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Paz-Bailey G, Adams LE, Deen J, Anderson KB, Katzelnick LC. Dengue. Lancet 2024; 403:667-682. [PMID: 38280388 DOI: 10.1016/s0140-6736(23)02576-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 11/01/2023] [Accepted: 11/15/2023] [Indexed: 01/29/2024]
Abstract
Dengue, caused by four closely related viruses, is a growing global public health concern, with outbreaks capable of overwhelming health-care systems and disrupting economies. Dengue is endemic in more than 100 countries across tropical and subtropical regions worldwide, and the expanding range of the mosquito vector, affected in part by climate change, increases risk in new areas such as Spain, Portugal, and the southern USA, while emerging evidence points to silent epidemics in Africa. Substantial advances in our understanding of the virus, immune responses, and disease progression have been made within the past decade. Novel interventions have emerged, including partially effective vaccines and innovative mosquito control strategies, although a reliable immune correlate of protection remains a challenge for the assessment of vaccines. These developments mark the beginning of a new era in dengue prevention and control, offering promise in addressing this pressing global health issue.
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Affiliation(s)
| | - Laura E Adams
- Centers for Disease Control and Prevention, San Juan, Puerto Rico
| | - Jacqueline Deen
- Institute of Child Health and Human Development, National Institutes of Health, University of the Philippines, Manila, Philippines
| | - Kathryn B Anderson
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Leah C Katzelnick
- Viral Epidemiology and Immunity Unit, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Cheng D, Huang SW, Chin WX, Hung SJ, Tsai HP, Chu JJH, Chao CH, Wang JR. Impact of Intrahost NS5 Nucleotide Variations on Dengue Virus Replication. Front Microbiol 2022; 13:894200. [PMID: 35865937 PMCID: PMC9294511 DOI: 10.3389/fmicb.2022.894200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Due to the nature of RNA viruses, their high mutation rates produce a population of closely related but genetically diverse viruses, termed quasispecies. To determine the role of quasispecies in DENV disease severity, 22 isolates (10 from mild cases, 12 from fatal cases) were obtained, amplified, and sequenced with Next Generation Sequencing using the Illumina MiSeq platform. Using variation calling, unique wildtype nucleotide positions were selected and analyzed for variant nucleotides between mild and fatal cases. The analysis of variant nucleotides between mild and fatal cases showed 6 positions with a significant difference of p < 0.05 with 1 position in the structural region, and 5 positions in the non-structural (NS) regions. All variations were found to have a higher percentage in fatal cases. To further investigate the genetic changes that affect the virus’s properties, reverse genetics (rg) viruses containing substitutions with the variations were generated and viral growth properties were examined. We found that the virus variant rgNS5-T7812G (G81G) had higher replication rates in both Baby hamster kidney cells (BHK-21) and Vero cells while rgNS5-C9420A (A617A) had a higher replication rate only in BHK-21 cells compared to wildtype virus. Both variants were considered temperature sensitive whereby the viral titers of the variants were relatively lower at 39°C, but was higher at 35 and 37°C. Additionally, the variants were thermally stable compared to wildtype at temperatures of 29, 37, and 39°C. In conclusion, viral quasispecies found in isolates from the 2015 DENV epidemic, resulted in variations with significant difference between mild and fatal cases. These variations, NS5-T7812G (G81G) and NS5-C9420A (A617A), affect viral properties which may play a role in the virulence of DENV.
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Affiliation(s)
- Dayna Cheng
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sheng-Wen Huang
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Tainan, Taiwan
| | - Wei-Xin Chin
- Department of Microbiology and Immunology, Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Su-Jhen Hung
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Tainan, Taiwan
| | - Huey-Pin Tsai
- Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Justin Jang Hann Chu
- Department of Microbiology and Immunology, Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Chiao-Hsuan Chao
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jen-Ren Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan
- *Correspondence: Jen-Ren Wang,
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Molteni E, Sudre CH, Canas LDS, Bhopal SS, Hughes RC, Chen L, Deng J, Murray B, Kerfoot E, Antonelli M, Graham M, Kläser K, May A, Hu C, Pujol JC, Wolf J, Hammers A, Spector TD, Ourselin S, Modat M, Steves CJ, Absoud M, Duncan EL. Illness Characteristics of COVID-19 in Children Infected with the SARS-CoV-2 Delta Variant. CHILDREN (BASEL, SWITZERLAND) 2022; 9:652. [PMID: 35626830 PMCID: PMC9140086 DOI: 10.3390/children9050652] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022]
Abstract
BACKGROUND The Delta (B.1.617.2) SARS-CoV-2 variant was the predominant UK circulating strain between May and November 2021. We investigated whether COVID-19 from Delta infection differed from infection with previous variants in children. METHODS Through the prospective COVID Symptom Study, 109,626 UK school-aged children were proxy-reported between 28 December 2020 and 8 July 2021. We selected all symptomatic children who tested positive for SARS-CoV-2 and were proxy-reported at least weekly, within two timeframes: 28 December 2020 to 6 May 2021 (Alpha (B.1.1.7), the main UK circulating variant) and 26 May to 8 July 2021 (Delta, the main UK circulating variant), with all children unvaccinated (as per national policy at the time). We assessed illness profiles (symptom prevalence, duration, and burden), hospital presentation, and presence of long (≥28 day) illness, and calculated odds ratios for symptoms presenting within the first 28 days of illness. RESULTS 694 (276 younger (5-11 years), 418 older (12-17 years)) symptomatic children tested positive for SARS-CoV-2 with Alpha infection and 706 (227 younger and 479 older) children with Delta infection. Median illness duration was short with either variant (overall cohort: 5 days (IQR 2-9.75) with Alpha, 5 days (IQR 2-9) with Delta). The seven most prevalent symptoms were common to both variants. Symptom burden over the first 28 days was slightly greater with Delta compared with Alpha infection (in younger children, 3 (IQR 2-5) symptoms with Alpha, 4 (IQR 2-7) with Delta; in older children, 5 (IQR 3-8) symptoms with Alpha, 6 (IQR 3-9) with Delta infection ). The odds of presenting several symptoms were higher with Delta than Alpha infection, including headache and fever. Few children presented to hospital, and long illness duration was uncommon, with either variant. CONCLUSIONS COVID-19 in UK school-aged children due to SARS-CoV-2 Delta strain B.1.617.2 resembles illness due to the Alpha variant B.1.1.7., with short duration and similar symptom burden.
