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Schambow RA, Hussain S, Antognoli MC, Kreindel S, Reyes R, Perez AM. Epidemiological Assessment of African Swine Fever Spread in the Dominican Republic. Pathogens 2023; 12:1414. [PMID: 38133297 PMCID: PMC10746036 DOI: 10.3390/pathogens12121414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 11/16/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023] Open
Abstract
Since African Swine Fever (ASF) was detected in the Dominican Republic in July 2021, it has negatively impacted the country's swine industry. Assessing the epidemiological situation is crucial to helping local authorities and industry stakeholders control the disease. Here, data on 155 reported outbreaks in the Dominican Republic from November 2022 to June 2023 were evaluated. Descriptive spatiotemporal analysis was performed to characterize disease distribution and spread, and between-herd R0 was calculated for the study period. The Knox test and a space-time permutation model were used to evaluate clustering. Data on clinical presentation, biosecurity measures, and suspected reasons for introduction were categorized and summarized. The majority (78%) of outbreaks occurred on backyard farms which generally had low biosecurity. Across farm types, the majority of pigs were still alive at the time of depopulation. Spatiotemporal findings and R0 estimates suggest an endemic pattern of disease geographically located centrally within the country. Clustering was detected even at small temporal and spatial distances due to outbreaks amongst neighboring backyard farms. These results provide critical information on the current state of the ASF epidemic in the Dominican Republic and will aid government officials and swine industry leaders in developing effective ASF control strategies.
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Affiliation(s)
- Rachel A. Schambow
- Center for Animal Health and Food Safety, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (S.H.); (A.M.P.)
| | - Syed Hussain
- Center for Animal Health and Food Safety, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (S.H.); (A.M.P.)
| | - Maria C. Antognoli
- International Services Action Programs, Animal Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO 80526, USA; (M.C.A.); (S.K.)
| | - Silvia Kreindel
- International Services Action Programs, Animal Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, CO 80526, USA; (M.C.A.); (S.K.)
| | - Raysa Reyes
- Instituto del Estudio de las Enfermedades Zoonóticas, Universidad Autónoma de Santo Domingo, Santo Domingo 10904, Dominican Republic;
| | - Andres M. Perez
- Center for Animal Health and Food Safety, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (S.H.); (A.M.P.)
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2
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Ito S, Bosch J, Jeong H, Aguilar-Vega C, Park J, Martínez-Avilés M, Sánchez-Vizcaíno JM. Spatio-Temporal Epidemiology of the Spread of African Swine Fever in Wild Boar and the Role of Environmental Factors in South Korea. Viruses 2022; 14:v14122779. [PMID: 36560783 PMCID: PMC9782897 DOI: 10.3390/v14122779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/22/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
Since the first confirmation of African swine fever (ASF) in domestic pig farms in South Korea in September 2019, ASF continues to expand and most notifications have been reported in wild boar populations. In this study, we first performed a spatio-temporal cluster analysis to understand ASF spread in wild boar. Secondly, generalized linear logistic regression (GLLR) model analysis was performed to identify environmental factors contributing to cluster formation. In the meantime, the basic reproduction number (R0) for each cluster was estimated to understand the growth of the epidemic. The cluster analysis resulted in the detection of 17 spatio-temporal clusters. The GLLR model analysis identified factors influencing cluster formation and indicated the possibility of estimating ASF epidemic areas based on environmental conditions. In a scenario only considering direct transmission among wild boar, R0 ranged from 1.01 to 1.5 with an average of 1.10, while, in another scenario including indirect transmission via an infected carcass, R0 ranged from 1.03 to 4.38 with an average of 1.56. We identified factors influencing ASF expansion based on spatio-temporal clusters. The results obtained would be useful for selecting priority areas for ASF control and would greatly assist in identifying efficient vaccination areas in the future.
