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Thi Hue Kien D, Edenborough K, da Silva Goncalves D, Thuy Vi T, Casagrande E, Thi Le Duyen H, Thi Long V, Thi Dui L, Thi Tuyet Nhu V, Thi Giang N, Thi Xuan Trang H, Lee E, Donovan-Banfield I, Thi Thuy Van H, Minh Nguyet N, Thanh Phong N, Van Vinh Chau N, Wills B, Yacoub S, Flores H, Simmons C. Genome evolution of dengue virus serotype 1 under selection by Wolbachia pipientis in Aedes aegypti mosquitoes. Virus Evol 2023; 9:vead016. [PMID: 37744653 PMCID: PMC10517695 DOI: 10.1093/ve/vead016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/26/2023] [Accepted: 03/03/2023] [Indexed: 09/26/2023] Open
Abstract
The introgression of antiviral strains of Wolbachia into Aedes aegypti mosquito populations is a public health intervention for the control of dengue. Plausibly, dengue virus (DENV) could evolve to bypass the antiviral effects of Wolbachia and undermine this approach. Here, we established a serial-passage system to investigate the evolution of DENV in Ae. aegypti mosquitoes infected with the wMel strain of Wolbachia. Using this system, we report on virus genetic outcomes after twenty passages of serotype 1 of DENV (DENV-1). An amino acid substitution, E203K, in the DENV-1 envelope protein was more frequently detected in the consensus sequence of virus populations passaged in wMel-infected Ae. aegypti than wild-type counterparts. Positive selection at residue 203 was reproducible; it occurred in passaged virus populations from independent DENV-1-infected patients and also in a second, independent experimental system. In wild-type mosquitoes and human cells, the 203K variant was rapidly replaced by the progenitor sequence. These findings provide proof of concept that wMel-associated selection of virus populations can occur in experimental conditions. Field-based studies are needed to explore whether wMel imparts selective pressure on DENV evolution in locations where wMel is established.
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Affiliation(s)
| | - Kathryn Edenborough
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Daniela da Silva Goncalves
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
| | - Tran Thuy Vi
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Etiene Casagrande
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Huynh Thi Le Duyen
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Vo Thi Long
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Le Thi Dui
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Vu Thi Tuyet Nhu
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Giang
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Huynh Thi Xuan Trang
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Elvina Lee
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
| | - I’ah Donovan-Banfield
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
| | - Huynh Thi Thuy Van
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | | | - Nguyen Thanh Phong
- Hospital for Tropical Diseases, 190 Ben Ham Tu, District 5, Ho Chi Minh City, Vietnam
| | - Nguyen Van Vinh Chau
- Hospital for Tropical Diseases, 190 Ben Ham Tu, District 5, Ho Chi Minh City, Vietnam
| | - Bridget Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sophie Yacoub
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
| | - Heather Flores
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Cameron Simmons
- World Mosquito Program, Institute of Vector-Borne Disease, Monash University, Clayton, VIC 3800, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
- Oxford University Clinical Research Unit, Hospital for Tropical Disease, Ho Chi Minh City, Vietnam
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Vuong NL, Quyen NTH, Tien NTH, Tuan NM, Kien DTH, Lam PK, Tam DTH, Van Ngoc T, Yacoub S, Jaenisch T, Geskus RB, Simmons CP, Wills BA. Higher Plasma Viremia in the Febrile Phase Is Associated With Adverse Dengue Outcomes Irrespective of Infecting Serotype or Host Immune Status: An Analysis of 5642 Vietnamese Cases. Clin Infect Dis 2020; 72:e1074-e1083. [PMID: 33340040 PMCID: PMC8204785 DOI: 10.1093/cid/ciaa1840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND One of the generally accepted constructs of dengue pathogenesis is that clinical disease severity is at least partially dependent upon plasma viremia, yet data on plasma viremia in primary versus secondary infections and in relation to clinically relevant endpoints remain limited and contradictory. METHODS Using a large database comprising detailed clinical and laboratory characterization of Vietnamese participants enrolled in a series of research studies executed over a 15-year period, we explored relationships between plasma viremia measured by reverse transcription-polymerase chain reaction and 3 clinically relevant endpoints-severe dengue, plasma leakage, and hospitalization-in the dengue-confirmed cases. All 4 dengue serotypes and both primary and secondary infections were well represented. In our logistic regression models we allowed for a nonlinear effect of viremia and for associations between viremia and outcome to differ by age, serotype, host immune status, and illness day at study enrollment. RESULTS Among 5642 dengue-confirmed cases we identified 259 (4.6%) severe dengue cases, 701 (12.4%) patients with plasma leakage, and 1441 of 4008 (40.0%) patients recruited in outpatient settings who were subsequently hospitalized. From the early febrile phase onwards, higher viremia increased the risk of developing all 3 endpoints, but effect sizes were modest (ORs ranging from 1.12-1.27 per 1-log increase) compared with the effects of a secondary immune response (ORs, 1.67-7.76). The associations were consistent across age, serotype, and immune status groups, and in the various sensitivity and subgroup analyses we undertook. CONCLUSIONS Higher plasma viremia is associated with increased dengue severity, regardless of serotype or immune status.
