1
|
Pinotti F, Kohnle L, Lourenço J, Gupta S, Hoque MA, Mahmud R, Biswas P, Pfeiffer D, Fournié G. Modelling the transmission dynamics of H9N2 avian influenza viruses in a live bird market. Nat Commun 2024; 15:3494. [PMID: 38693163 PMCID: PMC11063141 DOI: 10.1038/s41467-024-47703-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/08/2024] [Indexed: 05/03/2024] Open
Abstract
H9N2 avian influenza viruses (AIVs) are a major concern for the poultry sector and human health in countries where this subtype is endemic. By fitting a model simulating H9N2 AIV transmission to data from a field experiment, we characterise the epidemiology of the virus in a live bird market in Bangladesh. Many supplied birds arrive already exposed to H9N2 AIVs, resulting in many broiler chickens entering the market as infected, and many indigenous backyard chickens entering with pre-existing immunity. Most susceptible chickens become infected within one day spent at the market, owing to high levels of viral transmission within market and short latent periods, as brief as 5.3 hours. Although H9N2 AIV transmission can be substantially reduced under moderate levels of cleaning and disinfection, effective risk mitigation also requires a range of additional interventions targeting markets and other nodes along the poultry production and distribution network.
Collapse
Affiliation(s)
| | - Lisa Kohnle
- City University of Hong Kong, Hong Kong SAR, Hong Kong
| | - José Lourenço
- CBR (Biomedical Research Centre), Universidade Católica Portuguesa, Oeiras, Portugal
| | - Sunetra Gupta
- Department of Biology, University of Oxford, Oxford, UK
| | - Md Ahasanul Hoque
- Chattogram Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - Rashed Mahmud
- Chattogram Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - Paritosh Biswas
- Chattogram Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - Dirk Pfeiffer
- City University of Hong Kong, Hong Kong SAR, Hong Kong
- Royal Veterinary College, London, UK
| | - Guillaume Fournié
- Royal Veterinary College, London, UK
- INRAE, VetAgro Sup, UMR EPIA, Université de Lyon, Marcy l'Etoile, 69280, France
- INRAE, VetAgro Sup, UMR EPIA, Université Clermont Auvergne, Saint Genès Champanelle, 63122, France
| |
Collapse
|
2
|
Yang L, Fan M, Wang Y, Sun X, Zhu H. Effect of avian influenza scare on transmission of zoonotic avian influenza: A case study of influenza A (H7N9). Math Biosci 2024; 367:109125. [PMID: 38072124 DOI: 10.1016/j.mbs.2023.109125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/15/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024]
Abstract
Avian influenza scare is a human psychological factor that asserts both positive and negative effects on the transmission of zoonotic avian influenza. In order to study the dichotomous effect of avian influenza scare on disease transmission, taking H7N9 avian influenza as a typical case, a two-patch epidemic model is proposed. The global dynamics and the threshold criteria are established by LaSalle invariant principle and the theory of asymptotic autonomous system. To mitigate the negative effects and curb illegal poultry trade, a game-theoretic model is adopted to explore the optimal policy of culling subsidies to reasonably compensate stakeholders for their economic losses resulting from the scare. The optimal policy of culling subsidy is found to heavily depend on the penalty of illegal poultry trade, the stakeholders' income, the intensity of control measures, and the prevalence level of the disease. The negative effect of avian influenza scare on disease transmission is considerably more significant than the positive effect. In order to avoid a widespread outbreak of zoonotic avian influenza across the region, a comprehensive national global control strategy is essential and effective, even in the presence of the negative effect of the avian influenza scare.
Collapse
Affiliation(s)
- Liu Yang
- School of Mathematics and Statistics, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin, 130024, PR China; China Animal Health and Epidemiology Center, Qingdao, Shandong, 266032, PR China
| | - Meng Fan
- School of Mathematics and Statistics, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin, 130024, PR China.
| | - Youming Wang
- China Animal Health and Epidemiology Center, Qingdao, Shandong, 266032, PR China
| | - Xiangdong Sun
- China Animal Health and Epidemiology Center, Qingdao, Shandong, 266032, PR China
| | - Huaiping Zhu
- LAMPS, Department of Mathematics and Statistics, York university, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| |
Collapse
|
3
|
Fearnley L, Zheng Z. Live poultry markets beyond health risks: Understanding consumer preferences for live poultry in South China. Prev Vet Med 2023; 221:106060. [PMID: 37926060 DOI: 10.1016/j.prevetmed.2023.106060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023]
Abstract
Live poultry markets (LPMs) are veterinary and public health risks because of potential for zoonotic spillover of pathogens from diseased animals to humans. To control these health risks, veterinary and public health authorities in Asia, including China, have closed or restricted LPMs. In south China, however, LPM closure has been opposed or rendered infeasible by consumers who prefer to purchase live poultry. Previous scholarship has suggested this preference is due to cultural values of freshness. In this study, we present results from detailed interviews with shoppers in south China, including those who prefer live poultry and those who prefer pre-slaughtered poultry. We argue that broader concerns about food safety and quality, rather than freshness alone, drive the demand for LPMs. Live poultry provide sensory information that enable shoppers to evaluate safety and quality in ways that are not possible with pre-slaughtered, refrigerated meat. Based on these findings, we suggest that hygienic interventions into LPMs should recognize that not only freshness, but also trust, must be constructed and maintained in any intervention.
