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Nziza N, Jung W, Mendu M, Chen T, Julg B, Graham B, Ramilo O, Mejias A, Alter G. Longitudinal humoral analysis in RSV-infected infants identifies pre-existing RSV strain-specific G and evolving cross-reactive F antibodies. Immunity 2024:S1074-7613(24)00272-3. [PMID: 38876099 DOI: 10.1016/j.immuni.2024.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 01/16/2024] [Accepted: 05/20/2024] [Indexed: 06/16/2024]
Abstract
Respiratory syncytial virus (RSV) is among the most common causes of lower respiratory tract infection (LRTI) and hospitalization in infants. However, the mechanisms of immune control in infants remain incompletely understood. Antibody profiling against attachment (G) and fusion (F) proteins in children less than 2 years of age, with mild (outpatients) or severe (inpatients) RSV disease, indicated substantial age-dependent differences in RSV-specific immunity. Maternal antibodies were detectable for the first 3 months of life, followed by a long window of immune vulnerability between 3 and 6 months and a rapid evolution of FcγR-recruiting immunity after 6 months of age. Acutely ill hospitalized children exhibited lower G-specific antibodies compared with healthy controls. With disease resolution, RSV-infected infants generated broad functional RSV strain-specific G-responses and evolved cross-reactive F-responses, with minimal maternal imprinting. These data suggest an age-independent RSV G-specific functional humoral correlate of protection, and the evolution of RSV F-specific functional immunity with disease resolution.
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Affiliation(s)
- Nadège Nziza
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Wonyeong Jung
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Maanasa Mendu
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA; Harvard University, Cambridge, MA, USA
| | - Tina Chen
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Boris Julg
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Barney Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Octavio Ramilo
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA; Department of Pediatrics, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA.
| | - Asuncion Mejias
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA; Department of Pediatrics, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA.
| | - Galit Alter
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA.
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Generation and persistence of S1 IgG and neutralizing antibodies in post-COVID-19 patients. Infection 2021; 50:447-456. [PMID: 34668145 PMCID: PMC8525617 DOI: 10.1007/s15010-021-01705-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/22/2021] [Indexed: 11/01/2022]
Abstract
BACKGROUND Antibody-mediated immune response plays an important role in protection against reinfection. In the case of SARS-CoV-2 infection, the maximum duration of antibody response is still unknown. In this work, the generation of neutralizing antibodies (NAbs) and IgG antibodies against the S1 subunit (S1 IgG ) of SARS-CoV-2 and their possible duration were determined through decay models. METHODS 132 participants with SARS-CoV-2 infection were classified according to the severity of the disease. Seroconversion and persistence of S1 IgG antibodies and NAbs were determined by ELISA, samples were taken at two different times post-infection and duration of those antibodies was estimated using Linear Mixed Models (LMMs). RESULTS The highest amount of S1 IgGs antibodies was associated with age (41 years or older), greater severity of COVID-19 and male gender. NAbs production was associated with the same variables, except for age. The percentage of NAbs decay is higher in the asymptomatic group (P = 0.033), while in S1 IgG antibodies decay, no statistical difference was found between the 4 severity groups. An exponential decay model was built by using a LMM and similarly, two dispersion regions where constructed. The duration of S1 IgG antibodies was 744 days (668-781) for first region and 744 days (453-1231) for the second. Regarding NAbs, an adaptative LMM was used to model a logistic function, determining a duration of 267 days (215-347). CONCLUSION Humoral immunity to SARS-CoV-2 infection depends on the severity of the disease, gender and age. This immune response could be long-lasting as for other coronaviruses.