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Affiliation(s)
- Nguyen Lam Vuong
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam,University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam,Correspondence: N. L. Vuong, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet Street, Ward 1, District 5, Ho Chi Minh City, Vietnam ()
| | - Nguyen Than Ha Quyen
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Hanh Tien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Phung Khanh Lam
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Dong Thi Hoai Tam
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Tran Van Ngoc
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Sophie Yacoub
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Thomas Jaenisch
- Section of Clinical Tropical Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Ronald B Geskus
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Cameron P Simmons
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Institute for Vector-Borne Disease, Monash University, Clayton, Australia
| | - Bridget A Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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Quyen DL, Thanh Le N, Van Anh CT, Nguyen NB, Hoang DV, Montgomery JL, Kutcher SC, Hoang Le N, Hien NT, Hue Kien DT, Rabaa M, O’Neill SL, Simmons CP, Anh DD, Anders KL. Epidemiological, Serological, and Virological Features of Dengue in Nha Trang City, Vietnam. Am J Trop Med Hyg 2018; 98:402-409. [PMID: 29313471 PMCID: PMC5929208 DOI: 10.4269/ajtmh.17-0630] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/31/2017] [Indexed: 11/07/2022] Open
Abstract
Vietnam is endemic for dengue. We conducted a series of retrospective and prospective studies to characterize the epidemiology of dengue and population mobility patterns in Nha Trang city, Vietnam, with a view to rational design of trials of community-level interventions. A 10-year time series of dengue case notifications showed pronounced interannual variability, as well as spatial heterogeneity in ward-level dengue incidence (median annual coefficient of variation k = 0.47). Of 451 children aged 1-10 years enrolled in a cross-sectional serosurvey, almost one-third had evidence of a past dengue virus (DENV) infection, with older children more likely to have a multitypic response indicative of past exposure to ≥ 1 serotype. All four DENV serotypes were detected in hospitalized patients during 8 months of sampling in 2015. Mobility data collected from 1,000 children and young adults via prospective travel diaries showed that, although all ages spent approximately half of their daytime hours (5:00 am-9:00 pm) at home, younger age groups (≤ 14 years) spent a significantly greater proportion of their time within 500 m of home than older respondents. Together these findings inform the rational design of future trials of dengue preventive interventions in this setting by identifying 1) children < 7 years as an optimal target group for a flavivirus-naive serological cohort, 2) children and young adults as the predominant patient population for a study with a clinical end point of symptomatic dengue, and 3) substantial spatial and temporal variations in DENV transmission, with a consequent requirement for a trial to be large enough and of long enough duration to overcome this heterogeneity.
