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Thi Dien N, Thi Minh Khue N, Etaba A, Fournié G, Huyen LTT, Van Dai N, Tuan HA, Duc DV, Thi Thanh Hoa P, Van Duy N, Ton VD, Alarcon P. Mapping chicken production and distribution networks in Vietnam: An analysis of socio-economic factors and their epidemiological significances. Prev Vet Med 2023; 214:105906. [PMID: 37023633 DOI: 10.1016/j.prevetmed.2023.105906] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/22/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023]
Abstract
The growing chicken industry in Viet Nam has an increasingly important contribution to the country's food security, but its development requires careful planning to prevent disease risks. This study characterizes the chicken production and distribution networks in Vietnam and identifies potential factors that could promote disease emergence and transmission. Qualitative data were collected from interviews with 29 key informants from five stakeholder groups representing the main nodes from chicken production and distribution networks (PDN). Three main networks were identified based on production type: a colored broiler and spent hen network, a white (or exotic) broiler network, and an egg network. Colored chickens and spent hens are the most preferred commodity by vietnamese consumers and their PDN is composed of production units differing in their scale and management and with long distribution chains involving numerous small-scale independent stakeholders. Live bird markets plays a central role in this network, which is driven by consumers' preference for live chickens. The white chicken network presents an important duality, as it is composed of both a large number of independent household farms and traders operating independently with little chain coordination, and of large farms contracted by vertically-integrated companies. The egg PDN was the most organized network, being mostly controlled by large vertically-integrated companies. High level specialization and diversification of stakeholders is found in all three networks. Stakeholders' perceptions of the main factors promoting disease risk along the PDN were the low biosecurity in household farms and live bird markets, mobile traders, the informal slaughter of birds and the management of sick birds. Findings from this study can be used to plan future studies to support food system planners in the development of safer poultry production and distribution in Vietnam.
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2
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Islam A, Islam S, Islam M, Hossain ME, Munro S, Samad MA, Rahman MK, Shirin T, Flora MS, Hassan MM, Rahman MZ, Epstein JH. Prevalence and risk factors for avian influenza virus (H5 and H9) contamination in peri-urban and rural live bird markets in Bangladesh. Front Public Health 2023; 11:1148994. [PMID: 37151580 PMCID: PMC10158979 DOI: 10.3389/fpubh.2023.1148994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/27/2023] [Indexed: 05/09/2023] Open
Abstract
Avian influenza viruses (AIV) have been frequently detected in live bird markets (LBMs) around the world, primarily in urban areas, and have the ability to spillover to other species, including humans. Despite frequent detection of AIV in urban LBMs, the contamination of AIV on environmental surfaces in rural and peri-urban LBMs in Bangladesh is poorly documented. Therefore, we conducted this study to determine the prevalence of AIV subtypes within a subset of peri-urban and rural LBMs in Bangladesh and to further identify associated risk factors. Between 2017 and 2018, we collected faecal and offal samples from 200 stalls in 63 LBMs across four sub-districts. We tested the samples for the AIV matrix gene (M-gene) followed by H5, H7, and H9 subtypes using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). We performed a descriptive analysis of market cleanliness and sanitation practices in order to further elucidate the relationship between LBM biosecurity and AIV subtypes by species, sample types, and landscape. Subsequently, we conducted a univariate analysis and a generalized linear mixed model (GLMM) to determine the risk factors associated with AIV contamination at individual stalls within LBMs. Our findings indicate that practices related to hygiene and the circulation of AIV significantly differed between rural and peri-urban live bird markets. 42.5% (95% CI: 35.56-49.67) of stalls were positive for AIV. A/H5, A/H9, and A HA/Untyped were detected in 10.5% (95% CI: 6.62-15.60), 9% (95% CI: 5.42-13.85), and 24.0% (95% CI: 18.26-30.53) of stalls respectively, with no detection of A/H7. Significantly higher levels of AIV were found in the Sonali chicken strain compared to the exotic broiler, and in offal samples compared to fecal samples. In the GLMM analysis, we identified several significant risk factors associated with AIV contamination in LBMs at the stall level. These include: landscape (AOR: 3.02; 95% CI: 1.18-7.72), the number of chicken breeds present (AOR: 2.4; 95% CI: 1.01-5.67), source of birds (AOR: 2.35; 95% CI: 1.0-5.53), separation of sick birds (AOR: 3.04; 95% CI: 1.34-6.92), disposal of waste/dead birds (AOR: 3.16; 95% CI: 1.41-7.05), cleaning agent (AOR: 5.99; 95% CI: 2.26-15.82), access of dogs (AOR: 2.52; 95% CI: 1.12-5.7), wild birds observed on site (AOR: 2.31; 95% CI: 1.01-5.3). The study further revealed a substantial prevalence of AIV with H5 and H9 subtypes in peri-urban and rural LBMs. The inadequate biosecurity measures at poultry stalls in Bangladesh increase the risk of AIV transmission from poultry to humans. To prevent the spread of AIV to humans and wild birds, we suggest implementing regular surveillance at live bird markets and enhancing biosecurity practices in peri-urban and rural areas in Bangladesh.
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Affiliation(s)
- Ariful Islam
- EcoHealth Alliance, New York, NY, United States
- Centre for Integrative Ecology, School of Life and Environmental Science, Deakin University, Geelong Waurn Ponds, VIC, Australia
- *Correspondence: Ariful Islam,
| | - Shariful Islam
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Monjurul Islam
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Mohammad Enayet Hossain
- One Health Laboratory, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Sarah Munro
- EcoHealth Alliance, New York, NY, United States
| | - Mohammed Abdus Samad
- National Reference Laboratory for Avian Influenza, Bangladesh Livestock Research Institute (BLRI), Savar, Bangladesh
| | - Md. Kaisar Rahman
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Tahmina Shirin
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | | | - Mohammad Mahmudul Hassan
- Queensland Alliance for One Health Sciences, School of Veterinary Science, University of Queensland, Brisbane, QLD, Australia
| | - Mohammed Ziaur Rahman
- One Health Laboratory, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
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3
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Mbai J, Njoroge S, Obonyo M, Otieno C, Owiny M, Fèvre EM. Campylobacter positivity and public health risks in live bird markets in Busia, Kenya: A value chain analysis. Transbound Emerg Dis 2022; 69:e1839-e1853. [PMID: 35293702 PMCID: PMC9790384 DOI: 10.1111/tbed.14518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 12/30/2022]
Abstract
Live bird markets (LBMs) provide integral hubs for 95% of poultry produced for food. Surveillance systems in LBMs serving smallholder farmers in sub-saharan Africa are often non-functional, and data about public health risks and emerging pathogens are lacking. Studies in Kenya have reported 29-44% Campylobacter prevalence in poultry. We analysed such LBMs in Kenya for likely transmission of Campylobacter from poultry to humans. We conducted a cross-sectional survey among 186 live poultry traders (LPTs) in 14 LBMs in a region with widespread backyard poultry systems. A pretested structured questionnaire was administered to all LPTs having regular contacts with poultry to gather market data and risk information on campylobacteriosis. Campylobacter was detected in individual cloacal cultures and identified through PCR. The median score obtained from the outcome of risk assessment dichotomized respondents into high and low risk categories. We performed logistic regression at 95% confidence interval (CI) to compare market characteristics and Campylobacter positivity to risk categories to identify LBM-associated public health risks. Markets had a median of 13 traders, and mean age of 46.3 ± 13.7 years. Majority 162/186 (87.1%) were males. Market behavioural processes by LPTs varied: Only 58.6% LPTs held bird species separate; onsite slaughter (38.7%); encountered sick-bird (93%) and dead-bird (83%) amidst limited health inspection (31.2%). Campylobacter positivity in live birds was 43/112 (38.4%, 95% CI: 29.4-48.1). Risk information on campylobacteriosis was low 41/114 (36%, 95% CI: 27.2-45.5). Sanitary risks were related to accumulation of litter (adjusted prevalence odds ratio [aPOR]: 19.67, 95% CI: 3.01-128.52). Accessing hand-wash facilities (aPOR: .32, 95% CI: .13-.78) and access to information (aPOR: .24, 95% CI: .09-.61) were protective. Sanitary risks were related to poor hygiene. LBMs could be central surveillance sites for Campylobacter. Public health authorities/actors should consider appropriate targeting to improve sanitary measures and Campylobacter control strategies.
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Affiliation(s)
- Josephat Mbai
- Kenya Field Epidemiology and Laboratory Training Program, Kenyatta Hospital Grounds, Nairobi, Kenya
- International Livestock Research Institute, Nairobi, Kenya
- Government of Makueni County, Makueni, Kenya
| | - Samuel Njoroge
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Medical Research Institute KEMRI, Nairobi, Kenya
| | - Mark Obonyo
- Kenya Field Epidemiology and Laboratory Training Program, Kenyatta Hospital Grounds, Nairobi, Kenya
| | | | - Maurice Owiny
- Kenya Field Epidemiology and Laboratory Training Program, Kenyatta Hospital Grounds, Nairobi, Kenya
| | - Eric M Fèvre
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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4
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Kwon J, Youk S, Lee DH. Role of wild birds in the spread of clade 2.3.4.4e H5N6 highly pathogenic avian influenza virus into South Korea and Japan. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 101:105281. [PMID: 35395408 DOI: 10.1016/j.meegid.2022.105281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 03/26/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
H5Nx highly pathogenic avian influenza viruses (HPAIVs) have caused transboundary epizootics in poultry and wild birds. In 2016, the H5N6 subtype of clade 2.3.4.4e HPAIVs caused multiple outbreaks in Asia, including China, Japan, Korea, and Vietnam. However, the geographical spread pattern of 2.3.4.4e H5N6 HPAIV has not been clearly identified. To better understand the emergence and transmission history of 2.3.4.4e H5N6 HPAIV, we investigated the underlying epidemiologic processes associated with this viral spread by performing a Bayesian phylogeography analysis. The results revealed that wild waterfowl played a central role in the transboundary spread of clade 2.3.4.4e H5N6 HPAIV into both endemic and non-endemic countries, causing multiple incursions of the 2.3.4.4e H5N6 HPAIV into South Korea, Japan, and Vietnam. In our analysis, Guangdong province, China was estimated to be the most probable site where 2.3.4.4e H5N6 HPAIVs emerged prior to the transboundary transmissions. Continued genomic surveillance in both wild birds and poultry would be necessary for monitoring of HPAIV incursions. In addition, enhanced biosecurity would be key to preventing the HPAIV spread by minimizing contact between domestic poultry and wild birds.
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Affiliation(s)
- Junghoon Kwon
- College of Veterinary Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Sungsu Youk
- Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, GA, USA
| | - Dong-Hun Lee
- College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea.