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Affiliation(s)
- Erika Molteni
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Carole H. Sudre
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
- MRC Unit for Lifelong Health and Ageing, Department of Population Health Sciences, University College London, London WC1E 6BT, UK
- Centre for Medical Image Computing, Department of Computer Science, University College London, London WC1E 6BT, UK
| | - Liane Dos Santos Canas
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Sunil S. Bhopal
- Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
| | - Robert C. Hughes
- Department of Population Health, Faculty of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK;
| | - Liyuan Chen
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Jie Deng
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Benjamin Murray
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Eric Kerfoot
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Michela Antonelli
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Mark Graham
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Kerstin Kläser
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Anna May
- ZOE Limited London, London SE1 7RW, UK; (A.M.); (C.H.); (J.C.P.); (J.W.)
| | - Christina Hu
- ZOE Limited London, London SE1 7RW, UK; (A.M.); (C.H.); (J.C.P.); (J.W.)
| | | | - Jonathan Wolf
- ZOE Limited London, London SE1 7RW, UK; (A.M.); (C.H.); (J.C.P.); (J.W.)
| | - Alexander Hammers
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
- King’s College London & Guy’s and St Thomas’ PET Centre, London WC2R 2LS, UK
| | - Timothy D. Spector
- Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK; (T.D.S.); (C.J.S.)
| | - Sebastien Ourselin
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Marc Modat
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK; (E.M.); (C.H.S.); (L.D.S.C.); (L.C.); (J.D.); (B.M.); (E.K.); (M.A.); (M.G.); (K.K.); (A.H.); (S.O.); (M.M.)
| | - Claire J. Steves
- Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK; (T.D.S.); (C.J.S.)
- Department of Aging and Health, Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK
| | - Michael Absoud
- Children’s Neurosciences, Evelina London Children’s Hospital, St Thomas’ Hospital, King’s Health Partners, Academic Health Science Centre, London SE1 7EH, UK
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King’s College London, London WC2R 2LS, UK
| | - Emma L. Duncan
- Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK; (T.D.S.); (C.J.S.)
- Department of Endocrinology, Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK
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4
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Molteni E, Sudre CH, Canas LDS, Bhopal SS, Hughes RC, Chen L, Deng J, Murray B, Kerfoot E, Antonelli M, Graham M, Kläser K, May A, Hu C, Pujol JC, Wolf J, Hammers A, Spector TD, Ourselin S, Modat M, Steves CJ, Absoud M, Duncan EL. Illness Characteristics of COVID-19 in Children Infected with the SARS-CoV-2 Delta Variant. CHILDREN (BASEL, SWITZERLAND) 2022; 9:children9050652. [PMID: 35626830 DOI: 10.1101/2021.10.06.21264467] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 05/22/2023]
Abstract
BACKGROUND The Delta (B.1.617.2) SARS-CoV-2 variant was the predominant UK circulating strain between May and November 2021. We investigated whether COVID-19 from Delta infection differed from infection with previous variants in children. METHODS Through the prospective COVID Symptom Study, 109,626 UK school-aged children were proxy-reported between 28 December 2020 and 8 July 2021. We selected all symptomatic children who tested positive for SARS-CoV-2 and were proxy-reported at least weekly, within two timeframes: 28 December 2020 to 6 May 2021 (Alpha (B.1.1.7), the main UK circulating variant) and 26 May to 8 July 2021 (Delta, the main UK circulating variant), with all children unvaccinated (as per national policy at the time). We assessed illness profiles (symptom prevalence, duration, and burden), hospital presentation, and presence of long (≥28 day) illness, and calculated odds ratios for symptoms presenting within the first 28 days of illness. RESULTS 694 (276 younger (5-11 years), 418 older (12-17 years)) symptomatic children tested positive for SARS-CoV-2 with Alpha infection and 706 (227 younger and 479 older) children with Delta infection. Median illness duration was short with either variant (overall cohort: 5 days (IQR 2-9.75) with Alpha, 5 days (IQR 2-9) with Delta). The seven most prevalent symptoms were common to both variants. Symptom burden over the first 28 days was slightly greater with Delta compared with Alpha infection (in younger children, 3 (IQR 2-5) symptoms with Alpha, 4 (IQR 2-7) with Delta; in older children, 5 (IQR 3-8) symptoms with Alpha, 6 (IQR 3-9) with Delta infection ). The odds of presenting several symptoms were higher with Delta than Alpha infection, including headache and fever. Few children presented to hospital, and long illness duration was uncommon, with either variant. CONCLUSIONS COVID-19 in UK school-aged children due to SARS-CoV-2 Delta strain B.1.617.2 resembles illness due to the Alpha variant B.1.1.7., with short duration and similar symptom burden.
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Affiliation(s)
- Erika Molteni
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Carole H Sudre
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
- MRC Unit for Lifelong Health and Ageing, Department of Population Health Sciences, University College London, London WC1E 6BT, UK
- Centre for Medical Image Computing, Department of Computer Science, University College London, London WC1E 6BT, UK
| | - Liane Dos Santos Canas
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Sunil S Bhopal
- Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Robert C Hughes
- Department of Population Health, Faculty of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Liyuan Chen
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Jie Deng
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Benjamin Murray
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Eric Kerfoot
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Michela Antonelli
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Mark Graham
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Kerstin Kläser
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Anna May
- ZOE Limited London, London SE1 7RW, UK
| | | | | | | | - Alexander Hammers
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
- King's College London & Guy's and St Thomas' PET Centre, London WC2R 2LS, UK
| | - Timothy D Spector
- Department of Twin Research and Genetic Epidemiology, King's College London, London WC2R 2LS, UK
| | - Sebastien Ourselin
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Marc Modat
- School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK
| | - Claire J Steves
- Department of Twin Research and Genetic Epidemiology, King's College London, London WC2R 2LS, UK
- Department of Aging and Health, Guy's and St Thomas' NHS Foundation Trust, London SE1 7EH, UK
| | - Michael Absoud
- Children's Neurosciences, Evelina London Children's Hospital, St Thomas' Hospital, King's Health Partners, Academic Health Science Centre, London SE1 7EH, UK
- Department of Women and Children's Health, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King's College London, London WC2R 2LS, UK
| | - Emma L Duncan
- Department of Twin Research and Genetic Epidemiology, King's College London, London WC2R 2LS, UK
- Department of Endocrinology, Guy's and St Thomas' NHS Foundation Trust, London SE1 7EH, UK
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Yu X, Cheng G. Adaptive Evolution as a Driving Force of the Emergence and Re-Emergence of Mosquito-Borne Viral Diseases. Viruses 2022; 14:v14020435. [PMID: 35216028 PMCID: PMC8878277 DOI: 10.3390/v14020435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 02/06/2023] Open
Abstract
Emerging and re-emerging mosquito-borne viral diseases impose a significant burden on global public health. The most common mosquito-borne viruses causing recent epidemics include flaviviruses in the family Flaviviridae, including Dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV) and West Nile virus (WNV) and Togaviridae viruses, such as chikungunya virus (CHIKV). Several factors may have contributed to the recent re-emergence and spread of mosquito-borne viral diseases. Among these important causes are the evolution of mosquito-borne viruses and the genetic mutations that make them more adaptive and virulent, leading to widespread epidemics. RNA viruses tend to acquire genetic diversity due to error-prone RNA-dependent RNA polymerases, thus promoting high mutation rates that support adaptation to environmental changes or host immunity. In this review, we discuss recent findings on the adaptive evolution of mosquito-borne viruses and their impact on viral infectivity, pathogenicity, vector fitness, transmissibility, epidemic potential and disease emergence.
