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Patyk KA, Fields VL, Beam AL, Branan MA, McGuigan RE, Green A, Torchetti MK, Lantz K, Freifeld A, Marshall K, Delgado AH. Investigation of risk factors for introduction of highly pathogenic avian influenza H5N1 infection among commercial turkey operations in the United States, 2022: a case-control study. Front Vet Sci 2023; 10:1229071. [PMID: 37711433 PMCID: PMC10498466 DOI: 10.3389/fvets.2023.1229071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Abstract
Introduction The 2022-2023 highly pathogenic avian influenza (HPAI) H5N1 outbreak in the United States (U.S.) is the largest and most costly animal health event in U.S. history. Approximately 70% of commercial farms affected during this outbreak have been turkey farms. Methods We conducted a case-control study to identify potential risk factors for introduction of HPAI virus onto commercial meat turkey operations. Data were collected from 66 case farms and 59 control farms in 12 states. Univariate and multivariable analyses were conducted to compare management and biosecurity factors on case and control farms. Results Factors associated with increased risk of infection included being in an existing control zone, having both brooders and growers, having toms, seeing wild waterfowl or shorebirds in the closest field, and using rendering for dead bird disposal. Protective factors included having a restroom facility, including portable, available to crews that visit the farm and workers having access and using a shower at least some of the time when entering a specified barn. Discussion Study results provide a better understanding of risk factors for HPAI infection and can be used to inform prevention and control measures for HPAI on U.S. turkey farms.
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Affiliation(s)
- Kelly A. Patyk
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Victoria L. Fields
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Andrea L. Beam
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Matthew A. Branan
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Rachel E. McGuigan
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Alice Green
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Mia K. Torchetti
- National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, IA, United States
| | - Kristina Lantz
- National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, IA, United States
| | - Alexis Freifeld
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Katherine Marshall
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Amy H. Delgado
- Center for Epidemiology and Animal Health, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO, United States
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Islam A, Amin E, Islam S, Hossain ME, Al Mamun A, Sahabuddin M, Samad MA, Shirin T, Rahman MZ, Hassan MM. Annual trading patterns and risk factors of avian influenza A/H5 and A/H9 virus circulation in turkey birds ( Meleagris gallopavo) at live bird markets in Dhaka city, Bangladesh. Front Vet Sci 2023; 10:1148615. [PMID: 37470075 PMCID: PMC10352991 DOI: 10.3389/fvets.2023.1148615] [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: 05/12/2023] [Indexed: 07/21/2023] Open
Abstract
The impacts of the avian influenza virus (AIV) on farmed poultry and wild birds affect human health, livelihoods, food security, and international trade. The movement patterns of turkey birds from farms to live bird markets (LBMs) and infection of AIV are poorly understood in Bangladesh. Thus, we conducted weekly longitudinal surveillance in LBMs to understand the trading patterns, temporal trends, and risk factors of AIV circulation in turkey birds. We sampled a total of 423 turkeys from two LBMs in Dhaka between May 2018 and September 2019. We tested the swab 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 used exploratory analysis to investigate trading patterns, annual cyclic trends of AIV and its subtypes, and a generalized estimating equation (GEE) logistic model to determine the factors that influence the infection of H5 and H9 in turkeys. Furthermore, we conducted an observational study and informal interviews with traders and vendors to record turkey trading patterns, demand, and supply and turkey handling practices in LBM. We found that all trade routes of turkey birds to northern Dhaka are unidirectional and originate from the northwestern and southern regions of Bangladesh. The number of trades from the source district to Dhaka depends on the turkey density. The median distance that turkey was traded from its source district to Dhaka was 188 km (Q1 = 165, Q3 = 210, IQR = 45.5). We observed seasonal variation in the median and average distance of turkey. The qualitative findings revealed that turkey farming initially became reasonably profitable in 2018 and at the beginning of 2019. However, the fall in demand and production in the middle of 2019 may be related to unstable market pricing, high feed costs, a shortfall of adequate marketing facilities, poor consumer knowledge, and a lack of advertising. The overall prevalence of AIV, H5, and H9 subtypes in turkeys was 31% (95% CI: 26.6-35.4), 16.3% (95% CI: 12.8-19.8), and 10.2% (95% CI: 7.3-13.1) respectively. None of the samples were positive for H7. The circulation of AIV and H9 across the annual cycle showed no seasonality, whereas the circulation of H5 showed significant seasonality. The GEE revealed that detection of AIV increases in retail vendor business (OR: 1.71; 95% CI: 1.12-2.62) and the bird's health status is sick (OR: 10.77; 95% CI: 4.31-26.94) or dead (OR: 11.33; 95% CI: 4.30-29.89). We also observed that winter season (OR: 5.83; 95% CI: 2.80-12.14) than summer season, dead birds (OR: 61.71; 95% CI: 25.78-147.75) and sick birds (OR 8.33; 95% CI: 3.36-20.64) compared to healthy birds has a higher risk of H5 infection in turkeys. This study revealed that the turkeys movements vary by time and season from the farm to the LBM. This surveillance indicated year-round circulation of AIV with H5 and H9 subtypes in turkey birds in LBMs. The seasonality and health condition of birds influence H5 infection in birds. The trading pattern of turkey may play a role in the transmission of AIV viruses in the birds. The selling of sick turkeys infected with H5 and H9 highlights the possibility of virus transmission to other species of birds sold at LBMs and to people.
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Affiliation(s)
- Ariful Islam
- EcoHealth Alliance, New York, NY, United States
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC, Australia
| | - Emama Amin
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Shariful 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
| | - Abdullah Al Mamun
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Md. Sahabuddin
- One Health Laboratory, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mohammed Abdus Samad
- National Reference Laboratory for Avian Influenza, Bangladesh Livestock Research Institute (BLRI), Savar, Bangladesh
| | - Tahmina Shirin
- Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh
| | - Mohammed Ziaur Rahman
- One Health Laboratory, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mohammad Mahmudul Hassan
- Queensland Alliance for One Health Sciences, School of Veterinary Science, The University of Queensland, Brisbane, QLD, Australia
- Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Chattogram, Bangladesh
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Integration of Epidemiological and Genomic Data to Investigate H5N1 HPAI Outbreaks in Northern Italy in 2021-2022. Pathogens 2023; 12:pathogens12010100. [PMID: 36678449 PMCID: PMC9865711 DOI: 10.3390/pathogens12010100] [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: 12/16/2022] [Revised: 12/29/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Between October 2021 and April 2022, 317 outbreaks caused by highly pathogenic avian influenza (HPAI) H5N1 viruses were notified in poultry farms in the northeastern Italian regions. The complete genomes of 214 strains were used to estimate the genetic network based on the similarity of the viruses. An exponential random graph model (ERGM) was used to assess the effect of 'at-risk contacts', 'same owners', 'in-bound/out-bound risk windows overlap', 'genetic differences', 'geographic distances', 'same species', and 'poultry company' on the probability of observing a link within the genetic network, which can be interpreted as the potential propagation of the epidemic via lateral spread or a common source of infection. The variables 'same poultry company' (Est. = 0.548, C.I. = [0.179; 0.918]) and 'risk windows overlap' (Est. = 0.339, C.I. = [0.309; 0.368]) were associated with a higher probability of link formation, while the 'genetic differences' (Est. = -0.563, C.I. = [-0.640; -0.486]) and 'geographic distances' (Est. = -0.058, C.I. = [-0.078; -0.038]) indicated a reduced probability. The integration of epidemiological data with genomic analyses allows us to monitor the epidemic evolution and helps to explain the dynamics of lateral spreads casting light on the potential diffusion routes. The 2021-2022 epidemic stresses the need to further strengthen the biosecurity measures, and to encourage the reorganization of the poultry production sector to minimize the impact of future epidemics.
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Fallah Mehrabadi MH, Tehrani F, Shoushtari A, Bahonar A, Rabiee MH, Ghalyanchilangeroudi A, Ghafouri SA, Amirhajloo S. Outbreak Investigation of Officially Reported and Highly Pathogenic Avian Influenza (H5N8 Subtype) in Iran During 2016. ARCHIVES OF RAZI INSTITUTE 2021; 76:17-29. [PMID: 33818954 DOI: 10.22092/ari.2019.124904.1291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/01/2019] [Indexed: 09/30/2022]
Abstract
On 14 November 2016, an outbreak of highly pathogenic avian influenza (HPA) was reported from a commercial layer farm located in Malard, Tehran Province, Iran. This study aimed to investigate the HPAI H5N8 outbreaks in Iran. The questionnaire was prepared and completed through interviews with farm owners or field observations at the time of disease onset from November 2016 to February 2017. The HPAI H5N8 infection was confirmed in 30 different locations including 10 villages (33.3%), nine-layer farms (33%), two broiler breeder farms (6.67%), one layer breeder farm (3.3%), one turkey farm (3.3%), one partridge farm (3.3%), five national parks (16.7%), and one wetland (3.3%) in 12 provinces of Iran. The cumulative incidence rates of disease in villages, layer farms, broiler breeder farms, layer breeder farms, partridge farms, and turkey farms were 0.02%, 0.87%, 0.55%, 6.25%, 7.14%, and 0.69%, respectively. The findings reflect that among the investigated variables at infected locations, new birds entering the home in villages, live bird markets, inappropriate biosecurity conditions, transporting manure during the breeding period, close proximity of a common road to infected farms, and poultry movement inside (pullet) and outside were the most frequently observed possible risk factors for these outbreaks. In conclusion, attention should be focused on the study of the dynamics and movements of domestic poultry, investigation and modification of the structure of industrial poultry farms, training for all related people, enhancement of passive surveillance, an increase in biosecurity, raising the awareness of the authorities on the importance of the infection, and provision of the required credits and facilities.