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5
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Bauzile B, Sicard G, Guinat C, Andraud M, Rose N, Hammami P, Durand B, Paul MC, Vergne T. Unravelling direct and indirect contact patterns between duck farms in France and their association with the 2016-2017 epidemic of Highly Pathogenic Avian Influenza (H5N8). Prev Vet Med 2021; 198:105548. [PMID: 34920326 DOI: 10.1016/j.prevetmed.2021.105548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 11/10/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022]
Abstract
Live animal movements generate direct contacts (via the exchange of live animals) and indirect contacts (via the transit of transport vehicles) between farms, which can contribute to the spread of pathogens. However, most analyses focus solely on direct contacts and can therefore underestimate the contribution of live animal movements in the spread of infectious diseases. Here, we used French live duck movement data (2016-2018) from one of the largest transport companies to compare direct and indirect contact patterns between duck farms and evaluate how these patterns were associated with the French 2016-2017 epidemic of highly pathogenic avian influenza H5N8. A total number of 614 farms were included in the study, and two directed networks were generated: the animal introduction network (exchange of live ducks) and the transit network (transit of transport vehicles). Following descriptive analyses, these two networks were scrutinized in relation to farm infection status during the epidemic. Results showed that farms were substantially more connected in the transit network than in the animal introduction network and that the transit of transport vehicles generated more opportunities for transmission than the exchange of live animals. We also showed that animal introduction and transit networks' statistics decreased substantially during the epidemic (January-March 2017) compared to non-epidemic periods (January-March 2016 and January-March 2018). We estimated a probability of 33.3 % that a farm exposed to the infection through either of the two live duck movement networks (i.e. that was in direct or indirect contact with a farm that was reported as infected in the following seven days) becomes infected within seven days after the contact. However, we also demonstrated that the level of exposure of farms by these two contact patterns was low, leading only to a handful of transmission events through these routes. As a consequence, we showed that live animal movement patterns are efficient transmission routes for HPAI but have been efficiently reduced to limit the spread during the French 2020-2021 epidemic. These results underpin the relevance of studying indirect contacts resulting from the movement of animals to understand their transmission potential and the importance of accounting for both routes when designing disease control strategies.
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Affiliation(s)
- B Bauzile
- IHAP, ENVT, INRAE, Université de Toulouse, Toulouse, France.
| | - G Sicard
- IHAP, ENVT, INRAE, Université de Toulouse, Toulouse, France
| | - C Guinat
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Basel, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - M Andraud
- ANSES, EPISABE Unit, Ploufragan-Plouzané-Niort Laboratory, Ploufragan, France
| | - N Rose
- ANSES, EPISABE Unit, Ploufragan-Plouzané-Niort Laboratory, Ploufragan, France
| | - P Hammami
- ANSES, EPISABE Unit, Ploufragan-Plouzané-Niort Laboratory, Ploufragan, France
| | - B Durand
- Epidemiology Unit, Laboratory for Animal Health, ANSES, University Paris Est, Maisons-Alfort, France
| | - M C Paul
- IHAP, ENVT, INRAE, Université de Toulouse, Toulouse, France
| | - T Vergne
- IHAP, ENVT, INRAE, Université de Toulouse, Toulouse, France
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6
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Le KT, Stevenson MA, Isoda N, Nguyen LT, Chu DH, Nguyen TN, Nguyen LV, Tien TN, Le TT, Matsuno K, Okamatsu M, Sakoda Y. A systematic approach to illuminate a new hot spot of avian influenza virus circulation in South Vietnam, 2016-2017. Transbound Emerg Dis 2021; 69:e831-e844. [PMID: 34734678 DOI: 10.1111/tbed.14380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 03/30/2021] [Accepted: 10/16/2021] [Indexed: 11/27/2022]
Abstract
In South Vietnam, live bird markets (LBMs) are key in the value chain of poultry products and spread of avian influenza virus (AIV) although they may not be the sole determinant of AIV prevalence. For this reason, a risk analysis of AIV prevalence was conducted accounting for all value chain factors. A cross-sectional study of poultry flock managers and poultry on backyard farms, commercial (high biosecurity) farms, LBMs and poultry delivery stations (PDSs) in four districts of Vinh Long province was conducted between December 2016 and August 2017. A total of 3597 swab samples were collected from birds from 101 backyard farms, 50 commercial farms, 58 sellers in LBMs and 19 traders in PDSs. Swab samples were submitted for AIV isolation. At the same time a questionnaire was administered to flock managers asking them to provide details of their knowledge, attitude and practices related to avian influenza. Multiple correspondence analysis and a mixed-effects multivariable logistic regression model were developed to identify enterprise and flock manager characteristics that increased the risk of AIV positivity. A total of 274 birds were positive for AIV isolation, returning an estimated true prevalence of 7.6% [95% confidence interval (CI): 6.8%-8.5%]. The odds of a bird being AIV positive if it was from an LBM or PDS were 45 (95% CI: 3.4-590) and 25 (95% CI: 1.4-460), respectively, times higher to the odds of a bird from a commercial poultry farm being AIV positive. The odds of birds being AIV positive for respondents with a mixed (uncertain or inconsistent) level and a low level of knowledge about AI were 5.0 (95% CI: 0.20-130) and 3.5 (95% CI: 0.2-62), respectively, times higher to the odd of birds being positive for respondents with a good knowledge of AI. LBMs and PDSs should receive specific emphasis in AI control programs in Vietnam. Our findings provide evidence to support the hypothesis that incomplete respondent knowledge of AI and AIV spread mechanism were associated with an increased risk of AIV positivity. Delivery of education programs specifically designed for those in each enterprise will assist in this regard. The timing and frequency of delivery of education programs are likely to be important if the turnover of those working in LBMs and PDSs is high.
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Affiliation(s)
- Kien Trung Le
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mark A Stevenson
- Faculty of Veterinary and Agricultural Sciences, Asia-Pacific Centre for Animal Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Norikazu Isoda
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.,Division of Risk Analysis and Management, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Lam Thanh Nguyen
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.,Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho, Vietnam
| | - Duc-Huy Chu
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Vietnam
| | - Tien Ngoc Nguyen
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Vietnam
| | - Long Van Nguyen
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Vietnam
| | - Tien Ngoc Tien
- Regional Animal Health Office VII, Department of Animal Health, Ministry of Agriculture and Rural Development, Can Tho, Vietnam
| | - Tung Thanh Le
- Sub-Departments of Animal Health, Ministry of Agriculture and Rural Development, Vinh Long, Vietnam
| | - Keita Matsuno
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Masatoshi Okamatsu
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoshihiro Sakoda
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
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7
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Guinat C, Durand B, Vergne T, Corre T, Rautureau S, Scoizec A, Lebouquin-Leneveu S, Guérin JL, Paul MC. Role of Live-Duck Movement Networks in Transmission of Avian Influenza, France, 2016-2017. Emerg Infect Dis 2021; 26:472-480. [PMID: 32091357 PMCID: PMC7045841 DOI: 10.3201/eid2603.190412] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The relative roles that movement and proximity networks play in the spread of highly pathogenic avian influenza (HPAI) viruses are often unknown during an epidemic, preventing effective control. We used network analysis to explore the devastating epidemic of HPAI A(H5N8) among poultry, in particular ducks, in France during 2016–2017 and to estimate the likely contribution of live-duck movements. Approximately 0.2% of live-duck movements could have been responsible for between-farm transmission events, mostly early during the epidemic. Results also suggest a transmission risk of 35.5% when an infected holding moves flocks to another holding within 14 days before detection. Finally, we found that densely connected groups of holdings with sparse connections between groups overlapped farmer organizations, which represents important knowledge for surveillance design. This study highlights the importance of movement bans in zones affected by HPAI and of understanding transmission routes to develop appropriate HPAI control strategies.
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8
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Hood G, Roche X, Brioudes A, von Dobschuetz S, Fasina FO, Kalpravidh W, Makonnen Y, Lubroth J, Sims L. A literature review of the use of environmental sampling in the surveillance of avian influenza viruses. Transbound Emerg Dis 2021; 68:110-126. [PMID: 32652790 PMCID: PMC8048529 DOI: 10.1111/tbed.13633] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 05/07/2020] [Accepted: 05/13/2020] [Indexed: 02/05/2023]
Abstract
This literature review provides an overview of use of environmental samples (ES) such as faeces, water, air, mud and swabs of surfaces in avian influenza (AI) surveillance programs, focussing on effectiveness, advantages and gaps in knowledge. ES have been used effectively for AI surveillance since the 1970s. Results from ES have enhanced understanding of the biology of AI viruses in wild birds and in markets, of links between human and avian influenza, provided early warning of viral incursions, allowed assessment of effectiveness of control and preventive measures, and assisted epidemiological studies in outbreaks, both avian and human. Variation exists in the methods and protocols used, and no internationally recognized guidelines exist on the use of ES and data management. Few studies have performed direct comparisons of ES versus live bird samples (LBS). Results reported so far demonstrate reliance on ES will not be sufficient to detect virus in all cases when it is present, especially when the prevalence of infection/contamination is low. Multiple sample types should be collected. In live bird markets, ES from processing/selling areas are more likely to test positive than samples from bird holding areas. When compared to LBS, ES is considered a cost-effective, simple, rapid, flexible, convenient and acceptable way of achieving surveillance objectives. As a non-invasive technique, it can minimize effects on animal welfare and trade in markets and reduce impacts on wild bird communities. Some limitations of environmental sampling methods have been identified, such as the loss of species-specific or information on the source of virus, and taxonomic-level analyses, unless additional methods are applied. Some studies employing ES have not provided detailed methods. In others, where ES and LBS are collected from the same site, positive results have not been assigned to specific sample types. These gaps should be remedied in future studies.
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Affiliation(s)
- Grace Hood
- Food and Agriculture Organization of the United NationsRomeItaly
| | - Xavier Roche
- Food and Agriculture Organization of the United NationsRomeItaly
| | - Aurélie Brioudes
- Food and Agriculture Organization of the United NationsRegional Office for Asia and the PacificBangkokThailand
| | | | | | | | - Yilma Makonnen
- Food and Agriculture Organization of the United Nations, Sub-Regional Office for Eastern AfricaAddis AbabaEthiopia
| | - Juan Lubroth
- Food and Agriculture Organization of the United NationsRomeItaly
| | - Leslie Sims
- Asia Pacific Veterinary Information ServicesMelbourneAustralia
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9
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Zhou X, Gao L, Wang Y, Li Y, Zhang Y, Shen C, Liu A, Yu Q, Zhang W, Pekin A, Guo F, Smith C, Clements ACA, Edwards J, Huang B, Soares Magalhães RJ. Geographical variation in the risk of H7N9 human infections in China: implications for risk-based surveillance. Sci Rep 2020; 10:10372. [PMID: 32587266 PMCID: PMC7316858 DOI: 10.1038/s41598-020-66359-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 04/23/2020] [Indexed: 11/09/2022] Open
Abstract
The influenza A (H7N9) subtype remains a public health problem in China affecting individuals in contact with live poultry, particularly at live bird markets. Despite enhanced surveillance and biosecurity at LBMs H7N9 viruses are now more widespread in China. This study aims to quantify the temporal relationship between poultry surveillance results and the onset of human H7N9 infections during 2013-2017 and to estimate risk factors associated with geographical risk of H7N9 human infections in counties in Southeast China. Our results suggest that poultry surveillance data can potentially be used as early warning indicators for human H7N9 notifications. Furthermore, we found that human H7N9 incidence at county-level was significantly associated with the presence of wholesale LBMs, the density of retail LBMs, the presence of poultry virological positives, poultry movements from high-risk areas, as well as chicken population density and human population density. The results of this study can influence the current AI H7N9 control program by supporting the integration of poultry surveillance data with human H7N9 notifications as an early warning of the timing and areas at risk for human infection. The findings also highlight areas in China where monitoring of poultry movement and poultry infections could be prioritized.