Collapse
Affiliation(s)
- Lyle Fearnley
- Singapore University of Technology and Design, Singapore.
| | - Zhang Zheng
- Singapore University of Technology and Design, Singapore
| |
Collapse
|
4
|
Wei X, Wang L, Jia Q, Xiao J, Zhu G. Assessing different interventions against Avian Influenza A (H7N9) infection by an epidemiological model. One Health 2021; 13:100312. [PMID: 34458547 PMCID: PMC8379632 DOI: 10.1016/j.onehlt.2021.100312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/15/2021] [Accepted: 08/15/2021] [Indexed: 12/03/2022] Open
Abstract
This paper aims at evaluating the effectiveness of different intervention measures against the infection of avian influenza A (H7N9) by using an epidemiological model. The model formulates the intrinsic interactions of domestic poultry (DP), H7N9 virus and humans by ordinary differential equations and couples the essential roles of various interventions (including culling, vaccinating, screening, disinfecting, and reducing contact rate, etc). Qualitative analysis indicates that when the recruiting poultry is virus-free, there is a transmission threshold denoted by basic reproduction number which can determine the invasion of H7N9; and there is always a stable H7N9 endemic in case of persistent import of virus-carrying poultry, under which only complete vaccination or cutting off poultry-to-poultry/human contacts can stop H7N9 transmission. By performing numerical analysis of the model with biological background parameters, the intervention outcomes against H7N9 infection are further quantified. It is found that (1) reducing poultry-human/poultry interaction and per-contact infection probability, as well as culling DP, are highly effective in diminishing the infections of humans and DP; (2) the disease is prevented when larger than (1 − 0.1λp) proportion of DP is vaccinated, where λp is the DP-to-DP transmission rate; (3) cleaning and disinfecting environment play limited role in reducing the risk of infection; and (4) screening imported poultry is quite important for stopping disease diffusion, but it works little when local epidemic is prevailing. Combing these measures with real situations would be necessary for controlling H7N9 epidemics and reaching one health purpose.
Collapse
Affiliation(s)
- Xueli Wei
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
| | - Liying Wang
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
| | - Qiaojuan Jia
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China
| | - Guanghu Zhu
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
| |
Collapse
|
5
|
He D, Gu J, Gu M, Wu H, Li J, Zhan T, Chen Y, Xu N, Ge Z, Wang G, Hao X, Wang X, Hu J, Hu Z, Hu S, Liu X, Liu X. Genetic and antigenic diversity of H7N9 highly pathogenic avian influenza virus in China. INFECTION GENETICS AND EVOLUTION 2021; 93:104993. [PMID: 34242774 DOI: 10.1016/j.meegid.2021.104993] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/01/2021] [Accepted: 07/04/2021] [Indexed: 01/10/2023]
Abstract
Avian influenza virus (AIV) H7N9 that emerged in 2013 in eastern China is a novel zoonotic agent mainly circulating in poultry without clinical signs but causing severe disease with high fatality in humans in more than 5 waves. Since the emergence of highly pathogenic (HP) H7N9 variants in 2016, it has induced heavy losses in the poultry industry leading to the implementation of an intensive nationwide vaccination program at the end of wave 5 (September 2017). To characterize the ongoing evolution of H7N9 AIV, we conducted analyses of H7N9 glycoprotein genes obtained from 2013 to 2019. Bayesian analyses revealed a decreasing population size of HP H7N9 variants post wave 5. Phylogenetic topologies revealed that two novel small subclades were formed and carried several fixed amino acid mutations that were along HA and NA phylogenetic trees since wave 5. Some of the mutations were located at antigenic sites or receptor binding sites. The antigenic analysis may reveal a significant antigenic drift evaluated by hemagglutinin inhibition (HI) assay and the antigenicity of H7N9 AIV might evolute in large leaps in wave 7. Molecular simulations found that the mutations (V135T, S145P, and L226Q) around the HA receptor pocket increased the affinity to α2,3-linked sialic acid (SIA) while decreased to α2,6-linked SIA. Altered affinity may suggest that HP H7N9 variations aggravate the pathogenicity to poultry but lessen the threat to public health. Selection analyses showed that the HP H7N9 AIV experienced an increasing selection pressure since wave 5, and the national implementation of vaccination might intensify the role of natural selection during the evolution waves 6 and 7. In summary, our data provide important insights about the genetic and antigenic diversity of circulating HP H7N9 viruses from 2017 to 2019. Enhanced surveillance is urgently warranted to understand the current situation of HP H7N9 AIV.
Collapse
Affiliation(s)
- Dongchang He
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Jinyuan Gu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Min Gu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Huiguang Wu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Juan Li
- Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong, Shandong First Medical University, Shandong Academy of Medical Sciences, Tai'an 271000, China
| | - Tiansong Zhan
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Yu Chen
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Naiqing Xu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Zhichuang Ge
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Guoqing Wang
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Xiaoli Hao
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiaoquan Wang
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Jiao Hu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Zenglei Hu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Shunlin Hu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiaowen Liu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiufan Liu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China.
| |
Collapse
|
6
|
Zhu G, Kang M, Wei X, Tang T, Liu T, Xiao J, Song T, Ma W. Different intervention strategies toward live poultry markets against avian influenza A (H7N9) virus: Model-based assessment. ENVIRONMENTAL RESEARCH 2021; 198:110465. [PMID: 33220247 DOI: 10.1016/j.envres.2020.110465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/12/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Different interventions targeting live poultry markets (LPMs) are applied in China for controlling avian influenza A (H7N9), including LPM closure and "1110" policy (i.e., daily cleaning, weekly disinfection, monthly rest day, zero poultry stock overnight). However, the interventions' effectiveness has not been comprehensively assessed. METHODS Based on the available data (including reported cases, domestic poultry volume, and climate) collected in Guangdong Province between October 2013 and June 2017, we developed a new compartmental model that enabled us to infer H7N9 transmission dynamics. The model incorporated the intrinsic interplay among humans and poultry as well as the impacts of absolute humidity and LPM intervention, in which intervention strategies were parameterized and estimated by Markov chain Monte Carlo method. RESULTS There were 258 confirmed human H7N9 cases in Guangdong during the study period. If without interventions, the number would reach 646 (95%CI, 575-718) cases. Temporal, seasonal and permanent closures of LPMs can substantially reduce transmission risk, which might respectively reduce human infections by 67.2% (95%CI, 64.3%-70.1%), 75.6% (95%CI, 73.8%-77.5%), 86.6% (95%CI, 85.7-87.6%) in total four epidemic seasons, and 81.9% (95%CI, 78.7%-85.2%), 91.5% (95%CI, 89.9%-93.1%), 99.0% (95%CI, 98.7%-99.3%) in the last two epidemic seasons. Moreover, implementing the "1110" policy from 2014 to 2017 would reduce the cases by 34.1% (95%CI, 20.1%-48.0%), suggesting its limited role in preventing H7N9 transmission. CONCLUSIONS Our study quantified the effects of different interventions and execution time toward LPMs for controlling H7N9 transmission. The results highlighted the importance of closing LPMs during epidemic period, and supported permanent closure as a long-term plan.