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Zhi W, Xu Q, Chen Z, Jiang W, Wang T, Zhou Y, Yu H, Yan Y, Pan T. Respiratory syncytial virus infection in children and its correlation with climatic and environmental factors. J Int Med Res 2021; 49:3000605211044593. [PMID: 34590875 PMCID: PMC8489770 DOI: 10.1177/03000605211044593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE In this study, we aimed to investigate the clinical epidemiology of lower respiratory tract infections with different respiratory syncytial virus (RSV) subtypes in hospitalized children in Suzhou and their correlation with climatic and environmental factors. METHOD In this retrospective cross-sectional study, we collected nasopharyngeal secretion samples from children hospitalized with acute lower respiratory tract infection. We collected the clinical data of children with RSV infection, and compared and analyzed their epidemiological characteristics. RESULTS RSV-B was the dominant strain in 2016. In 2018, RSV-A was the dominant strain. The positive detection rate of RSV-A was negatively correlated with monthly mean temperature, monthly mean wind speed, total monthly rainfall, and O3 concentration and positively correlated with PM2.5, PM10, and NO2, SO2, and CO concentrations. The positive detection rate of RSV-B was negatively correlated with monthly average temperature, monthly total rainfall, monthly sunshine duration, and O3 concentration and positively correlated with CO concentration. CONCLUSIONS RSV-A was the main subtype detected in this study. The positive detection rate of RSV-A was related to temperature, wind speed, rainfall, PM2.5. PM10, and NO2, SO2, CO, and O3 concentrations. The positive detection rate of RSV-B was related to temperature, rainfall, sunshine time, and O3 concentration.
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Affiliation(s)
- Wanying Zhi
- Department of Respiration, Children's Hospital of Soochow University, Suzhou, China.,Department of Pediatrics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Qiuyan Xu
- Department of Pediatrics, The Affiliated Suzhou Science & Technology Town Hospital of Nanjing Medical University, Suzhou, China.,Branch of Science and Technology Town, Children's Hospital of Soochow University, Suzhou, China
| | - Zhengrong Chen
- Department of Respiration, Children's Hospital of Soochow University, Suzhou, China
| | - Wujun Jiang
- Department of Respiration, Children's Hospital of Soochow University, Suzhou, China
| | - Ting Wang
- Department of Respiration, Children's Hospital of Soochow University, Suzhou, China
| | - Yewen Zhou
- Department of Pediatrics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Haifei Yu
- Department of Pediatrics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yongdong Yan
- Department of Respiration, Children's Hospital of Soochow University, Suzhou, China
| | - Tao Pan
- Department of Neonatology, Children's Hospital of Soochow University, Suzhou, China
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Fakunle AG, Jafta N, Okekunle AP, Naidoo RN. Indoor microbiome and risk of lower respiratory tract infections among children under-five years: A meta-analysis. INDOOR AIR 2020; 30:795-804. [PMID: 32462684 DOI: 10.1111/ina.12698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 04/03/2020] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
We investigated whether exposure to microbiome within the indoor environment is associated with risk of lower respiratory tract infections (LRTI) among children under 5 years of age. Electronic scientific repositories; PubMed, Scopus, Web of Science, GreenFILE, EMBASE, and Cochrane library were searched and screened through July 2019 for published reports for inclusion in the meta-analysis. Studies were eligible for inclusion if they reported an adjusted measure of risk for LRTI associated with IM exposure, including the relative risk (RR) or odds ratio (OR) and confidence interval (CI). The pooled OR was computed using the inverse of variance method for weighting. Sensitivity analysis was used to evaluate the effect of individual studies, while heterogeneity was evaluated by I2 statistics using RevMan 5.3. Seven studies were eligible for inclusion in our meta-analysis. Exposure to a higher concentration of IM was associated with an increased risk of LRTI [OR:1.20 (1.11, 1.33), P < .0001]. The risk was stronger with exposure to total fungal concentration [OR:1.27 (1.13, 1.44), P < .0001] than visible molds [OR:1.20 (1.07, 1.34, P = .001]. Under-five children exposed to higher IM concentration are likely at increased risk of LRTI. Interventions addressing IM exposure should be considered in the management of LRTI among under-five children.