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Affiliation(s)
- Xiaoyan Zhou
- School of Veterinary Science, The University of Queensland, Brisbane, Australia.
| | - Lu Gao
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China
| | - Youming Wang
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China
| | - Yin Li
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China.,School of Veterinary and Biomedical Sciences, Murdoch University, Perth, Australia
| | - Yi Zhang
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China
| | - Chaojian Shen
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China
| | - Ailing Liu
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China
| | - Qi Yu
- Beijing Center for Animal Disease Prevention and Control, Beijing, PR China
| | - Wenyi Zhang
- Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, PR China
| | - Alexander Pekin
- School of Veterinary Science, The University of Queensland, Brisbane, Australia
| | - Fusheng Guo
- Food and Agriculture Organization of the United Nations (FAO), Bangkok, Thailand
| | - Carl Smith
- School of Business, The University of Queensland, Brisbane, Australia
| | - Archie C A Clements
- Faculty of Health Sciences, Curtin University, Perth, Australia.,Telethon Kids Institute, Perth, Australia
| | - John Edwards
- School of Veterinary Science, The University of Queensland, Brisbane, Australia.,China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China.,School of Veterinary and Biomedical Sciences, Murdoch University, Perth, Australia
| | - Baoxu Huang
- China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China.
| | - Ricardo J Soares Magalhães
- School of Veterinary Science, The University of Queensland, Brisbane, Australia.,Child Health Research Centre, The University of Queensland, Brisbane, Australia
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10
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Oluwayelu DO, Meseko CA, Ayinmode AB, Adebiyi AI, Lawani MA, Kakulu FO. Re-emergence of Highly Pathogenic Avian Influenza H5N1 in Nigeria, 2014-2016: Role of Social Network and Value Chain Forces in Interstate Transmission. Virol Sin 2020; 35:494-498. [PMID: 32236814 DOI: 10.1007/s12250-020-00201-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/17/2020] [Indexed: 10/24/2022] Open
Affiliation(s)
- Daniel Oladimeji Oluwayelu
- Department of Veterinary Microbiology, University of Ibadan, Ibadan, 200284, Nigeria. .,Centre for Control and Prevention of Zoonoses (CCPZ), University of Ibadan, Ibadan, 200284, Nigeria.
| | | | - Adekunle Bamidele Ayinmode
- Centre for Control and Prevention of Zoonoses (CCPZ), University of Ibadan, Ibadan, 200284, Nigeria.,Department of Veterinary Parasitology and Entomology, University of Ibadan, Ibadan, 200284, Nigeria
| | | | - Mike Aneshimi Lawani
- Gestational Diabetes Society of Nigeria, Mother and Child Hospital Annex, Akure, 340282, Nigeria
| | - Florence Omonele Kakulu
- Department of Veterinary and Pest Control Services, Federal Ministry of Agriculture, Abuja, 900247, Nigeria
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11
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Knowledge and remaining gaps on the role of animal and human movements in the poultry production and trade networks in the global spread of avian influenza viruses - A scoping review. PLoS One 2020; 15:e0230567. [PMID: 32196515 PMCID: PMC7083317 DOI: 10.1371/journal.pone.0230567] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 03/03/2020] [Indexed: 12/28/2022] Open
Abstract
Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence. The role of wild bird movements in this global spread has been extensively studied while the role of animal, human and fomite movement within commercial poultry production and trade networks remains poorly understood. The aim of this work is to better understand these roles in relation to the different routes of AI spread. A scoping literature review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using a search algorithm combining twelve domains linked to AI spread and animal/human movements within poultry production and trade networks. Only 28 out of 3,978 articles retrieved dealt especially with the role of animal, human and fomite movements in AI spread within the international trade network (4 articles), the national trade network (8 articles) and the production network (16 articles). While the role of animal movements in AI spread within national trade networks has been largely identified, human and fomite movements have been considered more at risk for AI spread within national production networks. However, the role of these movements has never been demonstrated with field data, and production networks have only been partially studied and never at international level. The complexity of poultry production networks and the limited access to production and trade data are important barriers to this knowledge. There is a need to study the role of animal and human movements within poultry production and trade networks in the global spread of AI in partnership with both public and private actors to fill this gap.
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12
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Assessing the role of live poultry trade in community-structured transmission of avian influenza in China. Proc Natl Acad Sci U S A 2020; 117:5949-5954. [PMID: 32123088 PMCID: PMC7084072 DOI: 10.1073/pnas.1906954117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The live poultry trade is thought to play an important role in the spread and maintenance of highly pathogenic avian influenza A viruses (HP AIVs) in Asia. Despite an abundance of small-scale observational studies, the role of the poultry trade in disseminating AIV over large geographic areas is still unclear, especially for developing countries with complex poultry production systems. Here we combine virus genomes and reconstructed poultry transportation data to measure and compare the spatial spread in China of three key subtypes of AIV: H5N1, H7N9, and H5N6. Although it is difficult to disentangle the contribution of confounding factors, such as bird migration and spatial distance, we find evidence that the dissemination of these subtypes among domestic poultry is geographically continuous and likely associated with the intensity of the live poultry trade in China. Using two independent data sources and network analysis methods, we report a regional-scale community structure in China that might explain the spread of AIV subtypes in the country. The identification of this structure has the potential to inform more targeted strategies for the prevention and control of AIV in China.
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13
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Li Y, Huang B, Shen C, Cai C, Wang Y, Edwards J, Zhang G, Robertson ID. Pig trade networks through live pig markets in Guangdong Province, China. Transbound Emerg Dis 2020; 67:1315-1329. [PMID: 31903722 PMCID: PMC7228257 DOI: 10.1111/tbed.13472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 11/28/2022]
Abstract
This study used social network analysis to investigate the indirect contact network between counties through the movement of live pigs through four wholesale live pig markets in Guangdong Province, China. All 14,118 trade records for January and June 2016 were collected from the markets and the patterns of pig trade in these markets analysed. Maps were developed to show the movement pathways. Evaluating the network between source counties was the primary objective of this study. A 1‐mode network was developed. Characteristics of the trading network were explored, and the degree, betweenness and closeness were calculated for each source county. Models were developed to compare the impacts of different disease control strategies on the potential magnitude of an epidemic spreading through this network. The results show that pigs from 151 counties were delivered to the four wholesale live pig markets in January and/or June 2016. More batches (truckloads of pigs sourced from one or more piggeries) were traded in these markets in January (8,001) than in June 2016 (6,117). The pigs were predominantly sourced from counties inside Guangdong Province (90%), along with counties in Hunan, Guangxi, Jiangxi, Fujian and Henan provinces. The major source counties (46 in total) contributed 94% of the total batches during the two‐month study period. Pigs were sourced from piggeries located 10 to 1,417 km from the markets. The distribution of the nodes' degrees in both January and June indicates a free‐scale network property, and the network in January had a higher clustering coefficient (0.54 vs. 0.39) and a shorter average pathway length (1.91 vs. 2.06) than that in June. The most connected counties of the network were in the central, northern and western regions of Guangdong Province. Compared with randomly removing counties from the network, eliminating counties with higher betweenness, degree or closeness resulted in a greater reduction of the magnitude of a potential epidemic. The findings of this study can be used to inform targeted control interventions for disease spread through this live pig market trade network in south China.
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Affiliation(s)
- Yin Li
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia.,China Animal Health and Epidemiology Center, Qingdao, China
| | - Baoxu Huang
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia.,China Animal Health and Epidemiology Center, Qingdao, China
| | - Chaojian Shen
- China Animal Health and Epidemiology Center, Qingdao, China
| | - Chang Cai
- Research and Innovation Office, Murdoch University, Murdoch, WA, Australia.,China Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology, Zhejiang Agricultural and Forestry University, Hangzhou, China
| | - Youming Wang
- China Animal Health and Epidemiology Center, Qingdao, China
| | - John Edwards
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia.,China Animal Health and Epidemiology Center, Qingdao, China
| | - Guihong Zhang
- South China Agriculture University, Guangzhou, China
| | - Ian D Robertson
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia.,China-Australia Joint Research and Training Centre for Veterinary Epidemiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
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14
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Nguyen LT, Stevenson MA, Firestone SM, Sims LD, Chu DH, Nguyen LV, Nguyen TN, Le KT, Isoda N, Matsuno K, Okamatsu M, Kida H, Sakoda Y. Spatiotemporal and risk analysis of H5 highly pathogenic avian influenza in Vietnam, 2014-2017. Prev Vet Med 2019; 178:104678. [PMID: 31113666 DOI: 10.1016/j.prevetmed.2019.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 03/10/2019] [Accepted: 04/13/2019] [Indexed: 10/27/2022]
Abstract
The aim of this study was to describe the spatiotemporal distribution of H5 HPAI outbreak reports for the period 2014-2017 and to identify factors associated with H5 HPAI outbreak reports. Throughout the study period, a total of 139 outbreaks of H5 HPAI in poultry were reported, due to either H5N1 (96 outbreaks) or H5N6 (43 outbreaks) subtype viruses. H5N1 HPAI outbreaks occurred in all areas of Vietnam while H5N6 HPAI outbreaks were only reported in the northern and central provinces. We counted the number of H5N1 and H5N6 outbreak report-positive districts per province over the four-year study period and calculated the provincial-level standardized morbidity ratio for H5N1 and H5N6 outbreak reports as the observed number of positive districts divided by the expected number. A mixed-effects, zero-inflated Poisson regression model was developed to identify risk factors for outbreak reports of each H5N1 and H5N6 subtype virus. Spatially correlated and uncorrelated random effects terms were included in this model to identify areas of the country where outbreak reports occurred after known risk factors had been accounted-for. The presence of an outbreak report in a province in the previous 6-12 months increased the provincial level H5N1 outbreak report risk by a factor of 2.42 (95% Bayesian credible interval [CrI] 1.27-4.60) while 1000 bird increases in the density of chickens decreased provincial level H5N6 outbreak report risk by a factor of 0.65 (95% CrI 0.38 to 0.97). We document distinctly different patterns in the spatial and temporal distribution of H5N1 and H5N6 outbreak reports. Most of the variation in H5N1 report risk was accounted-for by the fixed effects included in the zero-inflated Poisson model. In contrast, the amount of unaccounted-for risk in the H5N6 model was substantially greater than the H5N1 model. For H5N6 we recommend that targeted investigations should be carried out in provinces with relatively large spatially correlated random effect terms to identify likely determinants of disease. Similarly, investigations should be carried out in provinces with relatively low spatially correlated random effect terms to identify protective factors for disease and/or reasons for failure to report.
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Affiliation(s)
- Lam Thanh Nguyen
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan; Department of Veterinary Medicine, College of Agriculture, Can Tho University, Campus II, 3/2 Street, Ninh Kieu, Can Tho, Viet Nam
| | - Mark A Stevenson
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - Simon M Firestone
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Leslie D Sims
- Asia Pacific Veterinary Information Services, Montmorency, Victoria, 3094, Australia
| | - Duc Huy Chu
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Viet Nam
| | - Long Van Nguyen
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Viet Nam
| | - Tien Ngoc Nguyen
- Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi, Viet Nam
| | - Kien Trung Le
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan
| | - Norikazu Isoda
- Research Center for Zoonosis Control, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan; Global Institution for Collaborative Research and Education, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Keita Matsuno
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan; Global Institution for Collaborative Research and Education, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Masatoshi Okamatsu
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan
| | - Hiroshi Kida
- Research Center for Zoonosis Control, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan; Global Institution for Collaborative Research and Education, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Yoshihiro Sakoda
- Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan; Global Institution for Collaborative Research and Education, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.
