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Chen Y, Nguyet LA, Nhan LNT, Qui PT, Nhu LNT, Hong NTT, Ny NTH, Anh NT, Thanh LK, Phuong HT, Vy NHT, Thanh NTL, Khanh TH, Hung NT, Viet DC, Nam NT, Chau NVV, van Doorn HR, Tan LV, Clapham H. Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: A catalytic model with maternal immunity. Epidemics 2024; 46:100754. [PMID: 38428358 PMCID: PMC10945305 DOI: 10.1016/j.epidem.2024.100754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 02/05/2024] [Accepted: 02/24/2024] [Indexed: 03/03/2024] Open
Abstract
Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013-2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam.
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Affiliation(s)
- Yining Chen
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.
| | - Lam Anh Nguyet
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | | | - Phan Tu Qui
- Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam
| | | | | | - Nguyen Thi Han Ny
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Nguyen To Anh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Le Kim Thanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Huynh Thi Phuong
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Nguyen Ha Thao Vy
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | | | | | | | - Do Chau Viet
- Children's Hospital 2, Ho Chi Minh City, Viet Nam
| | | | - Nguyen Van Vinh Chau
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam
| | - H Rogier van Doorn
- Oxford University Clinical Research Unit, Hanoi, Viet Nam; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Le Van Tan
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Hannah Clapham
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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Welsh FC, Eguia RT, Lee JM, Haddox HK, Galloway J, Chau NVV, Loes AN, Huddleston J, Yu TC, Le MQ, Nhat NTD, Thanh NTL, Greninger AL, Chu HY, Englund JA, Bedford T, Matsen FA, Boni MF, Bloom JD. Age-dependent heterogeneity in the antigenic effects of mutations to influenza hemagglutinin. bioRxiv 2023:2023.12.12.571235. [PMID: 38168237 PMCID: PMC10760046 DOI: 10.1101/2023.12.12.571235] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population, and how this heterogeneity affects virus evolution. Here we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of the A/Hong Kong/45/2019 (H3N2) and A/Perth/16/2009 (H3N2) strains affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that fixed in influenza variants after 2020 cause the greatest escape from sera from younger individuals. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups, and suggest approaches to understand how this heterogeneous selection shapes viral evolution.
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Affiliation(s)
- Frances C Welsh
- Molecular and Cellular Biology Graduate Program, University of Washington, and Basic Sciences Division, Fred Hutch Cancer Center, Seattle, WA, 98109, USA
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Rachel T Eguia
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
| | - Juhye M Lee
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
| | - Hugh K Haddox
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Jared Galloway
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Nguyen Van Vinh Chau
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Andrea N Loes
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
| | - John Huddleston
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Timothy C Yu
- Molecular and Cellular Biology Graduate Program, University of Washington, and Basic Sciences Division, Fred Hutch Cancer Center, Seattle, WA, 98109, USA
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Mai Quynh Le
- National Institutes for Hygiene and Epidemiology, Hanoi, Vietnam
| | - Nguyen T D Nhat
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Nguyen Thi Le Thanh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Alexander L Greninger
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, 98195, USA
- Division of Allergy and Infectious Diseases, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Helen Y Chu
- Division of Allergy and Infectious Diseases, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Janet A Englund
- Seattle Children's Research Institute, Seattle, WA, 98109, USA
| | - Trevor Bedford
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Frederick A Matsen
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
| | - Maciej F Boni
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Jesse D Bloom
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Seattle, WA, 98109, USA
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Yang F, Servadio JL, Thanh NTL, Lam HM, Choisy M, Thai PQ, Thao TTN, Vy NHT, Phuong HT, Nguyen TD, Tam DTH, Hanks EM, Vinh H, Bjornstad ON, Chau NVV, Boni MF. A combination of annual and nonannual forces drive respiratory disease in the tropics. BMJ Glob Health 2023; 8:e013054. [PMID: 37935520 PMCID: PMC10632872 DOI: 10.1136/bmjgh-2023-013054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 06/06/2023] [Accepted: 10/08/2023] [Indexed: 11/09/2023] Open
Abstract