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Affiliation(s)
- Satoshi Ito
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
- Correspondence:
| | - Jaime Bosch
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
| | - Hyunkyu Jeong
- Dodram Pig Research Center, Daejeon 35377, Republic of Korea
| | - Cecilia Aguilar-Vega
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
| | - Jonghoon Park
- Independent Scholar, Daejeon 35377, Republic of Korea
| | | | - Jose Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
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3
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Guinat C, Valenzuela Agüí C, Vaughan TG, Scire J, Pohlmann A, Staubach C, King J, Świętoń E, Dán Á, Černíková L, Ducatez MF, Stadler T. Disentangling the role of poultry farms and wild birds in the spread of highly pathogenic avian influenza virus in Europe. Virus Evol 2022; 8:veac073. [PMID: 36533150 PMCID: PMC9752641 DOI: 10.1093/ve/veac073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/21/2022] [Accepted: 08/18/2022] [Indexed: 08/12/2023] Open
Abstract
In winter 2016-7, Europe was severely hit by an unprecedented epidemic of highly pathogenic avian influenza viruses (HPAIVs), causing a significant impact on animal health, wildlife conservation, and livestock economic sustainability. By applying phylodynamic tools to virus sequences collected during the epidemic, we investigated when the first infections occurred, how many infections were unreported, which factors influenced virus spread, and how many spillover events occurred. HPAIV was likely introduced into poultry farms during the autumn, in line with the timing of wild birds' migration. In Germany, Hungary, and Poland, the epidemic was dominated by farm-to-farm transmission, showing that understanding of how farms are connected would greatly help control efforts. In the Czech Republic, the epidemic was dominated by wild bird-to-farm transmission, implying that more sustainable prevention strategies should be developed to reduce HPAIV exposure from wild birds. Inferred transmission parameters will be useful to parameterize predictive models of HPAIV spread. None of the predictors related to live poultry trade, poultry census, and geographic proximity were identified as supportive predictors of HPAIV spread between farms across borders. These results are crucial to better understand HPAIV transmission dynamics at the domestic-wildlife interface with the view to reduce the impact of future epidemics.
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Affiliation(s)
- Claire Guinat
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse, Basel 4058, Switzerland
- Swiss Institute of Bioinformatics, Quartier Sorge, Lausanne 1015, Switzerland
| | - Cecilia Valenzuela Agüí
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse, Basel 4058, Switzerland
- Swiss Institute of Bioinformatics, Quartier Sorge, Lausanne 1015, Switzerland
| | - Timothy G Vaughan
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse, Basel 4058, Switzerland
- Swiss Institute of Bioinformatics, Quartier Sorge, Lausanne 1015, Switzerland
| | - Jérémie Scire
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse, Basel 4058, Switzerland
- Swiss Institute of Bioinformatics, Quartier Sorge, Lausanne 1015, Switzerland
| | - Anne Pohlmann
- Friedrich-Loeffler-Institut, Suedufer 10, Greifswald – Insel Riems 17489, Germany
| | - Christoph Staubach
- Friedrich-Loeffler-Institut, Suedufer 10, Greifswald – Insel Riems 17489, Germany
| | - Jacqueline King
- Friedrich-Loeffler-Institut, Suedufer 10, Greifswald – Insel Riems 17489, Germany
| | - Edyta Świętoń
- Department of Poultry Diseases, National Veterinary Research Institute, Al. Partyzantow 57, Pulawy 24-100, Poland
| | - Ádám Dán
- DaNAm Vet Molbiol, Herman Ottó utca 5, Kőszeg 9730, Hungary
| | - Lenka Černíková
- State Veterinary Institute Prague, Sidlistni 136/24, Prague 165 03, Czech Republic
| | - Mariette F Ducatez
- IHAP, Université de Toulouse, INRAE, ENVT, 23 chemin des capelles, Toulouse 31076, France
| | - Tanja Stadler
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse, Basel 4058, Switzerland
- Swiss Institute of Bioinformatics, Quartier Sorge, Lausanne 1015, Switzerland