Collapse
Affiliation(s)
- Guanghu Zhu
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin, 541004, China; Guangxi Key Laboratory of Cryptography and Information Security, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Min Kang
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Xueli Wei
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Tian Tang
- Guangxi Key Laboratory of Cryptography and Information Security, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Tao Liu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Tie Song
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China.
| | - Wenjun Ma
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China.
| |
Collapse
|
7
|
Guinat C, Tago D, Corre T, Selinger C, Djidjou-Demasse R, Paul M, Raboisson D, Nguyen Thi Thanh T, Inui K, Pham Thanh L, Padungtod P, Vergne T. Optimizing the early detection of low pathogenic avian influenza H7N9 virus in live bird markets. J R Soc Interface 2021; 18:20210074. [PMID: 33947269 PMCID: PMC8097223 DOI: 10.1098/rsif.2021.0074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In Southeast Asia, surveillance at live bird markets (LBMs) has been identified as crucial for detecting avian influenza viruses (AIV) and reducing the risk of human infections. However, the design of effective surveillance systems in LBMs remains complex given the rapid turn-over of poultry. We developed a deterministic transmission model to provide guidance for optimizing AIV surveillance efforts. The model was calibrated to fit one of the largest LBMs in northern Vietnam at high risk of low pathogenic H7N9 virus introduction from China to identify the surveillance strategy that optimizes H7N9 detection. Results show that (i) using a portable diagnostic device would slightly reduce the number of infected birds leaving the LBM before the first detection, as compared to a laboratory-based diagnostic strategy, (ii) H7N9 detection could become more timely by sampling birds staying overnight, just before new susceptible birds are introduced at the beginning of a working day, and (iii) banning birds staying overnight would represent an effective intervention to reduce the risk of H7N9 spread but would decrease the likelihood of virus detection if introduced. These strategies should receive high priority in Vietnam and other Asian countries at risk of H7N9 introduction.
Collapse
Affiliation(s)
- Claire Guinat
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | | | | | | | | | - Mathilde Paul
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | | | | | - Ken Inui
- FAO, Department of Animal Health (DAH), Ministry of Agriculture and Rural Development (MARD), Hanoi, Vietnam
| | | | | | | |
Collapse
|
8
|
Value chain analysis of yellow broiler industry in Guangxi, China to inform H7N9 influenza control strategies. Prev Vet Med 2021; 190:105328. [PMID: 33765448 DOI: 10.1016/j.prevetmed.2021.105328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 02/11/2021] [Accepted: 03/15/2021] [Indexed: 11/22/2022]
Abstract
Yellow broilers are the primary source of poultry consumption in China and the predominant trade of live poultry. However, knowledge of the value chain is limited, which is vital evidence for the effective control of H7N9 and other zoonotic avian influenzas. The aim of the study was to map the yellow broiler value chain in Guangxi Zhuang Autonomous Region, China and investigate its governance structure and practices relevant to the risk of H7N9 transmission. A value chain analysis was conducted in five areas of Guangxi from May to August 2018. To map the value chain, three focus group discussions (FGDs) were conducted and stakeholders, products and premises involved and their interactions were identified. Then, 55 key informant interviews (KIIs) collected qualitative data on stakeholders' profile, practices and interactions with other stakeholders and rules/norms that exist along the value chain. On-site observations were also carried out at different types of premises along the value chain to complement and validate findings of KIIs and FGDs. Participants were also asked to provide proportional estimates of each component in the value chain where possible. The qualitative data from FGDs, KIIs and on-site observations were analysed to create stakeholder profiles and a diagram of product flows and stakeholders' interactions. Thematic analysis was used to identify the governance structure of the value chains and practices relevant to the risk of H7N9 transmission. The stakeholders and premises involved in Guangxi yellow broiler production, wholesale and retail were described, as well as their interactions. Contract farming is extensively adopted in Guangxi; consequently yellow broiler grower companies are the dominant stakeholders. The trading platform was identified as a key premise linking farms and live bird markets. The thematic analysis highlighted poor biosecurity practices in different premises along the value chain, which was supported by on-site observations. The operation of trading platforms reported in this study presents a disease risk but is not considered in the current H7N9 control programs. The study suggested that biosecurity management gaps need to be addressed through government-industry partnerships that require engagement with private stakeholders in the planning and implementation of H7N9 control strategies incentivising participation of grower companies, wholesalers and retailers.
Collapse
|
9
|
Naguib MM, Verhagen JH, Mostafa A, Wille M, Li R, Graaf A, Järhult JD, Ellström P, Zohari S, Lundkvist Å, Olsen B. Global patterns of avian influenza A (H7): virus evolution and zoonotic threats. FEMS Microbiol Rev 2019; 43:608-621. [PMID: 31381759 PMCID: PMC8038931 DOI: 10.1093/femsre/fuz019] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/31/2019] [Indexed: 01/16/2023] Open
Abstract
Avian influenza viruses (AIVs) continue to impose a negative impact on animal and human health worldwide. In particular, the emergence of highly pathogenic AIV H5 and, more recently, the emergence of low pathogenic AIV H7N9 have led to enormous socioeconomical losses in the poultry industry and resulted in fatal human infections. While H5N1 remains infamous, the number of zoonotic infections with H7N9 has far surpassed those attributed to H5. Despite the clear public health concerns posed by AIV H7, it is unclear why specifically this virus subtype became endemic in poultry and emerged in humans. In this review, we bring together data on global patterns of H7 circulation, evolution and emergence in humans. Specifically, we discuss data from the wild bird reservoir, expansion and epidemiology in poultry, significant increase in their zoonotic potential since 2013 and genesis of highly pathogenic H7. In addition, we analysed available sequence data from an evolutionary perspective, demonstrating patterns of introductions into distinct geographic regions and reassortment dynamics. The integration of all aspects is crucial in the optimisation of surveillance efforts in wild birds, poultry and humans, and we emphasise the need for a One Health approach in controlling emerging viruses such as AIV H7.