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Affiliation(s)
- Duong Le Quyen
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Nguyen Thanh Le
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Cao Thi Van Anh
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Dong Van Hoang
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Simon C. Kutcher
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Nguyen Hoang Le
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Duong Thi Hue Kien
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Maia Rabaa
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Scott L. O’Neill
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Cameron P. Simmons
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne, Doherty Institute, Melbourne, Australia
| | - Dang Duc Anh
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
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Quyen NTH, Kien DTH, Rabaa M, Tuan NM, Vi TT, Van Tan L, Hung NT, Tuan HM, Van Tram T, Le Da Ha N, Quang HK, Doanh NQ, Van Vinh Chau N, Wills B, Simmons CP. Chikungunya and Zika Virus Cases Detected against a Backdrop of Endemic Dengue Transmission in Vietnam. Am J Trop Med Hyg 2017; 97:146-150. [PMID: 28719300 PMCID: PMC5508909 DOI: 10.4269/ajtmh.16-0979] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Between 2010 and 2014, four chikungunya and two Zika virus infections were identified among 8,105 febrile children in southern Vietnam. Zika viruses were linked to French Polynesian strains, chikungunya to Cambodian strains. Against a backdrop of endemic dengue transmission, chikungunya and Zika present an additional arboviral disease burden in Vietnam.
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Affiliation(s)
- Nguyen Than Ha Quyen
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Maia Rabaa
- Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom.,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Tran Thuy Vi
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Le Van Tan
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | | | | | | | | | | | | | - Bridget Wills
- Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom.,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Cameron P Simmons
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom.,Department of Microbiology and Immunology at the Doherty Institute, University of Melbourne, Parkville, Australia
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5
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Whitehorn J, Kien DTH, Quyen NTH, Wills B, Van Vinh Chau N, Tam DTH, Tuan NM, Jaenisch T, Hibberd M, Khor CC, Simmons CP. Genetic variants of MICB and PLCE1 and associations with the laboratory features of dengue. BMC Infect Dis 2017; 17:412. [PMID: 28599625 PMCID: PMC5466782 DOI: 10.1186/s12879-017-2514-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/01/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND A previous genome-wide association study identified 2 susceptibility loci for severe dengue at MICB rs3132468 and PLCE1 rs3740360 and further work showed these mutations to be also associated with less severe clinical presentations. The aim of this study was to determine if these specific loci were associated with laboratory features of dengue that correlate with clinical severity with the aim of elucidating the functional basis of these genetic variants. METHODS This was a case-only analysis of laboratory-confirmed dengue patients obtained from 2 prospective cohort studies and 1 randomised clinical trial in Vietnam (Trial registration: ISRCTN ISRCTN03147572. Registered 24th July 2012). 2742 dengue cases were successfully genotyped at MICB rs3132468 and PLCE1 rs3740360. Laboratory variables were compared between genotypes and stratified by DENV serotype. RESULTS The analysis showed no association between MICB and PLCE1 genotype and early viraemia level, platelet nadir, white cell count nadir, or maximum haematocrit in both overall analysis and in analysis stratified by serotype. DISCUSSION The lack of an association between genotype and viremia level may reflect the sampling procedures within the included studies. The study findings mean that the functional basis of these mutations remains unclear. TRIAL REGISTRATION ISRCTN ISRCTN03147572 . Registered 24th July 2012.
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Affiliation(s)
- James Whitehorn
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK. .,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam.
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Nguyen Than Ha Quyen
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Bridget Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nguyen Van Vinh Chau
- Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Dong Thi Hoai Tam
- Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | | | - Thomas Jaenisch
- Department of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Hibberd
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK.,Genome Institute of Singapore, Biopolis Way, Singapore, Singapore
| | - Chiea Chuen Khor
- School of Public Health, National University of Singapore, Singapore, Singapore.,Department of Paediatrics, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University of Singapore, Singapore, Singapore
| | - Cameron P Simmons
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute, Melbourne, VIC, 3010, Australia
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6
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Clapham HE, Quyen TH, Kien DTH, Dorigatti I, Simmons CP, Ferguson NM. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance. PLoS Comput Biol 2016; 12:e1004951. [PMID: 27213681 PMCID: PMC4877086 DOI: 10.1371/journal.pcbi.1004951] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 04/29/2016] [Indexed: 12/26/2022] Open
Abstract
Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection. Dengue is a globally important viral disease. Despite this, there is still much unknown about the immunology, virology and epidemiology of dengue. As for all viral infections, the interaction between virus and immune response is a complex one. Using data collected from patients, we model how the virus replicates in an infected individual and how the human antibody response acts to control that replication. We show that the timing and magnitude of the growth and decline of virus and antibody levels in dengue-infected patients are consistent with antibody playing a key role in controlling infection. Our results are of use in the evaluation of potential antiviral drugs and vaccines.