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Affiliation(s)
- Adekunle G Fakunle
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, Durban, South Africa
- Department of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Nkosana Jafta
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, Durban, South Africa
| | - Akinkunmi P Okekunle
- Department of Epidemiology and Medical Statistics, College of Medicine, Ibadan, Nigeria
- The Postgraduate College, University of Ibadan, Ibadan, Nigeria
| | - Rajen N Naidoo
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, Durban, South Africa
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Fakunle AG, Olusola B, Jafta N, Faneye A, Heederik D, Smit LA, Naidoo RN. Home Assessment of Indoor Microbiome (HAIM) in Relation to Lower Respiratory Tract Infections among Under-Five Children in Ibadan, Nigeria: The Study Protocol. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17061857. [PMID: 32183028 PMCID: PMC7143126 DOI: 10.3390/ijerph17061857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/22/2020] [Accepted: 03/03/2020] [Indexed: 12/15/2022]
Abstract
The association between household air pollution and lower respiratory tract infections (LRTI) among children under five years of age has been well documented; however, the extent to which the microbiome within the indoor environment contributes to this association is uncertain. The home assessment of indoor microbiome (HAIM) study seeks to assess the abundance of indoor microbiota (IM) in the homes of under-five children (U-5Cs) with and without LRTI. HAIM is a hospital- and community-based study involving 200 cases and 200 controls recruited from three children’s hospitals in Ibadan, Nigeria. Cases will be hospital-based patients with LRTI confirmed by a pediatrician, while controls will be community-based participants, matched to cases on the basis of sex, geographical location, and age (±3 months) without LRTI. The abundance of IM in houses of cases and controls will be investigated using active and passive air sampling techniques and analyzed by qualitative detection of bacterial 16SrRNA gene (V3–V4), fungal ITS1 region, and viral RNA sequencing. HAIM is expected to elucidate the relationship between exposure to IM and incidence of LRTI among U-5Cs and ultimately provide evidence base for strategic interventions to curtail the burgeoning burden of LRTI on the subcontinent.
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Affiliation(s)
- Adekunle G. Fakunle
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban 4041, South Africa;
- Department of Environmental Health Sciences, Faculty of Public Health, University of Ibadan, Ibadan 200212, Nigeria
- Correspondence: (A.G.F.); (R.N.N.); Tel.: +234-90-9395-6165 (A.G.F.); +27-824-379-333 (R.N.N.)
| | - Babatunde Olusola
- Department of Virology, College of Medicine, University of Ibadan, Ibadan 200212, Nigeria; (B.O.); (A.F.)
| | - Nkosana Jafta
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban 4041, South Africa;
| | - Adedayo Faneye
- Department of Virology, College of Medicine, University of Ibadan, Ibadan 200212, Nigeria; (B.O.); (A.F.)
| | - Dick Heederik
- Institute for Risk Assessment Sciences, Environmental Epidemiology Division (IRAS-EEPI), Utrecht University, 80177 Utrecht, The Netherlands; (D.H.)
| | - Lidwien A.M. Smit
- Institute for Risk Assessment Sciences, Environmental Epidemiology Division (IRAS-EEPI), Utrecht University, 80177 Utrecht, The Netherlands; (D.H.)
| | - Rajen N. Naidoo
- Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban 4041, South Africa;
- Correspondence: (A.G.F.); (R.N.N.); Tel.: +234-90-9395-6165 (A.G.F.); +27-824-379-333 (R.N.N.)
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Okamoto M, Dapat CP, Sandagon AMD, Batangan-Nacion LP, Lirio IC, Tamaki R, Saito M, Saito-Obata M, Lupisan SP, Oshitani H. Molecular Characterization of Respiratory Syncytial Virus in Children With Repeated Infections With Subgroup B in the Philippines. J Infect Dis 2018; 218:1045-1053. [PMID: 29722817 PMCID: PMC6107742 DOI: 10.1093/infdis/jiy256] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/01/2018] [Indexed: 11/26/2022] Open
Abstract
Background Human respiratory syncytial virus (RSV) is the leading cause of severe acute respiratory infection in infants and young children, which is characterized by repeated infections. However, the role of amino acid substitutions in repeated infections remains unclear. Hence, this study aimed to elucidate the genetic characteristics of RSV in children with repeated infections using molecular analyses of F and G genes. Methods We conducted a cohort study of children younger than 5 years in the Philippines. We collected nasopharyngeal swabs from children with acute respiratory symptoms and compared F and G sequences between initial and subsequent RSV infections. Results We examined 1802 children from May 2014 to January 2016 and collected 3471 samples. Repeated infections were observed in 25 children, including 4 with homologous RSV-B reinfections. Viruses from the 4 pairs of homologous reinfections had amino acid substitutions in the G protein mostly at O-glycosylation sites, whereas changes in the F protein were identified at antigenic sites V (L173S) and θ (Q209K), considered essential epitopes for the prefusion conformation of the F protein. Conclusions Amino acid substitutions in G and F proteins of RSV-B might have led to antigenic changes, potentially contributing to homologous reinfections observed in this study.