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Affiliation(s)
- M H Fallah Mehrabadi
- Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran.,Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
| | - F Tehrani
- Department of Health and Management of Poultry Diseases, Iranian Veterinary Organization, Tehran, Iran
| | - A Shoushtari
- Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
| | - A Bahonar
- Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - M H Rabiee
- Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - A Ghalyanchilangeroudi
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - S A Ghafouri
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University, Mashhad, Iran
| | - S Amirhajloo
- Department of Health and Management of Poultry Diseases, Iranian Veterinary Organization, Tehran, Iran
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5
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García C, Soriano JM, Cortés V, Sevilla-Navarro S, Marin C, Balaguer JL, Catalá-Gregori P. Monitoring serologic response to single in ovo vaccination with an immune complex vaccine against infectious bursal disease in broilers. Poult Sci 2021; 100:100999. [PMID: 33610895 PMCID: PMC7905475 DOI: 10.1016/j.psj.2021.01.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/29/2020] [Accepted: 01/01/2021] [Indexed: 11/30/2022] Open
Abstract
The infectious bursal disease (IBD) virus is one of the most resistant and prevalent virus worldwide in the poultry industry, being vaccination the main tool to control the disease. For this reason, consistent and uniform immunization of broiler flocks against IBD is necessary to avoid the disease spreading. The aim of this study was to apply and assess an epidemiologic mapping tool focused on the immunization by in ovo single broiler vaccination using an immune complex IBD vaccine. With this regard, 7,576 serum samples were collected from 603 broiler flocks raised in 354 Spanish farms. To do so, blood samples were randomly collected from birds with ages between 35 to 51 d, and the serum was analyzed by ELISA. The results obtained from this study suggested a high uniform immunization against IBDV and a protective immunization between 35 and 51 d of age, with mean titer values ranging between 6,331 and 7,426. In addition, seroprevalence titer data of this large-scale monitoring study fitted a polynomial equation with a R2 value of 0.77, helping to explain and predict the humoral response to IBD vaccination. This seroprevalence map was applied to broiler production and was based on business intelligence tool that incorporates newly developed mapping tool to cover the need of having real-time information of humoral response to IBD vaccination and could be an effective tool for veterinary services to control and prevent IBD.
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Affiliation(s)
- C García
- Center for Poultry Quality and Animal Feeding of the Valencian Community (CECAV), Castellón, Spain.
| | - J M Soriano
- Food & Health Lab, Institute of Materials Science, University of Valencia, 46980 Paterna, Valencia, Spain
| | - V Cortés
- Center for Poultry Quality and Animal Feeding of the Valencian Community (CECAV), Castellón, Spain
| | - S Sevilla-Navarro
- Center for Poultry Quality and Animal Feeding of the Valencian Community (CECAV), Castellón, Spain; Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Instituto de Ciencias Biomédicas, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, 46113 Moncada, Spain
| | - C Marin
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Instituto de Ciencias Biomédicas, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, 46113 Moncada, Spain
| | - J L Balaguer
- Department of Animal Production and Health, Veterinary Public Health and Food Science and Technology, Institute of Biomedical Sciences, Faculty of Veterinary Medicine, Cardenal Herrera-CEU University, CEU Universities, Moncada, Spain
| | - P Catalá-Gregori
- Center for Poultry Quality and Animal Feeding of the Valencian Community (CECAV), Castellón, Spain; Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Instituto de Ciencias Biomédicas, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, 46113 Moncada, Spain
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Harvey WT, Mulatti P, Fusaro A, Scolamacchia F, Zecchin B, Monne I, Marangon S. Spatiotemporal reconstruction and transmission dynamics during the 2016-17 H5N8 highly pathogenic avian influenza epidemic in Italy. Transbound Emerg Dis 2021; 68:37-50. [PMID: 31788978 PMCID: PMC8048528 DOI: 10.1111/tbed.13420] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/03/2019] [Accepted: 10/29/2019] [Indexed: 11/29/2022]
Abstract
Effective control of avian diseases in domestic populations requires understanding of the transmission dynamics facilitating viral emergence and spread. In 2016-17, Italy experienced a significant avian influenza epidemic caused by a highly pathogenic A(H5N8) virus, which affected domestic premises housing around 2.7 million birds, primarily in the north-eastern regions with the highest density of poultry farms (Lombardy, Emilia-Romagna and Veneto). We perform integrated analyses of genetic, spatiotemporal and host data within a Bayesian phylogenetic framework. Using continuous and discrete phylogeography, we estimate the locations of movements responsible for the spread and persistence of the epidemic. The information derived from these analyses on rates of transmission between regions through time can be used to assess the success of control measures. Using an approach based on phylogenetic-temporal distances between domestic cases, we infer the presence of cryptic wild bird-mediated transmission, information that can be used to complement existing epidemiological methods for distinguishing transmission within the domestic population from incursions across the wildlife-domestic interface, a common challenge in veterinary epidemiology. Spatiotemporal reconstruction of the epidemic reveals a highly skewed distribution of virus movements with a high proportion of shorter distance local movements interspersed with occasional long-distance dispersal events associated with wild birds. We also show how such inference be used to identify possible instances of human-mediated movements where distances between phylogenetically linked domestic cases are unusually high.
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Affiliation(s)
- William T. Harvey
- Boyd Orr Centre for Population and Ecosystem HealthInstitute of Biodiversity, Animal Health and Comparative MedicineCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Paolo Mulatti
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Alice Fusaro
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | | | - Bianca Zecchin
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Isabella Monne
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Stefano Marangon
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
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Scolamacchia F, Mulatti P, Mazzucato M, Barbujani M, Harvey WT, Fusaro A, Monne I, Marangon S. Different environmental gradients associated to the spatiotemporal and genetic pattern of the H5N8 highly pathogenic avian influenza outbreaks in poultry in Italy. Transbound Emerg Dis 2021; 68:152-167. [PMID: 32613724 PMCID: PMC8048857 DOI: 10.1111/tbed.13661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 05/28/2020] [Accepted: 05/28/2020] [Indexed: 10/29/2022]
Abstract
Comprehensive understanding of the patterns and drivers of avian influenza outbreaks is pivotal to inform surveillance systems and heighten nations' ability to quickly detect and respond to the emergence of novel viruses. Starting in early 2017, the Italian poultry sector has been involved in the massive H5N8 highly pathogenic avian influenza epidemic that spread in the majority of the European countries in 2016/2017. Eighty-three outbreaks were recorded in north-eastern Italy, where a densely populated poultry area stretches along the Lombardy, Emilia-Romagna and Veneto regions. The confirmed cases, affecting both the rural and industrial sectors, depicted two distinct epidemic waves. We adopted a combination of multivariate statistics techniques and multi-model regression selection and inference, to investigate how environmental factors relate to the pattern of outbreaks diversity with respect to their spatiotemporal and genetic diversity. Results showed that a combination of eco-climatic and host density predictors were associated with the outbreaks pattern, and variation along gradients was noticeable among genetically and geographically distinct groups of avian influenza cases. These regional contrasts may be indicative of a different mechanism driving the introduction and spreading routes of the influenza virus in the domestic poultry population. This methodological approach may be extended to different spatiotemporal scale to foster site-specific, ecologically informed risk mitigating strategies.
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Affiliation(s)
| | - Paolo Mulatti
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Matteo Mazzucato
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Marco Barbujani
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - William T. Harvey
- Boyd Orr Centre for Population and Ecosystem HealthInstitute of Biodiversity, Animal Health and Comparative MedicineCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Alice Fusaro
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Isabella Monne
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
| | - Stefano Marangon
- Istituto Zooprofilattico Sperimentale delle VenezieLegnaro (Padua)Italy
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Evaluation of strategies using simulation model to control a potential outbreak of highly pathogenic avian influenza among poultry farms in Central Luzon, Philippines. PLoS One 2020; 15:e0238815. [PMID: 32913363 PMCID: PMC7482972 DOI: 10.1371/journal.pone.0238815] [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: 05/07/2020] [Accepted: 08/23/2020] [Indexed: 12/18/2022] Open
Abstract
The Philippines confirmed its first epidemic of Highly Pathogenic Avian Influenza (HPAI) on August 11, 2017. It ended in November of 2017. Despite the successful management of the epidemic, reemergence is a continuous threat. The aim of this study was to conduct a mathematical model to assess the spatial transmission of HPAI among poultry farms in Central Luzon. Different control strategies and the current government protocol of 1 km radius pre-emptive culling (PEC) from infected farms were evaluated. The alternative strategies include 0.5km PEC, 1.5km PEC, 2 km PEC, 2.5 km PEC, and 3 km PEC, no pre-emptive culling (NPEC). The NPEC scenario was further modeled with a time of government notification set at 24hours, 48 hours, and 72 hours after the detection. Disease spread scenarios under each strategy were generated using an SEIR (susceptible-exposed-infectious-removed) stochastic model. A spatial transmission kernel was calculated and used to represent all potential routes of infection between farms. We assumed that the latent period occurs between 1–2 days, disease detection at 5–7 days post-infection, notification of authorities at 5–7 days post-detection and start of culling at 1–3 days post notification. The epidemic scenarios were compared based on the number of infected farms, the total number of culled farms, and the duration of the epidemic. Our results revealed that the current protocol is the most appropriate option compared with the other alternative interventions considered among farms with reproductive ratio (Ri) > 1. Shortening the culling radius to 0.5 km increased the duration of the epidemic. Further increase in the PEC zone decreased the duration of the epidemic but may not justify the increased number of farms to be culled. Nonetheless, the no-pre-emptive culling (NPEC) strategy can be an effective alternative to the current protocol if farm managers inform the government immediately within 24 hours of observation of the presence of HPAI in their farms. Moreover, if notification is made on days 1–3 after the detection, the scale and length of the outbreak have been significantly reduced. In conclusion, this study provided a comparison of various control measures for confronting the spread of HPAI infection using the simulation model. Policy makers can use this information to enhance the effectiveness of the current control strategy.