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Lim JS, Kim E, Ryu PD, Pak SI. Basic reproduction number of African swine fever in wild boars ( Sus scrofa) and its spatiotemporal heterogeneity in South Korea. J Vet Sci 2021; 22:e71. [PMID: 34553516 PMCID: PMC8460458 DOI: 10.4142/jvs.2021.22.e71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 11/21/2022] Open
Abstract
Background African swine fever (ASF) is a hemorrhagic fever occurring in wild boars (Sus scrofa) and domestic pigs. The epidemic situation of ASF in South Korean wild boars has increased the risk of ASF in domestic pig farms. Although basic reproduction number (R0) can be applied for control policies, it is challenging to estimate the R0 for ASF in wild boars due to surveillance bias, lack of wild boar population data, and the effect of ASF-positive wild boar carcass on disease dynamics. Objectives This study was undertaken to estimate the R0 of ASF in wild boars in South Korea, and subsequently analyze the spatiotemporal heterogeneity. Methods We detected the local transmission clusters using the spatiotemporal clustering algorithm, which was modified to incorporate the effect of ASF-positive wild boar carcass. With the assumption of exponential growth, R0 was estimated for each cluster. The temporal change of the estimates and its association with the habitat suitability of wild boar were analyzed. Results Totally, 22 local transmission clusters were detected, showing seasonal patterns occurring in winter and spring. Mean value of R0 of each cluster was 1.54. The estimates showed a temporal increasing trend and positive association with habitat suitability of wild boar. Conclusions The disease dynamics among wild boars seems to have worsened over time. Thus, in areas with a high elevation and suitable for wild boars, practical methods need to be contrived to ratify the control policies for wild boars.
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Affiliation(s)
- Jun-Sik Lim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Eutteum Kim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Pan-Dong Ryu
- College of Veterinary Medicine, Seoul National University, Seoul 08732, Korea
| | - Son-Il Pak
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea.
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Sichone J, Simuunza MC, Hang’ombe BM, Kikonko M. Estimating the basic reproduction number for the 2015 bubonic plague outbreak in Nyimba district of Eastern Zambia. PLoS Negl Trop Dis 2020; 14:e0008811. [PMID: 33166354 PMCID: PMC7652268 DOI: 10.1371/journal.pntd.0008811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 09/22/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Plague is a re-emerging flea-borne infectious disease of global importance and in recent years, Zambia has periodically experienced increased incidence of outbreaks of this disease. However, there are currently no studies in the country that provide a quantitative assessment of the ability of the disease to spread during these outbreaks. This limits our understanding of the epidemiology of the disease especially for planning and implementing quantifiable and cost-effective control measures. To fill this gap, the basic reproduction number, R0, for bubonic plague was estimated in this study, using data from the 2015 Nyimba district outbreak, in the Eastern province of Zambia. R0 is the average number of secondary infections arising from a single infectious individual during their infectious period in an entirely susceptible population. METHODOLOGY/PRINCIPAL FINDINGS Secondary epidemic data for the most recent 2015 Nyimba district bubonic plague outbreak in Zambia was analyzed. R0 was estimated as a function of the average epidemic doubling time based on the initial exponential growth rate of the outbreak and the average infectious period for bubonic plague. R0 was estimated to range between 1.5599 [95% CI: 1.382-1.7378] and 1.9332 [95% CI: 1.6366-2.2297], with average of 1.7465 [95% CI: 1.5093-1.9838]. Further, an SIR deterministic mathematical model was derived for this infection and this estimated R0 to be between 1.4 to 1.5, which was within the range estimated above. CONCLUSIONS/SIGNIFICANCE This estimated R0 for bubonic plague is an indication that each bubonic plague case can typically give rise to almost two new cases during these outbreaks. This R0 estimate can now be used to quantitatively analyze and plan measurable interventions against future plague outbreaks in Zambia.