INTRODUCTION It is well known that influenza and other respiratory viruses are wintertime-seasonal in temperate regions. However, respiratory disease seasonality in the tropics is less well understood. In this study, we aimed to characterise the seasonality of influenza-like illness (ILI) and influenza virus in Ho Chi Minh City, Vietnam. METHODS We monitored the daily number of ILI patients in 89 outpatient clinics from January 2010 to December 2019. We collected nasal swabs and tested for influenza from a subset of clinics from May 2012 to December 2019. We used spectral analysis to describe the periodic signals in the system. We evaluated the contribution of these periodic signals to predicting ILI and influenza patterns through lognormal and gamma hurdle models. RESULTS During 10 years of community surveillance, 66 799 ILI reports were collected covering 2.9 million patient visits; 2604 nasal swabs were collected, 559 of which were PCR-positive for influenza virus. Both annual and nonannual cycles were detected in the ILI time series, with the annual cycle showing 8.9% lower ILI activity (95% CI 8.8% to 9.0%) from February 24 to May 15. Nonannual cycles had substantial explanatory power for ILI trends (ΔAIC=183) compared with all annual covariates (ΔAIC=263) in lognormal regression. Near-annual signals were observed for PCR-confirmed influenza but were not consistent over time or across influenza (sub)types. The explanatory power of climate factors for ILI and influenza virus trends was weak. CONCLUSION Our study reveals a unique pattern of respiratory disease dynamics in a tropical setting influenced by both annual and nonannual drivers, with influenza dynamics showing near-annual periodicities. Timing of vaccination campaigns and hospital capacity planning may require a complex forecasting approach.
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Affiliation(s)
- Fuhan Yang
- Department of Biology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Joseph L Servadio
- Department of Biology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Nguyen Thi Le Thanh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Ha Minh Lam
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Marc Choisy
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pham Quang Thai
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Tran Thi Nhu Thao
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Nguyen Ha Thao Vy
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Huynh Thi Phuong
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran Dang Nguyen
- Department of Biology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Dong Thi Hoai Tam
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Ephraim M Hanks
- Department of Statistics and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ha Vinh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ottar N Bjornstad
- Department of Biology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Nguyen Van Vinh Chau
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Maciej F Boni
- Department of Biology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, USA
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
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4
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Yang F, Servadio JL, Le Thanh NT, Lam HM, Choisy M, Thai PQ, Nhu Thao TT, Thao Vy NH, Phuong HT, Nguyen TD, Hoai Tam DT, Hanks EM, Vinh H, Bjornstad ON, Van Vinh Chau N, Boni MF. A combination of annual and nonannual forces drive respiratory disease in the tropics. medRxiv 2023:2023.03.28.23287862. [PMID: 37034752 PMCID: PMC10081429 DOI: 10.1101/2023.03.28.23287862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Background It is well known that influenza and other respiratory viruses are wintertime-seasonal in temperate regions. However, respiratory disease seasonality in the tropics remains elusive. In this study, we aimed to characterize the seasonality of influenza-like illness (ILI) and influenza virus in Ho Chi Minh City (HCMC), Vietnam. Methods We monitored the daily number of ILI patients in 89 outpatient clinics from January 2010 to December 2019. We collected nasal swabs and tested for influenza from a subset of clinics from May 2012 to December 2019. We used spectral analysis to describe the periodicities in the system. We evaluated the contribution of these periodicities to predicting ILI and influenza patterns through lognormal and gamma hurdle models. Findings During ten years of community surveillance, 66,799 ILI reports were collected covering 2.9 million patient visits; 2604 nasal swabs were collected 559 of which were PCR-positive for influenza virus. Both annual and nonannual cycles were detected in the ILI time series, with the annual cycle showing 8.9% lower ILI activity (95% CI: 8.8%-9.0%) from February 24 to May 15. Nonannual cycles had substantial explanatory power for ILI trends (ΔAIC = 183) compared to all annual covariates (ΔAIC = 263). Near-annual signals were observed for PCR-confirmed influenza but were not consistent along in time or across influenza (sub)types. Interpretation Our study reveals a unique pattern of respiratory disease dynamics in a tropical setting influenced by both annual and nonannual drivers. Timing of vaccination campaigns and hospital capacity planning may require a complex forecasting approach.
