obtained by RT-PCR and sequencing. Three HRSV epidemic seasons were observed from August 2009 to December 2012, and an extreme outbreak of HRSV occurred in the 2009-2010 epidemic season. A genotype shift of predominant HRSV strains from B group in the 2009-2010 epidemic season to group A in the subsequent epidemic seasons was observed. Ten HRSV genotypes, including four group A genotypes NA1, NA3, NA4, and ON1, and six group B genotypes BA9, BA10, SAB4, CB1, BAc, and BA?, were detected in Shanghai. Seven genotypes (NA1, BA9-10, SAB4, CB1, BAc and BA?) were found in the 2009-2010 epidemic season. The co-circulation of multiple genotypes was associated with the extreme outbreak of HRSV among children with fever and respiratory symptoms in the 2009-2010 epidemic season.
Subject(s)
Genetic Variation , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Adolescent , Child , Child, Preschool , China/epidemiology , Disease Outbreaks , Female , Fever , Genotype , History, 21st Century , Humans , Infant , Infant, Newborn , Male , Molecular Sequence Data , Phylogeny , Prevalence , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/isolation & purificationABSTRACT
Human respiratory syncytial virus (HRSV) is the main cause of severe respiratory illness in young children and elderly people. We investigated the genetic characteristics of the circulating HRSV subgroup A (HRSV-A) to determine the distribution of genotype ON1, which has a 72-nucleotide duplication in attachment G gene. We obtained 456 HRSV-A positive samples between October 2008 and February 2013, which were subjected to sequence analysis. The first ON1 genotype was discovered in August 2011 and 273 samples were identified as ON1 up to February 2013. The prevalence of the ON1 genotype increased rapidly from 17.4% in 2011-2012 to 94.6% in 2012-2013. The mean evolutionary rate of G protein was calculated as 3.275 × 10(-3) nucleotide substitution/site/year and several positively selected sites for amino acid substitutions were located in the predicted epitope region. This basic and important information may facilitate a better understanding of HRSV epidemiology and evolution.
Subject(s)
Genotype , Mutation , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Viral Fusion Proteins/genetics , Amino Acid Sequence , Child , Child, Preschool , Epitopes/chemistry , Epitopes/immunology , Evolution, Molecular , Female , History, 21st Century , Humans , Infant , Male , Molecular Sequence Data , Phylogeny , Prevalence , Republic of Korea , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/immunology , Respiratory Syncytial Virus, Human/isolation & purification , Seasons , Selection, Genetic , Sequence AlignmentABSTRACT
RSV is the leading cause of lower respiratory-tract infections in infants and therefore demands in-depth epidemiological characterization. We investigated here the distribution of RSV types in Israel between the years 2005-2012. Clinical samples were collected from 11,018 patients hospitalized due to respiratory illnesses and were evaluated for the presence of various respiratory viruses, including RSV A and RSV B. Until 2008, each year was characterized by the presence of one dominant type of RSV. However, from 2008, both RSV A and B types were detected at significant levels, particularly among infants aged 0-2 years. Furthermore, significant changes in the RSV A and RSV B subtypes circulating in Israel since 2008 were observed. Finally, we demonstrate that, irrespectively of the changes observed in RSV epidemiology, when the pandemic H1N1pdm09 influenza virus appeared in 2009, RSV infections were delayed and were detected when infection with H1N1pdm09 had declined.
Subject(s)
Phylogeny , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Viruses/genetics , Base Sequence , Cluster Analysis , DNA Primers/genetics , History, 21st Century , Humans , Israel/epidemiology , Molecular Sequence Data , RNA, Viral/genetics , Respiratory Syncytial Virus Infections/history , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, RNASubject(s)
Giant Cells/pathology , Respiratory Syncytial Virus Infections/history , Respiratory Syncytial Viruses/physiology , Animals , Giant Cells/virology , History, 20th Century , Humans , Pan troglodytes/virology , Respiratory Syncytial Virus Infections/pathology , Respiratory Syncytial Virus Infections/virologyABSTRACT
From 1989 to 2011 in Kuala Lumpur, Malaysia, multiple genotypes from both respiratory syncytial virus (RSV) subgroups were found co-circulating each year. RSV-A subgroup predominated in 12 out of 17years with the remaining years predominated by RSV-B subgroup. Local RSV strains exhibited temporal clustering with RSV strains reported in previous epidemiological studies. Every few years, the existing predominant genotype was replaced by a new genotype. The RSV-A genotypes GA2, GA5 and GA7 were replaced by NA1 and NA2, while BA became the predominant RSV-B genotype. A unique local cluster, BA12, was seen in 2009, and the recently-described ON1 genotype with 72-nt duplication emerged in 2011. Our findings will have important implications for future vaccine intervention.