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Affiliation(s)
- Xi Yu
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Gong Cheng
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
- Correspondence:
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Sena MA, da Silva Castanha PM, Giles Guimarães AB, Oliveira PADS, da Silva MAL, Cordeiro MT, Moura P, Braga C, Vasconcelos LRS. Mannose-binding lectin levels and MBL2 gene polymorphisms are associated to dengue infection in Brazilian children at the early ages. Int J Infect Dis 2022; 117:212-219. [PMID: 35150914 DOI: 10.1016/j.ijid.2022.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/03/2022] [Accepted: 02/06/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The mannose-binding lectin (MBL) plays an important role in innate immunity. Genetically determined variations in serum levels of MBL may influence the susceptibility and clinical outcome of dengue infection in early life. METHODS We investigated MBL2 gene polymorphisms and serum levels of MBL (total and functional) in children with asymptomatic (n=17) and symptomatic (n=29), primary dengue infections, and age-matched uninfected children (n=84) enrolled in a Brazilian dengue birth cohort. Polymorphisms of the MBL2 gene were assessed by RT-PCR, while ELISA were used to quantify serum levels of MBL. RESULTS We found that the X allele and YX genotype in the MBL2 were more frequent in dengue cases than controls. Likewise, the LXPA haplotype was exclusively found in dengue cases, thus probably related to dengue infection in our setting. Moreover, we found a higher frequency of the O allele and AO genotype in control group. Serum levels of total and functional MBL were higher in dengue naïve infants than dengue cases. CONCLUSIONS MBL2 variants related to lower production of serum MBL were associated to dengue infection in infants, while intermediate to high levels of total and functional serum MBL were associated with protection. These findings highlight the role of MBL2 variants and serum levels of MBL in the susceptibility to dengue disease at early ages.
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Affiliation(s)
- Marília A Sena
- Aggeu Magalhães Institute - Oswaldo Cruz Foundation/FIOCRUZ, Recife, Brazil.
| | - Priscila Mayrelle da Silva Castanha
- Infectious Diseases and Microbiology Department, University of Pittsburgh, Pittsburgh, Pennsylvania, United States; Faculty of Medical Science, University of Pernambuco/UPE, Recife, Brazil
| | | | | | | | | | - Patricia Moura
- Faculty of Medical Science, University of Pernambuco/UPE, Recife, Brazil; Laboratory of Immunobiology and Pathology, University of Pernambuco/UPE, Recife, Brazil
| | - Cynthia Braga
- Aggeu Magalhães Institute - Oswaldo Cruz Foundation/FIOCRUZ, Recife, Brazil
| | - Luydson Richardson Silva Vasconcelos
- Aggeu Magalhães Institute - Oswaldo Cruz Foundation/FIOCRUZ, Recife, Brazil; Faculty of Medical Science, University of Pernambuco/UPE, Recife, Brazil; Laboratory of Immunobiology and Pathology, University of Pernambuco/UPE, Recife, Brazil
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Zhang L, Zhao L, Zhang Z, Hong W, Wang J, Qiu S, Yang H, Gan M, Sun J, Zhao J, Wang Y, Zhao J, Zhang F. Genetic and pathogenicity diversity of dengue virus type 2 strains circulating in Guangdong, China. BIOSAFETY AND HEALTH 2021. [DOI: 10.1016/j.bsheal.2021.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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8
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Bhatt P, Sabeena SP, Varma M, Arunkumar G. Current Understanding of the Pathogenesis of Dengue Virus Infection. Curr Microbiol 2021; 78:17-32. [PMID: 33231723 PMCID: PMC7815537 DOI: 10.1007/s00284-020-02284-w] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/04/2020] [Indexed: 12/26/2022]
Abstract
The pathogenesis of dengue virus infection is attributed to complex interplay between virus, host genes and host immune response. Host factors such as antibody-dependent enhancement (ADE), memory cross-reactive T cells, anti-DENV NS1 antibodies, autoimmunity as well as genetic factors are major determinants of disease susceptibility. NS1 protein and anti-DENV NS1 antibodies were believed to be responsible for pathogenesis of severe dengue. The cytokine response of cross-reactive CD4+ T cells might be altered by the sequential infection with different DENV serotypes, leading to further elevation of pro-inflammatory cytokines contributing a detrimental immune response. Fcγ receptor-mediated antibody-dependent enhancement (ADE) results in release of cytokines from immune cells leading to vascular endothelial cell dysfunction and increased vascular permeability. Genomic variation of dengue virus and subgenomic flavivirus RNA (sfRNA) suppressing host immune response are viral determinants of disease severity. Dengue infection can lead to the generation of autoantibodies against DENV NS1antigen, DENV prM, and E proteins, which can cross-react with several self-antigens such as plasminogen, integrin, and platelet cells. Apart from viral factors, several host genetic factors and gene polymorphisms also have a role to play in pathogenesis of DENV infection. This review article highlights the various factors responsible for the pathogenesis of dengue and also highlights the recent advances in the field related to biomarkers which can be used in future for predicting severe disease outcome.
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Affiliation(s)
- Puneet Bhatt
- Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
| | | | - Muralidhar Varma
- Dept of Infectious Diseases, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka 576101 India
| | - Govindakarnavar Arunkumar
- Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
- Present Address: WHO Country Office, Kathmandu, Nepal
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Calvez E, Somlor S, Viengphouthong S, Balière C, Bounmany P, Keosenhom S, Caro V, Grandadam M. Rapid genotyping protocol to improve dengue virus serotype 2 survey in Lao PDR. PLoS One 2020; 15:e0237384. [PMID: 32764809 PMCID: PMC7413503 DOI: 10.1371/journal.pone.0237384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/24/2020] [Indexed: 12/30/2022] Open
Abstract
Dengue fever is one of the major public health problems in Lao PDR. Over the last decade, dengue virus (DENV) epidemics were characterized by a novel predominant serotype accompanied by at least two other serotypes. Since 2008, DENV-2 circulated at a low level in Lao PDR but its epidemiologic profile changed at the end of 2018. Indeed, the number of confirmed DENV-2 cases suddenly increased in October 2018 and DENV-2 became predominant at the country level in early 2019. We developed a Genotype Screening Protocol (GSP) to determine the origin(s) of the Lao DENV-2 and study their genetic polymorphism. With a good correlation with full envelope gene sequencing data, this molecular epidemiology tool evidence the co-circulation of two highly polymorphic DENV-2 genotypes, i.e. Asian I and Cosmopolitan genotypes, over the last five years, suggesting multiple introductions of DENV-2 in the country. GSP approach provides relevant first line information that may help countries with limited laboratory resources to reinforce their capabilities to DENV-2 and to follow the epidemics progresses and assess situations at the regional level.