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15
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Exploring contacts facilitating transmission of influenza A(H5N1) virus between poultry farms in West Java, Indonesia: A major role for backyard farms? Prev Vet Med 2018; 156:8-15. [PMID: 29891149 DOI: 10.1016/j.prevetmed.2018.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 03/11/2018] [Accepted: 04/11/2018] [Indexed: 11/21/2022]
Abstract
Highly pathogenic avian influenza virus (HPAIV) H5N1 has been reported in Asia, including Indonesia since 2003. Although several risk factors related to the HPAIV outbreaks in poultry in Indonesia have been identified, little is known of the contact structure of farms of different poultry production types (backyard chickens, broilers, layers, and ducks). This study aims to quantify the contact rates associated with the movement of people, and movements of live birds and products and equipment that affect the risk of HPAIV H5N1 transmission between poultry farms in Indonesia. On 124 poultry farms in 6 districts in West Java, logbooks were distributed to record the movements of farmers/staff and visitors and their poultry contacts. Most movements in backyard chicken, commercial native chicken, broiler and duck farms were visits to and from other poultry farms, whilst in layer farms visits to and from poultry companies, visits to egg collection houses and visit from other poultry farms were most frequent. Over 75% of persons visiting backyard chicken and duck farms had previously visited other poultry farms on the same day. Visitors of backyard chicken farms had the highest average contact rate, either direct contact with poultry on other farms before the visits (1.35 contact/day) or contact during their visits in the farms (10.03 contact/day). These results suggest that backyard chicken farms are most at risk for transmission of HPAIV compared to farms of the other poultry production types. Since visits of farm-to-farm were high, backyard farms could also a potential source for HPAIV transmission to commercial poultry farms.
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16
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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.
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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
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17
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Radin JM, Shaffer RA, Lindsay SP, Araneta MRG, Raman R, Fowler JH. International chicken trade and increased risk for introducing or reintroducing highly pathogenic avian influenza A (H5N1) to uninfected countries. Infect Dis Model 2017; 2:412-418. [PMID: 30137719 PMCID: PMC6001958 DOI: 10.1016/j.idm.2017.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 08/18/2017] [Accepted: 09/20/2017] [Indexed: 11/17/2022] Open
Abstract
Every year billions of chickens are shipped thousands of miles around the globe in order to meet the ever increasing demands for this cheap and nutritious protein source. Unfortunately, transporting chickens internationally can also increase the chance for introducing zoonotic viruses, such as highly pathogenic avian influenza A (H5N1) to new countries. Our study used a retrospective analysis of poultry trading data from 2003 through 2011 to assess the risk of H5N1 poultry infection in an importing country. We found that the risk of infection in an importing country increased by a factor of 1.3 (95% CI: 1.1-1.5) for every 10-fold increase in live chickens imported from countries experiencing at least one H5N1 poultry case during that year. These results suggest that the risk in a particular country can be significantly reduced if imports from countries experiencing an outbreak are decreased during the year of infection or if biosecurity measures such as screening, vaccination, and infection control practices are increased. These findings show that limiting trade of live chickens or increasing infection control practices during contagious periods may be an important step in reducing the spread of H5N1 and other emerging avian influenza viruses.
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Affiliation(s)
- Jennifer M Radin
- Joint Doctoral Program in Public Health (Epidemiology), San Diego State University/University of California, San Diego, La Jolla, CA 92093, USA
| | - Richard A Shaffer
- Division of Epidemiology and Biostatistics, San Diego State University, San Diego, CA 92182, USA
| | - Suzanne P Lindsay
- Division of Epidemiology and Biostatistics, San Diego State University, San Diego, CA 92182, USA
| | - Maria Rosario G Araneta
- Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rema Raman
- Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - James H Fowler
- Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, CA 92093, USA.,Department of Political Sciences, University of California, San Diego, La Jolla, CA 92093, USA.,Division of Medical Genetics, University of California, San Diego, La Jolla, CA 92093, USA
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18
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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.
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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
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19
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Peyre M, Choisy M, Sobhy H, Kilany WH, Gély M, Tripodi A, Dauphin G, Saad M, Roger F, Lubroth J, Jobre Y. Added Value of Avian Influenza (H5) Day-Old Chick Vaccination for Disease Control in Egypt. Avian Dis 2017; 60:245-52. [PMID: 27309063 DOI: 10.1637/11131-050715-resnote] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The immunity profile against H5N1 highly pathogenic avian influenza (HPAI) in the commercial poultry value chain network in Egypt was modeled with the use of different vaccination scenarios. The model estimated the vaccination coverage, the protective seroconversion level, and the duration of immunity for each node of the network and vaccination scenario. Partial budget analysis was used to compare the benefit-cost of the different vaccination scenarios. The model predicted that targeting day-old chick avian influenza (AI) vaccination in industrial and large hatcheries would increase immunity levels in the overall poultry population in Egypt and especially in small commercial poultry farms (from <30% to >60%). This strategy was shown to be more efficient than the current strategy of using inactivated vaccines. Improving HPAI control in the commercial poultry sector in Egypt would have a positive impact to improve disease control.
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Affiliation(s)
- Marisa Peyre
- A UPR AGRIS, Centre International de Recherche en Agriculture pour le Développement, 34398, Montpellier, France
| | - Marc Choisy
- B UMR MIVEGEC, 34394, Montpellier, France; Oxford University Clinical Research Unit (OUCRU), Hanoi, Vietnam
| | - Heba Sobhy
- C Food and Agriculture Organization of the United Nations, P.O. Box 2223, Cairo, Egypt
| | - Walid H Kilany
- C Food and Agriculture Organization of the United Nations, P.O. Box 2223, Cairo, Egypt.,D Reference Laboratory for Veterinary Quality on Poultry Production, 12618, Cairo, Egypt
| | - Marie Gély
- A UPR AGRIS, Centre International de Recherche en Agriculture pour le Développement, 34398, Montpellier, France
| | - Astrid Tripodi
- E Food and Agriculture Organization of the United Nations, 00153, Rome, Italy
| | - Gwenaëlle Dauphin
- E Food and Agriculture Organization of the United Nations, 00153, Rome, Italy
| | - Mona Saad
- F General Organization for Veterinary Services, 12618, Cairo, Egypt
| | - François Roger
- A UPR AGRIS, Centre International de Recherche en Agriculture pour le Développement, 34398, Montpellier, France
| | - Juan Lubroth
- E Food and Agriculture Organization of the United Nations, 00153, Rome, Italy
| | - Yilma Jobre
- C Food and Agriculture Organization of the United Nations, P.O. Box 2223, Cairo, Egypt
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20
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Assessment of hygienic conditions of live bird markets on avian influenza in Chittagong metro, Bangladesh. Prev Vet Med 2017; 142:7-15. [PMID: 28606367 DOI: 10.1016/j.prevetmed.2017.04.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/19/2017] [Accepted: 04/25/2017] [Indexed: 11/23/2022]
Abstract
Live Bird Markets (LBMs) in Asian countries are considered as hubs for the spread and maintenance of different infectious diseases. In Bangladesh, LBMs are the major source of live and dressed poultry to consumers and until now only a few studies have been conducted targeting infectious agent status such as avian influenza virus (AIV) prevalence of LBMs in Bangladesh. Therefore, a cross sectional study was conducted using all 40 LBMs within the Chittagong Metropolitan Area (CMA) of Bangladesh targeting demographic information and hygienic status of LBMs in concurrence with AIV prevalence and its subtype distribution, as well as the associated risk factors for AIV. Pooled environmental swab samples were collected from 2 to 9 different sites per stall, with epidemiological data being obtained from a total of 290 stalls across 40 LBMs. The samples were evaluated by Real Time Reverse Transcriptase Polymerase Chain Reaction. The prevalence of AIV was 40% (95% CI: 20-60%; N=40) at a LBM level followed by 20.3% (CI: 10-30%, N=290) at a stall level. Specifically, the prevalence of H5, H7 and H9 subtypes at stall level were 2.8% (95% CI: 1-5%), 0% (CI: 0-1.3%) and 3.1% (CI: 1-6%), respectively. Generalized Estimating Equation model identified that the type of species sold (OR=2.5: Chicken and non-duck species versus Duck with other species), bird holding areas (OR=1.9: Cage versus Floor) and Hygienic score (OR=3.1: Score 3 or more versus score less than 3) as potential risk factors for the detection of AIV at stall level. These results suggest that housing chickens and ducks together in the stalls, birds kept on floors, and lack of adequate hygienic measures of the stall were the crucial factors for spreading AIV. This research outcome could be used to develop a proof-based program concerning environmental sanitation along with development of an effective surveillance system to reduce the AIV transmission through LBMs in Bangladesh.
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21
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Kurscheid J, Stevenson M, Durr PA, Toribio JALML, Kurscheid S, Ambarawati IGAA, Abdurrahman M, Fenwick S. Social network analysis of the movement of poultry to and from live bird markets in Bali and Lombok, Indonesia. Transbound Emerg Dis 2017; 64:2023-2033. [PMID: 28160424 DOI: 10.1111/tbed.12613] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Indexed: 11/29/2022]
Abstract
Highly pathogenic avian influenza H5N1 has resulted in large losses to the Indonesian poultry sector. Evidence suggests that live bird markets (LBMs) play an important role in the epidemiology of the disease. Knowledge of the frequency and type of contact between the various poultry market players should allow animal health authorities to develop a better understanding of factors influencing virus transmission between Indonesian villages. A questionnaire-based cross-sectional survey was conducted in 17 LBMs on the neighbouring Indonesian islands of Bali and Lombok to investigate the movement patterns of poultry to and from markets. Using social network analyses, a network of contacts was created for each island from a total of 413 live poultry traders and 134 customers. Individual nodes with high degree and/or betweenness were identified in each network. The Lombok network was more dense and connected than the Bali network indicating that disease transmission would be more efficient in the Lombok network. Our findings indicate that whilst live poultry are typically transported over relatively short distances of approximately 10 km, it is not uncommon for traders and customers to travel in excess of 100 km to buy or sell poultry, which may facilitate the spread of disease over a large geographical area. This study highlights the different roles markets play in poultry movement networks and their potential for disease dissemination. The identification of highly influential market nodes allows authorities to target HPAI surveillance activities to locations where disease is more likely to be present, which is crucial in low-resource settings.
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Affiliation(s)
- J Kurscheid
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, Australia.,Department of Global Health, Research School of Population Health, Australian National University, Acton, ACT, Australia
| | - M Stevenson
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Vic., Australia
| | - P A Durr
- Australian Animal Health Laboratory, Commonwealth Science and Industry Organisation, Geelong, Vic., Australia
| | - J-A L M L Toribio
- Faculty of Veterinary Science, Camden Campus, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW, Australia
| | - S Kurscheid
- John Curtin School of Medical Research, Australian National University, Acton, ACT, Australia
| | - I G A A Ambarawati
- Agribusiness Study Program, Faculty of Agriculture, Udayana University, Denpasar, Bali, Indonesia
| | - M Abdurrahman
- Research Center for Rural Development, Mataram University, Mataram, Lombok, Indonesia
| | - S Fenwick
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, Boston, MA, USA
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22
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Artois J, Lai S, Feng L, Jiang H, Zhou H, Li X, Dhingra MS, Linard C, Nicolas G, Xiao X, Robinson TP, Yu H, Gilbert M. H7N9 and H5N1 avian influenza suitability models for China: accounting for new poultry and live-poultry markets distribution data. STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT : RESEARCH JOURNAL 2017; 31:393-402. [PMID: 28298880 PMCID: PMC5329093 DOI: 10.1007/s00477-016-1362-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In the last two decades, two important avian influenza viruses infecting humans emerged in China, the highly pathogenic avian influenza (HPAI) H5N1 virus in the late nineties, and the low pathogenic avian influenza (LPAI) H7N9 virus in 2013. China is home to the largest population of chickens (4.83 billion) and ducks (0.694 billion), representing, respectively 23.1 and 58.6% of the 2013 world stock, with a significant part of poultry sold through live-poultry markets potentially contributing to the spread of avian influenza viruses. Previous models have looked at factors associated with HPAI H5N1 in poultry and LPAI H7N9 in markets. However, these have not been studied and compared with a consistent set of predictor variables. Significant progress was recently made in the collection of poultry census and live-poultry market data, which are key potential factors in the distribution of both diseases. Here we compiled and reprocessed a new set of poultry census data and used these to analyse HPAI H5N1 and LPAI H7N9 distributions with boosted regression trees models. We found a limited impact of the improved poultry layers compared to models based on previous poultry census data, and a positive and previously unreported association between HPAI H5N1 outbreaks and the density of live-poultry markets. In addition, the models fitted for the HPAI H5N1 and LPAI H7N9 viruses predict a high risk of disease presence for the area around Shanghai and Hong Kong. The main difference in prediction between the two viruses concerned the suitability of HPAI H5N1 in north-China around the Yellow sea (outlined with Tianjin, Beijing, and Shenyang city) where LPAI H7N9 has not spread intensely.