Collapse
Affiliation(s)
- Mahmoud M Naguib
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Husargatan 3, Uppsala University, Uppsala SE-75237, Sweden
- National Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, 7 Nadi El-Seid Street, Giza 12618, Egypt
| | - Josanne H Verhagen
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, 44008 Hus Vita, Kalmar SE-391 82 , Sweden
| | - Ahmed Mostafa
- Institute of Medical Virology, Justus Liebig University Giessen, Schubertstrasse 81, Giessen 35392, Germany
- Center of Scientific Excellence for Influenza Viruses, National Research Centre (NRC), 33 El-Buhouth street, Giza 12622, Egypt
| | - Michelle Wille
- WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Melbourne 3000, Victoria, Australia
| | - Ruiyun Li
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, Praed Street, London W2 1PG, United Kingdom
| | - Annika Graaf
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, Greifswald-Insel Riems 17493, Germany
| | - Josef D Järhult
- Zoonosis Science Center, Department of Medical Sciences, Uppsala University, Sjukhusvägen 85, Uppsala SE-75185, Sweden
| | - Patrik Ellström
- Zoonosis Science Center, Department of Medical Sciences, Uppsala University, Sjukhusvägen 85, Uppsala SE-75185, Sweden
| | - Siamak Zohari
- Department of Microbiology, National Veterinary Institute, Ulls väg 2B, Uppsala SE-75189, Sweden
| | - Åke Lundkvist
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Husargatan 3, Uppsala University, Uppsala SE-75237, Sweden
| | - Björn Olsen
- Zoonosis Science Center, Department of Medical Sciences, Uppsala University, Sjukhusvägen 85, Uppsala SE-75185, Sweden
| |
Collapse
|
10
|
Su K, Ye S, Li Q, Xie W, Yu H, Qi L, Xiong Y, Zhao H, Li B, Ling H, Tang Y, Xiao B, Rong R, Tang W, Li Y. Influenza A(H7N9) virus emerged and resulted in human infections in Chongqing, southwestern China since 2017. Int J Infect Dis 2019; 81:244-250. [PMID: 30797966 DOI: 10.1016/j.ijid.2019.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/07/2019] [Accepted: 02/13/2019] [Indexed: 12/09/2022] Open
Abstract
OBJECTIVES Influenza A(H7N9) virus has emerged and resulted in human infections in Chongqing, southwestern China since 2017. This study aimed to describe the epidemiological characteristics of the first epidemic in this region. METHODS The epidemiological data of patients were collected. Live poultry markets (LPMs), commercial poultry farms (CPFs) and backyard poultry farms (BPFs) were monitored, and poultry sources were registered. Samples derived from the patients, their close contacts, and the environments were tested for influenza A(H7N9) virus by real-time reverse transcriptase polymerase chain reaction. Genetic sequencing and phylogenetic analysis were also conducted. RESULTS Since the confirmation of the first patient infected with influenza A(H7N9) virus on March 5, 2017, nine patients had been identified within four months in Chongqing. Their mean age was 45 years, 77.8% were male, 66.7% were urban residents and 55.6% were of poultry related occupation. All patients became infected after exposure to live chickens. The median time interval from initial detection of influenza A(H7N9) virus in Chongqing to the patients' onset was 75 days. Since initial detection in February 2017, influenza A(H7N9) virus was detected in 21 (53.8%) counties within four months. The proportion of positive samples was 2.94% (337/11,451) from February 2017 to May 2018, and was higher (χ2=75.78, P<0.001) in LPMs (3.66%, 329/8979) than that in CPFs (0.41%, 5/1229) and BPFs (0.24%, 3/1243). The proportion of positive samples (34.4%, 22/64) at the premises to which the patients were exposed was significantly higher than that (5.7%, 257/4474) in premises with no patients. Phylogenetic analysis indicated that the viruses isolated in Chongqing belonged to the Yangtze River Delta lineage and resembled those circulated in Jiangsu and Anhui provinces between late 2016 and early 2017. CONCLUSION Influenza A(H7N9) virus was newly introduced into Chongqing most likely between late 2016 and early 2017, which swept across half of Chongqing territory and resulted in human infections within months. The most impacted premises and population were LPMs and poultry related workers respectively in the epidemic.
Collapse
Affiliation(s)
- Kun Su
- Department of Epidemiology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing 400038, People's Republic of China; Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Sheng Ye
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Qin Li
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Weijia Xie
- Department of Epidemiology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Hongyue Yu
- Department of Epidemiology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Li Qi
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Yu Xiong
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Han Zhao
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Baisong Li
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Hua Ling
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Yun Tang
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Bangzhong Xiao
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Rong Rong
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China
| | - Wenge Tang
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400042, People's Republic of China.
| | - Yafei Li
- Department of Epidemiology, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing 400038, People's Republic of China.
| |
Collapse
|
11
|
Cheng W, Wang X, Shen Y, Yu Z, Liu S, Cai J, Chen E. Comparison of the three waves of avian influenza A(H7N9) virus circulation since live poultry markets were permanently closed in the main urban areas in Zhejiang Province, July 2014-June 2017. Influenza Other Respir Viruses 2019; 12:259-266. [PMID: 29243376 PMCID: PMC5820431 DOI: 10.1111/irv.12532] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The sudden increase in the number of human cases infected with avian influenza A(H7N9) virus after September 2016 raised global concern. OBJECTIVES To assess the changes in epidemiological characteristics of H7N9 cases since the massive closure of live poultry markets (LPMs) in the main urban areas in Zhejiang province. METHODS We used descriptive statistics to compare epidemiological characteristics of the three distinct waves of H7N9 cases in Zhejiang province. The rural or urban cases were defined according to the location where the patients had exposure within 2 weeks before illness onset. RESULTS Between July 2014 and June 2017, 166 H7N9 cases were reported in Zhejiang province, with 45, 34, and 87 cases reported in the third, fourth, and fifth wave, respectively. Across the three waves, most reported cases were from rural areas. A similar percentage of cases in all three waves reported exposure to LPMs, raising poultry at home or around the house, as well as occupational exposure. Compared to the third (80.00%) and fourth wave (70.59%), a significantly larger proportion of cases from the non-LPMs closure areas were observed in the fifth wave (89.66%) (P = .034). CONCLUSION Epidemiological characteristics of human cases infected with avian influenza A(H7N9) virus had generally remained unchanged since the massive closure of LPMs in the main urban area of Zhejiang province. The sudden increase in the number of H7N9 cases in the fifth wave was mainly attributed to the excessive cases reported from areas where LPMs were not permanently closed.