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Affiliation(s)
- Fuhan Yang
- Department of Biology and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
| | - Joseph L Servadio
- Department of Biology and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
| | - Nguyen Thi Le Thanh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Ha Minh Lam
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Marc Choisy
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pham Quang Thai
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Tran Thi Nhu Thao
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, United States
| | - Nguyen Ha Thao Vy
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Huynh Thi Phuong
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran Dang Nguyen
- Department of Biology and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Dong Thi Hoai Tam
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Ephraim M Hanks
- Department of Statistics and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
| | - Ha Vinh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ottar N Bjornstad
- Department of Biology and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
| | - Nguyen Van Vinh Chau
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Maciej F Boni
- Department of Biology and Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, 16802, United States
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Thwaites CL, Thanh TT, Ny NTH, Nguyet LA, Nhat NTD, Thuy CT, Thanh NTL, Dung NT, Campbell J, Thai PQ, Tan LV, Choisy M, Boni MF. Seroprotection against tetanus in southern Vietnam. Vaccine 2023; 41:2208-2213. [PMID: 36849339 PMCID: PMC10580288 DOI: 10.1016/j.vaccine.2023.02.036] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/17/2023] [Accepted: 02/10/2023] [Indexed: 02/27/2023]
Abstract
BACKGROUND Ongoing tetanus cases and sporadic outbreaks of vaccine-preventable diseases associated with routine vaccination programmes remain problems in many low and middle-income countries, including Vietnam. With no human-to-human transmission or natural immunity, tetanus antibody levels indicate both individual risk of tetanus and gaps in vaccination programmes. METHODS To investigate gaps in immunity to tetanus in Vietnam, a country with a historically high level of tetanus vaccination coverage, tetanus antibodies were measure by ELISA from samples selected from a long-term serum bank, established for the purposes of general-population seroepidemiological investigations in southern Vietnam. Samples were selected from 10 provinces, focussing on age-groups targeted by national vaccination programmes for infants and pregnant women (Expanded Programme on Immunization, EPI, and Maternal and Neonatal Tetanus, MNT). RESULTS Antibodies were measured from a total of 3864 samples. Highest tetanus antibody concentrations occurred in children under 4 years old, over 90 % of whom had protective levels. Approximately 70 % of children aged 7-12 years had protective antibody concentrations although there was variation among provinces. For infants and children, there were no significant differences in tetanus protection between males and females, but for adults aged 20-35 years, in five of the ten provinces surveyed, protection against tetanus was higher in females (p < 0.05) who are eligible for booster doses under the MNT programme. In seven of ten provinces, antibody concentrations were inversely related to age (p < 0.01) and protection of older individuals was generally low. CONCLUSION Widespread immunity to tetanus toxoid is seen in infants and young children consistent with the high coverage rates reported for diptheria tetanus toxoid and pertussis (DTP) in Vietnam. However, the lower antibody concentrations seen in older children and men suggest reduced immunity to tetanus in populations not targeted by EPI and MNT programmes.
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Affiliation(s)
- C Louise Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Centre for Global Health and Tropical Medicine, University of Oxford, UK
| | - Tran Tan Thanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Nguyen Thi Han Ny
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Lam Anh Nguyet
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | | | - Cao Thu Thuy
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | | | | | - James Campbell
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Centre for Global Health and Tropical Medicine, University of Oxford, UK.
| | - Pham Quang Thai
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam; School of Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Viet Nam
| | - Le Van Tan
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Marc Choisy
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Centre for Global Health and Tropical Medicine, University of Oxford, UK
| | - Maciej F Boni
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam; Centre for Global Health and Tropical Medicine, University of Oxford, UK; Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, United States
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6
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Vinh DN, Nhat NTD, de Bruin E, Vy NHT, Thao TTN, Phuong HT, Anh PH, Todd S, Quan TM, Thanh NTL, Lien NTN, Ha NTH, Hong TTK, Thai PQ, Choisy M, Nguyen TD, Simmons CP, Thwaites GE, Clapham HE, Chau NVV, Koopmans M, Boni MF. Age-seroprevalence curves for the multi-strain structure of influenza A virus. Nat Commun 2021; 12:6680. [PMID: 34795239 PMCID: PMC8602397 DOI: 10.1038/s41467-021-26948-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/27/2021] [Indexed: 11/21/2022] Open
Abstract
The relationship between age and seroprevalence can be used to estimate the annual attack rate of an infectious disease. For pathogens with multiple serologically distinct strains, there is a need to describe composite exposure to an antigenically variable group of pathogens. In this study, we assay 24,402 general-population serum samples, collected in Vietnam between 2009 to 2015, for antibodies to eleven human influenza A strains. We report that a principal components decomposition of antibody titer data gives the first principal component as an appropriate surrogate for seroprevalence; this results in annual attack rate estimates of 25.6% (95% CI: 24.1% - 27.1%) for subtype H3 and 16.0% (95% CI: 14.7% - 17.3%) for subtype H1. The remaining principal components separate the strains by serological similarity and associate birth cohorts with their particular influenza histories. Our work shows that dimensionality reduction can be used on human antibody profiles to construct an age-seroprevalence relationship for antigenically variable pathogens.