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Affiliation(s)
- Michiko Okamoto
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Clyde P Dapat
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Ann Marie D Sandagon
- Tohoku-Research Institute for Tropical Medicine Collaborating Research Center on Emerging and Reemerging Infectious Diseases
| | | | - Irene C Lirio
- Research Institute for Tropical Medicine, Muntinlupa City, the Philippines
| | - Raita Tamaki
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Mayuko Saito
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Mariko Saito-Obata
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
- Tohoku-Research Institute for Tropical Medicine Collaborating Research Center on Emerging and Reemerging Infectious Diseases
| | - Socorro P Lupisan
- Research Institute for Tropical Medicine, Muntinlupa City, the Philippines
| | - Hitoshi Oshitani
- Department of Virology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
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Ogunsemowo O, Olaleye D, Odaibo G. Human Respiratory Syncytial Virus Subtypes A and B Infection Among Children Attending Primary and Secondary Health Care Facilities in Ibadan, Nigeria. ARCHIVES OF BASIC AND APPLIED MEDICINE 2018; 6:73-78. [PMID: 29905317 PMCID: PMC5997266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Human respiratory syncytial virus (HRSV) causes high morbidity and mortality in infants and young children. Although a high prevalence of HRSV has been reported in Nigeria, the subtype of the virus circulating in the country is not known. This crosssectional study was therefore designed to determine the subtypes of HRSV circulating among children in Ibadan. Two hundred and thirty-one nasopharyngeal and oropharyngeal swabs were collected from children presenting with respiratory infections in Secondary Health Facility (SHF) as well as those attending immunization centers in Primary Health Centers (PHCs) in Ibadan, Nigeria. Viral RNA was extracted directly from the clinical specimen and used for HRSV detection with a pair of primers that targets the conserved region of the viral matrix gene. HRSV-positive samples were subtyped using subtype-specific primers targeting the second hypervariable region of the G gene. The prevalence of HRSV infection was 8.7% and 34.6% among children attending the PHCs and SHF respectively. Both subtypes of HRSV were detected (co-circulating) among the study population. None of children was co-infected with of HRSV A and B. Overall, HRSV-A was the predominant subtype detected among children presenting with respiratory infection at the SHF while subtype B was predominant among participants attending PHCs for routine immunization. Higher disease severity scores were associated with HRSV-A infection than infection with HRSV-B. Only HRSV subtype A was detected from those diagnosed of bronchopneumonia and bronchiolitis. In conclusion, subtypes A and B co-circulating among children in Ibadan, with HRSV-A being the predominant subtype. Additional study including samples collected from other parts of the country over a longer period that will cover both wet and dry season will be done to determine the pattern of HRSV circulation in Nigeria.
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Pangesti KNA, Abd El Ghany M, Walsh MG, Kesson AM, Hill-Cawthorne GA. Molecular epidemiology of respiratory syncytial virus. Rev Med Virol 2018; 28. [PMID: 29377415 DOI: 10.1002/rmv.1968] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 01/10/2023]
Abstract
Respiratory syncytial virus (RSV) is a major cause of viral acute respiratory tract infections in young children. The virus is characterised by distinct seasonality that is dependent upon the latitude and its ability to cause reinfection. Respiratory syncytial virus demonstrates a complex molecular epidemiology pattern as multiple strains and/or genotypes cocirculate during a single epidemic. Previous studies have investigated the relationship between RSV genetic diversity, reinfection, and clinical features. Here, we review the evidence behind this relationship together with the impact that the advancement of whole genome sequencing will have upon our understanding and the need for reconsidering the classification of RSV genotypes.