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Affiliation(s)
- Elodie Calvez
- Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
- * E-mail:
| | - Somphavanh Somlor
- Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
| | | | | | | | - Sitsana Keosenhom
- Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
| | | | - Marc Grandadam
- Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
- Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
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10
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Ko HY, Salem GM, Chang GJJ, Chao DY. Application of Next-Generation Sequencing to Reveal How Evolutionary Dynamics of Viral Population Shape Dengue Epidemiology. Front Microbiol 2020; 11:1371. [PMID: 32636827 PMCID: PMC7318875 DOI: 10.3389/fmicb.2020.01371] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
Dengue viral (DENV) infection results in a wide spectrum of clinical manifestations from asymptomatic, mild fever to severe hemorrhage diseases upon infection. Severe dengue is the leading cause of pediatric deaths and/or hospitalizations, which are a major public health burden in dengue-endemic or hyperendemic countries. Like other RNA viruses, DENV continues to evolve. Adaptive mutations are obscured by the major consensus sequence (so-called wild-type sequences) and can only be identified once they become the dominant viruses in the virus population, a process that can take months or years. Traditional surveillance systems still rely on Sanger consensus sequencing. However, with the recent advancement of high-throughput next-generation sequencing (NGS) technologies, the genome-wide investigation of virus population within-host and between-hosts becomes achievable. Thus, viral population sequencing by NGS can increase our understanding of the changing epidemiology and evolution of viral genomics at the molecular level. This review focuses on the studies within the recent decade utilizing NGS in different experimental and epidemiological settings to understand how the adaptive evolution of dengue variants shapes the dengue epidemic and disease severity through its transmission. We propose three types of studies that can be pursued in the future to enhance our surveillance for epidemic prediction and better medical management.
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Affiliation(s)
- Hui-Ying Ko
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Gielenny M Salem
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Gwong-Jen J Chang
- Arboviral Diseases Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, United States
| | - Day-Yu Chao
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
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11
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Salvo MA, Aliota MT, Moncla LH, Velez ID, Trujillo AI, Friedrich TC, Osorio JE. Tracking dengue virus type 1 genetic diversity during lineage replacement in an hyperendemic area in Colombia. PLoS One 2019; 14:e0212947. [PMID: 30845200 PMCID: PMC6405123 DOI: 10.1371/journal.pone.0212947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/12/2019] [Indexed: 12/16/2022] Open
Abstract
Dengue virus (DENV) is a flavivirus responsible for the most common and burdensome arthropod-borne viral disease of humans[1]. DENV evolution has been extensively studied on broad geographic and time scales, using sequences from a single gene[2,3]. It is believed that DENV evolution in humans is dominated primarily by purifying selection due to the constraint of maintaining fitness in both humans and mosquitoes[4,5]. Few studies have explored DENV evolutionary dynamics using whole genome sequences, nor have they explored changes in viral diversity that occur during intra-epidemic periods. We used deep sequencing of the viral coding region to characterize DENV-1 evolution in a Colombian population sampled during two high-prevalence dengue seasons in which serotype dominance shifted. Our data demonstrate patterns of strain extinction and replacement within DENV-1 as its prevalence waned and DENV-3 became established. A comparison of whole-genome versus single-gene-based phylogenetic analyses highlights an important difference in evolutionary patterns. We report a trend of higher nonsynonymous to synonymous diversity ratios among non-structural (NS) genes, and statistically significantly higher values among these ratios in the NS1 gene after DENV-1 strain replacement. These results suggest that positive selection could be driving DENV evolution within individual communities. Signals of positive selection coming from distinct samples may be drowned out when combining multiple regions with differing patterns of endemic transmission as commonly done by large-scale geo-temporal assessments. Here, we frame our findings within a small, local transmission history which aids significance. Moreover, these data suggest that the NS1 gene, rather than the E gene, may be a target of positive selection, although not mutually exclusive, and potentially useful sentinel of adaptive changes at the population level.
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Affiliation(s)
- Mauricio A. Salvo
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Matthew T. Aliota
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Louise H. Moncla
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ivan D. Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Andrea I. Trujillo
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Thomas C. Friedrich
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jorge E. Osorio
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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12
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Genetic Determinants of the Re-Emergence of Arboviral Diseases. Viruses 2019; 11:v11020150. [PMID: 30759739 PMCID: PMC6410223 DOI: 10.3390/v11020150] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/03/2019] [Accepted: 02/06/2019] [Indexed: 01/06/2023] Open
Abstract
Mosquito-borne diseases constitute a large portion of infectious diseases, causing more than 700,000 deaths annually. Mosquito-transmitted viruses, such as yellow fever, dengue, West Nile, chikungunya, and Zika viruses, have re-emerged recently and remain a public health threat worldwide. Global climate change, rapid urbanization, burgeoning international travel, expansion of mosquito populations, vector competence, and host and viral genetics may all together contribute to the re-emergence of arboviruses. In this brief review, we summarize the host and viral genetic determinants that may enhance infectivity in the host, viral fitness in mosquitoes and viral transmission by mosquitoes.
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Tsai JJ, Liu CK, Tsai WY, Liu LT, Tyson J, Tsai CY, Lin PC, Wang WK. Seroprevalence of dengue virus in two districts of Kaohsiung City after the largest dengue outbreak in Taiwan since World War II. PLoS Negl Trop Dis 2018; 12:e0006879. [PMID: 30356316 PMCID: PMC6218099 DOI: 10.1371/journal.pntd.0006879] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 11/05/2018] [Accepted: 09/28/2018] [Indexed: 12/27/2022] Open
Abstract
Dengue virus (DENV) is the leading cause of arboviral diseases in humans worldwide. In this study, we investigated the seroprevalence of DENV infection in two districts of Kaohsiung City, a metropolis in southern Taiwan, where major dengue outbreaks have occurred in the past three decades. We enrolled 1,088 participants from the Sanmin and Nanzih districts after the dengue outbreak of 2015, the largest in Taiwan since World War II, and found an overall DENV seroprevalence of 12.4% (95% confidence interval: 10.5–13.4%) based on the InBios DENV IgG ELISA kit. The ratios of clinically inapparent to symptomatic infections were 2.86 and 4.76 in Sanmin and Nanzih districts, respectively. Consistent with higher case numbers during recent outbreaks, the DENV seroprevalence was higher in Sanmin district (16.4%) than in Nanzih district (6.9%), suggesting district differences in seroprevalence and highlighting the importance of screening the DENV immune status of each individual before using the currently available DENV vaccine, Dengvaxia. In the two districts, the seroprevalence rates increased from 2.1% (in the 30–39-year age group) to 17.1% (60–69) and 50% (70–79). The pattern of a sharp and significant increase in seroprevalence in the 70–79-year age group correlated with a dramatic increase in the proportion of clinically severe DENV infections among total dengue cases in that age group. This differed from observations in the Americas and Southeast Asia and suggested that a large proportion of monotypically immune individuals together with other risk factors may contribute to clinically severe dengue among the elderly in Taiwan. Dengue virus (DENV) is the most important cause of mosquito-borne viral disease in humans worldwide. Investigating DENV seroprevalence in Kaohsiung City after the largest dengue outbreak in Taiwan since World War II, we found an overall seroprevalence of 12.4% and heterogeneity in seroprevalence within a metropolis; this together with the low efficacy and potential disease enhancement of the currently available dengue vaccine (Dengvaxia) in DENV-naive individuals highlighted the importance of checking the DENV immune status of individuals prior to Dengvaxia vaccination. The pattern of a sharp and significant increase in DENV seroprevalence in the 70–79 year age group in Kaohsiung City was different from that in the Americas and Southeast Asia, and suggested that a large proportion of monotypically immune individuals in that age group together with other risk factors may contribute to clinically severe dengue disease among the elderly in Taiwan.