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MESH Headings
- Algorithms
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Geography
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Humans
- Immunoglobulin G/blood
- Immunoglobulin G/immunology
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza A Virus, H1N1 Subtype/physiology
- Influenza A Virus, H3N2 Subtype/immunology
- Influenza A Virus, H3N2 Subtype/physiology
- Influenza A virus/classification
- Influenza A virus/immunology
- Influenza A virus/physiology
- Influenza, Human/epidemiology
- Influenza, Human/immunology
- Influenza, Human/virology
- Models, Theoretical
- Seroepidemiologic Studies
- Time Factors
- Vietnam/epidemiology
- Virus Replication/immunology
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Affiliation(s)
- Dao Nguyen Vinh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Duy Nhat
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Erwin de Bruin
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Nguyen Ha Thao Vy
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Tran Thi Nhu Thao
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Huynh Thi Phuong
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Pham Hong Anh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Stacy Todd
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Liverpool School of Tropical Medicine, Liverpool, UK
- Tropical and Infectious Disease Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, England
| | - Tran Minh Quan
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Le Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | | | | | | | - Pham Quang Thai
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Marc Choisy
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tran Dang Nguyen
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Cameron P Simmons
- Institute of Vector Borne Disease, Monash University, Melbourne, VIC, Australia
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Hannah E Clapham
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | | | - Marion Koopmans
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Maciej F Boni
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, USA.
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7
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Delabouglise A, Thanh NTL, Xuyen HTA, Nguyen-Van-Yen B, Tuyet PN, Lam HM, Boni MF. Poultry farmer response to disease outbreaks in smallholder farming systems in southern Vietnam. eLife 2020; 9:59212. [PMID: 32840482 PMCID: PMC7505654 DOI: 10.7554/elife.59212] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 05/22/2020] [Accepted: 08/21/2020] [Indexed: 01/24/2023] Open
Abstract
Avian influenza outbreaks have been occurring on smallholder poultry farms in Asia for two decades. Farmer responses to these outbreaks can slow down or accelerate virus transmission. We used a longitudinal survey of 53 small-scale chicken farms in southern Vietnam to investigate the impact of outbreaks with disease-induced mortality on harvest rate, vaccination, and disinfection behaviors. We found that in small broiler flocks (≤16 birds/flock) the estimated probability of harvest was 56% higher when an outbreak occurred, and 214% higher if an outbreak with sudden deaths occurred in the same month. Vaccination and disinfection were strongly and positively correlated with the number of birds. Small-scale farmers – the overwhelming majority of poultry producers in low-income countries – tend to rely on rapid sale of birds to mitigate losses from diseases. As depopulated birds are sent to markets or trading networks, this reactive behavior has the potential to enhance onward transmission. The past few decades have seen the circulation of avian influenza viruses increase in domesticated poultry, regularly creating outbreaks associated with heavy economic loss. In addition, these viruses can sometimes ‘jump’ into humans, potentially allowing new diseases – including pandemics – to emerge. The Mekong river delta, in southern Vietnam, is one of the regions with the highest circulation of avian influenza. There, a large number of farmers practice poultry farming on a small scale, with limited investments in disease prevention such as vaccination or disinfection. Yet, it was unclear how the emergence of an outbreak could change the behavior of farmers. To learn more, Delabouglise et al. monitored 53 poultry farms, with fewer than 1000 chickens per farm, monthly for over a year and a half. In particular, they tracked when outbreaks occurred on each farm, and how farmers reacted. Overall, poultry farms with more than 17 chickens were more likely to vaccinate their animals and use disinfection practices than smaller farms. However, disease outbreaks did not affect vaccination or disinfection practices. When an outbreak occurred, farmers with fewer than 17 chickens tended to sell their animals earlier. For instance, they were 214% more likely to send their animals to market if an outbreak with sudden deaths occurred that month. Even if they do not make as much money selling immature individuals, this strategy may allow them to mitigate economical loss: they can sell animals that may die soon, saving on feeding costs and potentially avoiding further contamination. However, as animals were often sold alive in markets or to itinerant sellers, this practice increases the risk of spreading diseases further along the trade circuits. These data could be most useful to regional animal health authorities, which have detailed knowledge of local farming systems and personal connections in the communities where they work. This can allow them to effect change. They could work with small poultry farmers to encourage them to adopt efficient disease management strategies. Ultimately, this could help control the spread of avian influenza viruses, and potentially help to avoid future pandemics.