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Affiliation(s)
| | - Moataz Abd El Ghany
- Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia.,Marie Bashir Institute of Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia
| | - Michael G Walsh
- Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia.,Marie Bashir Institute of Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia
| | - Alison M Kesson
- Marie Bashir Institute of Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia.,Discipline of Child and Adolescent Health, The University of Sydney, Sydney, Australia.,Department of Infectious Diseases and Microbiology, The Children's Hospital at Westmead, Sydney, Australia
| | - Grant A Hill-Cawthorne
- School of Public Health, The University of Sydney, Sydney, Australia.,Marie Bashir Institute of Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia
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Genetic diversity of human respiratory syncytial virus circulating among children in Ibadan, Nigeria. PLoS One 2018; 13:e0191494. [PMID: 29360861 PMCID: PMC5779668 DOI: 10.1371/journal.pone.0191494] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 01/06/2018] [Indexed: 11/19/2022] Open
Abstract
Human respiratory syncytial virus (HRSV) is the most common viral cause of acute lower respiratory tract infections (LRTIs) in infants and young children however, without an effective vaccine licensed for human use till date. Information on the circulating genotypes of HRSV from regions with high-burden of infection is vital in the global efforts towards the development of protective vaccine. We report here the genotypes of HRSV circulating among children in Ibadan, the first of such from Nigeria.Nasopharyngeal and oropharyngeal swabs collected from 231 children presenting with respiratory infections in some health facilities for care as well as those attending immunization centers for routine vaccination in Ibadan, Nigeria were used for the study. The 2nd hypervariable (HVR2) region of the glycoprotein (G) gene of HRSV was amplified and sequenced using HRSV group specific primers. HRSV was detected in 41 out of the 231 samples. Thirty-three of the isolates were successfully subtyped(22 subtype A and 11 subtype B). Fourteen of the subtype A and all the subtype B were successfully sequenced and genotyped. Phylogenetic analysis showed that genotype ON1 with 72 nucleotide (nt) duplication was the major subgroup A virus (11 of 14) detected together with genotype NA2. All the HRSV subtype B detected belong to the BA genotype with characteristic 60nt duplication. The ON1 genotypes vary considerably from the prototype strain due to amino acid substitutions including T292I which has not been reported elsewhere. The NA2 genotypes have mutations on four antigenic sites within the HVR2relative to the prototype A2. In conclusion, three genotypes of HRSV were found circulating in Ibadan, Nigeria. Additional study that will include isolates from other parts of the country will be done to determine the extent of genotype diversity of HRSV circulating in Nigeria.
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Walsh EE, Hall CB. Respiratory Syncytial Virus (RSV). MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7173590 DOI: 10.1016/b978-1-4557-4801-3.00160-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Molecular epidemiology and disease severity of human respiratory syncytial virus in Vietnam. PLoS One 2013; 8:e45436. [PMID: 23349659 PMCID: PMC3551923 DOI: 10.1371/journal.pone.0045436] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 08/17/2012] [Indexed: 11/19/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of acute respiratory infections (ARIs) in children worldwide and can cause high mortality, especially in developing countries. However, information on the clinical and molecular characteristics of RSV infection in developing countries is limited. From April 2010 to May 2011, 1,082 nasopharyngeal swabs were collected from children with ARI admitted to the Children's Hospital 2, Ho Chi Minh City, Vietnam. Samples were screened for RSV and genotyped by reverse transcription-PCR and sequencing. Demographic and clinical data was also recorded. RSV was found in 23.8% (257/1,082) of samples. RSV A was the dominant subgroup, accounting for 91.4% (235/257), followed by RSV B, 5.1% (13/257), and 9 cases (3.5%) were mixed infection of these subgroups. The phylogenetic analysis revealed that all group A strains belonged to the GA2 genotype. All group B strains belonged to the recently identified BA genotype, and further clustered into 2 recently described subgenotypes BA9 and BA10. One GA2 genotype strain had a premature stop codon which shortened the G protein length. RSV infection was significantly associated with younger age and higher severity score than those without. Co-infection with other viruses did not affect disease severity. RSV A caused more severe disease than RSV B. The results from this study will not only contribute to the growing database on the molecular diversity of RSV circulating worldwide but may be also useful in clinical management and vaccine development.