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Affiliation(s)
- Jih-Jin Tsai
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ching-Kuan Liu
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- * E-mail: (CKL); (WKW)
| | - Wen-Yang Tsai
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
| | - Li-Teh Liu
- Department of Medical Laboratory Science and Biotechnology, College of Medicine and Life Science, Chung-Hwa University of Medical Technology, Tainan, Taiwan
| | - Jasmine Tyson
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
| | - Ching-Yi Tsai
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ping-Chang Lin
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wei-Kung Wang
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
- * E-mail: (CKL); (WKW)
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14
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Tsai JJ, Lin PC, Tsai CY, Wang YH, Liu LT. Low frequency of asymptomatic dengue virus-infected donors in blood donor centers during the largest dengue outbreak in Taiwan. PLoS One 2018; 13:e0205248. [PMID: 30296301 PMCID: PMC6175512 DOI: 10.1371/journal.pone.0205248] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 09/23/2018] [Indexed: 12/27/2022] Open
Abstract
To determine the prevalence of asymptomatic dengue virus-infected blood donors during the largest dengue outbreak in Taiwan history occurred in 2015, we examined the evidence of dengue virus (DENV) infection by the detection of DENV RNA genome using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), DENV NS1 antigen using rapid diagnosis test (RDT) and anti-dengue antibody using IgM/IgG capture enzyme-linked immunosorbent assay (capture ELISA) and RDT in eight thousand serum samples from blood donations to the blood centers of the Taiwan Blood Services Foundation (TBSF) in Kaohsiung City and Tainan City during the largest dengue outbreak in Taiwan history occurred in 2015. Only one serum sample was positive for DENV RNA detection by using dengue-specific real-time RT-PCR, the virus was DENV-2 determined by serotype-specific real-time RT-PCR and sequencing, and the DENVs in the serum were confirmed as being infectious by a plaque assay. The recipient of this blood did not develop any dengue fever symptom on follow-up. None of the samples was NS1 RDT-reactive. Seventeen IgM-positive samples were identified. There was a low prevalence of asymptomatic confirmed or probable DENV-infected blood donors in our study (0.013% and 0.21%, respectively), and no symptomatic transfusion-transmitted dengue (TT dengue) was developed during the largest dengue outbreak in Taiwan history in highly endemic areas and periods.
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Affiliation(s)
- Jih-Jin Tsai
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Ping-Chang Lin
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Ching-Yi Tsai
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Ying-Hui Wang
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Li-Teh Liu
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medical Technology, Chung-Hwa University of Medical Technology, Tainan City, Taiwan
- * E-mail:
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15
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Ko HY, Li YT, Chao DY, Chang YC, Li ZRT, Wang M, Kao CL, Wen TH, Shu PY, Chang GJJ, King CC. Inter- and intra-host sequence diversity reveal the emergence of viral variants during an overwintering epidemic caused by dengue virus serotype 2 in southern Taiwan. PLoS Negl Trop Dis 2018; 12:e0006827. [PMID: 30286095 PMCID: PMC6191158 DOI: 10.1371/journal.pntd.0006827] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/16/2018] [Accepted: 09/10/2018] [Indexed: 12/23/2022] Open
Abstract
Purifying selection during dengue viral infection has been suggested as the driving force of viral evolution and the higher complexity of the intra-host quasi-species is thought to offer an adaptive advantage for arboviruses as they cycle between arthropod and vertebrate hosts. However, very few studies have been performed to investigate the viral genetic changes within (intra-host) and between (inter-host) humans in a spatio-temporal scale. Viruses of different serotypes from various countries imported to Taiwan cause annual outbreaks. During 2001-2003, two consecutive outbreaks were caused by dengue virus serotype 2 (DENV-2) and resulted in a larger-scale epidemic with more severe dengue cases in the following year. Phylogenetic analyses showed that the viruses from both events were similar and related to the 2001 DENV-2 isolate from the Philippines. We comprehensively analyzed viral sequences from representative dengue patients and identified three consensus genetic variants, group Ia, Ib and II, with different spatio-temporal population dynamics. The phylodynamic analysis suggested group Ib variants, characterized by lower genetic diversity, transmission rate, and intra-host variant numbers, might play the role of maintenance variants. The residential locations among the patients infected by group Ib variants were in the outer rim of case clusters throughout the 2001-2003 period whereas group Ia and II variants were located in the centers of case clusters, suggesting that group Ib viruses might serve as "sheltered overwintering" variants in an undefined ecological niche. Further deep sequencing of the viral envelope (E) gene directly from individual patient serum samples confirmed the emergence of variants belonging to three quasi-species (group Ia, Ib, and II) and the ancestral role of the viral variants in the latter phase of the 2001 outbreak contributed to the later, larger-scale epidemic beginning in 2002. These findings enhanced our understanding of increasing epidemic severity over time in the same epidemic area. It also highlights the importance of combining phylodynamic and deep sequencing analysis as surveillance tools for detecting dynamic changes in viral variants, particularly searching for and monitoring any specific viral subpopulation. Such subpopulations might have selection advantages in both fitness and transmissibility leading to increased epidemic severity.
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Affiliation(s)
- Hui-Ying Ko
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Yao-Tsun Li
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Day-Yu Chao
- School of Veterinary Medicine, Institute of Microbiology and Public Health, National Chung-Hsing University, Taichung, Taiwan, Republic of China
- * E-mail: (DYC); (GJC); (CCK)
| | - Yun-Cheng Chang
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Zheng-Rong T. Li
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Melody Wang
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Chuan-Liang Kao
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Tzai-Hung Wen
- Department of Geography, College of Science, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Pei-Yun Shu
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Gwong-Jen J. Chang
- Arboviral Diseases Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
- * E-mail: (DYC); (GJC); (CCK)
| | - Chwan-Chuen King
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
- * E-mail: (DYC); (GJC); (CCK)
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16
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Socio-demographic inequalities in the clinical characteristics of dengue haemorrhagic fever in the city of Rio de Janeiro, Brazil, 2007-2008. Epidemiol Infect 2018; 146:359-366. [PMID: 29338803 DOI: 10.1017/s0950268817003119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In 2007-2008, the city of Rio de Janeiro underwent an epidemiological change, with increases in the incidence in children and in severe forms of dengue. To describe the clinical profile and spatial distribution of dengue we performed an ecological study based on dengue surveillance data using the Brazilian classification (2005): dengue fever, dengue haemorrhagic fever (DHF) and dengue with complications. χ 2 test was used to describe the clinical and socio-demographic variables (P < 0.05). Spatial distribution of incidence and case-fatality was explored with thematic maps, Moran and Geary indices (P < 0.05). Of the total of 151 527 dengue cases, 38 808 met the inclusion criteria; 42.4% <18 years; 22.9% dengue with complications and 2.7% DHF. Case-fatality was higher in infants (1.4%) and in DHF (7.7%). Bleeding was more frequent in adolescents and adults while plasma leakage was more common in preschoolers and schoolchildren. The highest incidence was found in the West Zone of the city, in a different area from that of the worst case-fatality (P < 0.05). Although the incidence of DHF was higher in schoolchildren, infants showed higher case-fatality. The area with the highest case-fatality did not present the highest incidence, which suggests problems in the organization of health services.