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Affiliation(s)
- Jean Artois
- Spatial Epidemiology Lab. (SpELL), Université Libre de Bruxelles, Brussels, Belgium
| | - Shengjie Lai
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206 China
- WorldPop, Department of Geography and Environment, University of Southampton, Southampton, SO17 1BJ UK
- Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai, 200032 China
| | - Luzhao Feng
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206 China
| | - Hui Jiang
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206 China
| | - Hang Zhou
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206 China
| | - Xiangping Li
- Institute of Biodiversity Science, Fudan University, Shanghai, 200433 China
| | - Madhur S. Dhingra
- Spatial Epidemiology Lab. (SpELL), Université Libre de Bruxelles, Brussels, Belgium
- Department of Animal Husbandry & Dairying, Government of Haryana, Pashudhan Bhawan, Bays No. 9-12, Sector -2, Panchkula, Haryana 134109 India
| | - Catherine Linard
- Spatial Epidemiology Lab. (SpELL), Université Libre de Bruxelles, Brussels, Belgium
- Department of Geography, Université de Namur, Namur, Belgium
| | - Gaëlle Nicolas
- Spatial Epidemiology Lab. (SpELL), Université Libre de Bruxelles, Brussels, Belgium
| | - Xiangming Xiao
- Department of Microbiology and Plant Biology, Center for Spatial AnalysisUniversity of Oklahoma, 101 David L. Boren Blvd, Norman, OK 73019 USA
| | - Timothy P. Robinson
- Livestock Systems and Environment (LSE), International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Hongjie Yu
- Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai, 200032 China
| | - Marius Gilbert
- Spatial Epidemiology Lab. (SpELL), Université Libre de Bruxelles, Brussels, Belgium
- Fonds National de la Recherche Scientifique, Brussels, Belgium
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Manabe T, Yamaoka K, Tango T, Binh NG, Co DX, Tuan ND, Izumi S, Takasaki J, Chau NQ, Kudo K. Chronological, geographical, and seasonal trends of human cases of avian influenza A (H5N1) in Vietnam, 2003-2014: a spatial analysis. BMC Infect Dis 2016; 16:64. [PMID: 26847341 PMCID: PMC4743110 DOI: 10.1186/s12879-016-1391-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/27/2016] [Indexed: 11/10/2022] Open
Abstract
Background Human cases of highly pathogenic avian influenza A (H5N1) virus infection continue to occur in Southeast Asia. The objective of this study was to identify when and where human H5N1 cases have occurred in Vietnam and how the situation has changed from the beginning of the H5N1 outbreaks in 2003 through 2014, to assist with implementing methods of targeted disease management. Methods We assessed the disease clustering and seasonal variation of human H5N1 cases in Vietnam to evaluate the geographical and monthly timing trends. The clustering of H5N1 cases and associated mortality were examined over three time periods: the outbreak period (2003–2005), the post-outbreak (2006–2009), and the recent period (2010–2014) using the flexibly shaped space-time scan statistic. The most likely cases to co-cluster and the elevated risks for incidence and mortality were assessed via calculation of the relative risk (RR). The H5N1 case seasonal variation was analysed as the cyclic trend in incidence data using Roger’s statistical test. Results Between 2003 and 2005, H5N1 cases (RR: 2.15, p = 0.001) and mortality (RR: 2.49, p = 0.021) were significantly clustered in northern Vietnam. After 2010, H5N1 cases tended to occur on the border with Cambodia in the south, while H5N1 mortality clustered significantly in the Mekong delta area (RR: 6.62, p = 0.002). A significant seasonal variation was observed (p < 0.001), with a higher incidence of morbidity in December through April. Conclusions These findings indicate that clinical preparedness for H5N1 in Vietnam needs to be strengthened in southern Vietnam in December–April. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1391-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Toshie Manabe
- Teikyo University, Graduate School of Public Health, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan. .,Department of Hygiene and Public Health, Teikyo University School of Medicine, Tokyo, Japan. .,Waseda University, 1-21-1 Nishi-Waseda, Shinjuku-ku, Tokyo, Japan. .,University of Tsukuba, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan.
| | - Kazue Yamaoka
- Teikyo University, Graduate School of Public Health, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan.
| | - Toshiro Tango
- Teikyo University, Graduate School of Public Health, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan. .,Center for Medical Statistics, Tokyo, Japan.
| | - Nguyen Gia Binh
- Bach Mai Hospital, Intensive Care Unit, 78 Giai Phong, Dong Da, Hanoi, Vietnam.
| | - Dao Xuan Co
- Bach Mai Hospital, Intensive Care Unit, 78 Giai Phong, Dong Da, Hanoi, Vietnam.
| | - Nguyen Dang Tuan
- Bach Mai Hospital, Intensive Care Unit, 78 Giai Phong, Dong Da, Hanoi, Vietnam.
| | - Shinyu Izumi
- National Center for Global Health and Medicine, Division of Pulmonary Medicine, Tokyo, Japan.
| | - Jin Takasaki
- National Center for Global Health and Medicine, Division of Pulmonary Medicine, Tokyo, Japan.
| | - Ngo Quy Chau
- Department of Pulmonary Medicine, Bach Mai Hospital, 78 Giai Phong, Dong Da, Hanoi, Vietnam.
| | - Koichiro Kudo
- Waseda University, 1-21-1 Nishi-Waseda, Shinjuku-ku, Tokyo, Japan. .,Koto Hospital, 6-8-5 Ojima, Koto-ku, Tokyo, Japan.
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24
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Millman AJ, Havers F, Iuliano AD, Davis CT, Sar B, Sovann L, Chin S, Corwin AL, Vongphrachanh P, Douangngeun B, Lindblade KA, Chittaganpitch M, Kaewthong V, Kile JC, Nguyen HT, Pham DV, Donis RO, Widdowson MA. Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China. Emerg Infect Dis 2016; 21:741-9. [PMID: 25897654 PMCID: PMC4412232 DOI: 10.3201/eid2105.141756] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This virus is unlikely to have spread substantially among humans in Vietnam, Thailand, Cambodia, and Laos. During February 2013–March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear. We compared epidemiologic and virologic features of A(H5N1) and A(H7N9) and used human and animal influenza surveillance data collected during April 2013–May 2014 from 4 Southeast Asia countries to assess the likelihood that A(H7N9) would have gone undetected during 2014. Surveillance in Vietnam and Cambodia detected human A(H5N1) cases; no A(H7N9) cases were detected in humans or poultry in Southeast Asia. Although we cannot rule out the possible spread of A(H7N9), substantial spread causing severe disease in humans is unlikely.
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25
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Disease Control, Public Health and Food Safety: Food Policy Lessons from Sub-Saharan Africa. INTERNATIONAL FOOD LAW AND POLICY 2016. [PMCID: PMC7138434 DOI: 10.1007/978-3-319-07542-6_42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
This chapter reviews the agro-economic environment in Sub-Saharan Africa as it relates to animal production, public health, and disease control to contextualize the concept of risk and food safety. Drawing mostly from the experience of Zambia, it analyzes food safety actors and interests in Sub-Saharan Africa, and provides an outline of the general regulatory framework that is in place on the continent, to explain how food safety governance is impacted by different interest groups and agendas. Two case studies are provided, zoonotic tuberculosis and avian influenza. The chapter demonstrates how the two zoonoses, both important food safety concerns, have been prioritized differently in the case of Zambia, as a result of multiple socio-political and economic factors. The chapter concludes that, in order to be useful, a definition of food safety risks should include multiple contextual issues and stakeholders along the food supply chain. It is important to keep in mind what national food safety governance actors perceive the risks to be, and how their definitions fit into the broader picture of food safety in general. Food safety governance regulatory processes should take into consideration local realities, local food supply chains and local food safety threats to ensure the appropriateness and sustainability of any and all disease control measures instituted. Context will always matter, and therefore, local ecological, biological and policy considerations should be given primacy.
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26
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Abstract
It is essential to understand the latest situation regarding avian coronaviruses (ACoVs), commonly referred to as the well-known avian infectious bronchitis virus (IBV), given that new and diverse types of IBV are continually being identified worldwide, particularly ones that are isolated from commercial poultry and associated with a wide range of disease conditions. The existing IBVs continue to evolve in various geographic areas in Asia, which results in the recombination and co-circulation between IBV types. This makes it increasingly difficult to prevent and control IBV infections, despite routine vaccination. Some ACoVs have also been identified in other avian species and they may pose a threat of cross-transmission to commercial sectors. The present review provides an overview of IBV circulation and the dynamic emergence of new variants found throughout Asia via the recombination of IBV strains. In addition to commercial poultry, backyard poultry and free-ranging birds may serve as a ‘hub’ for ACoV transmission within a particular area. These birds may be capable of spreading viruses, either to areas of close proximity, or to remote places via migration and trade.
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Affiliation(s)
- Naruepol Promkuntod
- a Department of Livestock Development, National Institute of Animal Health, Veterinary Research and Development Center (Southern Region) , Thungsong , Nakhon Si Thammarat , Thailand
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27
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Biswas PK, Giasuddin M, Nath BK, Islam MZ, Debnath NC, Yamage M. Biosecurity and Circulation of Influenza A (H5N1) Virus in Live-Bird Markets in Bangladesh, 2012. Transbound Emerg Dis 2015; 64:883-891. [PMID: 26663031 DOI: 10.1111/tbed.12454] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 11/29/2022]
Abstract
Bangladesh has been considered as one of the five countries endemic with highly pathogenic avian influenza A subtype H5N1 (HPAI H5N1). Live-bird markets (LBMs) in south Asian countries are believed to play important roles in the transmission of HPAI H5N1 and others due to its central location as a hub of the poultry trading. Food and Agriculture Organization (FAO) of the United Nations has been promoting improved biosecurity in LBMs in Bangladesh. In 2012, by enrolling 32 large LBMs: 10 with FAO interventions and 22 without assistance, we assessed the virus circulation in the selected LBMs by applying standard procedures to investigate market floors, poultry stall floors, poultry-holding cases and slaughter areas and the overall biosecurity using a questionnaire-based survey. Relative risk (RR) was examined to compare the prevalence of HPAI H5N1 in the intervened and non-intervened LBMs. The measures practised in significantly more of the FAO-intervened LBMs included keeping of slaughter remnants in a closed container; decontamination of poultry vehicles at market place; prevention of crows' access to LBM, market/floor cleaning by market committee; wet cleaning; disinfection of floor/poultry stall after cleaning; and good supply of clean water at market (P < 0.05). Conversely, disposal of slaughter remnants elsewhere at market and dry cleaning were in operation in more of the FAO non-intervened LBMs (P < 0.05). The RR for HPAI H5N1 in the intervened and non-intervened LBMs was 1.1 (95% confidence interval 0.44-2.76), suggesting that the proportion positive of the virus in the two kinds of LBM did not vary significantly (P = 0.413). These observations suggest that the viruses are still maintained at the level of production in farms and circulating in LBMs in Bangladesh regardless of interventions, albeit at lower levels than in other endemic countries.