Collapse
Affiliation(s)
- Wei Cheng
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Xiaoxiao Wang
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Ye Shen
- Department of Epidemiology and BiostatisticsUniversity of GeorgiaAthensGAUSA
| | - Zhao Yu
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Shelan Liu
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Jian Cai
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Enfu Chen
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| |
Collapse
|
12
|
Li R, Zhang T, Bai Y, Li H, Wang Y, Bi Y, Chang J, Xu B. Live Poultry Trading Drives China's H7N9 Viral Evolution and Geographical Network Propagation. Front Public Health 2018; 6:210. [PMID: 30140667 PMCID: PMC6094976 DOI: 10.3389/fpubh.2018.00210] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/09/2018] [Indexed: 01/02/2023] Open
Abstract
The on-going reassortment, human-adapted mutations, and spillover events of novel A(H7N9) avian influenza viruses pose a significant challenge to public health in China and globally. However, our understanding of the factors that disseminate the viruses and drive their geographic distributions is limited. We applied phylogenic analysis to examine the inter-subtype interactions between H7N9 viruses and the closest H9N2 lineages in China during 2010-2014. We reconstructed and compared the inter-provincial live poultry trading and viral propagation network via phylogeographic approach and network similarity technique. The substitution rates of the isolated viruses in live poultry markets and the characteristics of localized viral evolution were also evaluated. We discovered that viral propagation was geographically-structured and followed the live poultry trading network in China, with distinct north-to-east paths of spread and circular transmission between eastern and southern regions. The epicenter of H7N9 has moved from the Shanghai-Zhejiang region to Guangdong Province was also identified. Besides, higher substitution rate was observed among isolates sampled from live poultry markets, especially for those H7N9 viruses. Live poultry trading in China may have driven the network-structured expansion of the novel H7N9 viruses. From this perspective, long-distance geographic expansion of H7N9 were dominated by live poultry movements, while at local scales, diffusion was facilitated by live poultry markets with highly-evolved viruses.
Collapse
Affiliation(s)
- Ruiyun Li
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science Beijing Normal University, Beijing, China
| | - Tao Zhang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science Tsinghua University, Beijing, China
| | - Yuqi Bai
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science Tsinghua University, Beijing, China
| | | | - Yong Wang
- Chinese Academy of Surveying and Mapping Beijing, China
| | - Yuhai Bi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology Chinese Academy of Sciences, Beijing, China
| | - Jianyu Chang
- College of Veterinary Medicine China Agricultural University, Beijing, China
| | - Bing Xu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science Beijing Normal University, Beijing, China.,Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science Tsinghua University, Beijing, China
| |
Collapse
|
13
|
Moyen N, Ahmed G, Gupta S, Tenzin T, Khan R, Khan T, Debnath N, Yamage M, Pfeiffer DU, Fournie G. A large-scale study of a poultry trading network in Bangladesh: implications for control and surveillance of avian influenza viruses. BMC Vet Res 2018; 14:12. [PMID: 29329534 PMCID: PMC5767022 DOI: 10.1186/s12917-018-1331-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 01/02/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it. RESULTS Poultry trading practices varied according to the size of the LBMs and to the type of poultry traded. Industrial broiler chickens, the most commonly traded poultry, were generally sold in LBMs close to their production areas, whereas ducks and backyard chickens were moved over longer distances, and their transport involved several intermediates. The poultry trading network composed of 445 nodes (73.2% were LBMs) was highly connected and disassortative. However, the removal of only 5.6% of the nodes (25 LBMs with the highest betweenness scores), reduced the network's connectedness, and the maximum size of output and input domains by more than 50%. CONCLUSIONS Poultry types need to be discriminated in order to understand the way in which poultry trading networks are shaped, and the level of risk of disease spread that these networks may promote. Knowledge of the network structure could be used to target control and surveillance interventions to a small number of LBMs.
Collapse
Affiliation(s)
- N Moyen
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, Hertfordshire, AL9 7TA, UK.
| | - G Ahmed
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - S Gupta
- School of Veterinary Science, The University of Queensland, Gatton, 4343, Qld, Australia.,Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - T Tenzin
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh.,National Centre for Animal Health, Thimphu, Bhutan
| | - R Khan
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - T Khan
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - N Debnath
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - M Yamage
- Emergency Centre for Transboundary Animal Diseases, Food and Agriculture Organisation of the United Nations, Dhaka, Bangladesh
| | - D U Pfeiffer
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, Hertfordshire, AL9 7TA, UK.,College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - G Fournie
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, Hertfordshire, AL9 7TA, UK
| |
Collapse
|
14
|
Epidemiological and clinical characteristics of humans with avian influenza A (H7N9) infection in Guangdong, China, 2013–2017. Int J Infect Dis 2017; 65:148-155. [DOI: 10.1016/j.ijid.2017.07.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 11/23/2022] Open
|
15
|
Nguyen TTT, Fearnley L, Dinh XT, Tran TTA, Tran TT, Nguyen VT, Tago D, Padungtod P, Newman SH, Tripodi A. A Stakeholder Survey on Live Bird Market Closures Policy for Controlling Highly Pathogenic Avian Influenza in Vietnam. Front Vet Sci 2017; 4:136. [PMID: 28879203 PMCID: PMC5572285 DOI: 10.3389/fvets.2017.00136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 08/07/2017] [Indexed: 11/19/2022] Open
Abstract
Extensive research in Vietnam and elsewhere has shown that live bird markets (LBMs) play a significant role in the ecology and zoonotic transmission of avian influenzas (AIs) including H5N1 and H7N9. Vietnam has a large number of LBMs reflecting the consumer preferences for live poultry. Under pressure to mitigate risks for H7N9 and other zoonotic AIs, Vietnam is considering, among other mitigation measures, temporary closures of LBMs as a policy to reduce risk of AI outbreaks. However, the efficacy of market closure is debated, particularly because little is known about how poultry traders may react, and whether trading may emerge outside formal marketplaces. Combining efforts of anthropologists, economists, sociologists, and veterinarians can be useful to elucidate the drivers behind poultry traders’ reactions and better understanding the barriers to implementing risk mitigation measures. In this paper, we present results from a stakeholder survey of LBM stakeholders in Vietnam. Our qualitative data show that trading outside formal markets is very likely to occur in the event of a temporary LBM market closure. Our data show that the poultry value chain in Vietnam remains highly flexible, with traders willing and able to trade poultry in many possible locations. Our results indicate that simplification of the poultry value chain along with strict enforcement, engagement of stakeholders, and adequate communication would be a necessary prerequisite before market closure could be an effective policy.