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Investigation and quantification of prevalent risk factors for the introduction of avian influenza in European poultry farms. WORLD POULTRY SCI J 2019. [DOI: 10.1017/s0043933910000486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Barnes B, Scott A, Hernandez-Jover M, Toribio JA, Moloney B, Glass K. Modelling high pathogenic avian influenza outbreaks in the commercial poultry industry. Theor Popul Biol 2019; 126:59-71. [DOI: 10.1016/j.tpb.2019.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/23/2018] [Accepted: 02/15/2019] [Indexed: 10/27/2022]
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Glass K, Barnes B, Scott A, Toribio JA, Moloney B, Singh M, Hernandez-Jover M. Modelling the impact of biosecurity practices on the risk of high pathogenic avian influenza outbreaks in Australian commercial chicken farms. Prev Vet Med 2019; 165:8-14. [PMID: 30851932 DOI: 10.1016/j.prevetmed.2019.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/04/2019] [Accepted: 02/04/2019] [Indexed: 01/29/2023]
Abstract
As of 2018, Australia has experienced seven outbreaks of highly pathogenic avian influenza (HPAI) in poultry since 1976, all of which involved chickens. There is concern that increases in free-range farming could heighten HPAI outbreak risk due to the potential for greater contact between chickens and wild birds that are known to carry low pathogenic avian influenza (LPAI). We use mathematical models to assess the effect of a shift to free-range farming on the risk of HPAI outbreaks of H5 or H7 in the Australian commercial chicken industry, and the potential for intervention strategies to reduce this risk. We find that a shift of 25% of conventional indoor farms to free-range farming practices would result in a 6-7% increase in the risk of a HPAI outbreak. Current practices to treat water are highly effective, reducing the risk of outbreaks by 25-28% compared to no water treatment. Halving wild bird presence in feed storage areas could reduce risk by 16-19% while halving wild bird access of potential bridge-species to sheds could reduce outbreak risk by 23-25%, and relatively small improvements in biosecurity measures could entirely compensate for increased risks due to the increasing proportion of free-range farms in the industry. The short production cycle and cleaning practices for chicken meat sheds considerably reduce the risk that an introduced low pathogenic avian influenza virus is maintained in the flock until it is detected as HPAI through increased mortality of chickens. These findings help explain HPAI outbreak history in Australia and suggest practical changes in biosecurity practices that could reduce the risk of future outbreaks.
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Affiliation(s)
- K Glass
- Research School of Population Health, Australian National University, Australia.
| | - B Barnes
- Research School of Population Health, Australian National University, Australia
| | - A Scott
- Sydney School of Veterinary Science, University of Sydney, Australia
| | - J-A Toribio
- Sydney School of Veterinary Science, University of Sydney, Australia
| | - B Moloney
- New South Wales Department of Primary Industries, Australia
| | - M Singh
- Sydney School of Veterinary Science, University of Sydney, Australia
| | - M Hernandez-Jover
- School of Animal and Veterinary Sciences and Graham Centre for Agricultural Innovation, Charles Sturt University, Australia
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Mulatti P, Fusaro A, Scolamacchia F, Zecchin B, Azzolini A, Zamperin G, Terregino C, Cunial G, Monne I, Marangon S. Integration of genetic and epidemiological data to infer H5N8 HPAI virus transmission dynamics during the 2016-2017 epidemic in Italy. Sci Rep 2018; 8:18037. [PMID: 30575785 PMCID: PMC6303474 DOI: 10.1038/s41598-018-36892-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/24/2018] [Indexed: 12/30/2022] Open
Abstract
Between October 2016 and December 2017, several European Countries had been involved in a massive Highly Pathogenic Avian Influenza (HPAI) epidemic sustained by H5N8 subtype virus. Starting on December 2016, also Italy was affected by H5N8 HPAI virus, with cases occurring in two epidemic waves: the first between December 2016 and May 2017, and the second in July-December 2017. Eighty-three outbreaks were recorded in poultry, 67 of which (80.72%) occurring in the second wave. A total of 14 cases were reported in wild birds. Epidemiological information and genetic analyses were conjointly used to get insight on the spread dynamics. Analyses indicated multiple introductions from wild birds to the poultry sector in the first epidemic wave, and noteworthy lateral spread from October 2017 in a limited geographical area with high poultry densities. Turkeys, layers and backyards were the mainly affected types of poultry production. Two genetic sub-groups were detected in the second wave in non-overlapping geographical areas, leading to speculate on the involvement of different wild bird populations. The integration of epidemiological data and genetic analyses allowed to unravel the transmission dynamics of H5N8 virus in Italy, and could be exploited to timely support in implementing tailored control measures.
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Affiliation(s)
- P Mulatti
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy.
| | - A Fusaro
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - F Scolamacchia
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - B Zecchin
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - A Azzolini
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - G Zamperin
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - C Terregino
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - G Cunial
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - I Monne
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
| | - S Marangon
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, (Padua), Italy
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13
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Kim WH, An JU, Kim J, Moon OK, Bae SH, Bender JB, Cho S. Risk factors associated with highly pathogenic avian influenza subtype H5N8 outbreaks on broiler duck farms in South Korea. Transbound Emerg Dis 2018; 65:1329-1338. [PMID: 29673109 DOI: 10.1111/tbed.12882] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Indexed: 11/29/2022]
Abstract
Highly Pathogenic Avian Influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in South Korea in 2014 resulting in significant damage to the poultry industry. Between 2014 and 2016, the pandemic disease caused significant economic loss and social disruption. To evaluate the risk factors for HPAI infection in broiler duck farms, we conducted a retrospective case-control study on broiler duck farms. Forty-three farms with confirmed laboratories on premises were selected as the case group, and 43 HPAI-negative farms were designated as the control group. Control farms were matched based on farm location and were within a 3-km radius from the case premises. Spatial and environmental factors were characterized by site visit and plotted through a geographic information system (GIS). Univariable and multivariable logistic regression models were developed to assess possible risk factors associated with HPAI broiler duck farm infection. Four final variables were identified as risk factors in a final multivariable logistic model: "Farms with ≥7 flocks" (odds ratio [OR] = 6.99, 95% confidence interval [CI] 1.34-37.04), "Farm owner with ≥15 years of raising poultry career" (OR = 7.91, 95% CI 1.69-37.14), "Presence of any poultry farms located within 500 m of the farm" (OR = 6.30, 95% CI 1.08-36.93) and "Not using a faecal removal service" (OR = 27.78, 95% CI 3.89-198.80). This highlights that the HPAI H5N8 outbreaks in South Korea were associated with farm owner education, number of flocks and facilities and farm biosecurity. Awareness of these factors may help to reduce the spread of HPAI H5N8 across broiler duck farms in Korea during epidemics. Greater understanding of the risk factors for H5N8 may improve farm vulnerability to HPAI and other subtypes and help to establish policies to prevent re-occurrence. These findings are relevant to global prevention recommendations and intervention protocols.
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Affiliation(s)
- W-H Kim
- BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - J-U An
- BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - J Kim
- BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - O-K Moon
- Animal and Plant Quarantine Agency, Gimcheon, Korea
| | - S H Bae
- Department of Geography Education, Kangwon National University, Chuncheon, Korea
| | - J B Bender
- Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - S Cho
- BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, Korea
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14
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Kapczynski DR, Dorsey K, Chrzastek K, Moraes M, Jackwood M, Hilt D, Gardin Y. Vaccine Protection of Turkeys Against H5N1 Highly Pathogenic Avian Influenza Virus with a Recombinant Turkey Herpesvirus Expressing the Hemagglutinin Gene of Avian Influenza. Avian Dis 2017; 60:413-7. [PMID: 27309280 DOI: 10.1637/11267-090115-reg] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Outbreaks of H5 highly pathogenic avian influenza (HPAI) in commercial poultry are a constant threat to animal health and food supplies. While vaccination can enhance protection and reduce the spread of disease, there is considerable evidence that the level of immunity required for protection varies by subtype and virulence of field virus. In this study, the efficacy of a recombinant turkey herpesvirus (rHVT) vector vaccine expressing the hemagglutinin gene from a clade 2.2 AI virus (A/Swan/Hungary/4999/2006) was evaluated in turkeys for protection against challenge with A/Whooper Swan/Mongolia/L244/2005 H5N1 HPAI clade 2.2. One-day-old turkeys received a single vaccination and were challenged at 4 wk postvaccination with 2 × 10(6) 50% embryo infectious dose per bird. The results demonstrate that following H5N1 HPAI challenge 96% protection was observed in rHVT-AI vaccinated turkeys. The oral and cloacal swabs taken from challenged birds demonstrated that vaccinated birds had lower incidence and titers of viral shedding compared with sham-vaccinated birds. From respiratory and gastrointestinal tracts, there was a greater than 6 log10 reduction in shedding in vaccinated birds as compared with the controls. This study provides support for the use of a commercially available rHVT-AI vaccine to protect turkeys against H5N1 HPAI.