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Affiliation(s)
- P K Biswas
- Department of Microbiology and Veterinary Public Health, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - M Giasuddin
- National Reference Laboratories for Avian Influenza, Bangladesh Livestock Research Institute, Savar, Dhaka, Bangladesh
| | - B K Nath
- Department of Dairy and Poultry Science, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - M Z Islam
- Department of Microbiology and Veterinary Public Health, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - N C Debnath
- Department of Microbiology and Veterinary Public Health, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh.,Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nation, Dhaka, Bangladesh
| | - M Yamage
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nation, Dhaka, Bangladesh
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28
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Amaku M, Grisi-Filho JHDH, Negreiros RL, Dias RA, Ferreira F, Ferreira Neto JS, Cipullo RI, Marques FS, Ossada R. Infectious disease surveillance in animal movement networks: An approach based on the friendship paradox. Prev Vet Med 2015; 121:306-13. [PMID: 26277202 DOI: 10.1016/j.prevetmed.2015.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 07/31/2015] [Accepted: 08/01/2015] [Indexed: 10/23/2022]
Abstract
The network of animal movements among livestock premises is an important topological structure for the spread of infectious diseases. The central focus of this study was to analyze strategies for selecting premises based on the friendship paradox ("your friends have more friends than you do") - in which premises that neighbor randomly selected premises are sampled for surveillance or control - to determine whether these strategies are viable alternatives for the surveillance and control of diseases in scenarios with insufficient data on animal movement. To test the effectiveness of these strategies, we performed three sets of simulations. In the first set, we examined the risk of spreading an infectious disease using the cattle movement network of the state of Mato Grosso, Brazil. All tested strategies based on the friendship paradox have comparable performance to the hub control strategy (controlling premises that sold more animals) and superior performance to random sampling in terms of both reducing the risk of purchasing infected animals and the number of premises that need to be controlled. In the second and third sets of simulations, we observed that the friendship paradox strategies were more sensitive than the random sampling strategy to detect cases and disease, respectively. The survey of the entire animal movement network to identify animal premises with a key role in trade is not always possible, either because the data are insufficient or because informal trade is significant. If surveying the network is not possible, all approaches based on knowledge of the network become useless. As an alternative, knowing that there is a hidden movement network that follows rules inherent to all networks, such as the friendship paradox, can be used to our advantage. Strategies based on the friendship paradox do not assume knowledge of the animal movement network and therefore may be viable alternatives for the surveillance or control of infectious diseases in the absence of network information, thus optimizing the use of human and financial resources.
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Affiliation(s)
- Marcos Amaku
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil.
| | | | | | - Ricardo Augusto Dias
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil
| | - Fernando Ferreira
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil
| | | | - Rafael Ishibashi Cipullo
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil
| | | | - Raul Ossada
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil
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29
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Baudon E, Fournié G, Hiep DT, Pham TTH, Duboz R, Gély M, Peiris M, Cowling BJ, Ton VD, Peyre M. Analysis of Swine Movements in a Province in Northern Vietnam and Application in the Design of Surveillance Strategies for Infectious Diseases. Transbound Emerg Dis 2015; 64:411-424. [PMID: 26040303 DOI: 10.1111/tbed.12380] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Indexed: 02/06/2023]
Abstract
While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a prerequisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta Province (northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades, that is between farms of equivalent sizes, whereas the other had pyramidal trades, that is from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that northern provinces were highly connected and showed some connection with central and southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector and to make recommendations for disease control.
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Affiliation(s)
- E Baudon
- School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Animal and Integrated Risk Management Research Unit (AGIRs), French Agricultural Research Center for International Development (CIRAD), Montpellier, France
| | - G Fournié
- Veterinary Epidemiology and Public Health Group, Production and Population Health Department, Royal Veterinary College, North Mymms, Hatfield, Hertfordshire, UK
| | - D T Hiep
- Hanoi University of Agriculture, Gia Lam, Hanoi, Vietnam
| | - T T H Pham
- Animal and Integrated Risk Management Research Unit (AGIRs), French Agricultural Research Center for International Development (CIRAD), Montpellier, France
| | - R Duboz
- Animal and Integrated Risk Management Research Unit (AGIRs), French Agricultural Research Center for International Development (CIRAD), Montpellier, France
| | - M Gély
- Animal and Integrated Risk Management Research Unit (AGIRs), French Agricultural Research Center for International Development (CIRAD), Montpellier, France
| | - M Peiris
- School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - B J Cowling
- School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - V D Ton
- Hanoi University of Agriculture, Gia Lam, Hanoi, Vietnam
| | - M Peyre
- Animal and Integrated Risk Management Research Unit (AGIRs), French Agricultural Research Center for International Development (CIRAD), Montpellier, France
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30
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Brioudes A, Gummow B. Understanding Pig and Poultry Trade Networks and Farming Practices Within the Pacific Islands as a Basis for Surveillance. Transbound Emerg Dis 2015; 64:284-299. [DOI: 10.1111/tbed.12370] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 12/01/2022]
Affiliation(s)
- A. Brioudes
- Discipline of Veterinary Sciences; College of Public Health, Medical and Veterinary Sciences; James Cook University; Townsville Qld Australia
| | - B. Gummow
- Discipline of Veterinary Sciences; College of Public Health, Medical and Veterinary Sciences; James Cook University; Townsville Qld Australia
- Department of Production Animal Studies; Faculty of Veterinary Science; University of Pretoria; Pretoria South Africa
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31
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Wiratsudakul A, Paul MC, Bicout DJ, Tiensin T, Triampo W, Chalvet-Monfray K. Modeling the dynamics of backyard chicken flows in traditional trade networks in Thailand: implications for surveillance and control of avian influenza. Trop Anim Health Prod 2014; 46:845-53. [PMID: 24668078 DOI: 10.1007/s11250-014-0575-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2014] [Indexed: 11/28/2022]
Abstract
In Southeast Asia, traditional poultry marketing chains have been threatened by epidemics caused by the highly pathogenic avian influenza H5N1 (HPAI H5N1) virus. In Thailand, the trade of live backyard chickens is based on the activities of traders buying chickens from villages and supplying urban markets with chicken meat. This study aims to quantify the flows of chickens traded during a 1-year period in a province of Thailand. A compartmental stochastic dynamic model was constructed to illustrate trade flows of live chickens from villages to slaughterhouses. Live poultry movements present important temporal variations with increased activities during the 15 days preceding the Chinese New Year and, to a lesser extent, other festivals (Qingming Festival, Thai New Year, Hungry Ghost Festival, and International New Year). The average distance of poultry movements ranges from 4 to 25 km, defining a spatial scale for the risk of avian influenza that spread through traditional poultry marketing chains. Some characteristics of traditional poultry networks in Thailand, such as overlapping chicken supply zones, may facilitate disease diffusion over longer distances through combined expansion and relocation processes. This information may be of use in tailoring avian influenza and other emerging infectious poultry disease surveillance and control programs provided that the cost-effectiveness of such scenarios is also evaluated in further studies.
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Affiliation(s)
- Anuwat Wiratsudakul
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, 999 Phuttamonthon 4 Rd., Salaya, Phuttamonthon, Nakhon Pathom, 73170, Thailand,
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Fuller T, Havers F, Xu C, Fang LQ, Cao WC, Shu Y, Widdowson MA, Smith TB. Identifying areas with a high risk of human infection with the avian influenza A (H7N9) virus in East Asia. J Infect 2014; 69:174-81. [PMID: 24642206 DOI: 10.1016/j.jinf.2014.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 03/04/2014] [Accepted: 03/07/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The rapid emergence, spread, and disease severity of avian influenza A (H7N9) in China has prompted concerns about a possible pandemic and regional spread in the coming months. The objective of this study was to predict the risk of future human infections with H7N9 in China and neighboring countries by assessing the association between H7N9 cases at sentinel hospitals and putative agricultural, climatic, and demographic risk factors. METHODS This cross-sectional study used the locations of H7N9 cases and negative cases from China's influenza-like illness surveillance network. After identifying H7N9 risk factors with logistic regression, we used Geographic Information Systems (GIS) to construct predictive maps of H7N9 risk across Asia. RESULTS Live bird market density was associated with human H7N9 infections reported in China from March-May 2013. Based on these cases, our model accurately predicted the virus' spread into Guangxi autonomous region in February 2014. Outside China, we find there is a high risk that the virus will spread to northern Vietnam, due to the import of poultry from China. CONCLUSIONS Our risk map can focus efforts to improve surveillance in poultry and humans, which may facilitate early identification and treatment of human cases.
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Affiliation(s)
- Trevon Fuller
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, 619 Charles E. Young Dr. East, Los Angeles, CA 90095, USA.
| | - Fiona Havers
- Epidemic Intelligence Service assigned to Influenza Division, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS-A04, Atlanta, GA 30333, USA
| | - Cuiling Xu
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, 155 Changbai Rd, Changping District, Beijing 102206, People's Republic of China
| | - Li-Qun Fang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No. 20, Dongda Street, Fengtai District, Beijing 100071, People's Republic of China
| | - Wu-Chun Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No. 20, Dongda Street, Fengtai District, Beijing 100071, People's Republic of China
| | - Yuelong Shu
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, 155 Changbai Rd, Changping District, Beijing 102206, People's Republic of China
| | - Marc-Alain Widdowson
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS-A04, Atlanta, GA 30333, USA
| | - Thomas B Smith
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, 619 Charles E. Young Dr. East, Los Angeles, CA 90095, USA; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Dr. East, Los Angeles, CA 90095, USA
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Costard S, Fournié G, Pfeiffer DU. Using risk assessment as part of a systems approach to the control and prevention of HPAIV H5N1. ECOHEALTH 2014; 11:36-43. [PMID: 24488190 DOI: 10.1007/s10393-014-0907-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 11/20/2013] [Accepted: 01/06/2014] [Indexed: 06/03/2023]
Abstract
Since its emergence in China in 1996, highly pathogenic avian influenza virus subtype H5N1 has spread across Asia, Africa, and Europe. Countries had to promptly implement control and prevention measures. Numerous research and capacity building initiatives were conducted in the affected regions to improve the capacity of national animal health services to support the development of risk-based mitigation strategies. This paper reviews and discusses risk assessments initiated in several South-East Asian and African countries under one of these projects. Despite important data gaps, the risk assessment results improved the ability of policy makers to design appropriate risk management policies. Disease risk was strongly influenced by various human behavioral factors. The ongoing circulation of HPAIV H5N1 in several Asian countries and in Egypt, despite major disease control efforts, supports the need for an interdisciplinary approach to development of tailored risk management policies, in accordance with the EcoHealth paradigm and the broad concept of risk governance. In particular, active stakeholders engagement and integration of economic and social studies into the policy making process are needed to optimize compliance and sustainable behavioral changes, thereby increasing the effectiveness of mitigation strategies.