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Affiliation(s)
- Hannah E Clapham
- MRC Centre for Outbreak Analysis and Modelling, DIDE, Imperial College, London, United Kingdom
- * E-mail: ;
| | - Than Ha Quyen
- Oxford University Clinical Research Unit-Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit-Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Ilaria Dorigatti
- MRC Centre for Outbreak Analysis and Modelling, DIDE, Imperial College, London, United Kingdom
| | - Cameron P Simmons
- Oxford University Clinical Research Unit-Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute, Melbourne, Australia
| | - Neil M Ferguson
- MRC Centre for Outbreak Analysis and Modelling, DIDE, Imperial College, London, United Kingdom
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7
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Ferguson NM, Kien DTH, Clapham H, Aguas R, Trung VT, Chau TNB, Popovici J, Ryan PA, O'Neill SL, McGraw EA, Long VT, Dui LT, Nguyen HL, Chau NVV, Wills B, Simmons CP. Modeling the impact on virus transmission of Wolbachia-mediated blocking of dengue virus infection of Aedes aegypti. Sci Transl Med 2015; 7:279ra37. [PMID: 25787763 DOI: 10.1126/scitranslmed.3010370] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Dengue is the most common arboviral infection of humans and is a public health burden in more than 100 countries. Aedes aegypti mosquitoes stably infected with strains of the intracellular bacterium Wolbachia are resistant to dengue virus (DENV) infection and are being tested in field trials. To mimic field conditions, we experimentally assessed the vector competence of A. aegypti carrying the Wolbachia strains wMel and wMelPop after challenge with viremic blood from dengue patients. We found that wMelPop conferred strong resistance to DENV infection of mosquito abdomen tissue and largely prevented disseminated infection. wMel conferred less resistance to infection of mosquito abdomen tissue, but it did reduce the prevalence of mosquitoes with infectious saliva. A mathematical model of DENV transmission incorporating the dynamics of viral infection in humans and mosquitoes was fitted to the data collected. Model predictions suggested that wMel would reduce the basic reproduction number, R0, of DENV transmission by 66 to 75%. Our results suggest that establishment of wMelPop-infected A. aegypti at a high frequency in a dengue-endemic setting would result in the complete abatement of DENV transmission. Establishment of wMel-infected A. aegypti is also predicted to have a substantial effect on transmission that would be sufficient to eliminate dengue in low or moderate transmission settings but may be insufficient to achieve complete control in settings where R0 is high. These findings develop a framework for selecting Wolbachia strains for field releases and for calculating their likely impact.
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Affiliation(s)
- Neil M Ferguson
- Medical Research Council Centre for Outbreak Analysis and Modelling, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK.
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Hannah Clapham
- Medical Research Council Centre for Outbreak Analysis and Modelling, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Ricardo Aguas
- Medical Research Council Centre for Outbreak Analysis and Modelling, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Vu Tuan Trung
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Tran Nguyen Bich Chau
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Jean Popovici
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Peter A Ryan
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Scott L O'Neill
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Elizabeth A McGraw
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Vo Thi Long
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Le Thi Dui
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Hoa L Nguyen
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam
| | - Nguyen Van Vinh Chau
- Hospital for Tropical Diseases, 190 Ben Hám Tú, District 5, Ho Chi Minh City 748010, Vietnam
| | - Bridget Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam. Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 7FZ, UK
| | - Cameron P Simmons
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Võ Vǎn Kiêt, District 5, Ho Chi Minh City 748010, Vietnam. Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 7FZ, UK. Department of Microbiology and Immunology and Nossal Institute of Global Health, University of Melbourne, Carlton, Victoria 3010, Australia
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8
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Whitehorn J, Nguyen CVV, Khanh LP, Kien DTH, Quyen NTH, Tran NTT, Hang NT, Truong NT, Hue Tai LT, Cam Huong NT, Nhon VT, Van Tram T, Farrar J, Wolbers M, Simmons CP, Wills B. Lovastatin for the Treatment of Adult Patients With Dengue: A Randomized, Double-Blind, Placebo-Controlled Trial. Clin Infect Dis 2015; 62:468-476. [PMID: 26565005 PMCID: PMC4725386 DOI: 10.1093/cid/civ949] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 10/29/2015] [Indexed: 11/30/2022] Open
Abstract