Collapse
Affiliation(s)
- Thi Thanh Thuy Nguyen
- Emergency Center for Transboundary Animal Diseases, Food and Agriculture Organization of the United Nations, Ha Noi, Vietnam
| | - Lyle Fearnley
- Singapore University of Technology and Design, Singapore, Singapore
| | | | | | - Trong Tung Tran
- Department of Livestock Production, Ministry of Agriculture and Rural Development, Ha Noi, Vietnam
| | - Van Trong Nguyen
- Department of Livestock Production, Ministry of Agriculture and Rural Development, Ha Noi, Vietnam
| | - Damian Tago
- Emergency Center for Transboundary Animal Diseases, Food and Agriculture Organization of the United Nations, Regional Office for Asia and the Pacific, Bangkok, Thailand
| | - Pawin Padungtod
- Emergency Center for Transboundary Animal Diseases, Food and Agriculture Organization of the United Nations, Ha Noi, Vietnam
| | - Scott H Newman
- Emergency Center for Transboundary Animal Diseases, Food and Agriculture Organization of the United Nations, Ha Noi, Vietnam
| | - Astrid Tripodi
- Animal Health Service, Food and Agriculture Organization of the United Nations, Rome, Italy
| |
Collapse
|
16
|
Influenza A H5N1 and H7N9 in China: A spatial risk analysis. PLoS One 2017; 12:e0174980. [PMID: 28376125 PMCID: PMC5380336 DOI: 10.1371/journal.pone.0174980] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/19/2017] [Indexed: 11/19/2022] Open
Abstract
Background Zoonotic avian influenza poses a major risk to China, and other parts of the world. H5N1 has remained endemic in China and globally for nearly two decades, and in 2013, a novel zoonotic influenza A subtype H7N9 emerged in China. This study aimed to improve upon our current understanding of the spreading mechanisms of H7N9 and H5N1 by generating spatial risk profiles for each of the two virus subtypes across mainland China. Methods and findings In this study, we (i) developed a refined data set of H5N1 and H7N9 locations with consideration of animal/animal environment case data, as well as spatial accuracy and precision; (ii) used this data set along with environmental variables to build species distribution models (SDMs) for each virus subtype in high resolution spatial units of 1km2 cells using Maxent; (iii) developed a risk modelling framework which integrated the results from the SDMs with human and chicken population variables, which was done to quantify the risk of zoonotic transmission; and (iv) identified areas at high risk of H5N1 and H7N9 transmission. We produced high performing SDMs (6 of 8 models with AUC > 0.9) for both H5N1 and H7N9. In all our SDMs, H7N9 consistently showed higher AUC results compared to H5N1, suggesting H7N9 suitability could be better explained by environmental variables. For both subtypes, high risk areas were primarily located in south-eastern China, with H5N1 distributions found to be more diffuse and extending more inland compared to H7N9. Conclusions We provide projections of our risk models to public health policy makers so that specific high risk areas can be targeted for control measures. We recommend comparing H5N1 and H7N9 prevalence rates and survivability in the natural environment to better understand the role of animal and environmental transmission in human infections.
Collapse
|
17
|
Ge E, Zhang R, Li D, Wei X, Wang X, Lai PC. Estimating Risks of Inapparent Avian Exposure for Human Infection: Avian Influenza Virus A (H7N9) in Zhejiang Province, China. Sci Rep 2017; 7:40016. [PMID: 28054599 PMCID: PMC5214706 DOI: 10.1038/srep40016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 11/09/2016] [Indexed: 11/09/2022] Open
Abstract
Inapparent avian exposure was suspected for the sporadic infection of avian influenza A(H7N9) occurring in China. This type of exposure is usually unnoticed and difficult to model and measure. Infected poultry with avian influenza H7N9 virus typically remains asymptomatic, which may facilitate infection through inapparent poultry/bird exposure, especially in a country with widespread practice of backyard poultry. The present study proposed a novel approach that integrated ecological and case-control methods to quantify the risk of inapparent avian exposure on human H7N9 infection. Significant associations of the infection with chicken and goose densities, but not with duck density, were identified after adjusting for spatial clustering effects of the H7N9 cases across multiple geographic scales of neighborhood, community, district and city levels. These exposure risks varied geographically in association with proximity to rivers and lakes that were also proxies for inapparent exposure to avian-related environment. Males, elderly people, and farmers were high-risk subgroups for the virus infection. These findings enable health officials to target educational programs and awareness training in specific locations to reduce the risks of inapparent exposure.