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Affiliation(s)
- Solenne Costard
- Veterinary Epidemiology, Economics and Public Health Group (VEEPH), Department of Production and Population Health, Royal Veterinary College, London, UK,
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Chen C, Lu S, Du P, Wang H, Yu W, Song H, Xu J. Silent geographical spread of the H7N9 virus by online knowledge analysis of the live bird trade with a distributed focused crawler. Emerg Microbes Infect 2013; 2:e89. [PMID: 26038450 PMCID: PMC3880875 DOI: 10.1038/emi.2013.91] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/20/2013] [Accepted: 11/12/2013] [Indexed: 11/09/2022]
Abstract
Unlike those infected by H5N1, birds infected by the newly discovered H7N9 virus have no observable clinical symptoms. Public health workers in China do not know where the public health threat lies. In this study, we used a distributed focused crawler to analyze online knowledge of the live bird trade in first-wave provinces, namely, Jiangsu, Zhejiang, Anhui, and Shanghai, to track the new H7N9 virus and predict its spread. Of the 18 provinces proposed to be at high risk of infection, 10 reported human infections and one had poultry specimens that tested positive. Five provinces (Xinjiang, Yunnan, Guizhou, Shaanxi, and Tibet) as well as Hong Kong, Macao, and Taiwan were proposed to have no risk of H7N9 virus infection from the live bird trade. These data can help health authorities and the public to respond rapidly to reduce damage related to the spread of the virus.
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Affiliation(s)
- Chen Chen
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, China
| | - Shan Lu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, China
| | - Pengcheng Du
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, China
| | - Haiyin Wang
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China
| | - Weiwen Yu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China
| | - Huawen Song
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, China
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Sonnberg S, Webby RJ, Webster RG. Natural history of highly pathogenic avian influenza H5N1. Virus Res 2013; 178:63-77. [PMID: 23735535 PMCID: PMC3787969 DOI: 10.1016/j.virusres.2013.05.009] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 05/03/2013] [Accepted: 05/20/2013] [Indexed: 12/27/2022]
Abstract
The ecology of highly pathogenic avian influenza (HPAI) H5N1 has significantly changed from sporadic outbreaks in terrestrial poultry to persistent circulation in terrestrial and aquatic poultry and potentially in wild waterfowl. A novel genotype of HPAI H5N1 arose in 1996 in Southern China and through ongoing mutation, reassortment, and natural selection, has diverged into distinct lineages and expanded into multiple reservoir hosts. The evolution of Goose/Guangdong-lineage highly pathogenic H5N1 viruses is ongoing: while stable interactions exist with some reservoir hosts, these viruses are continuing to evolve and adapt to others, and pose an un-calculable risk to sporadic hosts, including humans.
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Affiliation(s)
- Stephanie Sonnberg
- Department of Infectious Diseases St. Jude Children's Research Hospital 262 Danny Thomas Drive MS 330, Memphis, TN, 38103 USA
| | - Richard J. Webby
- Department of Infectious Diseases St. Jude Children's Research Hospital 262 Danny Thomas Drive MS 330, Memphis, TN, 38103 USA
| | - Robert G. Webster
- corresponding author, Department of Infectious Diseases St. Jude Children's Research Hospital 262 Danny Thomas Drive MS 330, Memphis, TN, 38103 USA Tel +1 901 595 3400 Fax +1 901 595 8559
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Guan Y, Smith GJ. The emergence and diversification of panzootic H5N1 influenza viruses. Virus Res 2013; 178:35-43. [PMID: 23735533 PMCID: PMC4017639 DOI: 10.1016/j.virusres.2013.05.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 04/23/2013] [Accepted: 05/20/2013] [Indexed: 02/05/2023]
Abstract
The Asian highly pathogenic avian influenza H5N1 virus was first detected in the goose population of Guangdong, China in 1996. The viruses in this lineage are unique in their ecological success, demonstrating an extremely broad host range and becoming established in poultry over much of Asia and in Africa. H5N1 viruses have also diverged into multiple clades and subclades that generally do not cross neutralize, which has greatly confounded control measures in poultry and pre-pandemic vaccine strain selection. Although H5N1 viruses currently cannot transmit efficiently between mammals they exhibit high mortality in humans and recent experimental studies have shown that it is possible to generate an H5N1 virus that is transmissible in mammals. In addition to causing unprecedented economic losses, the long-term presence of the H5N1 virus in poultry and its frequent introductions to humans continue to pose a significant pandemic threat. Here we provide a summary of the genesis, molecular epidemiology and evolution of this H5N1 lineage, particularly the factors that have contributed to the continued diversification and ecological success of H5N1 viruses, with particular reference to the poultry production systems they have emerged from.
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Affiliation(s)
- Yi Guan
- State Key Laboratory of Emerging Infectious Diseases and Center of Influenza Research, The University of Hong Kong, Hong Kong SAR, China
- International Institution of Infection and Immunity, Shantou University Medical College, Shantou, China
| | - Gavin J.D. Smith
- Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857
- Duke Global Health Institute, Duke University, Box 90519, Durham, North Carolina 27708
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Interventions for avian influenza A (H5N1) risk management in live bird market networks. Proc Natl Acad Sci U S A 2013; 110:9177-82. [PMID: 23650388 DOI: 10.1073/pnas.1220815110] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Highly pathogenic avian influenza virus subtype H5N1 is endemic in Asia, with live bird trade as a major disease transmission pathway. A cross-sectional survey was undertaken in northern Vietnam to investigate the structure of the live bird market (LBM) contact network and the implications for virus spread. Based on the movements of traders between LBMs, weighted and directed networks were constructed and used for social network analysis and individual-based modeling. Most LBMs were connected to one another, suggesting that the LBM network may support large-scale disease spread. Because of cross-border trade, it also may promote transboundary virus circulation. However, opportunities for disease control do exist. The implementation of thorough, daily disinfection of the market environment as well as of traders' vehicles and equipment in only a small number of hubs can disconnect the network dramatically, preventing disease spread. These targeted interventions would be an effective alternative to the current policy of a complete ban of LBMs in some areas. Some LBMs that have been banned still are very active, and they likely have a substantial impact on disease dynamics, exhibiting the highest levels of susceptibility and infectiousness. The number of trader visits to markets, information that can be collected quickly and easily, may be used to identify LBMs suitable for implementing interventions. This would not require prior knowledge of the force of infection, for which laboratory-confirmed surveillance would be necessary. These findings are of particular relevance for policy development in resource-scarce settings.
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Social network analysis used to assess the relationship between the spread of avian influenza and movement patterns of backyard chickens in Ratchaburi, Thailand. Res Vet Sci 2013; 95:82-6. [PMID: 23528640 DOI: 10.1016/j.rvsc.2013.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 02/17/2013] [Accepted: 02/27/2013] [Indexed: 11/24/2022]
Abstract
In this study, we describe the movement and trading patterns of the backyard chicken in Ratchaburi, Thailand by using social network analysis with egocentric approach. From questionnaire results, we found that there is a close relationship between chicken owners' houses and fresh markets, and we concluded that this relationship needs attention from authorities to prevent future outbreaks of avian flu. Control measures should be applied over pathways to prevent and control highly pathogenic avian influenza subtype H5N1 in the backyard farming system. Results of our study may be useful to relevant authorities and researchers seeking to understand how H5N1 spreads in Ratchaburi. This may reflect on the spread of H5N1 throughout Thailand.
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A one health perspective on HPAI H5N1 in the Greater Mekong sub-region. Comp Immunol Microbiol Infect Dis 2012; 36:309-19. [PMID: 23260375 DOI: 10.1016/j.cimid.2012.11.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 11/18/2012] [Accepted: 11/24/2012] [Indexed: 11/23/2022]
Abstract
Highly pathogenic avian influenza H5N1 has been a global concern for almost 10 years since its epidemic emergence in South-east Asia in 2003/2004. Despite large investment of resources into the region, the infection has not been eradicated and continues to result in outbreaks in poultry and a small number of human fatalities. This review synthesizes the knowledge base generated by a vast number of research activities conducted in the region and beyond, and adopts an interdisciplinary perspective consistent with the one health paradigm towards analysing the problem and formulating possible policy solutions. A key outcome of the work has been the need to integrate socio-economic and anthropological dimensions with any disease control and prevention activities traditionally informed by primarily epidemiological, virological and pathological attributes of the infection in poultry and wild waterbirds. Recommendations at a broad conceptual level are presented that acknowledge the diversity in the region with respect to livestock production, as well as the changing nature of the risk landscape as a consequence of the rapid economic development which some of the countries in the Greater Mekong sub-region are currently undergoing, as well as their strong trade links with China as the major economic power in East Asia.
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Soares Magalhães RJ, Zhou X, Jia B, Guo F, Pfeiffer DU, Martin V. Live poultry trade in Southern China provinces and HPAIV H5N1 infection in humans and poultry: the role of Chinese New Year festivities. PLoS One 2012; 7:e49712. [PMID: 23166751 PMCID: PMC3500328 DOI: 10.1371/journal.pone.0049712] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 10/11/2012] [Indexed: 12/02/2022] Open
Abstract
Background The number of outbreaks of highly pathogenic avian influenza virus of the H5N1 subtype (HPAIV H5N1) over the past 5 years has been drastically reduced in China but sporadic infections in poultry and humans are still occurring. In this study, we aimed to investigate seasonal patterns in the association between the movement of live poultry originating from southern China and HPAIV H5N1 infection history in humans and poultry in China. Methodology/Principal Findings During January to April 2010, longitudinal questionnaire surveys were carried out monthly in four wholesale live bird markets (LBMs) in Hunan and Guangxi provinces of South China. Using social network analysis, we found an increase in the number of observed links and degree centrality between LBMs and poultry sources in February and March compared to the months of January and April. The association of some live poultry traders (LPT’s) with a limited set of counties (within the catchment area of LBMs) in the months of February and March may support HPAIV H5N1 transmission and contribute to perpetuating HPAIV H5N1 virus circulation among certain groups of counties. The connectivity among counties experiencing human infection was significantly higher compared to counties without human infection for the months of January, March and April. Conversely, counties with poultry infections were found to be significantly less connected than counties without poultry infection for the month of February. Conclusions/Significance Our results show that temporal variation in live poultry trade in Southern China around the Chinese New Year festivities is associated with higher HPAIV H5N1 infection risk in humans and poultry. This study has shown that capturing the dynamic nature of poultry trade networks in Southern China improves our ability to explain the spatiotemporal dissemination in avian influenza viruses in China.
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Affiliation(s)
- Ricardo J Soares Magalhães
- Infectious Disease Epidemiology Unit, School of Population Health, University of Queensland, Brisbane, Australia.