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Affiliation(s)
- Joseph Sichone
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
- School of Health Sciences, University of Zambia, Lusaka, Zambia
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals, University of Zambia, Lusaka, Zambia
| | - Martin C. Simuunza
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals, University of Zambia, Lusaka, Zambia
| | - Bernard M. Hang’ombe
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals, University of Zambia, Lusaka, Zambia
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Mervis Kikonko
- Department of Mathematics and Statistics, School of Natural Sciences, University of Zambia, Lusaka, Zambia
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Marcon A, Linden A, Satran P, Gervasi V, Licoppe A, Guberti V. R 0 Estimation for the African Swine Fever Epidemics in Wild Boar of Czech Republic and Belgium. Vet Sci 2019; 7:E2. [PMID: 31892104 PMCID: PMC7157672 DOI: 10.3390/vetsci7010002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/21/2019] [Accepted: 12/22/2019] [Indexed: 12/23/2022] Open
Abstract
African swine fever (ASF) is a contagious haemorrhagic fever that affects both domesticated and wild pigs. Since ASF reached Europe wild boar populations have been a reservoir for the virus. Collecting reliable data on infected individuals in wild populations is challenging, and this makes it difficult to deploy an effective eradication strategy. However, for diseases with high lethality rate, infected carcasses can be used as a proxy for the number of infected individuals at a certain time. Then R0 parameter can be used to estimate the time distribution of the number of newly infected individuals for the outbreak. We estimated R0 for two ASF outbreaks in wild boar, in Czech Republic and Belgium, using the exponential growth method. This allowed us to estimate both R0 and the doubling time (Td) for those infections. The results are R0 = 1.95, Td = 4.39 for Czech Republic and R0 = 1.65, Td = 6.43 for Belgium. We suggest that, if estimated as early as possible, R0 and Td can provide an expected course for the infection against which to compare the actual data collected in the field. This would help to assess if passive surveillance is properly implemented and hence to verify the efficacy of the applied control measures.
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Affiliation(s)
- Andrea Marcon
- ISPRA Istituto Superiore per la Ricerca e la Protezione Ambientale, 40064 Ozzano E. (BO), Italy; (V.G.); (V.G.)
| | - Annick Linden
- FARAH Research Center, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium;
| | - Petr Satran
- State Veterinary Administration of the Czech Republic, 100/7 Slezská, Prague, Czech Republic;
| | - Vincenzo Gervasi
- ISPRA Istituto Superiore per la Ricerca e la Protezione Ambientale, 40064 Ozzano E. (BO), Italy; (V.G.); (V.G.)
| | - Alain Licoppe
- Department of Environmental and Agricultural Studies, Public Service of Wallonia, 5030 Gembloux, Belgium;
| | - Vittorio Guberti
- ISPRA Istituto Superiore per la Ricerca e la Protezione Ambientale, 40064 Ozzano E. (BO), Italy; (V.G.); (V.G.)
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7
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Hill SC, Hansen R, Watson S, Coward V, Russell C, Cooper J, Essen S, Everest H, Parag KV, Fiddaman S, Reid S, Lewis N, Brookes SM, Smith AL, Sheldon B, Perrins CM, Brown IH, Pybus OG. Comparative micro-epidemiology of pathogenic avian influenza virus outbreaks in a wild bird population. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180259. [PMID: 31056057 PMCID: PMC6553603 DOI: 10.1098/rstb.2018.0259] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2019] [Indexed: 12/13/2022] Open
Abstract
Understanding the epidemiological dynamics of highly pathogenic avian influenza virus (HPAIV) in wild birds is crucial for guiding effective surveillance and control measures. The spread of H5 HPAIV has been well characterized over large geographical and temporal scales. However, information about the detailed dynamics and demographics of individual outbreaks in wild birds is rare and important epidemiological parameters remain unknown. We present data from a wild population of long-lived birds (mute swans; Cygnus olor) that has experienced three outbreaks of related H5 HPAIVs in the past decade, specifically, H5N1 (2007), H5N8 (2016) and H5N6 (2017). Detailed demographic data were available and intense sampling was conducted before and after the outbreaks; hence the population is unusually suitable for exploring the natural epidemiology, evolution and ecology of HPAIV in wild birds. We show that key epidemiological features remain remarkably consistent across multiple outbreaks, including the timing of virus incursion and outbreak duration, and the presence of a strong age-structure in morbidity that likely arises from an equivalent age-structure in immunological responses. The predictability of these features across a series of outbreaks in a complex natural population is striking and contributes to our understanding of HPAIV in wild birds. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'. This issue is linked with the subsequent theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'.