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Affiliation(s)
- Alexis Delabouglise
- Center for Infectious Diseases Dynamics, The Pennsylvania State University, University Park, United States.,UMR ASTRE, CIRAD, INRAE, Université de Montpellier, Montpellier, France
| | - Nguyen Thi Le Thanh
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Huynh Thi Ai Xuyen
- Ca Mau sub-Department of Livestock Production and Animal Health, Ca Mau, Viet Nam
| | - Benjamin Nguyen-Van-Yen
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam.,École Normale Supérieure, CNRS UMR 8197, Paris, France
| | - Phung Ngoc Tuyet
- Ca Mau sub-Department of Livestock Production and Animal Health, Ca Mau, Viet Nam
| | - Ha Minh Lam
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Maciej F Boni
- Center for Infectious Diseases Dynamics, The Pennsylvania State University, University Park, United States.,Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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8
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Anh DD, Choisy M, Clapham HE, Cuong HQ, Dung VTV, Duong TN, Hang NLK, Ha HTT, Hien NT, Hoa TTN, Hung TTM, Huong VTL, Huyen DTT, Khanh NC, Lewycka SO, Linley E, Mai LTQ, Nadjm B, Nghia ND, Pebody R, Phuong HVM, Tan LM, Van Tan L, Thai PQ, Thanh LV, Le Thanh NT, Thuy NTT, Thuong NT, Thanh LT, Thao NTT, Tuan NA, Uyen PTN, Rogier van Doorn H. Plans for Nationwide Serosurveillance Network in Vietnam. Emerg Infect Dis 2019; 26. [PMID: 31855527 PMCID: PMC6924907 DOI: 10.3201/eid2601.190641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In recent years, serosurveillance has gained momentum as a way of determining disease transmission and immunity in populations, particularly with respect to vaccine-preventable diseases. At the end of 2017, the Oxford University Clinical Research Unit and the National Institute of Hygiene and Epidemiology held a meeting in Vietnam with national policy makers, researchers, and international experts to discuss current seroepidemiologic projects in Vietnam and future needs and plans for nationwide serosurveillance. This report summarizes the meeting and the plans that were discussed to set up nationwide serosurveillance in Vietnam.
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9
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Lam HM, Phuong HT, Thao Vy NH, Le Thanh NT, Dung PN, Ngoc Muon TT, Van Vinh Chau N, Rodríguez-Barraquer I, Cummings DAT, Wills BA, Boni MF, Rabaa MA, Clapham HE. Serological inference of past primary and secondary dengue infection: implications for vaccination. J R Soc Interface 2019; 16:20190207. [PMID: 31362614 PMCID: PMC6685028 DOI: 10.1098/rsif.2019.0207] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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] [Indexed: 12/16/2022] Open
Abstract
Owing to the finding that Dengvaxia® (the only licensed dengue vaccine to date) increases the risk of severe illness among seronegative recipients, the World Health Organization has recommended screening individuals for their serostatus prior to vaccination. To decide whether and how to carry out screening, it is necessary to estimate the transmission intensity of dengue and to understand the performance of the screening method. In this study, we inferred the annual force of infection (FOI; a measurement of transmission intensity) of dengue virus in three locations in Vietnam: An Giang (FOI = 0.04 for the below 10 years age group and FOI = 0.20 for the above 10 years age group), Ho Chi Minh City (FOI = 0.12) and Quang Ngai (FOI = 0.05). In addition, we show that using a quantitative approach to immunoglobulin G (IgG) levels (measured by indirect enzyme-linked immunosorbent assays) can help to distinguish individuals with primary exposures (primary seropositive) from those with secondary exposures (secondary seropositive). We found that primary-seropositive individuals—the main targets of the vaccine—tend to have a lower IgG level, and, thus, they have a higher chance of being misclassified as seronegative than secondary-seropositive cases. However, screening performance can be improved by incorporating patient age and transmission intensity into the interpretation of IgG levels.