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12
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Melero JA, Moore ML. Influence of respiratory syncytial virus strain differences on pathogenesis and immunity. Curr Top Microbiol Immunol 2013; 372:59-82. [PMID: 24362684 DOI: 10.1007/978-3-642-38919-1_3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Molecular epidemiology studies have provided convincing evidence of antigenic and sequence variability among respiratory syncytial virus (RSV) isolates. Circulating viruses have been classified into two antigenic groups (A and B) that correlate with well-delineated genetic groups. Most sequence and antigenic differences (both inter- and intra-groups) accumulate in two hypervariable segments of the G-protein gene. Sequences of the G gene have been used for phylogenetic analyses. These studies have shown a worldwide distribution of RSV strains with both local and global replacement of dominant viruses with time. Although data are still limited, there is evidence that strain variation may contribute to differences in pathogenicity. In addition, there is some but limited evidence that RSV variation may be, at least partially, immune (antibody) driven. However, there is the paradox in RSV that, in contrast to other viruses (e.g., influenza viruses) the epitopes recognized by the most effective RSV-neutralizing antibodies are highly conserved. In contrast, antibodies that recognize strain-specific epitopes are poorly neutralizing. It is likely that this apparent contradiction is due to the lack of a comprehensive knowledge of the duration and specificities of the human antibody response against RSV antigens. Since there are some data supporting a group- (or clade-) specific antibody response after a primary infection in humans, it may be wise to consider the incorporation of strains representative of groups A and B (or their antigens) in future RSV vaccine development.
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Affiliation(s)
- José A Melero
- Unidad de Biología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain,
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13
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The incidence and clinical burden of respiratory syncytial virus disease identified through hospital outpatient presentations in Kenyan children. PLoS One 2012; 7:e52520. [PMID: 23300695 PMCID: PMC3530465 DOI: 10.1371/journal.pone.0052520] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/15/2012] [Indexed: 11/09/2022] Open
Abstract
Background There is little information that describe the burden of respiratory syncytial virus (RSV) associated disease in the tropical African outpatient setting. Methods We studied a systematic sample of children aged <5 years presenting to a rural district hospital in Kenya with acute respiratory infection (ARI) between May 2002 and April 2004. We collected clinical data and screened nasal wash samples for RSV antigen by immunofluorescence. We used a linked demographic surveillance system to estimate disease incidence. Results Among 2143 children tested, 166 (8%) were RSV positive (6% among children with upper respiratory tract infection and 12% among children with lower respiratory tract infection (LRTI). RSV was more likely in LRTI than URTI (p<0.001). 51% of RSV cases were aged 1 year or over. RSV cases represented 3.4% of hospital outpatient presentations. Relative to RSV negative cases, RSV positive cases were more likely to have crackles (RR = 1.63; 95% CI 1.34–1.97), nasal flaring (RR = 2.66; 95% CI 1.40–5.04), in-drawing (RR = 2.24; 95% CI 1.47–3.40), fast breathing for age (RR = 1.34; 95% CI 1.03–1.75) and fever (RR = 1.54; 95% CI 1.33–1.80). The estimated incidence of RSV-ARI and RSV-LRTI, per 100,000 child years, among those aged <5 years was 767 and 283, respectively. Conclusion The burden of childhood RSV-associated URTI and LRTI presenting to outpatients in this setting is considerable. The clinical features of cases associated with an RSV infection were more severe than cases without an RSV diagnosis.
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Ohuma EO, Okiro EA, Ochola R, Sande CJ, Cane PA, Medley GF, Bottomley C, Nokes DJ. The natural history of respiratory syncytial virus in a birth cohort: the influence of age and previous infection on reinfection and disease. Am J Epidemiol 2012; 176:794-802. [PMID: 23059788 PMCID: PMC3481264 DOI: 10.1093/aje/kws257] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
This study aimed to quantify the effect of age, time since last infection, and infection history on the rate of respiratory syncytial virus infection and the effect of age and infection history on the risk of respiratory syncytial virus disease. A birth cohort of 635 children in Kilifi, Kenya, was monitored for respiratory syncytial virus infections from January 31, 2002, to April 22, 2005. Predictors of infection were examined by Cox regression and disease risk by binomial regression. A total of 598 respiratory syncytial virus infections were identified (411 primary, 187 repeat), with 409 determined by antigen assay and 189 by antibody alone (using a “most pragmatic” serologic definition). The incidence decreased by 70% following a primary infection (adjusted hazard ratio = 0.30, 95% confidence interval: 0.21, 0.42; P < 0.001) and by 59% following a secondary infection (hazard ratio = 0.41, 95% confidence interval: 0.22, 0.73; P = 0.003), for a period lasting 6 months. Relative to the age group <6 months, all ages exhibited a higher incidence of infection. A lower risk of severe disease following infection was independently associated with increasing age (P < 0.001) but not reinfection. In conclusion, observed respiratory syncytial virus incidence was lowest in the first 6 months of life, immunity to reinfection was partial and short lived, and disease risk was age related.