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Affiliation(s)
- Sarah C. Hill
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Rowena Hansen
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Samantha Watson
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Vivien Coward
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Christine Russell
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Jayne Cooper
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Steve Essen
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Holly Everest
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Kris V. Parag
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Steven Fiddaman
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Scott Reid
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Nicola Lewis
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
- The Royal Veterinary College, Royal College Street, London, UK
| | - Sharon M. Brookes
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Adrian L. Smith
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Ben Sheldon
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Christopher M. Perrins
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Ian H. Brown
- Department of Virology, Animal and Plant Health Agency – Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Oliver G. Pybus
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
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8
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Abdrakhmanov SK, Tyulegenov SB, Korennoy FI, Sultanov AA, Sytnik II, Beisembaev KK, Bainiyazov AA, Munsey AE, Perez AM, VanderWaal K. Spatiotemporal analysis of foot-and-mouth disease outbreaks in the Republic of Kazakhstan, 1955 - 2013. Transbound Emerg Dis 2018. [PMID: 29542873 DOI: 10.1111/tbed.12864] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Foot-and-mouth disease (FMD) poses a significant obstacle to international trade and economic development, and for that reason, FMD prevention, control and eradication are major goals guiding animal health policy in most countries. The purpose of this study was to conduct a retrospective spatiotemporal analysis of FMD outbreaks among livestock in the Republic of Kazakhstan (RK) from 1955 to 2013. During that time, several FMD control strategies were implemented in RK, which culminated with the World Organization for Animal Health (OIE) recognition of RK as a country that is FMD-free with partial vaccination (2015). Here, we describe and analyse the changes in spatial and temporal dynamics of FMD under different control strategies that were utilized as the country progressively moved towards eradication of the disease. A total number of 5,260 FMD outbreaks of serotype O and A (including the A22 lineage) were recorded in the cattle, pig and small ruminant populations of RK during that period. We found that outbreaks occurred in spatiotemporal clusters only prior to 1970, which is before ring vaccination around outbreaks was first employed. This finding suggests that ring vaccination substantially reduced local spread and prevented large FMD epidemics in the country. Disease incidence steadily decreased after the implementation of ring vaccination and culling of infected animals, with spatiotemporal clusters only occurring as a result of an introduction of an antigenically distinct variant of serotype A. From 1955 to 1984, FMD outbreaks demonstrated two seasonal peaks of incidence in the spring and fall. In contrast, only the peak in spring was observed between 1984 and 2013. Quantitative knowledge on how different policy and alternative control strategies contributed to RK achieving FMD-free status could improve prospects for continued control in RK and inform control strategies in other FMD-endemic regions.