Dengue is a viral disease for which there is currently no therapeutic agent. We investigated the potential of lovastatin in the treatment of dengue. Lovastatin was safe and well tolerated, but did not demonstrate a therapeutic benefit. Background. Dengue endangers billions of people in the tropical world, yet no therapeutic is currently available. In part, the severe manifestations of dengue reflect inflammatory processes affecting the vascular endothelium. In addition to lipid lowering, statins have pleiotropic effects that improve endothelial function, and epidemiological studies suggest that outcomes from a range of acute inflammatory syndromes are improved in patients already on statin therapy. Methods. Following satisfactory review of a short pilot phase (40 mg lovastatin vs placebo in 30 cases), we performed a randomized, double-blind, placebo-controlled trial of 5 days of 80 mg lovastatin vs placebo in 300 Vietnamese adults with a positive dengue NS1 rapid test presenting within 72 hours of fever onset. The primary outcome was safety. Secondary outcomes included comparisons of disease progression rates, fever clearance times, and measures of plasma viremia and quality of life between the treatment arms. Results. Adverse events occurred with similar frequency in both groups (97/151 [64%] placebo vs 82/149 [55%] lovastatin; P = .13), and were in keeping with the characteristic clinical and laboratory features of acute dengue. We also observed no difference in serious adverse events or any of the secondary outcome measures. Conclusions. We found lovastatin to be safe and well tolerated in adults with dengue. However, although the study was not powered to address efficacy, we found no evidence of a beneficial effect on any of the clinical manifestations or on dengue viremia. Continuing established statin therapy in patients who develop dengue is safe. Chinese Clinical Trials Registration. ISRCTN03147572.
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Affiliation(s)
- James Whitehorn
- London School of Hygiene and Tropical Medicine, United Kingdom.,Oxford University Clinical Research Unit
| | | | | | | | | | | | | | | | | | | | | | | | - Jeremy Farrar
- Oxford University Clinical Research Unit.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Oxford University, United Kingdom
| | - Marcel Wolbers
- Oxford University Clinical Research Unit.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Oxford University, United Kingdom
| | - Cameron P Simmons
- Oxford University Clinical Research Unit.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Oxford University, United Kingdom.,Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne, Victoria, Australia
| | - Bridget Wills
- Oxford University Clinical Research Unit.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Oxford University, United Kingdom
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9
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Tuan NM, Nhan HT, Chau NVV, Hung NT, Tuan HM, Tram TV, Ha NLD, Loi P, Quang HK, Kien DTH, Hubbard S, Chau TNB, Wills B, Wolbers M, Simmons CP. Sensitivity and specificity of a novel classifier for the early diagnosis of dengue. PLoS Negl Trop Dis 2015; 9:e0003638. [PMID: 25836753 PMCID: PMC4383489 DOI: 10.1371/journal.pntd.0003638] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/23/2015] [Indexed: 11/19/2022] Open
Abstract
Background Dengue is the commonest arboviral disease of humans. An early and accurate diagnosis of dengue can support clinical management, surveillance and disease control and is central to achieving the World Health Organisation target of a 50% reduction in dengue case mortality by 2020. Methods 5729 children with fever of <72hrs duration were enrolled into this multicenter prospective study in southern Vietnam between 2010-2012. A composite of gold standard diagnostic tests identified 1692 dengue cases. Using statistical methods, a novel Early Dengue Classifier (EDC) was developed that used patient age, white blood cell count and platelet count to discriminate dengue cases from non-dengue cases. Results The EDC had a sensitivity of 74.8% (95%CI: 73.0-76.8%) and specificity of 76.3% (95%CI: 75.2-77.6%) for the diagnosis of dengue. As an adjunctive test alongside NS1 rapid testing, sensitivity of the composite test was 91.6% (95%CI: 90.4-92.9%). Conclusions We demonstrate that the early diagnosis of dengue can be enhanced beyond the current standard of care using a simple evidence-based algorithm. The results should support patient management and clinical trials of specific therapies. Dengue is a very common acute infectious disease in the tropical world. Health care professionals are able to better care for dengue patients if they can make an early diagnosis and make a plan for case management. This current study investigated fever in 5729 children in Vietnam with 3 days or less of fever and identified 1692 dengue cases using advanced, gold standard methods. We systematically collected a range of medical and laboratory findings on each patient when they entered the study and used statistical tools to determine if these medical and laboratory findings could enable early diagnosis, independent of sophisticated, gold-standard laboratory tests. Our results, called the Early Dengue Classifier, had performance characteristics suggesting it could improve the diagnostic proficiency of health care professionals. However the performance of the Early Dengue Classifier is not perfect and likely will not change the practice of experienced doctors in dengue endemic settings. Our study highlights the need for 2nd generation, easy-to-use rapid diagnostic tests that can accurately diagnose dengue in the first few days of fever.