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Progress towards understanding the pathogenesis of dengue hemorrhagic fever. Virol Sin 2016; 32:16-22. [PMID: 27853992 PMCID: PMC6702245 DOI: 10.1007/s12250-016-3855-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/12/2016] [Indexed: 01/22/2023] Open
Abstract
Dengue virus (DENV) is a mosquito-borne virus belonging to the Flaviviridae family. There are 4 serotypes of DENV that cause human disease through transmission by mosquito vectors. DENV infection results in a broad spectrum of clinical symptoms, ranging from mild fever to dengue hemorrhagic fever (DHF), the latter of which can progress to dengue shock syndrome (DSS) and death. Researchers have made unremitting efforts over the last half-century to understand DHF pathogenesis. DHF is probably caused by multiple factors, such as virus-specific antibodies, viral antigens and host immune responses. This review summarizes the current progress of studies on DHF pathogenesis, which may provide important information for achieving effective control of dengue in the future.
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Abstract
Dengue is widespread throughout the tropics and local spatial variation in dengue virus transmission is strongly influenced by rainfall, temperature, urbanization and distribution of the principal mosquito vector Aedes aegypti. Currently, endemic dengue virus transmission is reported in the Eastern Mediterranean, American, South-East Asian, Western Pacific and African regions, whereas sporadic local transmission has been reported in Europe and the United States as the result of virus introduction to areas where Ae. aegypti and Aedes albopictus, a secondary vector, occur. The global burden of the disease is not well known, but its epidemiological patterns are alarming for both human health and the global economy. Dengue has been identified as a disease of the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change. According to the WHO, dengue control is technically feasible with coordinated international technical and financial support for national programmes. This Primer provides a general overview on dengue, covering epidemiology, control, disease mechanisms, diagnosis, treatment and research priorities.
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Affiliation(s)
- Maria G Guzman
- Institute of Tropical Medicine 'Pedro Kouri', PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Autopista Novia del Mediodia, Km 6 1/2, Havana 11400, Cuba
| | - Duane J Gubler
- Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore
| | - Alienys Izquierdo
- Institute of Tropical Medicine 'Pedro Kouri', PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Autopista Novia del Mediodia, Km 6 1/2, Havana 11400, Cuba
| | - Eric Martinez
- Institute of Tropical Medicine 'Pedro Kouri', PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Autopista Novia del Mediodia, Km 6 1/2, Havana 11400, Cuba
| | - Scott B Halstead
- Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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Abstract
Dengue provides the most abundant example in human medicine and the greatest human illness burden caused by the phenomenon of intrinsic antibody-dependent infection enhancement (iADE). In this immunopathological phenomenon infection of monocytes or macrophages using infectious immune complexes suppresses innate antiviral systems, permitting logarithmic intracellular growth of dengue virus. The four dengue viruses evolved from a common ancestor yet retain similar ecology and pathogenicity, but although infection with one virus provides short-term cross-protection against infection with a different type, millions of secondary dengue infections occur worldwide each year. When individuals are infected in the virtual absence of cross-protective dengue antibodies, the dengue vascular permeability syndrome (DVPS) may ensue. This occurs in around 2 to 4% of second heterotypic dengue infections. A complete understanding of the biologic mechanism of iADE, dengue biology, and the mechanism of host responses to dengue infection should lead to a comprehensive and complete understanding of the pathogenesis of DVPS. A crucial emphasis must be placed on understanding ADE. Clinical and epidemiological observations of DVPS define the research questions and provide research parameters. This article will review knowledge related to dengue ADE and point to areas where there has been little research progress. These observations relate to the two stages of dengue illnesses: afferent phenomena are those that promote the success of the microorganism to infect and survive; efferent phenomena are those mounted by the host to inhibit infection and replication and to eliminate the infectious agent and infected tissues. Data will be discussed as "knowns" and "unknowns."
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Ali A, Ali I. The Complete Genome Phylogeny of Geographically Distinct Dengue Virus Serotype 2 Isolates (1944-2013) Supports Further Groupings within the Cosmopolitan Genotype. PLoS One 2015; 10:e0138900. [PMID: 26414178 PMCID: PMC4587552 DOI: 10.1371/journal.pone.0138900] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 09/04/2015] [Indexed: 11/19/2022] Open
Abstract
Dengue virus serotype 2 (DENV-2) isolates have been implicated in deadly outbreaks of dengue fever (DF) and dengue hemorrhagic fever (DHF) in several regions of the world. Phylogenetic analysis of DENV-2 isolates collected from particular countries has been performed using partial or individual genes but only a few studies have examined complete whole-genome sequences collected worldwide. Herein, 50 complete genome sequences of DENV-2 isolates, reported over the past 70 years from 19 different countries, were downloaded from GenBank. Phylogenetic analysis was conducted and evolutionary distances of the 50 DENV-2 isolates were determined using maximum likelihood (ML) trees or Bayesian phylogenetic analysis created from complete genome nucleotide (nt) and amino acid (aa) sequences or individual gene sequences. The results showed that all DENV-2 isolates fell into seven main groups containing five previously defined genotypes. A Cosmopolitan genotype showed further division into three groups (C-I, C-II, and C-III) with the C-I group containing two subgroups (C-IA and C-IB). Comparison of the aa sequences showed specific mutations among the various groups of DENV-2 isolates. A maximum number of aa mutations was observed in the NS5 gene, followed by the NS2A, NS3 and NS1 genes, while the smallest number of aa substitutions was recorded in the capsid gene, followed by the PrM/M, NS4A, and NS4B genes. Maximum evolutionary distances were found in the NS2A gene, followed by the NS4A and NS4B genes. Based on these results, we propose that genotyping of DENV-2 isolates in future studies should be performed on entire genome sequences in order to gain a complete understanding of the evolution of various isolates reported from different geographical locations around the world.