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Affiliation(s)
- Darrell R Kapczynski
- A Exotic and Emerging Avian Disease Research Unit, U.S. National Poultry Health Research Center, Agricultural Research Service, USDA, 934 College Station Road, Athens, GA 30605
| | | | - Klaudia Chrzastek
- A Exotic and Emerging Avian Disease Research Unit, U.S. National Poultry Health Research Center, Agricultural Research Service, USDA, 934 College Station Road, Athens, GA 30605
| | | | - Mark Jackwood
- C Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA
| | - Debra Hilt
- C Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA
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15
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Mulatti P, Zecchin B, Monne I, Vieira JT, Dorotea T, Terregino C, Lorenzetto M, Piccolomini LL, Santi A, Massi P, Bonfanti L, Marangon S. H7N7 Highly Pathogenic Avian Influenza in Poultry Farms in Italy in 2016. Avian Dis 2017; 61:261-266. [DOI: 10.1637/11540-112516-case.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- P. Mulatti
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - B. Zecchin
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - I. Monne
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | | | - T. Dorotea
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - C. Terregino
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - M. Lorenzetto
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - L. Loli Piccolomini
- Servizio Prevenzione Collettiva e Sanità Pubblica, Direzione Generale Cura della persona, Persona, Salute e Welfare, Regione Emilia-Romagna, 40127, Bologna, Italy
| | - A. Santi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, 40127, Bologna, Italy
| | - P. Massi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, 47122, Forlì, Italy
| | - L. Bonfanti
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
| | - S. Marangon
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020, Legnaro, Padua, Italy
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16
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Hoummady S, Hua J, Muller C, Pouchelon JL, Blondot M, Gilbert C, Desquilbet L. Investigation of risk factors for mortality in aged guide dogs: A retrospective cohort study. Prev Vet Med 2016; 132:125-129. [PMID: 27616361 DOI: 10.1016/j.prevetmed.2016.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/01/2016] [Accepted: 09/03/2016] [Indexed: 01/17/2023]
Abstract
The overall median lifespan of domestic dogs has been estimated to 9-12 years, but little is known about risk factors for mortality in aged and a priori healthy dogs. The objective of this retrospective cohort study was to determine which characteristics are associated with mortality in aged and a priori healthy guide dogs, in a retrospective cohort study of 116 guide dogs followed from a systematic geriatric examination at the age of 8-10 years old. A geriatric grid collected the clinical data and usual biological parameters were measured at the time of examination. Univariate (Kaplan-Meier estimates) and multivariable (Cox proportional hazard model) survival analyses were used to assess the associations with time to all-cause death. The majority of dogs were Golden Retrievers (n=48) and Labrador Retrievers (n=27). Median age at geriatric examination was 8.9 years. A total of 76 dogs died during follow-up, leading to a median survival time from geriatric examination of 4.4 years. After adjustment for demographic and biological variables, an increased alanine amionotransferase level (adjusted Hazard Ratio (adjusted HR), 6.2; 95% confidence interval [95%CI], 2.0-19.0; P<0.01), presenting skin nodules (adjusted HR, 1.9; 95% CI, 1.0-3.4; P=0.04), and not being a Labrador Retriever (adjusted HR, 3.3; 95%CI, 1.4-10; P<0.01) were independently associated with a shorter time to death. This study documents independent associations of alanine aminotransferase level, skin nodules and breed with mortality in aged guide dogs. These results may be useful for preventive medical care when conducting a geriatric examination in working dogs.
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Affiliation(s)
- S Hoummady
- UMR-CNRS-MNHN 7179, 1 avenue du Petit Chateau, 91800 Brunoy, France; Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704 Maisons-Alfort, France.
| | - J Hua
- Dr Locci veterinary clinic, Drancy F-93700, France
| | - C Muller
- Saint Bernard veterinary clinic, Lomme F-59160, France
| | - J L Pouchelon
- Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704 Maisons-Alfort, France
| | - M Blondot
- Ecole des Chiens Guides de Paris, 105 avenue de Saint-Maurice, F-75015 Paris, France
| | - C Gilbert
- UMR-CNRS-MNHN 7179, 1 avenue du Petit Chateau, 91800 Brunoy, France; Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704 Maisons-Alfort, France
| | - L Desquilbet
- UMR-CNRS-MNHN 7179, 1 avenue du Petit Chateau, 91800 Brunoy, France; Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704 Maisons-Alfort, France
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17
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Sero-surveillance and risk factors for avian influenza and Newcastle disease virus in backyard poultry in Oman. Prev Vet Med 2015; 122:145-53. [DOI: 10.1016/j.prevetmed.2015.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 09/08/2015] [Accepted: 09/20/2015] [Indexed: 11/21/2022]
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18
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Controlling highly pathogenic avian influenza outbreaks: An epidemiological and economic model analysis. Prev Vet Med 2015; 121:142-50. [PMID: 26087887 DOI: 10.1016/j.prevetmed.2015.06.006] [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: 10/19/2014] [Revised: 06/02/2015] [Accepted: 06/04/2015] [Indexed: 11/23/2022]
Abstract
Outbreaks of highly pathogenic avian influenza (HPAI) can cause large losses for the poultry sector and for animal disease controlling authorities, as well as risks for animal and human welfare. In the current simulation approach epidemiological and economic models are combined to compare different strategies to control highly pathogenic avian influenza in Dutch poultry flocks. Evaluated control strategies are the minimum EU strategy (i.e., culling of infected flocks, transport regulations, tracing and screening of contact flocks, establishment of protection and surveillance zones), and additional control strategies comprising pre-emptive culling of all susceptible poultry flocks in an area around infected flocks (1 km, 3 km and 10 km) and emergency vaccination of all flocks except broilers around infected flocks (3 km). Simulation results indicate that the EU strategy is not sufficient to eradicate an epidemic in high density poultry areas. From an epidemiological point of view, this strategy is the least effective, while pre-emptive culling in 10 km radius is the most effective of the studied strategies. But these two strategies incur the highest costs due to long duration (EU strategy) and large-scale culling (pre-emptive culling in 10 km radius). Other analysed pre-emptive culling strategies (i.e., in 1 km and 3 km radius) are more effective than the analysed emergency vaccination strategy (in 3 km radius) in terms of duration and size of the epidemics, despite the assumed optimistic vaccination capacity of 20 farms per day. However, the total costs of these strategies differ only marginally. Extending the capacity for culling substantially reduces the duration, size and costs of the epidemic. This study demonstrates the strength of combining epidemiological and economic model analysis to gain insight in a range of consequences and thus to serve as a decision support tool in the control of HPAI epidemics.
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19
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Chaudhry M, Rashid HB, Thrusfield M, Welburn S, Bronsvoort BM. A case-control study to identify risk factors associated with avian influenza subtype H9N2 on commercial poultry farms in Pakistan. PLoS One 2015; 10:e0119019. [PMID: 25774768 PMCID: PMC4361405 DOI: 10.1371/journal.pone.0119019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 01/26/2015] [Indexed: 11/19/2022] Open
Abstract
A 1:1 matched case-control study was conducted to identify risk factors for avian influenza subtype H9N2 infection on commercial poultry farms in 16 districts of Punjab, and 1 administrative unit of Pakistan. One hundred and thirty-three laboratory confirmed positive case farms were matched on the date of sample submission with 133 negative control farms. The association between a series of farm-level characteristics and the presence or absence of H9N2 was assessed by univariable analysis. Characteristics associated with H9N2 risk that passed the initial screening were included in a multivariable conditional logistic regression model. Manual and automated approaches were used, which produced similar models. Key risk factors from all approaches included selling of eggs/birds directly to live bird retail stalls, being near case/infected farms, a previous history of infectious bursal disease (IBD) on the farm and having cover on the water storage tanks. The findings of current study are in line with results of many other studies conducted in various countries to identify similar risk factors for AI subtype H9N2 infection. Enhancing protective measures and controlling risks identified in this study could reduce spread of AI subtype H9N2 and other AI viruses between poultry farms in Pakistan.