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Affiliation(s)
- E O Ohuma
- Kenya Medical Research Institute, Centre for Geographic Medicine Research, Kilifi, Kenya.
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High frequency of repeated infections due to emerging genotypes of human respiratory syncytial viruses among children during eight successive epidemic seasons in Japan. J Clin Microbiol 2010; 49:1034-40. [PMID: 21177891 DOI: 10.1128/jcm.02132-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In eight successive seasons (2001 to 2009), a total of 726 human respiratory syncytial virus (HRSV) infections from a total of 1,560 children with acute lower respiratory tract illness were identified. Molecular analysis of the attachment (G) protein gene confirmed that 52 (7.8%) children were infected more than once with any of the 3 genotypes of HRSV-A (genotypes GA5, NA1, and NA2) and/or 6 genotypes of HRSV-B (genotypes BA4, BA5, and BA7 to BA10). Repeated infections in 46 cases (82.1%) occurred in the next season, and only one case occurred in the same season (10-day interval). First infections were 33 (63.5%) HRSV-A cases and 19 (36.5%) HRSV-B cases, whereas second infections occurred in 35 (67.3%) HRSV-A cases and 17 (32.7%) HRSV-B cases. Third infections were attributed to 4 (100.0%) HRSV-A cases. Homologous subgroup reinfections were detected in 28 cases, 23 HRSV-A cases and 5 HRSV-B cases (P = 0.005), whereas homologous genotype reinfections were detected only for 5 HRSV-A cases (2GA5 and 3NA2) but not any HRSV-B case. Heterologous subgroup reinfections were detected in 28 cases, 12 cases from HRSV-A-to-HRSV-B reinfections and 16 cases from HRSV-B-to-HRSV-A reinfections. Genotypes NA1 and NA2 had higher numbers of heterologous genotype infections than did other genotypes. Our observations suggest that repeated infections occur more frequently in HRSV-A strains than in HRSV-B strains, and heterologous genotype reinfections occur more frequently than homologous genotype reinfections, especially in the case of the emerging genotypes NA1 and NA2 of HRSV-A strains that circulated in the community during our study period.
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Murata Y, Lightfoote PM, Biear JN, Falsey AR, Walsh EE. Humoral response to the central unglycosylated region of the respiratory syncytial virus attachment protein. Vaccine 2010; 28:6242-6. [PMID: 20655403 DOI: 10.1016/j.vaccine.2010.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 07/02/2010] [Accepted: 07/02/2010] [Indexed: 10/19/2022]
Abstract
To characterize the humoral response to the unglycosylated central region of the respiratory syncytial virus (RSV) attachment (G) protein, we generated glutathione S-transferase (GST)-RSV G subdomains (central core (CC), residues 151-190; proximal central core (PCC), 151-172; and distal central core (DCC), 173-190) to screen paired sera from RSV subtype A- or B-infected adults in hospitalized or outpatient settings. Following RSV infection, a >or=4-fold increase in homo- and heterosubtypic IgG response was noted in most subjects against the RSV G CC and PCC regions; in contrast, such titer increases against the RSV G DCC was only noted in a homosubtypic manner. Our results have implications for RSV G-based serological diagnostics and vaccine development.