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Affiliation(s)
- S K Abdrakhmanov
- S. Seifullin Kazakh Agrotechnical University, Astana, Kazakhstan
| | - S B Tyulegenov
- Republican state enterprise "National veterinary reference center", Committee for Veterinary control and supervision of the Ministry of agriculture of the Republic of Kazakhstan, Astana, Kazakhstan
| | - F I Korennoy
- Federal Centre for Animal Health (FGBI "ARRIAH"), Vladimir, Russia
| | - A A Sultanov
- Kazakh Research Veterinary Institute, Almaty, Kazakhstan
| | - I I Sytnik
- Republican state enterprise "National veterinary reference center", Committee for Veterinary control and supervision of the Ministry of agriculture of the Republic of Kazakhstan, Astana, Kazakhstan
| | - K K Beisembaev
- S. Seifullin Kazakh Agrotechnical University, Astana, Kazakhstan
| | - A A Bainiyazov
- S. Seifullin Kazakh Agrotechnical University, Astana, Kazakhstan
| | - A E Munsey
- Department of Veterinary Population Medicine, University of Minnesota Twin Cities, St. Paul, MN, USA
| | - A M Perez
- Department of Veterinary Population Medicine, University of Minnesota Twin Cities, St. Paul, MN, USA
| | - K VanderWaal
- Department of Veterinary Population Medicine, University of Minnesota Twin Cities, St. Paul, MN, USA
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9
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Grear DA, Hall JS, Dusek RJ, Ip HS. Inferring epidemiologic dynamics from viral evolution: 2014-2015 Eurasian/North American highly pathogenic avian influenza viruses exceed transmission threshold, R0 = 1, in wild birds and poultry in North America. Evol Appl 2017; 11:547-557. [PMID: 29636805 PMCID: PMC5891053 DOI: 10.1111/eva.12576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/02/2017] [Indexed: 12/18/2022] Open
Abstract
Highly pathogenic avian influenza virus (HPAIV) is a multihost pathogen with lineages that pose health risks for domestic birds, wild birds, and humans. One mechanism of intercontinental HPAIV spread is through wild bird reservoirs, and wild birds were the likely sources of a Eurasian (EA) lineage HPAIV into North America in 2014. The introduction resulted in several reassortment events with North American (NA) lineage low‐pathogenic avian influenza viruses and the reassortant EA/NA H5N2 went on to cause one of the largest HPAIV poultry outbreaks in North America. We evaluated three hypotheses about novel HPAIV introduced into wild and domestic bird hosts: (i) transmission of novel HPAIVs in wild birds was restricted by mechanisms associated with highly pathogenic phenotypes; (ii) the HPAIV poultry outbreak was not self‐sustaining and required viral input from wild birds; and (iii) reassortment of the EA H5N8 generated reassortant EA/NA AIVs with a fitness advantage over fully Eurasian lineages in North American wild birds. We used a time‐rooted phylodynamic model that explicitly incorporated viral population dynamics with evolutionary dynamics to estimate the basic reproductive number (R0) and viral migration among host types in domestic and wild birds, as well as between the EA H5N8 and EA/NA H5N2 in wild birds. We did not find evidence to support hypothesis (i) or (ii) as our estimates of the transmission parameters suggested that the HPAIV outbreak met or exceeded the threshold for persistence in wild birds (R0 > 1) and poultry (R0 ≈ 1) with minimal estimated transmission among host types. There was also no evidence to support hypothesis (iii) because R0 values were similar among EA H5N8 and EA/NA H5N2 in wild birds. Our results suggest that this novel HPAIV and reassortments did not encounter any transmission barriers sufficient to prevent persistence when introduced to wild or domestic birds.