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Affiliation(s)
- Mamoona Chaudhry
- Division of Infection and Pathway Medicine, The University of Edinburgh Medical School, Edinburgh, Scotland, United Kingdom
- * E-mail:
| | - Hamad B. Rashid
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, Abdul Qadir Jilani Road, Lahore, Pakistan
| | - Michael Thrusfield
- The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, Roslin, Midlothian, Edinburgh, Scotland, United Kingdom
| | - Sue Welburn
- Division of Infection and Pathway Medicine, The University of Edinburgh Medical School, Edinburgh, Scotland, United Kingdom
| | - Barend MdeC. Bronsvoort
- The University of Edinburgh, Roslin Institute at the R(D)SVS, Easter Bush, Roslin, Midlothian, Edinburgh, Scotland, United Kingdom
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20
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Bonfanti L, Monne I, Tamba M, Santucci U, Massi P, Patregnani T, Loli Piccolomini L, Natalini S, Ferri G, Cattoli G, Marangon S. Highly pathogenic H7N7 avian influenza in Italy. Vet Rec 2014; 174:382. [PMID: 24659030 DOI: 10.1136/vr.102202] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- L Bonfanti
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, Legnaro, Padua 35020, Italy
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21
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Emergence of a highly pathogenic avian influenza virus from a low-pathogenic progenitor. J Virol 2014; 88:4375-88. [PMID: 24501401 DOI: 10.1128/jvi.03181-13] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Avian influenza (AI) viruses of the H7 subtype have the potential to evolve into highly pathogenic (HP) viruses that represent a major economic problem for the poultry industry and a threat to global health. However, the emergence of HPAI viruses from low-pathogenic (LPAI) progenitor viruses currently is poorly understood. To investigate the origin and evolution of one of the most important avian influenza epidemics described in Europe, we investigated the evolutionary and spatial dynamics of the entire genome of 109 H7N1 (46 LPAI and 63 HPAI) viruses collected during Italian H7N1 outbreaks between March 1999 and February 2001. Phylogenetic analysis revealed that the LPAI and HPAI epidemics shared a single ancestor, that the HPAI strains evolved from the LPAI viruses in the absence of reassortment, and that there was a parallel emergence of mutations among HPAI and later LPAI lineages. Notably, an ultradeep-sequencing analysis demonstrated that some of the amino acid changes characterizing the HPAI virus cluster were already present with low frequency within several individual viral populations from the beginning of the LPAI H7N1 epidemic. A Bayesian phylogeographic analysis revealed stronger spatial structure during the LPAI outbreak, reflecting the more rapid spread of the virus following the emergence of HPAI. The data generated in this study provide the most complete evolutionary and phylogeographic analysis of epidemiologically intertwined high- and low-pathogenicity viruses undertaken to date and highlight the importance of implementing prompt eradication measures against LPAI to prevent the appearance of viruses with fitness advantages and unpredictable pathogenic properties. IMPORTANCE The Italian H7 AI epidemic of 1999 to 2001 was one of the most important AI outbreaks described in Europe. H7 viruses have the ability to evolve into HP forms from LP precursors, although the mechanisms underlying this evolutionary transition are only poorly understood. We combined epidemiological information, whole-genome sequence data, and ultradeep sequencing approaches to provide the most complete characterization of the evolution of HPAI from LPAI viruses undertaken to date. Our analysis revealed that the LPAI viruses were the direct ancestors of the HPAI strains and identified low-frequency minority variants with HPAI mutations that were present in the LPAI samples. Spatial analysis provided key information for the design of effective control strategies for AI at both local and global scales. Overall, this work highlights the importance of implementing rapid eradication measures to prevent the emergence of novel influenza viruses with severe pathogenic properties.
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Abstract
ABSTRACT The ongoing H7N9 influenza epizootic in China once again presents us questions about the origin of pandemics and how to recognize them in early stages of development. Over the past ~135 years, H7 influenza viruses have neither caused pandemics nor been recognized as having undergone human adaptation. Yet several unusual properties of these viruses, including their poultry epizootic potential, mammalian adaptation, and atypical clinical syndromes in rarely infected humans, suggest that they may be different from other avian influenza viruses, thus questioning any assurance that the likelihood of human adaptation is low. At the same time, the H7N9 epizootic provides an opportunity to learn more about the mammalian/human adaptational capabilities of avian influenza viruses and challenges us to integrate virologic and public health research and surveillance at the animal-human interface.
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23
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Wang Y, Jiang Z, Jin Z, Tan H, Xu B. Risk factors for infectious diseases in backyard poultry farms in the Poyang Lake area, China. PLoS One 2013; 8:e67366. [PMID: 23840680 PMCID: PMC3688663 DOI: 10.1371/journal.pone.0067366] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 05/16/2013] [Indexed: 11/19/2022] Open
Abstract
Emergence and transmission of infectious diseases have an enormous impact on the poultry industry and present a serious threat to the health of humans and wild birds. Noncommercial poultry operations, such as backyard poultry facilities in China, are potential sources of virus exchange between commercial poultry and wild birds. It is particularly critical in wetland areas where backyard poultry have close contact with commercial poultry and migratory birds, therefore increasing the risk of contracting infectious diseases. To evaluate the transmission risks, a cross-sectional study was undertaken in the Poyang Lake area, China, involving 309 residents in the backyard poultry farms in three counties (Region A, B, and C) of Jiangxi Province. We examined the backyard poultry population, poultry species, presence of poultry deaths from infectious diseases, food sources, and biosecurity practices. Region B ranked highest for biosecurity while region C ranked lowest. The risks of infectious diseases were assessed by adjusted odds ratio based on multivariate logistic regression analysis. Potential risk factors in the three regions of the study site were compared. In Region A, significant factor was contact of poultry with wild birds (OR: 6.573, 95% CI: 2.148–20.115, P=0.001). In Region B, the most significant factor was contact of poultry with neighboring backyard waterfowls (OR: 3.967, 95% CI: 1.555–10.122, P=0.004). In Region C, significant factors were poultry purchase from local live bird markets (OR: 3.740, 95% CI: 1.243–11.255, P=0.019), and contact of poultry with wild birds (OR: 3.379, 95% CI: 1.058–10.791, P=0.040). In summary, backyard poultry was significantly affected by neighboring commercial poultry and close contact with wild birds. The results are expected to improve our understanding of the transmission risks of infectious diseases in a typical backyard poultry environment in rural China, and address the need to improve local farming practices and take preventive measures.
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Affiliation(s)
- Yong Wang
- School of Environment, Tsinghua University, Beijing, China
| | - Zhiben Jiang
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Zhenyu Jin
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Hua Tan
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Bing Xu
- School of Environment, Tsinghua University, Beijing, China
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
- Department of Geography, University of Utah, Salt Lake City, Utah, United States of America
- *
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24
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Nickbakhsh S, Matthews L, Dent JE, Innocent GT, Arnold ME, Reid SWJ, Kao RR. Implications of within-farm transmission for network dynamics: consequences for the spread of avian influenza. Epidemics 2013; 5:67-76. [PMID: 23746799 PMCID: PMC3694308 DOI: 10.1016/j.epidem.2013.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 02/21/2013] [Accepted: 03/04/2013] [Indexed: 11/06/2022] Open
Abstract
Cross-scale dynamics were investigated for avian influenza in British poultry. Transmission risk is dependent on the assumed within-flock transmission mode. Transmission risk may not scale with transmissibility or flock size. Transmission risk corresponds with between-farm impact for 28% of farms. These results have implications for targeted disease control at the farm-level.
The importance of considering coupled interactions across multiple population scales has not previously been studied for highly pathogenic avian influenza (HPAI) in the British commercial poultry industry. By simulating the within-flock transmission of HPAI using a deterministic S-E-I-R model, and by incorporating an additional environmental class representing infectious faeces, we tracked the build-up of infectious faeces within a poultry house over time. A measure of the transmission risk (TR) was computed for each farm by linking the amount of infectious faeces present each day of an outbreak with data describing the daily on-farm visit schedules for a major British catching company. Larger flocks tended to have greater levels of these catching-team visits. However, where density-dependent contact was assumed, faster outbreak detection (according to an assumed mortality threshold) led to a decreased opportunity for catching-team visits to coincide with an outbreak. For this reason, maximum TR-levels were found for mid-range flock sizes (~25,000–35,000 birds). When assessing all factors simultaneously using multivariable linear regression on the simulated outputs, those related to the pattern of catching-team visits had the largest effect on TR, with the most important movement-related factor depending on the mode of transmission. Using social network analysis on a further database to inform a measure of between-farm connectivity, we identified a large fraction of farms (28%) that had both a high TR and a high potential impact at the between farm level. Our results have counter-intuitive implications for between-farm spread that could not be predicted based on flock size alone, and together with further knowledge of the relative importance of transmission risk and impact, could have implications for improved targeting of control measures.
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Affiliation(s)
- Sema Nickbakhsh
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Road, G61 1QH, Scotland, UK.
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Patyk KA, Helm J, Martin MK, Forde-Folle KN, Olea-Popelka FJ, Hokanson JE, Fingerlin T, Reeves A. An epidemiologic simulation model of the spread and control of highly pathogenic avian influenza (H5N1) among commercial and backyard poultry flocks in South Carolina, United States. Prev Vet Med 2013; 110:510-24. [PMID: 23398856 DOI: 10.1016/j.prevetmed.2013.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/10/2013] [Accepted: 01/12/2013] [Indexed: 10/27/2022]
Abstract
Epidemiologic simulation modeling of highly pathogenic avian influenza (HPAI) outbreaks provides a useful conceptual framework with which to estimate the consequences of HPAI outbreaks and to evaluate disease control strategies. The purposes of this study were to establish detailed and informed input parameters for an epidemiologic simulation model of the H5N1 strain of HPAI among commercial and backyard poultry in the state of South Carolina in the United States using a highly realistic representation of this poultry population; to estimate the consequences of an outbreak of HPAI in this population with a model constructed from these parameters; and to briefly evaluate the sensitivity of model outcomes to several parameters. Parameters describing disease state durations; disease transmission via direct contact, indirect contact, and local-area spread; and disease detection, surveillance, and control were established through consultation with subject matter experts, a review of the current literature, and the use of several computational tools. The stochastic model constructed from these parameters produced simulated outbreaks ranging from 2 to 111 days in duration (median 25 days), during which 1 to 514 flocks were infected (median 28 flocks). Model results were particularly sensitive to the rate of indirect contact that occurs among flocks. The baseline model established in this study can be used in the future to evaluate various control strategies, as a tool for emergency preparedness and response planning, and to assess the costs associated with disease control and the economic consequences of a disease outbreak.