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Affiliation(s)
- Ha Minh Lam
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Huynh Thi Phuong
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Ha Thao Vy
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Le Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Pham Ngoc Dung
- Laboratory Department, An Giang Central General Hospital, An Giang, Vietnam
| | - Thai Thi Ngoc Muon
- Department of Biochemistry, Quang Ngai General Hospital, Quang Ngai, Vietnam
| | | | | | - Derek A T Cummings
- Department of Biology, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Bridget A Wills
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Maciej F Boni
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - Maia A Rabaa
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Hannah E Clapham
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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10
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Delabouglise A, Nguyen-Van-Yen B, Thanh NTL, Xuyen HTA, Tuyet PN, Lam HM, Boni MF. Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region. BMC Vet Res 2019; 15:205. [PMID: 31208467 PMCID: PMC6580564 DOI: 10.1186/s12917-019-1949-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 09/28/2018] [Accepted: 06/04/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. METHOD Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. RESULTS Median flock population sizes were 16 for chickens (IQR: 10-40), 32 for ducks (IQR: 18-101) and 11 for Muscovy ducks (IQR: 7-18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01-0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall's coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). CONCLUSION The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity.
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Affiliation(s)
- Alexis Delabouglise
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, Millenium Sciences Complex, Pollock road, University Park, PA, 16802, USA.
| | - Benjamin Nguyen-Van-Yen
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,École Normale Supérieure, CNRS UMR 8197, 46 rue d'Ulm, Paris, France
| | - Nguyen Thi Le Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Huynh Thi Ai Xuyen
- Ca Mau sub-Department of Livestock Production and Animal Health, Ca Mau, Vietnam
| | - Phung Ngoc Tuyet
- Ca Mau sub-Department of Livestock Production and Animal Health, Ca Mau, Vietnam
| | - Ha Minh Lam
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Maciej F Boni
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, Millenium Sciences Complex, Pollock road, University Park, PA, 16802, USA.,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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11
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Lam HM, Wesolowski A, Hung NT, Nguyen TD, Nhat NTD, Todd S, Vinh DN, Vy NHT, Thao TTN, Thanh NTL, Tin PT, Minh NNQ, Bryant JE, Buckee CO, Ngoc TV, Chau NVV, Thwaites GE, Farrar J, Tam DTH, Vinh H, Boni MF. Nonannual seasonality of influenza-like illness in a tropical urban setting. Influenza Other Respir Viruses 2018; 12:742-754. [PMID: 30044029 PMCID: PMC6185894 DOI: 10.1111/irv.12595] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 12/11/2017] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular. METHODS To obtain a detailed picture of influenza-like illness (ILI) patterns in the tropics, we established an mHealth study in community clinics in Ho Chi Minh City (HCMC). During 2009-2015, clinics reported daily case numbers via SMS, with a subset performing molecular diagnostics for influenza virus. This real-time epidemiology network absorbs 6000 ILI reports annually, one or two orders of magnitude more than typical surveillance systems. A real-time online ILI indicator was developed to inform clinicians of the daily ILI activity in HCMC. RESULTS From August 2009 to December 2015, 63 clinics were enrolled and 36 920 SMS reports were received, covering approximately 1.7M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong nonannual dynamics with a dominant periodicity of 206 days. This was confirmed by time series decomposition, stepwise regression, and a forecasting exercise showing that median forecasting errors are 30%-40% lower when using a 206-day cycle. In ILI patients from whom nasopharyngeal swabs were taken, 31.2% were positive for influenza. There was no correlation between the ILI time series and the time series of influenza, influenza A, or influenza B (all P > 0.15). CONCLUSION This suggests, for the first time, that a nonannual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism.