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Affiliation(s)
| | - Ho Thi Nhan
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | | | - Ha Manh Tuan
- Children’s Hospital No. 2, Ho Chi Minh City, Vietnam
| | - Ta Van Tram
- Tien Giang Provincial Hospital, My Tho, Tien Giang Province, Vietnam
| | - Nguyen Le Da Ha
- Dong Nai Children’s Hospital, Bien Hoa, Dong Nai Province, Vietnam
| | - Phan Loi
- Long An Provincial Hospital, Tan An, Long An Province, Vietnam
| | - Han Khoi Quang
- Binh Duong Provincial Hospital, Thu Dau Mot, Binh Duong Province, Vietnam
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Sonya Hubbard
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria, Australia
| | - Tran Nguyen Bich Chau
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Bridget Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Marcel Wolbers
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Cameron P. Simmons
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria, Australia
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Nossal Institute of Global Health, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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10
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Whitehorn J, Kien DTH, Nguyen NM, Nguyen HL, Kyrylos PP, Carrington LB, Tran CNB, Quyen NTH, Thi LV, Le Thi D, Truong NT, Luong TTH, Nguyen CVV, Wills B, Wolbers M, Simmons CP. Comparative Susceptibility of Aedes albopictus and Aedes aegypti to Dengue Virus Infection After Feeding on Blood of Viremic Humans: Implications for Public Health. J Infect Dis 2015; 212:1182-90. [PMID: 25784733 PMCID: PMC4577038 DOI: 10.1093/infdis/jiv173] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/09/2015] [Indexed: 11/12/2022] Open
Abstract
Aedes albopictus is secondary to Aedes aegypti as a vector of dengue viruses (DENVs) in settings of endemicity, but it plays an important role in areas of dengue emergence. This study compared the susceptibility of these 2 species to DENV infection by performing 232 direct blood-feeding experiments on 118 viremic patients with dengue in Vietnam. Field-derived A. albopictus acquired DENV infections as readily as A. aegypti after blood feeding. Once infected, A. albopictus permitted higher concentrations of DENV RNA to accumulate in abdominal tissues, compared with A. aegypti. However, the odds of A. albopictus having infectious saliva were lower than the odds observed for A. aegypti (odds ratio, 0.70; 95% confidence interval, .52–.93). These results quantitate the susceptibility of A. albopictus to DENV infection and will assist parameterization of models for predicting disease risk in settings where A. albopictus is present.