Collapse
Affiliation(s)
- Erjia Ge
- Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Renjie Zhang
- Zhejiang Provincial Center for Disease Prevention &Control, Hangzhou, P.R. China
| | - Dengkui Li
- School of Mathematics &Statistics, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Xiaolin Wei
- Division of Clinical Public Health and Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Xiaomeng Wang
- Zhejiang Provincial Center for Disease Prevention &Control, Hangzhou, P.R. China
| | | |
Collapse
|
18
|
Offeddu V, Cowling BJ, Peiris JM. Interventions in live poultry markets for the control of avian influenza: a systematic review. One Health 2016; 2:55-64. [PMID: 27213177 PMCID: PMC4871622 DOI: 10.1016/j.onehlt.2016.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 02/17/2016] [Accepted: 03/14/2016] [Indexed: 11/19/2022] Open
Abstract
Background Live poultry markets (LPMs) pose a threat to public health by promoting the amplification and dissemination of avian influenza viruses (AIVs) and by providing the ideal setting for zoonotic influenza transmission. Objective This review assessed the impact of different interventions implemented in LPMs to control the emergence of zoonotic influenza. Methods Publications were identified through a systematic literature search in the PubMed, MEDLINE and Web of Science databases. Eligible studies assessed the impact of different interventions, such as temporary market closure or a ban on holding poultry overnight, in reducing i) AIV-detection rates in birds and the market environment or ii) influenza incidence in humans. Unpublished literature, reviews, editorials, cross-sectional studies, theoretical models and publications in languages other than English were excluded. Relevant findings were extracted and critically evaluated. For the comparative analysis of findings across studies, standardized outcome measures were computed as i) the relative risk reduction (RRR) of AIV-detection in LPMs and ii) incidence rate ratios (IRRs) of H7N9-incidence in humans. Results A total of 16 publications were identified and reviewed. Collectively, the data suggest that AIV-circulation can be significantly reduced in the LPM-environment and among market-birds through (i) temporary LPM closure, (ii) periodic rest days (iii) market depopulation overnight and (iv) improved hygiene and disinfection. Overall, the findings indicate that the length of stay of poultry in the market is a critical control point to interrupt the AIV-replication cycle within LPMs. In addition, temporary LPM closure was associated with a significant reduction of the incidence of zoonotic influenza. The interpretation of these findings is limited by variations in the implementation of interventions. In addition, some of the included studies were of ecologic nature or lacked an inferential framework, which might have lead to cosiderable confounding and bias. Conclusions The evidence collected in this review endorses permanent LPM-closure as a long-term objective to reduce the zoonotic risk of avian influenza, although its economic and socio-political implications favour less drastic interventions, e.g. weekly rest days, for implementation in the short-term. •Avian influenza viruses (AIVs) can infect humans. Bird-to-human transmission is particularly intense in live poultry markets. •Periodic rest days, overnight depopulation or sale bans of certain species significantly reduce AIV-circulation in the markets. •Market closure would lastingly reduce the risk of animal and human infection.
Collapse
Key Words
- influenza a virus
- live poultry market
- a/h7n9
- a/h9n2
- closure
- rest day
- c/d, cleansing and disinfection
- glm, general linear model
- irr, incidence rate ratio
- lbm, live bird market
- lpm, live poultry market
- ndv, newcastle disease virus
- or, odds ratio
- pue, pneumonia of unknown etiology
- rlpm, retail live poultry market
- rr, relative risk
- rrr, relative risk reduction
- rt-pcr, reverse transcription polymerase chain reaction
- wlpm, wholesale live poultry market
Collapse
Affiliation(s)
- Vittoria Offeddu
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Benjamin J. Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - J.S. Malik Peiris
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
- Centre of Influenza Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| |
Collapse
|
19
|
Wang L, Cowling BJ, Wu P, Yu J, Li F, Zeng L, Wu JT, Li Z, Leung GM, Yu H. Human exposure to live poultry and psychological and behavioral responses to influenza A(H7N9), China. Emerg Infect Dis 2016; 20:1296-305. [PMID: 25076186 PMCID: PMC4111172 DOI: 10.3201/eid2008.131821] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Exposure was common in urban and rural areas and remains a potential risk factor for human infection. To investigate human exposure to live poultry and changes in risk perception and behavior after the April 2013 influenza A(H7N9) outbreak in China, we surveyed 2,504 urban residents in 5 cities and 1,227 rural residents in 4 provinces and found that perceived risk for influenza A(H7N9) was low. The highest rate of exposure to live poultry was reported in Guangzhou, where 47% of those surveyed reported visiting a live poultry market >1 times in the previous year. Most (77%) urban respondents reported that they visited live markets less often after influenza A(H7N9) cases were first identified in China in March 2013, but only 30% supported permanent closure of the markets to control the epidemic. In rural areas, 48% of respondents reported that they raised backyard poultry. Exposure to live commercial and private poultry is common in urban and rural China and remains a potential risk factor for human infection with novel influenza viruses.
Collapse
|
20
|
Molia S, Boly IA, Duboz R, Coulibaly B, Guitian J, Grosbois V, Fournié G, Pfeiffer DU. Live bird markets characterization and trading network analysis in Mali: Implications for the surveillance and control of avian influenza and Newcastle disease. Acta Trop 2016; 155:77-88. [PMID: 26708995 DOI: 10.1016/j.actatropica.2015.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/02/2015] [Accepted: 12/13/2015] [Indexed: 11/25/2022]
Abstract
Live bird markets (LBMs) play an important role in the transmission of avian influenza (AI) and Newcastle disease (ND) viruses in poultry. Our study had two objectives: (1) characterizing LBMs in Mali with a focus on practices influencing the risk of transmission of AI and ND, and (2) identifying which LBMs should be targeted for surveillance and control based on properties of the live poultry trade network. Two surveys were conducted in 2009-2010: a descriptive study in all 96 LBMs of an area encompassing approximately 98% of the Malian poultry population and a network analysis study in Sikasso county, the main poultry supplying county for the capital city Bamako. Regarding LBMs' characteristics, risk factors for the presence of AI and ND viruses (being open every day, more than 2 days before a bird is sold, absence of zoning to segregate poultry-related work flow areas, waste removal or cleaning and disinfecting less frequently than on a daily basis, trash disposal of dead birds and absence of manure processing) were present in 80-100% of the LBMs. Furthermore, LBMs tended to have wide catchment areas because of consumers' preference for village poultry meat, thereby involving a large number of villages in their supply chain. In the poultry trade network from/to Sikasso county, 182 traders were involved and 685 links were recorded among 159 locations. The network had a heterogeneous degree distribution and four hubs were identified based on measures of in-degrees, out-degrees and betweenness: the markets of Medine and Wayerma and the fairs of Farakala and Niena. These results can be used to design biosecurity-improvement interventions and to optimize the prevention, surveillance and control of transmissible poultry diseases in Malian LBMs. Further studies should investigate potential drivers (seasonality, prices) of the poultry trade network and the acceptability of biosecurity and behavior-change recommendations in the Malian socio-cultural context.
Collapse
|
21
|
Wu P, Jiang H, Wu JT, Chen E, He J, Zhou H, Wei L, Yang J, Yang B, Qin Y, Fang VJ, Li M, Tsang TK, Zheng J, Lau EHY, Cao Y, Chai C, Zhong H, Li Z, Leung GM, Feng L, Gao GF, Cowling BJ, Yu H. Poultry market closures and human infection with influenza A(H7N9) virus, China, 2013-14. Emerg Infect Dis 2015; 20:1891-4. [PMID: 25340354 PMCID: PMC4214308 DOI: 10.3201/eid2011.140556] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Closure of live poultry markets was implemented in areas affected by the influenza virus A(H7N9) outbreak in China during winter, 2013–14. Our analysis showed that closing live poultry markets in the most affected cities of Guangdong and Zhejiang provinces was highly effective in reducing the risk for H7N9 infection in humans.