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Affiliation(s)
- Ha Minh Lam
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Amy Wesolowski
- Center for Communicable Disease DynamicsDepartment of EpidemiologyHarvard T.H. Chan School of Public HealthBostonMassachusetts
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNew Jersey
| | - Nguyen Thanh Hung
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Tran Dang Nguyen
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Nguyen Thi Duy Nhat
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Stacy Todd
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Liverpool School of Tropical MedicineLiverpoolUK
| | - Dao Nguyen Vinh
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Nguyen Ha Thao Vy
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Tran Thi Nhu Thao
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Nguyen Thi Le Thanh
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | | | - Ngo Ngoc Quang Minh
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Children's Hospital No. 1Ho Chi Minh CityVietnam
| | - Juliet E. Bryant
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Caroline O. Buckee
- Center for Communicable Disease DynamicsDepartment of EpidemiologyHarvard T.H. Chan School of Public HealthBostonMassachusetts
| | - Tran Van Ngoc
- Hospital for Tropical DiseasesHo Chi Minh CityVietnam
| | | | - Guy E. Thwaites
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Jeremy Farrar
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Wellcome TrustLondonUK
| | - Dong Thi Hoai Tam
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
| | - Ha Vinh
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Hospital for Tropical DiseasesHo Chi Minh CityVietnam
- Department of Infectious DiseasesPham Ngoc Thach University of MedicineHo Chi Minh CityVietnam
| | - Maciej F. Boni
- Oxford University Clinical Research UnitWellcome Trust Major Overseas ProgrammeHo Chi Minh CityVietnam
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineUniversity of OxfordOxfordUK
- Center for Infectious Disease DynamicsDepartment of BiologyPennsylvania State UniversityUniversity ParkPennsylvania
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12
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Todd S, Huong NTC, Thanh NTL, Vy NHT, Hung NT, Thao TTN, Phuong HT, van Doorn R, Hang VTT, Chau NVV, Read JM, Lalloo DG, Boni MF. Primary care influenza-like illness surveillance in Ho Chi Minh City, Vietnam 2013-2015. Influenza Other Respir Viruses 2018; 12:623-631. [PMID: 29858879 PMCID: PMC6086852 DOI: 10.1111/irv.12574] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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] [Accepted: 05/11/2018] [Indexed: 12/22/2022] Open
Abstract
Background Year‐round transmission of influenza has been detected in Vietnam through both national surveillance and other epidemiological studies. Understanding the demographic and clinical features of influenza‐like illness (ILI) presenting to primary care in urban Vietnam is vital to understand these transmission dynamics. Methods An observational study of patients with ILI in Ho Chi Minh City, Vietnam, was conducted between August 2013 and November 2015 in a mix of public and private primary care settings. Molecular testing for influenza A and influenza B and 12 other respiratory viruses was performed. Results A total of 1152 ILI patients were recruited. 322 and 136 subjects tested positive for influenza A and influenza B, respectively. 193 subjects tested positive for another respiratory virus; most commonly rhinovirus and parainfluenza virus 3. Influenza was detected in 81% of the 116 study weeks. Three peaks of influenza activity were detected; an H3N2 peak April‐June 2014, an influenza B peak July‐December 2014, and a mixed H3N2 and H1N1 peak March‐September 2015. Subjects recruited from private clinics were more likely to have higher income and to have reported previous influenza vaccination. Antibiotic use was common (50.3%) despite limited evidence of bacterial infection. Conclusion Influenza in southern Vietnam has complex transmission dynamics including periods of intense influenza activity of alternating types and subtypes. Broadening surveillance from hospital to the community in tropical settings is feasible and a valuable for improving our understanding of the global spread and evolution of the virus.