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Affiliation(s)
- Daniel A Grear
- United States Geological Survey National Wildlife Health Center Madison WI USA
| | - Jeffrey S Hall
- United States Geological Survey National Wildlife Health Center Madison WI USA
| | - Robert J Dusek
- United States Geological Survey National Wildlife Health Center Madison WI USA
| | - Hon S Ip
- United States Geological Survey National Wildlife Health Center Madison WI USA
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Sanz I, Rojo S, Tamames S, Eiros JM, Ortiz de Lejarazu R. Heterologous Humoral Response against H5N1, H7N3, and H9N2 Avian Influenza Viruses after Seasonal Vaccination in a European Elderly Population. Vaccines (Basel) 2017; 5:E17. [PMID: 28714923 PMCID: PMC5620548 DOI: 10.3390/vaccines5030017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/17/2022] Open
Abstract
Avian influenza viruses are currently one of the main threats to human health in the world. Although there are some screening reports of antibodies against these viruses in humans from Western countries, most of these types of studies are conducted in poultry and market workers of Asian populations. The presence of antibodies against avian influenza viruses was evaluated in an elderly European population. An experimental study was conducted, including pre- and post-vaccine serum samples obtained from 174 elderly people vaccinated with seasonal influenza vaccines of 2006-2007, 2008-2009, 2009-2010, and 2010-2011 Northern Hemisphere vaccine campaigns. The presence of antibodies against A/H5N1, A/H7N3, and A/H9N2 avian influenza viruses were tested by using haemaglutination inhibition assays. Globally, heterotypic antibodies were found before vaccination in 2.9% of individuals against A/H5N1, 1.2% against A/H7N3, and 25.9% against A/H9N2. These pre-vaccination antibodies were present at titers ≥1/40 in 1.1% of individuals against A/H5N1, in 1.1% against H7N3, and in 0.6% against the A/H9N2 subtype. One 76 year-old male showed pre-vaccine antibodies (Abs) against those three avian influenza viruses, and another three individuals presented Abs against two different viruses. Seasonal influenza vaccination induced a significant number of heterotypic seroconversions against A/H5N1 (14.4%) and A/H9N2 (10.9%) viruses, but only one seroconversion was observed against the A/H7N3 subtype. After vaccination, four individuals showed Abs titers ≥1/40 against those three avian viruses, and 55 individuals against both A/H5N1 and A/H9N2. Seasonal vaccination is able to induce some weak heterotypic responses to viruses of avian origin in elderly individuals with no previous exposure to them. However, this response did not accomplish the European Medicament Agency criteria for influenza vaccine efficacy. The results of this study show that seasonal vaccines induce a broad response of heterotypic antibodies against avian influenza viruses, albeit at a low level.
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Affiliation(s)
- Ivan Sanz
- Valladolid National Influenza Centre, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
- Microbiology Service, Hospital Clínico Universitario de Valladolid, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
| | - Silvia Rojo
- Valladolid National Influenza Centre, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
- Microbiology Service, Hospital Clínico Universitario de Valladolid, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
| | - Sonia Tamames
- Consejería de Sanidad, Junta de Castilla y León, Paseo de Zorrilla 1, 47007 Valladolid, Spain.
| | - José María Eiros
- Valladolid National Influenza Centre, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
- Microbiology Service, Hospital Universitario Río Hortega, Calle Dulzaina 2, 47012 Valladolid, Spain.
| | - Raúl Ortiz de Lejarazu
- Valladolid National Influenza Centre, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
- Microbiology Service, Hospital Clínico Universitario de Valladolid, Avenida Ramón y Cajal s/n, 47005 Valladolid, Spain.
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11
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Korennoy FI, Gulenkin VM, Gogin AE, Vergne T, Karaulov AK. Estimating the Basic Reproductive Number for African Swine Fever Using the Ukrainian Historical Epidemic of 1977. Transbound Emerg Dis 2016; 64:1858-1866. [PMID: 27667658 DOI: 10.1111/tbed.12583] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 11/30/2022]
Abstract
In 1977, Ukraine experienced a local epidemic of African swine fever (ASF) in the Odessa region. A total of 20 settlements were affected during the course of the epidemic, including both large farms and backyard households. Thanks to timely interventions, the virus circulation was successfully eradicated within 6 months, leading to no additional outbreaks. Detailed report of the outbreak's investigation has been publically available from 2014. The report contains some quantitative data that allow studying the ASF-spread dynamics in the course of the epidemic. In our study, we used this historical epidemic to estimate the basic reproductive number of the ASF virus both within and between farms. The basic reproductive number (R0 ) represents the average number of secondary infections caused by one infectious unit during its infectious period in a susceptible population. Calculations were made under assumption of an exponential initial growth by fitting the approximating curve to the initial segments of the epidemic curves. The R0 both within farm and between farms was estimated at 7.46 (95% confidence interval: 5.68-9.21) and 1.65 (1.42-1.88), respectively. Corresponding daily transmission rates were estimated at 1.07 (0.81-1.32) and 0.09 (0.07-0.10). These estimations based on historical data are consistent with those using data generated by the recent epidemic currently affecting eastern Europe. Such results contribute to the published knowledge on the ASF transmission dynamics under natural conditions and could be used to model and predict the spread of ASF in affected and non-affected regions and to evaluate the effectiveness of different control measures.