Collapse
|
22
|
Kang M, He J, Song T, Rutherford S, Wu J, Lin J, Huang G, Tan X, Zhong H. Environmental Sampling for Avian Influenza A(H7N9) in Live-Poultry Markets in Guangdong, China. PLoS One 2015; 10:e0126335. [PMID: 25933138 PMCID: PMC4416787 DOI: 10.1371/journal.pone.0126335] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/01/2015] [Indexed: 12/03/2022] Open
Abstract
Background To provide an increased understanding of avian influenza A(H7N9) activity in live-poultry market in space and time and hence improve H7N9 epidemic control, an ongoing environmental sampling program in multiple live-poultry markets across Guangdong, China was conducted during March 2013–June 2014. Methods A total of 625 live-poultry markets throughout 21 prefecture areas took part in the study. A total of 10 environmental sites in markets for sampling were identified to represent 4 different poultry-related activity areas. At least 10 environmental samples were collected from each market every month. The real time RT-PCR was performed to detect the avian influenza A(H7N9) virus. Field survey was conducted to investigate the sanitation status of live-poultry markets. Results There were 109 human infections with H7N9 avian influenza in Guangdong, of which 37 (34%) died. A total of 18741 environmental swabs were collected and subjected to real-time RT-PCR test, of which 905(4.83%) were found positive for H7N9 virus. There were 201 (32.16%) markets affected by H7N9 in 16 prefecture areas. The detection of H7N9 virus in markets spiked in winter months. 63.33% markets (38/60) had no physical segregation for poultry holding, slaughter or sale zones. Closing live-poultry market significantly decreased the H7N9 detection rate from 14.83% (112/755) to 1.67% (5/300). Conclusions This study indicates the importance of live-poultry market surveillance based on environmental sampling for H7N9 Avian Influenza control. Improving live-poultry market management and sanitation and changing consumer practices are critical to reduce the risk of H7N9 infection.
Collapse
Affiliation(s)
- Min Kang
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Jianfeng He
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Tie Song
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Shannon Rutherford
- Centre for Environment and Population Health, School of Environment, Griffith University, Brisbane, Australia
| | - Jie Wu
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Jinyan Lin
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Guofeng Huang
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Xiaohua Tan
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
| | - Haojie Zhong
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, People’s Republic of China
- * E-mail:
| |
Collapse
|
23
|
Zhang Y, Shen Z, Ma C, Jiang C, Feng C, Shankar N, Yang P, Sun W, Wang Q. Cluster of human infections with avian influenza A (H7N9) cases: a temporal and spatial analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:816-28. [PMID: 25599373 PMCID: PMC4306894 DOI: 10.3390/ijerph120100816] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/07/2015] [Indexed: 12/03/2022]
Abstract
Objectives: This study aims to describe the spatial and temporal characteristics of human infections with H7N9 virus in China using data from February 2013 to March 2014 from the websites of every province’s Population and Family Planning Commission. Methods: A human infection with H7N9 virus dataset was summarized by county to analyze its spatial clustering, and by date of illness onset to analyze its space-time clustering using the ESRI® Geographic Information System (GIS) software ArcMap™ 10.1 and SatScan. Results: Based on active surveillance data, the distribution map of H7N9 cases shows that compared to the rest of China, the areas from near the Yangtze River delta (YRD) to farther south around the Pearl River delta (PRD) had the highest densities of H7N9 cases. The case data shows a strong space-time clustering in the areas on and near the YRD from 26 March to 18 April 2013 and a weak space-time clustering only in the areas on and near the PRD between 3 and 4 February 2014. However, for the rest of the study period, H7N9 cases were spatial-temporally randomly distributed. Conclusions: Our results suggested that the spatial-temporal clustering of H7N9 in China between 2013 and 2014 is fundamentally different.
Collapse
Affiliation(s)
- Yi Zhang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Zhixiong Shen
- Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA 70118, USA.
| | - Chunna Ma
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Chengsheng Jiang
- Maryland Institute for Applied Environmental Health, School of Public Health in University of Maryland, College Park, MD 20742, USA.
| | - Cindy Feng
- School of Public Health & The Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Nivedita Shankar
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
| | - Peng Yang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Wenjie Sun
- School of Food Science, Guangdong Pharmaceutical University, Zhongshan 528458, China.
| | - Quanyi Wang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| |
Collapse
|
24
|
Feng L, Wu JT, Liu X, Yang P, Tsang TK, Jiang H, Wu P, Yang J, Fang VJ, Qin Y, Lau EH, Li M, Zheng J, Peng Z, Xie Y, Wang Q, Li Z, Leung GM, Gao GF, Yu H, Cowling BJ. Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14. ACTA ACUST UNITED AC 2014; 19. [PMID: 25523971 DOI: 10.2807/1560-7917.es2014.19.49.20984] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.
Collapse
Affiliation(s)
- L Feng
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Fragaszy E, Hayward A. Emerging respiratory infections: influenza, MERS-CoV, and extensively drug-resistant tuberculosis. THE LANCET RESPIRATORY MEDICINE 2014; 2:970-2. [PMID: 25466351 PMCID: PMC7128637 DOI: 10.1016/s2213-2600(14)70250-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Ellen Fragaszy
- Farr Institute of Health Informatics Research, University College London, 222 Euston Road, London NW1 2DA, UK
| | - Andrew Hayward
- Farr Institute of Health Informatics Research, University College London, 222 Euston Road, London NW1 2DA, UK.
| |
Collapse
|
26
|
Vong S. Editorial commentary: some perspectives regarding risk factors for a(H7N9) influenza virus infection in humans. Clin Infect Dis 2014; 59:795-7. [PMID: 24928289 DOI: 10.1093/cid/ciu424] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sirenda Vong
- Emerging Disease Surveillance and Response, World Health Organization, Beijing, China
| |
Collapse
|