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Affiliation(s)
- Kelly A Patyk
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Centers for Epidemiology and Animal Health, 2150 Centre Avenue, Building B, Fort Collins, CO 80526, USA.
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26
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Longworth N, Mourits MCM, Saatkamp HW. Economic Analysis of HPAI Control in the Netherlands II: Comparison of Control Strategies. Transbound Emerg Dis 2012. [DOI: 10.1111/tbed.12034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N. Longworth
- Business Economics; Wageningen University; KN Wageningen The Netherlands
| | - M. C. M. Mourits
- Business Economics; Wageningen University; KN Wageningen The Netherlands
| | - H. W. Saatkamp
- Business Economics; Wageningen University; KN Wageningen The Netherlands
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27
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Slota KE, Hill AE, Keefe TJ, Bowen RA, Pabilonia KL. Biosecurity and bird movement practices in upland game bird facilities in the United States. Avian Dis 2011; 55:180-6. [PMID: 21793431 DOI: 10.1637/9509-082310-reg.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Since 1996, the emergence of Asian-origin highly pathogenic avian influenza subtype H5N1 has spurred great concern for the global poultry industry. In the United States, there is concern over the potential of a foreign avian disease incursion into the country. Noncommercial poultry operations, such as upland game bird facilities in the United States, may serve as a potential source of avian disease introduction to other bird populations including the commercial poultry industry, backyard flocks, or wildlife. In order to evaluate how to prevent disease transmission from these facilities to other populations, we examined biosecurity practices and bird movement within the upland game bird industry in the United States. Persons that held a current permit to keep, breed, or release upland game birds were surveyed for information on biosecurity practices, flock and release environments, and bird movement parameters. Biosecurity practices vary greatly among permit holders. Many facilities allow for interaction between wild birds and pen-reared birds, and there is regular long-distance movement of live adult birds among facilities. Results suggest that upland game bird facilities should be targeted for biosecurity education and disease surveillance efforts.
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Affiliation(s)
- Katharine E Slota
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 W. Drake Road, Fort Collins, CO 80523, USA.
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28
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Cecchinato M, Comin A, Bonfanti L, Terregino C, Monne I, Lorenzetto M, Marangona S. Epidemiology and control of low pathogenicity avian influenza infections in rural poultry in Italy. Avian Dis 2011; 55:13-20. [PMID: 21500630 DOI: 10.1637/9500-081310-reg.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We analyzed the involvement of the rural poultry sector in outbreaks of low pathogenicity avian influenza (AI) in Italy in 2007-2009 and discuss possible measures for improving monitoring and control. A description of how the rural poultry sector is organized also is provided. Data were obtained by the AI surveillance system established in the areas affected by the outbreaks. The surveillance activities identified two H7N3 epidemics, in 2007 and 2009, both of which mainly involved the rural sector, yet these activities did not allow for the prompt eradication of the disease. Additional strategies could be adopted to avoid the persistence of AI within the rural sector, based on the regulation and control of poultry holdings at the top of the production chain.
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Affiliation(s)
- M Cecchinato
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10, 35020 Legnaro (PD), Italy.
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29
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Rorres C, Pelletier STK, Bruhn MC, Smith G. Ongoing estimation of the epidemic parameters of a stochastic, spatial, discrete-time model for a 1983-84 avian influenza epidemic. Avian Dis 2011; 55:35-42. [PMID: 21500633 DOI: 10.1637/9429-061710-reg.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We formulate a stochastic, spatial, discrete-time model of viral "Susceptible, Exposed, Infectious, Recovered" animal epidemics and apply it to an avian influenza epidemic in Pennsylvania in 1983-84. Using weekly data for the number of newly infectious cases collected during the epidemic, we find estimates for the latent period of the virus and the values of two parameters within the transmission kernel of the model. These data are then jackknifed on a progressive weekly basis to show how our estimates can be applied to an ongoing epidemic to generate continually improving values of certain epidemic parameters.
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Affiliation(s)
- C Rorres
- School of Veterinary Medicine, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA.
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30
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Protective efficacy of H5 inactivated vaccines in meat turkey poults after challenge with Egyptian variant highly pathogenic avian influenza H5N1 virus. Vet Microbiol 2011; 150:28-34. [DOI: 10.1016/j.vetmic.2010.12.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 11/20/2010] [Accepted: 12/07/2010] [Indexed: 11/23/2022]
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31
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Smith G, Dunipace S. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks. Epidemics 2011; 3:71-5. [PMID: 21624777 DOI: 10.1016/j.epidem.2011.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 01/20/2011] [Accepted: 01/31/2011] [Indexed: 11/17/2022] Open
Abstract
This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of strategies focused one host type (e.g. commercial flocks only) necessarily underestimate the level of effort to an extent that may matter to policy makers.
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Affiliation(s)
- G Smith
- School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Kennett Square, PA 19348, USA.
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32
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Stegeman A, Bouma A, de Jong MCM. Use of epidemiologic models in the control of highly pathogenic avian influenza. Avian Dis 2010; 54:707-12. [PMID: 20521719 DOI: 10.1637/8821-040209-review.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the past decades, mathematical models have become more and more accepted as a tool to develop surveillance programs and to evaluate the efficacy of intervention measures for the control of infectious diseases such as highly pathogenic avian influenza. Predictive models are used to simulate the effect of various control measures on the course of an epidemic; analytical models are used to analyze data from outbreaks or from experiments. A key parameter in both types of models is the reproductive ratio, which indicates whether virus can be transmitted in the population, resulting in an epidemic, or not. Parameters obtained from real data using the analytical models can subsequently be used in predictive models to evaluate control strategies or surveillance programs. Examples of the use of these models are described here.
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Affiliation(s)
- Arjan Stegeman
- Faculty of Veterinary Medicine, Department of Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL, Utrecht, The Netherlands.
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33
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Dorea FC, Vieira AR, Hofacre C, Waldrip D, Cole DJ. Stochastic model of the potential spread of highly pathogenic avian influenza from an infected commercial broiler operation in Georgia. Avian Dis 2010; 54:713-9. [PMID: 20521720 DOI: 10.1637/8706-031609-resnote.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The potential spread of highly pathogenic avian influenza among commercial broiler farms in Georgia, U. S. A., was mathematically modeled. The dynamics of the spread within the first infected flock were estimated using an SEIR (susceptible-exposed-infectious-recovered) deterministic model, and predicted that grower detection of flock infection is most likely 5 days after virus introduction. Off-farm spread of virus was estimated stochastically for this period, predicting a mean range of exposed farms from 0-5, depending on the density of farms in the area. Modeled off-farm spread was most frequently associated with feed trucks (highest daily probability and number of farm visits) and with company personnel or hired help (highest level of bird contact).
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Affiliation(s)
- F C Dorea
- Poultry Diagnostic Research Center, University of Georgia, 953 College Station Road, Athens, GA 30605, USA.
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34
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Comin A, Stegeman JA, Klinkenberg D, Busani L, Marangon S. Design and results of an intensive monitoring programme for avian influenza in meat-type turkey flocks during four epidemics in northern Italy. Zoonoses Public Health 2010; 58:244-51. [PMID: 20604911 DOI: 10.1111/j.1863-2378.2010.01343.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Surveillance programmes for low pathogenicity (LPAI) and high pathogenicity avian influenza (HPAI) infections in poultry are compulsory for EU Member States; yet, these programmes have rarely been evaluated. In Italy, following a 1999 HPAI epidemic, control measures, including vaccination and monitoring, were implemented in the densely populated poultry area (DPPA) where all epidemics in Italy have been concentrated. We evaluated the monitoring system for its capacity to detect outbreaks rapidly in meat-type turkey flocks. The evaluation was performed in vaccination areas and high-risk areas in the DPPA, in 2000-2005, during which four epidemics occurred. Serum samples and cloacal swabs were taken from vaccinated birds and unvaccinated (sentinel) birds. We compared the detection rate of active, passive and targeted surveillance, by vaccination status, using multinomial logistic regression. A total of 13 275 samplings for serological testing and 4889 samplings for virological testing were performed; 6315 production cycles of different bird species were tested. The outbreaks detection rate in meat-type turkeys was 61% for active surveillance (n = 222/363 outbreaks), 32% for passive surveillance and 7% for targeted surveillance. The maximum likelihood predicted values for the detection rates differed by vaccination status: in unvaccinated flocks, it was 50% for active surveillance, 40% for passive surveillance and 10% for targeted surveillance, compared to respectively 79%, 17% and 4% for vaccinated flocks. Active surveillance seems to be most effective in detecting infection, especially when a vaccination programme is in place. This is the first evaluation of the effectiveness of different types of surveillance in monitoring LPAI infections in vaccinated poultry using field data.