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Affiliation(s)
- James Whitehorn
- London School of Hygiene and Tropical Medicine Oxford University Clinical Research Unit
| | | | | | | | | | | | | | | | | | - Dui Le Thi
- Oxford University Clinical Research Unit
| | | | | | | | - Bridget Wills
- Oxford University, United Kingdom Oxford University Clinical Research Unit
| | - Marcel Wolbers
- Oxford University, United Kingdom Oxford University Clinical Research Unit
| | - Cameron P Simmons
- Oxford University, United Kingdom Oxford University Clinical Research Unit University of Melbourne, Australia
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11
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Anders KL, Nga LH, Thuy NTV, Ngoc TV, Tam CT, Tai LTH, Truong NT, Duyen HTL, Trung VT, Kien DTH, Wolbers M, Wills B, Chau NVV, Tho ND, Simmons CP. Households as foci for dengue transmission in highly urban Vietnam. PLoS Negl Trop Dis 2015; 9:e0003528. [PMID: 25680106 PMCID: PMC4332484 DOI: 10.1371/journal.pntd.0003528] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/09/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Dengue control programs commonly employ reactive insecticide spraying around houses of reported cases, with the assumption that most dengue virus (DENV) transmission occurs in the home. Focal household transmission has been demonstrated in rural settings, but it is unclear whether this holds true in dense and mobile urban populations. We conducted a prospective study of dengue clustering around households in highly urban Ho Chi Minh City, Vietnam. METHODS We enrolled 71 index cases with suspected dengue (subsequently classified as 52 dengue cases and 19 non-dengue controls); each initiated the enrollment of a cluster of 25-35 household members and neighbors who were followed up over 14 days. Incident DENV infections in cluster participants were identified by RT-PCR, NS1-ELISA, and/or DENV-IgM/-IgG seroconversion, and recent infections by DENV-IgM positivity at baseline. PRINCIPAL FINDINGS/CONCLUSIONS There was no excess risk of DENV infection within dengue case clusters during the two-week follow-up, compared to control clusters, but the prevalence of recent DENV infection at baseline was two-fold higher in case clusters than controls (OR 2.3, 95%CI 1.0-5.1, p = 0.05). Prevalence of DENV infection in Aedes aegypti was similar in case and control houses, and low overall (1%). Our findings are broadly consistent with household clustering of dengue risk, but indicate that any clustering is at a short temporal scale rather than sustained chains of localized transmission. This suggests that reactive perifocal insecticide spraying may have a limited impact in this setting.
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Affiliation(s)
- Katherine L. Anders
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
- * E-mail:
| | - Le Hong Nga
- Preventive Medicine Centre, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Van Thuy
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Tran Van Ngoc
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Cao Thi Tam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | | | - Huynh Thi Le Duyen
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Vu Tuan Trung
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Marcel Wolbers
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Bridget Wills
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | - Cameron P. Simmons
- Oxford University Clinical Research Unit—Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
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12
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Nguyen NM, Thi Hue Kien D, Tuan TV, Quyen NTH, Tran CNB, Vo Thi L, Thi DL, Nguyen HL, Farrar JJ, Holmes EC, Rabaa MA, Bryant JE, Nguyen TT, Nguyen HTC, Nguyen LTH, Pham MP, Nguyen HT, Luong TTH, Wills B, Nguyen CVV, Wolbers M, Simmons CP. Host and viral features of human dengue cases shape the population of infected and infectious Aedes aegypti mosquitoes. Proc Natl Acad Sci U S A 2013; 110:9072-7. [PMID: 23674683 PMCID: PMC3670336 DOI: 10.1073/pnas.1303395110] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1-4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.
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Affiliation(s)
- Nguyet Minh Nguyen
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Trung Vu Tuan
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | | | - Chau N. B. Tran
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Long Vo Thi
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Dui Le Thi
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Hoa Lan Nguyen
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Jeremy J. Farrar
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, United Kingdom
| | - Edward C. Holmes
- Sydney Emerging Infections and Biosecurity Institute, School of Biological Sciences and Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia
- Fogarty International Center, National Institutes of Health, Bethesda, MD 20892;
| | - Maia A. Rabaa
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