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Poolkhet C, Chairatanayuth P, Thongratsakul S, Yatbantoong N, Kasemsuwan S, Damchoey D, Rukkwamsuk T. Social Network Analysis for Assessment of Avian Influenza Spread and Trading Patterns of Backyard Chickens in Nakhon Pathom, Suphan Buri and Ratchaburi, Thailand. Zoonoses Public Health 2012; 60:448-55. [DOI: 10.1111/zph.12022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kudo K, Binh NG, Manabe T, Co DX, Tuan ND, Izumi S, Takasaki J, Minh DH, Thuy PTP, Van VTT, Hanh TT, Chau NQ. Clinical preparedness for severe pneumonia with highly pathogenic avian influenza A (H5N1): experiences with cases in Vietnam. Respir Investig 2012. [PMID: 23199978 DOI: 10.1016/j.resinv.2012.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Avian influenza A (H5N1) in human presents a global pandemic threat, and preparedness is urgently required in high-risk countries. METHODS A retrospective chart review was conducted on 8 patients with H5N1 infection (aged 2-30 years; 3 fatal) who were hospitalized in Bach Mai Hospital (BMH), Vietnam, or in affiliated hospitals with consultation by physicians in BMH between 2007 and 2010. Demographic background, chest radiographs, and clinical and laboratory data were evaluated to determine the critical issues in relation to clinical outcomes. Treatment of 4 patients with acute respiratory distress syndrome (ARDS) (2 fatal) was assessed for renal replacement therapy using continuous hemodiafiltration (CHDF), polymyxin B-immobilized (PMX) hemoperfusion, or their combination. RESULTS Patients had direct contact with dead/sick poultry infected with H5N1 virus or lived in areas where H5N1 poultry outbreaks had been reported at the same time as their illness. Time to initiation of oseltamivir from symptom onset was 2-6 days for survivors and 7-9 days for non-survivors. All patients except one had infiltrative shadows on chest radiographs on admission. Patients with delayed treatment developed ARDS. Renal replacement therapy contributed to patient survival, with improvement of oxygenation and a dramatic decrease in serum cytokine levels if initiated earlier. CONCLUSIONS Understanding local H5N1 poultry outbreaks and chest radiography assist early diagnosis and initiation of antiviral treatment. Developing a network among local and tertiary care hospitals can reduce the time to initiation of treatment. CHDF and PMX hemoperfusion are possible candidates for effective treatment of ARDS with H5N1 if applied earlier.
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Affiliation(s)
- Koichiro Kudo
- National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.
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Gilbert M, Pfeiffer DU. Risk factor modelling of the spatio-temporal patterns of highly pathogenic avian influenza (HPAIV) H5N1: a review. Spat Spatiotemporal Epidemiol 2012; 3:173-83. [PMID: 22749203 PMCID: PMC3389348 DOI: 10.1016/j.sste.2012.01.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 11/25/2011] [Accepted: 01/30/2012] [Indexed: 10/14/2022]
Abstract
Highly pathogenic avian influenza virus (HPAIV) H5N1 continues to impact on smallholder livelihoods, to constrain development of the poultry production sector, and to cause occasional human fatalities. HPAI H5N1 outbreaks have occurred in a variety of ecological systems with economic, agricultural and environmental differences. This review aimed to identify common risk factors amongst spatial modelling studies conducted in these different agro-ecological systems, and to identify gaps in our understanding of the disease's spatial epidemiology. Three types of variables with similar statistical association with HPAI H5N1 presence across studies and regions were identified: domestic waterfowl, several anthropogenic variables (human population density, distance to roads) and indicators of water presence. Variables on socio-economic conditions, poultry trade, wild bird distribution and movements were comparatively rarely considered. Few studies have analysed the HPAI H5N1 distribution in countries such as Egypt and Indonesia, where HPAIV H5N1 continues to circulate extensively.
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Affiliation(s)
- Marius Gilbert
- Biological Control and Spatial Ecology, Université Libre de Bruxelles, av FD Roosevelt 50, B-1050 Brussels, Belgium.
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Mwacalimba KK. Globalised disease control and response distortion: a case study of avian influenza pandemic preparedness in Zambia. CRITICAL PUBLIC HEALTH 2012. [DOI: 10.1080/09581596.2012.710739] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Identifying live bird markets with the potential to act as reservoirs of avian influenza A (H5N1) virus: a survey in northern Viet Nam and Cambodia. PLoS One 2012; 7:e37986. [PMID: 22675502 PMCID: PMC3366999 DOI: 10.1371/journal.pone.0037986] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 04/27/2012] [Indexed: 11/22/2022] Open
Abstract
Wet markets are common in many parts of the world and may promote the emergence, spread and maintenance of livestock pathogens, including zoonoses. A survey was conducted in order to assess the potential of Vietnamese and Cambodian live bird markets (LBMs) to sustain circulation of highly pathogenic avian influenza virus subtype H5N1 (HPAIV H5N1). Thirty Vietnamese and 8 Cambodian LBMs were visited, and structured interviews were conducted with the market managers and 561 Vietnamese and 84 Cambodian traders. Multivariate and cluster analysis were used to construct a typology of traders based on their poultry management practices. As a result of those practices and large poultry surplus (unsold poultry reoffered for sale the following day), some poultry traders were shown to promote conditions favorable for perpetuating HPAIV H5N1 in LBMs. More than 80% of these traders operated in LBMs located in the most densely populated areas, Ha Noi and Phnom Penh. The profiles of sellers operating at a given LBM could be reliably predicted using basic information about the location and type of market. Consequently, LBMs with the largest combination of risk factors for becoming virus reservoirs could be easily identified, potentially allowing control strategies to be appropriately targeted. These findings are of particular relevance to resource-scarce settings with extensively developed LBM systems, commonly found in South-East Asia.
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Detection of HPAI H5N1 viruses in ducks sampled from live bird markets in Vietnam. Epidemiol Infect 2012; 141:601-11. [PMID: 22651930 DOI: 10.1017/s0950268812001112] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Vietnam, highly pathogenic avian influenza (HPAI) H5N1 infections in poultry often occur without concomitant clinical signs and outbreaks are not consistently reported. Live bird markets represent a convenient site for surveillance that does not rely on farmers' notifications. Two H5N1 surveys were conducted at live bird markets/slaughter points in 39 districts (five provinces) in the Red River, Mekong delta, and central Vietnam during January and May 2011. Oropharyngeal and rectal swab samples from 12 480 ducks were tested for H5N1 by reverse transcription-polymerase chain reaction in pools of five. Traders and stallholders were interviewed using standardized questionnaires; 3·3% of pools tested positive. The highest prevalence (6·6%) corresponded to the Mekong delta, and no H5N1 was detected in the two Red River provinces. The surveys identified key risk behaviours of traders and stallholders. It is recommended that market surveys are implemented over time as a tool to evaluate progress in HPAI control in Vietnam.
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Choi KS, Lee EK, Jeon WJ, Kwon JH, Lee JH, Sung HW. Molecular epidemiologic investigation of lentogenic Newcastle disease virus from domestic birds at live bird markets in Korea. Avian Dis 2012; 56:218-23. [PMID: 22545549 DOI: 10.1637/9699-030311-resnote.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A Newcastle disease surveillance program was conducted at live bird markets in Korea to expand our epidemiologic understanding of the disease in Korea. During the surveillance program, 10 lentogenic Newcastle disease viruses (NDVs) were isolated and identified from apparently healthy chickens and ducks at live bird markets. The lentogenic viruses had sequence motifs of either 112GKQGRL117 (n = 8) or 112GRQGRL117 (n = 2) at the F0 cleavage site. Sequencing and phylogenetic analyses of NDV isolates based on the hypervariable region of the F protein revealed two different genotypes: genotypes I (n = 8) and II (n = 2). Genotype I viruses were most closely related to the NDV V4 strain (n = 7) or the NDV Ulster 2C strain (n = 1). In contrast, genotype II viruses clustered with the NDV vaccine strains (LaSota and VG/GA) that are commonly used as live vaccines in Korea. The epidemiologic importance of NDV at live bird markets in Korea is discussed.
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Affiliation(s)
- Kang-Seuk Choi
- OIE Reference Laboratory for Newcastle Disease, Avian Diseases Division, Animal, Plant and Fisheries Quarantine and Inspection Agency, 175 Anyang-ro, Anyang, Gyeonggi 430-757, Republic of Korea
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48
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Carrel M, Wan XF, Nguyen T, Emch M. Highly pathogenic H5N1 avian influenza viruses exhibit few barriers to gene flow in Vietnam. ECOHEALTH 2012; 9:60-9. [PMID: 22350419 PMCID: PMC3771539 DOI: 10.1007/s10393-012-0749-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/20/2012] [Accepted: 01/25/2012] [Indexed: 05/13/2023]
Abstract
Locating areas where genetic change is inhibited can illuminate underlying processes that drive evolution of pathogens. The persistence of highly pathogenic H5N1 avian influenza in Vietnam since 2003, and the continuous molecular evolution of Vietnamese avian influenza viruses, indicates that local environmental factors are supportive not only of incidence but also of viral adaptation. This article explores whether gene flow is constant across Vietnam, or whether there exist boundary areas where gene flow exhibits discontinuity. Using a dataset of 125 highly pathogenic H5N1 avian influenza viruses, principal components analysis and wombling analysis are used to indicate the location, magnitude, and statistical significance of genetic boundaries. Results show that a small number of geographically minor boundaries to gene flow in highly pathogenic H5N1 avian influenza viruses exist in Vietnam, but that overall there is little division in genetic exchange. This suggests that differences in genetic characteristics of viruses from one region to another are not the result of barriers to H5N1 viral exchange in Vietnam, and that H5N1 avian influenza is able to spread relatively unimpeded across the country.
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Affiliation(s)
- Margaret Carrel
- Department of Geography, University of Iowa, Iowa City, IA 52242, USA.
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Trevennec K, Chevalier V, Grosbois V, Garcia JM, Thu HH, Berthouly-Salazar C, Peiris JSM, Roger F. Looking for avian influenza in remote areas. A case study in Northern Vietnam. Acta Trop 2011; 120:160-6. [PMID: 21840292 DOI: 10.1016/j.actatropica.2011.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 07/26/2011] [Accepted: 07/30/2011] [Indexed: 11/29/2022]
Abstract
Epidemiological surveys of avian influenza infections rarely focus on backyard poultry systems in remote locations because areas with low levels of poultry production are considered to have little influence on the emergence, re-emergence, persistence or spread of avian influenza viruses. In addition, routine disease investigations in remote areas often are neglected due to the lower availability and relatively high cost of veterinary services there. A bank of avian sera collected in 2005 from ethnic minority households in Ha Giang province (Northern Vietnam), located on the Chinese border, was analysed to estimate the seroprevalence of avian influenza virus (AIV) during a H5N1 epidemic and to identify potential risk factors for infection. The results suggest that the chicken population had been exposed to AIV with a seroprevalence rate of 7.2% [1.45; 10.5]. The H5 and H9 subtypes were identified with a seroprevalence of 3.25% [2.39; 4.11] and 1.12% [0.61; 1.63], respectively. The number of inhabitants in a village and the distance to the main national road were the most influential risk factors of AIV infection, and high-risk clusters were located along the road leading to China. These two results suggest a virus spread through commercial poultry exchanges and a possible introduction of AIV from southern China. Remote areas and small-scale farms may play an under-estimated role in the spread and persistence of AIV.
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Affiliation(s)
- K Trevennec
- French Agricultural Research Center for International Development (CIRAD), Animal and Integrated Risk Management Research Unit, Baillarguet Campus, Montpellier Cedex 5, France.
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50
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Martin V, Zhou X, Marshall E, Jia B, Fusheng G, FrancoDixon MA, DeHaan N, Pfeiffer DU, Soares Magalhães RJ, Gilbert M. Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis. Prev Vet Med 2011; 102:196-205. [PMID: 21925753 PMCID: PMC7127115 DOI: 10.1016/j.prevetmed.2011.07.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.
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Affiliation(s)
- Vincent Martin
- Food and Agriculture Organization of the United Nations, Beijing, PR China.
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