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Affiliation(s)
- Yoshihiko Murata
- Division of Infectious Diseases, Department of Medicine, University of Rochester School of Medicine and Dentistry and Infectious Diseases Unit, Rochester General Hospital, 601 Elmwood Avenue Box 689, Rochester, NY 14642, USA. Yoshihiko
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Goins CL, Chappell CP, Shashidharamurthy R, Selvaraj P, Jacob J. Immune complex-mediated enhancement of secondary antibody responses. THE JOURNAL OF IMMUNOLOGY 2010; 184:6293-8. [PMID: 20439912 DOI: 10.4049/jimmunol.0902530] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunologic memory is a hallmark of the vertebrate immune system. The first antigenic exposure leads to a slow and modest immune response, whereas repeated exposure, even many years later, leads to a rapid and exaggerated response that is two to three orders of magnitude greater than the primary. In the case of humoral immunity, the increased efficacy of recall responses is due to the production of amplified levels of Ag-specific Ab, as well as the accelerated kinetics of their production. Current thinking suggests that this is due to selective activation of long-lived, Ag-specific memory B cells. A downside of restricting secondary responses solely to memory cells is that the repertoire of the memory B cell pool remains static while pathogens continue to evolve. In this study, we propose that during secondary responses, naive Ag-specific B cells participate alongside memory cells. We show that immune complexes formed in vivo between the Ag and pre-existing Abs from the primary response activate these naive B cells, inducing them to respond with accelerated kinetics and increased magnitude. Thus, the continued recruitment of new B cell clones after each antigenic exposure enables the immune system to stay abreast of rapidly changing pathogens.
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Affiliation(s)
- Chelsey L Goins
- Department of Microbiology and Immunology, Emory Vaccine Center, Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
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Wang H, Ooi EV, Ang PO. Antiviral activities of extracts from Hong Kong seaweeds. J Zhejiang Univ Sci B 2009; 9:969-76. [PMID: 19067465 DOI: 10.1631/jzus.b0820154] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We extracted six Hong Kong brown seaweed species with hot water for their antiviral properties. The cytotoxicity and antiviral activity of these extracts were tested by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenlytetrezolium bromide] method, cytopathic effect reduction assay, and plaque reduction assay. The antiviral effect was further determined by flow cytometric analysis. The results showed that most of these extracts inhibited the propagation of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) standard strains with very low cytotoxicity to the host cells. The extracts of Hydroclathrus clathratus and Lobophora variegata showed more potential anti-HSV activities than the extracts of the other four seaweeds. They also had moderate anti- respiratory syncytial virus (RSV) activities but could not inhibit influenza A virus. Hydroclathrus clathratus was further extracted by diluted acid and alkali and the antiviral effects of the extracts were also detected. The result showed that the hot water extract contained the main carbohydrate components that exhibited the antiviral activities against various strains of HSV, including the acyclovir-resistant strain. HI-3, a compound fractionated from this hot water extract, showed a dose-dependent anti-HSV activity in flow cytometric analysis and plaque reduction assay.
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Affiliation(s)
- Hui Wang
- Medical College, Jinan University, Guangzhou 510632, China.
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Current World Literature. Curr Opin Pulm Med 2008; 14:266-73. [DOI: 10.1097/mcp.0b013e3282ff8c19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Identifying infections with respiratory syncytial virus by using specific immunoglobulin G (IgG) and IgA enzyme-linked immunosorbent assays with oral-fluid samples. J Clin Microbiol 2008; 46:1659-62. [PMID: 18305129 DOI: 10.1128/jcm.02190-07] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Currently, respiratory syncytial virus (RSV) infection is identified in epidemiological studies by virus antigen or nucleic acid detection in combination with serology. Oral-fluid specimens may provide a noninvasive alternative to blood, and oral fluid is more suitable for sampling outside of the clinic setting. We evaluated an indirect enzyme-linked immunosorbent assay for the detection of RSV-specific immunoglobulin G (IgG) and IgA by using oral-fluid samples collected from individuals with RSV infections confirmed by an immunofluorescent antibody test. For five children sampled repeatedly from birth, antibody profiles in oral fluid quite consistently tracked those in paired sera, and RSV infections were detected by rising titers of antibodies of at least one Ig class. Specific IgG responses were generally more reliable than IgA responses, except in early infancy, where the reverse was sometimes true. For a further five young children from whom oral fluid was collected weekly following RSV infection, boosted antibody responses, frequently of a transient nature, lasting a few weeks, were observed; specific IgG responses were of longer duration and more pronounced than specific IgA responses. Our data show significant promise for the use of oral fluid alone in RSV infection surveillance. The observed rapid dynamics of the antibody responses are informative in defining study sampling intervals.
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