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Affiliation(s)
- A Comin
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy.
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35
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Iglesias I, Martínez M, Muñoz MJ, de la Torre A, Sánchez-Vizcaíno JM. First case of highly pathogenic avian influenza in poultry in Spain. Transbound Emerg Dis 2010; 57:282-5. [PMID: 20545911 DOI: 10.1111/j.1865-1682.2010.01145.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In October 2009, highly pathogenic avian influenza virus (HPAIV) was isolated for the first time in poultry in Spain. Sequencing analysis revealed that it was an H7N7 HPAIV. The progenitors of H7 HPAIV strains involved in recent European poultry outbreaks were simultaneously circulating in wild birds. The infected Spanish farm is located close to a reservoir abundant in wild birds. Epidemiological investigation found no links to other poultry holdings and those located in the control area were negative for AIV. Previous spatial risk analyses had identified the area where the infected holding is located to beat high relative risk for the introduction and presence of H5N1 HPAIV by wild birds. We suggest a risk-based surveillance scheme that targets smaller geographical units but maintains the number of wild birds being sampled, as early detection of potentially pathogenic AIV is crucial in preventing spread to poultry.
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Affiliation(s)
- I Iglesias
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera de Algete a El Casar, Valdeolmos, Madrid, Spain.
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36
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Mulatti P, Kitron U, Jacquez GM, Mannelli A, Marangon S. Evaluation of the risk of neighbourhood infection of H7N1 Highly Pathogenic Avian Influenza in Italy using Q statistic. Prev Vet Med 2010; 95:267-74. [PMID: 20451272 DOI: 10.1016/j.prevetmed.2010.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 04/11/2010] [Accepted: 04/13/2010] [Indexed: 10/19/2022]
Abstract
Exposure to the risk of neighbourhood infection was estimated for the H7N1 Highly Pathogenic Avian Influenza (HPAI) epidemic that affected Northern Italy between 1999 and 2000. The two most affected regions (Lombardy and Veneto) were analyzed and the epidemic was divided into three phases. Q statistics were used to evaluate exposure to the risk of neighbourhood infection using two measures. First, a local Q statistic (Qikt) assessed daily exposure for each farm as a function of the number of neighbouring infected farms that were in their infectious period, weighted by the distance between farms. This allowed us to identify the daily time course of risk for each farm and, at any given time, local groups of farms defined by high risk. Second, for each farm a summary statistic of exposure risk within each phase (Qiph) was obtained by summing Qikt over the duration of each phase. This allowed identification of farms defined by persistent, high exposure risk within each phase of the epidemic. Statistical significance was evaluated using conditional Monte Carlo simulation, and significant values of Qiph were mapped to assess the variation of the risk of neighbourhood infection through the phases. Qikt was larger for farms in Lombardy and the reduction of exposed farms was more marked for Veneto. Although the highest value of Qiph was observed in Veneto, in each phase most of the significant values were in Lombardy. In the last phase of the epidemic, a large reduction in the number of farms significantly exposed to the risk of neighbourhood infection was observed in the Veneto region, along with generally low values of Qiph. This may be explained by differences in control measures in the two regions, including pre-emptive slaughtering of farms considered at high risk of infection. The Q statistic allowed us to quantify geographic, time-dynamic variations in exposure to neighbourhood infection, and to generate hypotheses on the efficacy of control measures.
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Affiliation(s)
- Paolo Mulatti
- Istituto Zooprofilattico Sperimentale delle Venezie-IZSVe, Viale dell'Università 10, 35020 Legnaro, Padua, Italy.
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37
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Dorigatti I, Mulatti P, Rosà R, Pugliese A, Busani L. Modelling the spatial spread of H7N1 avian influenza virus among poultry farms in Italy. Epidemics 2010; 2:29-35. [PMID: 21352774 DOI: 10.1016/j.epidem.2010.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 01/26/2010] [Accepted: 01/30/2010] [Indexed: 11/29/2022] Open
Abstract
We analysed the between-farm transmission of the H7N1 highly pathogenic avian influenza virus that disrupted the Italian poultry production in the 1999-2000 epidemic with a SEIR model with a spatial transmission kernel, accounting for the containment measures actually undertaken. We found significant differences in susceptibility between species and a reduction in transmissibility after the first phase. We performed simulations to assess the effectiveness of the implemented and new control measures. The most effective measure was the ban on restocking. An earlier start of pre-emptive culling promotes eradication; restricted pre-emptive culling delays eradication but causes lower losses.
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Affiliation(s)
- I Dorigatti
- Department of Mathematics, University of Trento, via Sommarive 14, 38123 Povo, Tn, Italy.
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38
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Trampel DW, Zack JT, Clouse TL, Bickett-Weddle DA, Brown GB, Rao VS, Hurd HS, Garris GI, Roth JA. A federal and state transport plan for movement of eggs and egg products from commercial egg production premises in a high-pathogenicity avian influenza control area. J Am Vet Med Assoc 2009; 235:1412-9. [PMID: 20001773 DOI: 10.2460/javma.235.12.1412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Darrell W Trampel
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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39
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Evaluation of interventions and vaccination strategies for low pathogenicity avian influenza: spatial and space-time analyses and quantification of the spread of infection. Epidemiol Infect 2009; 138:813-24. [PMID: 19845996 DOI: 10.1017/s0950268809991038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In recent years the control of low pathogenicity avian influenza (LPAI) viruses of the H5 and H7 subtypes has increasingly become a concern. We evaluated the measures (stamping out, controlled marketing, emergency and preventive vaccination, farm density reduction and restocking in homogenous areas) implemented to control the LPAI epidemics that occurred in Italy between 2000 and 2005, using a combination of spatial and space-time analyses and estimates of the basic reproduction ratio (R0). Clustering of infected farms decreased over the years, indicating the effectiveness of the control strategies implemented. Controlled marketing [relative risk (RR) 0.46, 95% confidence interval (CI) 0.27-0.80], emergency (RR 0.47, 95% CI 0.39-0.57) and preventive vaccination (RR 0.19, 95% CI 0.09-0.41) were the most effective measures, yet R0<1 was only for preventive vaccination. Our results are useful for identifying the most effective measures for reducing the risk of the spread of LPAI and optimizing the allocation of resources.
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40
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Risk factors for highly pathogenic H7N1 avian influenza virus infection in poultry during the 1999–2000 epidemic in Italy. Vet J 2009; 181:171-7. [DOI: 10.1016/j.tvjl.2008.02.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 01/03/2008] [Accepted: 02/13/2008] [Indexed: 11/22/2022]
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41
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Bos MEH, Nielen M, Koch G, Bouma A, De Jong MCM, Stegeman A. Back-calculation method shows that within-flock transmission of highly pathogenic avian influenza (H7N7) virus in the Netherlands is not influenced by housing risk factors. Prev Vet Med 2009; 88:278-85. [PMID: 19178968 DOI: 10.1016/j.prevetmed.2008.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 10/24/2008] [Accepted: 12/11/2008] [Indexed: 10/21/2022]
Abstract
To optimize control of an avian influenza outbreak knowledge of within-flock transmission is needed. This study used field data to estimate the transmission rate parameter (beta) and the influence of risk factors on within-flock transmission of highly pathogenic avian influenza (HPAI) H7N7 virus in the 2003 epidemic in The Netherlands. The estimation is based on back-calculation of daily mortality data to fit a susceptible-infectious-dead format, and these data were analysed with a generalized linear model. This back-calculation method took into account the uncertainty of the length of the latent period, the survival of an infection by some birds and the influence of farm characteristics. After analysing the fit of the different databases created by back-calculation, it could be concluded that an absence of the latency period provided the best fit. The transmission rate parameter (beta) from these field data was estimated at 4.50 per infectious chicken per day (95% CI: 2.68-7.57), which was lower than what was reported from experimental data. In contrast to general belief, none of the studied risk factors (housing system, flock size, species, age of the birds in weeks and date of depopulation) had significant influence on the estimated beta.
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Affiliation(s)
- Marian E H Bos
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, The Netherlands.
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42
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Kayali G, Ortiz EJ, Chorazy ML, Gray GC. Evidence of previous avian influenza infection among US turkey workers. Zoonoses Public Health 2009; 57:265-72. [PMID: 19486492 DOI: 10.1111/j.1863-2378.2009.01231.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The threat of an influenza pandemic is looming, with new cases of sporadic avian influenza infections in man frequently reported. Exposure to diseased poultry is a leading risk factor for these infections. In this study, we used logistic regression to investigate serological evidence of previous infection with avian influenza subtypes H4, H5, H6, H7, H8, H9, H10, and H11 among 95 adults occupationally exposed to turkeys in the US Midwest and 82 unexposed controls. Our results indicate that farmers practising backyard, organic or free-ranging turkey production methods are at an increased risk of infection with avian influenza. Among these farmers, the adjusted odds ratios (ORs) for elevated microneutralization assay titres against avian H4, H5, H6, H9, and H10 influenza strains ranged between 3.9 (95% CI 1.2-12.8) and 15.3 (95% CI 2.0-115.2) when compared to non-exposed controls. The measured ORs were adjusted for antibody titres against human influenza viruses and other exposure variables. These data suggest that sometime in their lives, the workers had been exposed to low pathogenicity avian influenza viruses. These findings support calls for inclusion of agricultural workers in priority groups in pandemic influenza preparedness efforts. These data further support increasing surveillance and other preparedness efforts to include not only confinement poultry facilities, but more importantly, also small scale farms.