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Affiliation(s)
- Stacy Todd
- Liverpool School of Tropical Medicine, Liverpool, UK.,Tropical and Infectious Disease Unit, Royal Liverpool and Broadgreen University Hospital, Liverpool, UK.,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | | | - Nguyen Thi Le Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Ha Thao Vy
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thanh Hung
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Tran Thi Nhu Thao
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Huynh Thi Phuong
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Rogier van Doorn
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Vu Thi Ty Hang
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Van Vinh Chau
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Jonathan M Read
- Centre for Health Informatics Computing and Statistics, Lancaster Medical School, Lancaster University, Lancaster, UK.,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - David G Lalloo
- Liverpool School of Tropical Medicine, Liverpool, UK.,Tropical and Infectious Disease Unit, Royal Liverpool and Broadgreen University Hospital, Liverpool, UK
| | - Maciej F Boni
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, USA
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13
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Quan TM, Phuong HT, Vy NHT, Thanh NTL, Lien NTN, Hong TTK, Dung PN, Chau NVV, Boni MF, Clapham HE. Evidence of previous but not current transmission of chikungunya virus in southern and central Vietnam: Results from a systematic review and a seroprevalence study in four locations. PLoS Negl Trop Dis 2018; 12:e0006246. [PMID: 29425199 PMCID: PMC5823466 DOI: 10.1371/journal.pntd.0006246] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 09/14/2017] [Revised: 02/22/2018] [Accepted: 01/18/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Arbovirus infections are a serious concern in tropical countries due to their high levels of transmission and morbidity. With the outbreaks of chikungunya (CHIKV) in surrounding regions in recent years and the fact that the environment in Vietnam is suitable for the vectors of CHIKV, the possibility of transmission of CHIKV in Vietnam is of great interest. However, information about CHIKV activity in Vietnam remains limited. METHODOLOGY In order to address this question, we performed a systematic review of CHIKV in Vietnam and a CHIKV seroprevalence survey. The seroprevalence survey tested for CHIKV IgG in population serum samples from individuals of all ages in 2015 from four locations in Vietnam. PRINCIPAL FINDINGS The four locations were An Giang province (n = 137), Ho Chi Minh City (n = 136), Dak Lak province (n = 137), and Hue City (n = 136). The findings give us evidence of some CHIKV activity: 73/546 of overall samples were seropositive (13.4%). The age-adjusted seroprevalences were 12.30% (6.58-18.02), 13.42% (7.16-19.68), 7.97% (3.56-12.38), and 3.72% (1.75-5.69) in An Giang province, Ho Chi Minh City, Dak Lak province, and Hue City respectively. However, the age-stratified seroprevalence suggests that the last transmission ended around 30 years ago, consistent with results from the systematic review. We see no evidence for on-going transmission in three of the locations, though with some evidence of recent exposure in Dak Lak, most likely due to transmission in neighbouring countries. Before the 1980s, when transmission was occurring, we estimate on average 2-4% of the population were infected each year in HCMC and An Giang and Hue (though transmision ended earlier in Hue). We estimate lower transmission in Dak Lak, with around 1% of the population infected each year. CONCLUSION In conclusion, we find evidence of past CHIKV transmission in central and southern Vietnam, but no evidence of recent sustained transmission. When transmission of CHIKV did occur, it appeared to be widespread and affect a geographically diverse population. The estimated susceptibility of the population to chikungunya is continually increasing, therefore the possibility of future CHIKV transmission in Vietnam remains.
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Affiliation(s)
- Tran Minh Quan
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- * E-mail:
| | - Huynh Thi Phuong
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Ha Thao Vy
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Le Thanh
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Nam Lien
- Microbiology Department, Hue Central Hospital, Hue, Thua Thien Hue province, Vietnam
| | - Tran Thi Kim Hong
- Laboratory Department, Dak Lak General Hospital, Buon Ma Thuot, Vietnam
| | - Pham Ngoc Dung
- Laboratory Department, An Giang General Hospital, An Giang province, Vietnam
| | | | - Maciej F. Boni
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Hannah E. Clapham
- Mathematical Modelling Department, Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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14
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Le Nhon NT, Le Thanh NT, Tuy My CP, Noh SK. Control of both molecular weight and comonomer response of ethylene polymerization via utilization of alkyl branches at the para-xylene bridge of new dinuclear constrained geometry catalysts. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Thanh NTL, Noh SK, Lyoo WS, Lee DH. POLYMERIZATION OF ISOBUTYL VINYL ETHER CATALYSED BY DINUCLEAR HALF-TITANOCENES. Chinese J Polym Sci 2008. [DOI: 10.1142/s0256767908003345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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