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Affiliation(s)
- Akhtar Ali
- Department of Biological Science, The University of Tulsa, Tulsa Oklahoma, 74104, United States of America
- * E-mail:
| | - Ijaz Ali
- Department of Biological Science, The University of Tulsa, Tulsa Oklahoma, 74104, United States of America
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Hapuarachchi HC, Chua RCR, Shi Y, Thein TL, Lee LK, Lee KS, Lye DC, Ng LC, Leo YS. Clinical outcome and genetic differences within a monophyletic Dengue virus type 2 population. PLoS One 2015; 10:e0121696. [PMID: 25811657 PMCID: PMC4374945 DOI: 10.1371/journal.pone.0121696] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 02/03/2015] [Indexed: 12/28/2022] Open
Abstract
The exact mechanisms of interplay between host and viral factors leading to severe dengue are yet to be fully understood. Even though previous studies have implicated specific genetic differences of Dengue virus (DENV) in clinical severity and virus attenuation, similar studies with large-scale, whole genome screening of monophyletic virus populations are limited. Therefore, in the present study, we compared 89 whole genomes of DENV-2 cosmopolitan clade III isolates obtained from patients diagnosed with dengue fever (DF, n = 58), dengue hemorrhagic fever (DHF, n = 30) and dengue shock syndrome (DSS, n = 1) in Singapore between July 2010 and January 2013, in order to determine the correlation of observed viral genetic differences with clinical outcomes. Our findings showed no significant difference between the number of primary and secondary infections that progressed to DHF and DSS (p>0.05) in our study cohort. Despite being highly homogenous, study isolates possessed 39 amino acid substitutions of which 10 substitutions were fixed in three main groups of virus isolates. None of those substitutions were specifically associated with DHF and DSS. Notably, two evolutionarily unique virus groups possessing C-P43T+NS1-S103T+NS2A-V83I+NS3-R337K+ NS3-I600T+ NS5-P136S and NS2A-T119N mutations were exclusively found in patients with DF, the benign form of DENV infections. Those mutants were significantly associated with mild disease outcome. These observations indicated that disease progression into DHF and DSS within our patient population was more likely to be due to host than virus factors. We hypothesize that selection for potentially less virulent groups of DENV-2 in our study cohort may be an evolutionary adaptation of viral strains to extend their survival in the human-mosquito transmission cycle.
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Affiliation(s)
| | - Rachel Choon Rong Chua
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #06-05-08, Singapore 138667
| | - Yuan Shi
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #06-05-08, Singapore 138667
| | - Tun Lin Thein
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433
| | - Linda Kay Lee
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433
| | - Kim Sung Lee
- School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, 535 Clementi Road, Singapore 599489
| | - David Chien Lye
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #06-05-08, Singapore 138667
- * E-mail:
| | - Yee Sin Leo
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433
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22
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Rodriguez-Roche R, Gould EA. Understanding the dengue viruses and progress towards their control. BIOMED RESEARCH INTERNATIONAL 2013; 2013:690835. [PMID: 23936833 PMCID: PMC3722981 DOI: 10.1155/2013/690835] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 05/08/2013] [Indexed: 01/12/2023]
Abstract
Traditionally, the four dengue virus serotypes have been associated with fever, rash, and the more severe forms, haemorrhagic fever and shock syndrome. As our knowledge as well as understanding of these viruses increases, we now recognise not only that they are causing increasing numbers of human infections but also that they may cause neurological and other clinical complications, with sequelae or fatal consequences. In this review we attempt to highlight some of these features in the context of dengue virus pathogenesis. We also examine some of the efforts currently underway to control this "scourge" of the tropical and subtropical world.
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Affiliation(s)
- Rosmari Rodriguez-Roche
- Pedro Kouri Tropical Medicine Institute, WHO/PAHO Collaborating Centre for the Study of Dengue and Its Vector, Havana, Cuba.
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23
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Lin CH, Schiøler KL, Jepsen MR, Ho CK, Li SH, Konradsen F. Dengue outbreaks in high-income area, Kaohsiung City, Taiwan, 2003-2009. Emerg Infect Dis 2013; 18:1603-11. [PMID: 23017369 PMCID: PMC3471615 DOI: 10.3201/eid1810.111929] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cases distribute in a clustered pattern, and elderly persons have the highest risk for illness and death. Kaohsiung City, a modern metropolis of 1.5 million persons, has been the focus of dengue virus activity in Taiwan for several decades. The aim of this study was to provide a temporal and spatial description of dengue virus epidemiology in Kaohsiung City by using data for all laboratory-confirmed dengue cases during 2003–2009. We investigated age- and sex-dependent incidence rates and the spatiotemporal patterns of all cases confirmed through passive or active surveillance. Elderly persons were at particularly high risk for dengue virus–related sickness and death. Of all confirmed cases, ≈75% were detected through passive surveillance activities; case-patients detected through active surveillance included immediate family members, neighbors, and colleagues of confirmed case-patients. Changing patterns of case clustering could be due to the effect of unmeasured environmental and demographic factors.
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24
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Rodriguez-Roche R, Villegas E, Cook S, Poh Kim PAW, Hinojosa Y, Rosario D, Villalobos I, Bendezu H, Hibberd ML, Guzman MG. Population structure of the dengue viruses, Aragua, Venezuela, 2006-2007. Insights into dengue evolution under hyperendemic transmission. INFECTION GENETICS AND EVOLUTION 2011; 12:332-44. [PMID: 22197765 PMCID: PMC3919160 DOI: 10.1016/j.meegid.2011.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 12/08/2011] [Accepted: 12/10/2011] [Indexed: 12/16/2022]
Abstract
During the past three decades there has been a notable increase in dengue disease severity in Venezuela. Nevertheless, the population structure of the viruses being transmitted in this country is not well understood. Here, we present a molecular epidemiological study on dengue viruses (DENV) circulating in Aragua State, Venezuela during 2006-2007. Twenty-one DENV full-length genomes representing all of the four serotypes were amplified and sequenced directly from the serum samples. Notably, only DENV-2 was associated with severe disease. Phylogenetic trees constructed using Bayesian methods indicated that only one genotype was circulating for each serotype. However, extensive viral genetic diversity was found in DENV isolated from the same area during the same period, indicating significant in situ evolution since the introduction of these genotypes. Collectively, the results suggest that the non-structural (NS) proteins may play an important role in DENV evolution, particularly NS1, NS2A and NS4B proteins. The phylogenetic data provide evidence to suggest that multiple introductions of DENV have occurred from the Latin American region into Venezuela and vice versa. The implications of the significant viral genetic diversity generated during hyperendemic transmission, particularly in NS protein are discussed and considered in the context of future development and use of human monoclonal antibodies as antivirals and tetravalent vaccines.