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Affiliation(s)
- G Kayali
- Center for Emerging Infectious Diseases, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA.
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43
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Martinez M, Perez AM, de la Torre A, Iglesias I, Muñoz MJ. Association Between Number of Wild Birds Sampled for Identification of H5N1 Avian Influenza Virus and Incidence of the Disease in the European Union. Transbound Emerg Dis 2008; 55:393-403. [DOI: 10.1111/j.1865-1682.2008.01046.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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44
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Bos ME, Nielen M, Koch G, Stegeman A, De Jong MC. Effect of H7N1 vaccination on highly pathogenic avian influenza H7N7 virus transmission in turkeys. Vaccine 2008; 26:6322-8. [DOI: 10.1016/j.vaccine.2008.09.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 09/04/2008] [Accepted: 09/04/2008] [Indexed: 11/29/2022]
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45
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Mohammed SL, Lehmann HP, Kim GR. A proposed taxonomy for characterization and assessment of avian influenza outbreaks. Int J Med Inform 2008; 78:182-92. [PMID: 18805050 DOI: 10.1016/j.ijmedinf.2008.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2007] [Revised: 06/28/2008] [Accepted: 06/30/2008] [Indexed: 11/19/2022]
Abstract
PURPOSE The speed and high potential impact of avian influenza's (AI) on local bird populations, poultry economies and human health make timely and coordinated characterization, assessment and response to possible threats essential. To collaborate effectively, stakeholders (public health, medical, veterinary, and agricultural professionals) must be able to communicate and record findings, assessments, and actions in a standard fashion. We seek to discern a taxonomy of concepts and relationships that are important to the stakeholder community when sharing information about the characterization and assessment of an AI outbreak, according to a consistent and common perspective, interpretation, and level of detail. METHODS To derive concepts relevant to AI characterization and assessment, we reviewed selected journal articles, reporting and laboratory forms, and public health websites associated with AI case reporting. We mapped concepts to existing medical terminologies within the Unified Medical Language System when possible, using the National Library of Medicine's MetaMap program. RESULTS From 54 distinct information sources, we extracted 1113 concepts, of which 533 mapped to 15 medical terminologies; 580 did not map to specific terminologies. Using a combination of semantic type-relationship matching and expert consensus, we constructed the proposed taxonomy, with linkages to existing terminologies where pragmatic. CONCLUSION The proposed taxonomy describes core knowledge, data and communication needs for the characterization and assessment of AI outbreaks in the context of existing medical terminologies across different domains. We also describe areas for further work.
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Affiliation(s)
- Sule L Mohammed
- Division of Health Sciences Informatics, School of Medicine, Johns Hopkins University, 2024 East Monument Street, Suite 1-201, Baltimore, MD 21205, USA.
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46
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Dent JE, Kao RR, Kiss IZ, Hyder K, Arnold M. Contact structures in the poultry industry in Great Britain: exploring transmission routes for a potential avian influenza virus epidemic. BMC Vet Res 2008; 4:27. [PMID: 18651959 PMCID: PMC2526082 DOI: 10.1186/1746-6148-4-27] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 07/23/2008] [Indexed: 11/16/2022] Open
Abstract
Background The commercial poultry industry in United Kingdom (UK) is worth an estimated £3.4 billion at retail value, producing over 174 million birds for consumption per year. An epidemic of any poultry disease with high mortality or which is zoonotic, such as avian influenza virus (AIV), would result in the culling of significant numbers of birds, as seen in the Netherlands in 2003 and Italy in 2000. Such an epidemic would cost the UK government millions of pounds in compensation costs, with further economic losses through reduction of international and UK consumption of British poultry. In order to better inform policy advisers and makers on the potential for a large epidemic in GB, we investigate the role that interactions amongst premises within the British commercial poultry industry could play in promoting an AIV epidemic, given an introduction of the virus in a specific part of poultry industry in Great Britain (GB). Results Poultry premises using multiple slaughterhouses lead to a large number of premises being potentially connected, with the resultant potential for large and sometimes widespread epidemics. Catching companies can also potentially link a large proportion of the poultry population. Critical to this is the maximum distance traveled by catching companies between premises and whether or not between-species transmission could occur within individual premises. Premises closely linked by proximity may result in connections being formed between different species and or sectors within the industry. Conclusion Even quite well-contained epidemics have the potential for geographically widespread dissemination, potentially resulting in severe logistical problems for epidemic control, and with economic impact on a large part of the country. Premises sending birds to multiple slaughterhouses or housing multiple species may act as a bridge between otherwise separate sectors of the industry, resulting in the potential for large epidemics. Investment into further data collection and analyses on the importance of industry structure as a determinant for spread of AIV would enable us to use the results from this study to contribute to policy on disease control.
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Affiliation(s)
- Jennifer E Dent
- Centre for Epidemiology and Risk Analysis, VLA, New Haw, Addlestone, Surrey, KT15 3NB, UK.
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Animal health and welfare aspects of avian influenza and the risk of its introduction into the EU poultry holdings - Scientific opinion of the Panel on Animal Health and Welfare. EFSA J 2008. [DOI: 10.2903/j.efsa.2008.715] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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48
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Nishiguchi A, Kobayashi S, Yamamoto T, Ouchi Y, Sugizaki T, Tsutsui T. Risk Factors for the Introduction of Avian Influenza Virus into Commercial Layer Chicken Farms During the Outbreaks Caused by a Low-Pathogenic H5N2 Virus in Japan in 2005. Zoonoses Public Health 2007; 54:337-43. [DOI: 10.1111/j.1863-2378.2007.01074.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Mannelli A, Busani L, Toson M, Bertolini S, Marangon S. Transmission parameters of highly pathogenic avian influenza (H7N1) among industrial poultry farms in northern Italy in 1999–2000. Prev Vet Med 2007; 81:318-22. [PMID: 17531332 DOI: 10.1016/j.prevetmed.2007.04.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 03/26/2007] [Accepted: 04/15/2007] [Indexed: 10/23/2022]
Abstract
We estimated between-farm transmission parameters of the highly pathogenic avian-influenza (HPAI) epidemic that struck the poultry industry of northern Italy (including turkeys, layer hens, broilers, gamebirds, and waterfowl) from December 1999 through April 2000. We estimated the average number of susceptible farms that were infected with HPAI virus by each infectious farm during a day (beta) with a generalised linear model (GLM). The HPAI's reproductive ratios (R(h); the average number of new infected farms (IFs) that were caused by an infectious farm) were calculated separately for the regions of Lombardy and Veneto, where 382 out of 413 (92.5%) of IFs were located. In both regions, R(h) decreased to approximately 1 during the second month of the epidemic (showing that its containment had been initiated). Subsequently, during the last two months of the epidemic, beta and R(h) were reduced to 0.04/day and 0.6, respectively, in Veneto and to 0.07/day and 0.8 in Lombardy. The reduction of the susceptible population through strict control measures, including pre-emptive slaughter of at-risk poultry flocks, was implemented to a greatest extent in Veneto and this might have been associated with a more rapid control of the epidemic in this region than in Lombardy.
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Affiliation(s)
- A Mannelli
- Dipartimento di Produzioni Animali, Epidemiologia ed Ecologia, Via Leonardo da Vinci 44, 10095 Grugliasco (To), Italy.
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50
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Mulatti P, Kitron U, Mannelli A, Ferré N, Marangona S. Spatial analysis of the 1999-2000 highly pathogenic avian influenza (H7N1) epidemic in northern Italy. Avian Dis 2007; 51:421-4. [PMID: 17494598 DOI: 10.1637/7549-033106r.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effect of proximity on infected premises was evaluated during the highly pathogenic avian influenza (HPAI) epidemic that struck northern Italy in 1999-2000 by quantifying the spatial and temporal clustering of cases. The epidemic was caused by an H7N1 subtype of type A influenza virus that originated from a low-pathogenic AI virus that spread among poultry farms in northeastern Italy in 1999 and eventually became virulent by mutation. More than 90% of 413 infected premises were located in Lombardy and Veneto regions; of 382 outbreaks, 60% occurred in the Lombardy region and 40% in the Veneto region. Global and local spatial statistics were used to estimate the location and degree of clustering of cases with respect to the population at risk. Outbreaks were spatially clustered primarily in Lombardy, with a large cluster in Brescia province and another in Mantua province, on the border of Veneto. Time series analysis was used to assess the temporal clustering of outbreaks. Temporal aggregation increased during the first 5 wk and decreased thereafter (probably as a result of eradication measures enforced in the Veneto region). Spatio-temporal clustering was assessed considering the Temporal Risk Window (TRW), the time period during which premises remain infectious and infection can spread to neighboring premises. The clustering pattern was similar to the one detected when considering spatial clustering (i.e., the larger clusters were identified in the Brescia and Mantua provinces of Lombardy). These results highlight the role of proximity in the spread of AI virus and, when considering the TRW, indicate the possible direction of virus spread.
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Affiliation(s)
- P Mulatti
- Centro Regionale per l'Epidemiologia Veterinaria, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro PD, Italy
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