| | - Juliet E. Bryant
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, United Kingdom
| | | | | | | | - Mai Phuong Pham
- Hospital for Tropical Diseases, District 5, Ho Chi Minh City, Vietnam; and
| | - Hung The Nguyen
- Hospital for Tropical Diseases, District 5, Ho Chi Minh City, Vietnam; and
| | - Tai Thi Hue Luong
- Hospital for Tropical Diseases, District 5, Ho Chi Minh City, Vietnam; and
| | - Bridget Wills
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, United Kingdom
| | | | - Marcel Wolbers
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, United Kingdom
| | - Cameron P. Simmons
- Oxford University Clinical Research Unit, District 5, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, United Kingdom
- Nossal Institute for Global Health, University of Melbourne, VIC 3010, Australia
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13
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Whitehorn J, Chau TNB, Nguyet NM, Kien DTH, Quyen NTH, Trung DT, Pang J, Wills B, Van Vinh Chau N, Farrar J, Hibberd ML, Khor CC, Simmons CP. Genetic variants of MICB and PLCE1 and associations with non-severe dengue. PLoS One 2013; 8:e59067. [PMID: 23536857 PMCID: PMC3594159 DOI: 10.1371/journal.pone.0059067] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/11/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND A recent genome-wide association study (GWAS) identified susceptibility loci for dengue shock syndrome (DSS) at MICB rs3132468 and PLCE1 rs3740360. The aim of this study was to define the extent to which MICB (rs3132468) and PLCE1 (rs3740360) were associated with less severe clinical phenotypes of pediatric and adult dengue. METHODS 3961 laboratory-confirmed dengue cases and 5968 controls were genotyped at MICB rs3132468 and PLCE1 rs3740360. Per-allele odds ratios (OR) with 95% confidence intervals (CI) were calculated for each patient cohort. Pooled analyses were performed for adults and paediatrics respectively using a fixed effects model. RESULTS Pooled analysis of the paediatric and adult cohorts indicated a significant association between MICB rs3132468 and dengue cases without shock (OR = 1.15; 95%CI: 1.07 - 1.24; P = 0.0012). Similarly, pooled analysis of pediatric and adult cohorts indicated a significant association between dengue cases without shock and PLCE1 rs3740360 (OR = 0.92; 95%CI: 0.85 - 0.99; P = 0.018). We also note significant association between both SNPs (OR = 1.48; P = 0.0075 for MICB rs3132468 and OR = 0.75, P = 0.041 for PLCE1 rs3740360) and dengue in infants. DISCUSSION This study confirms that the MICB rs3132468 and PLCE1 rs3740360 risk genotypes are not only associated with DSS, but are also associated with less severe clinical phenotypes of dengue, as well as with dengue in infants. These findings have implications for our understanding of dengue pathogenesis.
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Affiliation(s)
- James Whitehorn
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom.
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Dung TTN, Phat VV, Nga TVT, My PVT, Duy PT, Campbell JI, Thuy CT, Hoang NVM, Van Minh P, Le Phuc H, Tuyet PTN, Vinh H, Kien DTH, Huy HLA, Vinh NT, Nga TTT, Hau NTT, Chinh NT, Thuong TC, Tuan HM, Simmons C, Farrar JJ, Baker S. The validation and utility of a quantitative one-step multiplex RT real-time PCR targeting rotavirus A and norovirus. J Virol Methods 2012; 187:138-43. [PMID: 23046990 PMCID: PMC3528950 DOI: 10.1016/j.jviromet.2012.09.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 09/21/2012] [Accepted: 09/25/2012] [Indexed: 12/17/2022]
Abstract
Rotavirus (RoV) and Norovirus (NoV) are the main causes of viral gastroenteritis. Currently, there is no validated multiplex real-time PCR that can detect and quantify RoV and NoV simultaneously. The aim of the study was to develop, validate, and internally control a multiplex one-step RT real-time PCR to detect and quantify RoV and NoV in stool samples. PCR sensitivity was assessed by comparing amplification against the current gold standard, enzyme immunoassay (EIA), on stool samples from 94 individuals with diarrhea and 94 individuals without diarrhea. PCR detected 10% more RoV positive samples than EIA in stools samples from patients with diarrhea. PCR detected 23% more NoV genogroup II positive samples from individuals with diarrhea and 9% more from individuals without diarrhea than EIA, respectively. Genotyping of the PCR positive/EIA negative samples suggested the higher rate of PCR positivity, in comparison to EIA, was due to increased sensitivity, rather than nonspecific hybridization. Quantitation demonstrated that the viral loads of RoV and NoV in the stools of diarrheal patients were an order of magnitude greater than in individuals without diarrhea. This internally controlled real-time PCR method is robust, exhibits a high degree of reproducibility, and may have a greater utility and sensitivity than commercial EIA kits.
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Affiliation(s)
- Tran Thi Ngoc Dung
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
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