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Affiliation(s)
- F I Korennoy
- Federal Center for Animal Health (FGBI ARRIAH), Vladimir, Russia
| | - V M Gulenkin
- Federal Center for Animal Health (FGBI ARRIAH), Vladimir, Russia
| | - A E Gogin
- National Research Institute for Veterinary Virology and Microbiology of Russia (SSINRRIVV&M), Pokrov, Russia
| | - T Vergne
- Royal Veterinary College, University of London, London, UK
| | - A K Karaulov
- Federal Center for Animal Health (FGBI ARRIAH), Vladimir, Russia
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Iglesias I, Muñoz MJ, Montes F, Perez A, Gogin A, Kolbasov D, de la Torre A. Reproductive Ratio for the Local Spread of African Swine Fever in Wild Boars in the Russian Federation. Transbound Emerg Dis 2015; 63:e237-e245. [PMID: 25704269 DOI: 10.1111/tbed.12337] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Indexed: 12/01/2022]
Abstract
African swine fever (ASF) has caused the swine industry of the Russian Federation substantial economic losses over the last 7 years, and the disease spread from there to a number of neighbouring countries. Wild boar has been involved in the spread of the disease both at local and at transboundary levels. Understanding ASF dynamics in wild boars is prerequisite to preventing the spread and to designing and applying effective surveillance and control plans. The reproductive ratio (R0 ) is an epidemiological indicator commonly used to quantify the extent of disease spread. Here, it was estimated in nine spatio-temporal clusters of ASF in wild boar cases in the Russian Federation (2007-2013). Clusters were defined by exploring the maximum distance of association of ASF cases using K Ripley analysis and spatio-temporal scan statistics. A maximum spatial association of 133 km in wild boar cases was identified which is within de the conventional radius of surveillance zone (100-150 km). The mean range value of R0 = 1.58 (1.13-3.77) was lower compared to values previously estimated for ASF transmission within farms but similar to early estimates between farm (R0 = 2-3), in domestic pigs using notification data in the Russian Federation. Results obtained provide quantitative knowledge on the epidemiology of ASF in wild boars in the Russian Federation. They identify the ASF transmission rate value in affected natural wild populations, for the first time, which could provide basis for modelling ASF transmission and suggest that current surveillance radius should be reviewed to make surveillance in wild nature more targeted and effective.
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Affiliation(s)
- I Iglesias
- Epidemiology & Environmental Health Department, Animal Health Research Center (INIA-CISA), Madrid, Spain.
| | - M J Muñoz
- Epidemiology & Environmental Health Department, Animal Health Research Center (INIA-CISA), Madrid, Spain
| | | | - A Perez
- College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, USA
| | - A Gogin
- State Research Institution National Research Institute for Veterinary Virology and Microbiology of Russia, Pokrov, Russia
| | - D Kolbasov
- State Research Institution National Research Institute for Veterinary Virology and Microbiology of Russia, Pokrov, Russia
| | - A de la Torre
- Epidemiology & Environmental Health Department, Animal Health Research Center (INIA-CISA), Madrid, Spain
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Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks. Vet Microbiol 2014; 168:78-87. [PMID: 24287046 DOI: 10.1016/j.vetmic.2013.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/21/2013] [Accepted: 10/24/2013] [Indexed: 11/23/2022]
Abstract
EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m(2): 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2-7 EID50. Depending on the strain, the basic reproduction number (R0) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R0 estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R0. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV.
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