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25
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Phylogenetic characterization of dengue virus type 2 in Espírito Santo, Brazil. Mol Biol Rep 2011; 39:71-80. [DOI: 10.1007/s11033-011-0711-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 04/23/2011] [Indexed: 10/18/2022]
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26
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Dengue virus RNA purification from human plasma: a comparison of two techniques. Mol Biol Rep 2010; 38:4979-83. [PMID: 21161397 DOI: 10.1007/s11033-010-0642-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 12/03/2010] [Indexed: 10/18/2022]
Abstract
Dengue virus RNA purification from human plasma is useful for research and clinical purposes. Dengue is endemic in the Espirito Santo State, Brazil, and it is progressively becoming a hard-to-control public health problem. Dengue virus types 1, 2 and 3 are currently found in Brazilian territory, and recently Dengue virus type 4 has been reported to enter Brazilian borders. This virus spreads rapidly during epidemic outbreaks, and thousands of patients are infected annually, with an underestimated number of deaths in consequence of hemorrhagic Dengue. Because this disease affects mainly developing countries, it is imperative that a robust, rapid and low cost method for viral nucleic acid purification is found. In this manuscript we compare two RNA extraction methods from serum/plasma of patients with clinical diagnosis of dengue. The QIAamp(®) UltraSens Virus Kit (Qiagen Inc., Valencia, USA) and the less expensive Chomczynski-Sacchi method were used to analyze a total of 47 samples. After nucleic acid purification, reverse transcription and polymerase chain reaction amplification with dengue virus type 2 specific primers were performed. This subtype is the most prevalent in our geographical location. Thirty-four samples were positive when RNA was extracted by the Chomczynski-Sacchi technique, whereas only 27 of these were positive when the QIAamp(®) UltraSens Virus Kit was used. These results favor the utilization of the more affordable technique for the purification of viral RNA, which is especially important for developing countries.
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Steel A, Gubler DJ, Bennett SN. Natural attenuation of dengue virus type-2 after a series of island outbreaks: a retrospective phylogenetic study of events in the South Pacific three decades ago. Virology 2010; 405:505-12. [PMID: 20663532 PMCID: PMC3150181 DOI: 10.1016/j.virol.2010.05.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 03/12/2010] [Accepted: 05/26/2010] [Indexed: 10/19/2022]
Abstract
Dengue is an expanding arboviral disease of variable severity characterized by the emergence of virus strains with greater fitness, epidemic potential and possibly virulence. To investigate the role of dengue virus (DENV) strain variation on epidemic activity we studied DENV-2 viruses from a series of South Pacific islands experiencing outbreaks of varying intensity and clinical severity. Initially appearing in 1971 in Tahiti and Fiji, the virus was responsible for subsequent epidemics in American Samoa, New Caledonia and Niue Island in 1972, reaching Tonga in 1973 where there was near-silent transmission for over a year. Based on whole-genome sequencing and phylogenetic analysis on 20 virus isolates, Tonga viruses were genetically unique, clustering in a single clade. Substitutions in the pre-membrane (prM) and nonstructural genes NS2A and NS4A correlated with the attenuation of the Tongan viruses and suggest that genetic change may play a significant role in dengue epidemic severity.
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Affiliation(s)
- Argon Steel
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, Asia-Pacific Institute of Tropical Medicine and Infectious Diseases, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
| | - Duane J. Gubler
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, Asia-Pacific Institute of Tropical Medicine and Infectious Diseases, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
- Program on Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857
| | - Shannon N. Bennett
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, Asia-Pacific Institute of Tropical Medicine and Infectious Diseases, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
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Abstract
Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.
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Webster DP, Farrar J, Rowland-Jones S. Progress towards a dengue vaccine. THE LANCET. INFECTIOUS DISEASES 2009; 9:678-87. [PMID: 19850226 DOI: 10.1016/s1473-3099(09)70254-3] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The spread of dengue virus throughout the tropics represents a major, rapidly growing public health problem with an estimated 2.5 billion people at risk of dengue fever and the life-threatening disease, severe dengue. A safe and effective vaccine for dengue is urgently needed. The pathogenesis of severe dengue results from a complex interaction between the virus, the host, and, at least in part, immune-mediated mechanisms. Vaccine development has been slowed by fears that immunisation might predispose individuals to the severe form of dengue infection. A pipeline of candidate vaccines now exists, including live attenuated, inactivated, chimeric, DNA, and viral-vector vaccines, some of which are at the stage of clinical testing. In this Review, we present what is understood about dengue pathogenesis and its implications for vaccine design, the progress that is being made in the development of a vaccine, and the future challenges.
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Affiliation(s)
- Daniel P Webster
- Department of Infectious Diseases and Microbiology, John Radcliffe Hospital, Oxford, UK.
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Medlock J, Luz PM, Struchiner CJ, Galvani AP. The impact of transgenic mosquitoes on dengue virulence to humans and mosquitoes. Am Nat 2009; 174:565-77. [PMID: 19737112 PMCID: PMC3409587 DOI: 10.1086/605403] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Dengue is a major public health concern in the tropics and subtropics. Innovative transgenic strategies to render Aedes aegypti mosquitoes, the primary vector of dengue, incompetent for dengue transmission are under development. We modeled the evolutionary impact of different transgenic mosquito strategies on dengue-induced mortality, that is, dengue virulence, to both humans and mosquitoes. This model incorporates various evolutionary trade-offs in dengue virus epidemiological traits, for example, a trade-off between dengue transmission rate and its virulence to humans. Our results indicate that strategies that block transmission or reduce mosquito biting impose selection on dengue virulence in humans. This selection can be for either higher or lower virulence, depending on the interaction between the effect of the transgene and the trade-offs in epidemiological traits, highlighting the need for detailed quantitative data to understand more fully the impact of mosquito transgenesis on dengue virulence. Dengue virulence in mosquitoes can be selected on by transgenic strategies of blocking transmission, decreased mosquito biting, increased mosquito background mortality, and increased mosquito infection-induced mortality. Our results suggest that dengue control strategies that raise mosquito background mortality or mosquito infection-induced mortality pose less risk of causing increased virulence to humans than strategies that block transmission or reduce mosquito biting.
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Affiliation(s)
- Jan Medlock
- Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
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Emergence of the severe syndrome and mortality associated with dengue and dengue-like illness: historical records (1890 to 1950) and their compatibility with current hypotheses on the shift of disease manifestation. Clin Microbiol Rev 2009; 22:186-201, Table of Contents. [PMID: 19366911 DOI: 10.1128/cmr.00052-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Outbreaks of the severe dengue syndrome, dengue hemorrhagic fever (DHF), emerged beginning in the 1950s, marking a dramatic change in the dengue syndrome. While intense investigations in multiple directions have been conducted for many years to elucidate the intrinsic mechanisms conducive to the development of DHF, no consensus has yet emerged. Meanwhile, relatively little attention has been paid to the occurrence of severe dengue and death prior to the 1950s. This comprehensive review was designed to evaluate outbreak records in the early dengue history to better understand the epidemiologic background and other factors that existed before the emergence of DHF outbreaks. By applying a set of stringent criteria to remove unreliable data as much as possible and by interpreting the results conservatively, a short list of etiologically more reliable outbreaks with high mortality was obtained. The results show that severe dengue syndrome, clinically very much compatible with DHF, occurred far more frequently in multiple locations than it had been assumed before; that the magnitudes of mortality in several outbreaks were not negligible; and that the epidemiologic background features shared among these outbreaks in the early period were, with the exceptions of more limited demographic changes, generally similar to the post-1950 conditions.
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