Characterization and management of interaction risks between livestock and wild ungulates on outdoor pig farms in Spain

Abstract Background To control the transmission of relevant shared diseases, such as animal tuberculosis (TB) and African swine fever (ASF), it is essential to reduce the risk of interaction between livestock and wild ungulates. In Eastern and Central Europe, the current spread of ASF virus affecting wild boar and domestic pigs (especially those raised outdoors and/or in backyards) has devastated the pig sector in affected regions and is seriously threatening other exporting countries. Here, we evaluated the risk of wildlife-livestock interactions on 45 outdoor pig farms in Spain, the second largest pork producer in the EU and then proposed biosecurity-related actions. An integrated, systematic wildlife risk mitigation protocol based on interviews, questionnaires and field audits was developed and applied on each farm. Results Most of the interaction risk points were associated with water sources (84.2%; 701/832), mainly springs and ponds, which accounted for almost all the specific points with high or very high risk scores. The risk of interaction at feeding points (6.9%; 57/832) and those associated with facilities for livestock and/or game management (8.9%; 74/832) were rated as low and very low risk, respectively. Wild boar were present and hunted on 69% of the farms. Supplementary feeding for wild ungulate species (mainly wild boar) was provided on almost half (48.9%; 22/45) the surveyed farms. Risk mitigation actions were categorised to target water access, waterers, food, other livestock species, grazing, wildlife, and offal disposal. Of the total number of actions (n = 2016), 82.7% were identified as priority actions while 17.3% represented alternative options which were identified less cost-effective. On average, 37.1 (median: 32; range 14–113) action proposals per study farm were made and 2.0 (median: 1; range 0–4) per risk point. The mean estimated cost of implementing the proposed priority actions was 14,780 €/farm (25.7 €/hectare and 799.4 €/risk point). Conclusions This study expands the knowledge of interaction risks between domestic pigs and wild ungulates in outdoor pig farming systems and highlights the importance of considering local risks and management practices when designing and prioritising adapted wildlife risk mitigation and biosecurity actions. This practical and feasible protocol developed for Mediterranean ecosystems is easily transferable to professionals and can be adapted to extensive (outdoor) production or epidemiological systems in other European regions.

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Selected aspects related to epidemiology, pathogenesis, immunity, and control of African swine fever

Journal of Veterinary Research ◽

10.1515/jvetres-2016-0017 ◽

2016 ◽

Vol 60 (2) ◽

pp. 119-125 ◽

Cited By ~ 3

Author(s):

Grzegorz Woźniakowski ◽

Magdalena Frączyk ◽

Krzysztof Niemczuk ◽

Zygmunt Pejsak

Keyword(s):

Wild Boar ◽

Viral Infections ◽

Specific Treatment ◽

African Swine Fever ◽

New Era ◽

Wild Boars ◽

Domestic Pigs ◽

Rate Of Spread ◽

International Transport ◽

Socio Economic Impact

Abstract African swine fever (ASF) is currently one of the most severe viral infections of domestic pigs, wild boars, and other hosts belonging to Suidae family. ASF is also considered as the most complex and devastating infectious and haemorrhagic disease of swine due to its severe socio-economic impact and transboundary character. ASF it is a notifiable disease and due to the lack of specific treatment and vaccine, the disease can be only limited by the administrative measures comprising wild boar hunting and stamping out of affected pigs. ASF occurred for the first time in Kenya in 1921 while in Europe (Portugal) the virus was detected at the end of the 1950s. In spite of successful eradication of this threat in a number of affected regions, the virus remains endemic in both feral and domestic pigs in Africa and Sardinia. The ‘new era’ of ASF started in 2007 after its re-introduction to Georgia. Following its intensive expansion, the virus spread to other Caucasian countries, including the territory of the Russian Federation. In 2014 the virus reached Ukraine, Belarus, and, consequently, European Union countries: Lithuania, Latvia, Estonia, and Poland. The occurrence of ASF in wild boars and pigs had a severe impact on both epidemiology and economy because of the national and international transport and trade consequences. Up to date, starting from the February 2014, eighty ASF cases in wild boar and three outbreaks in domestic pigs have been diagnosed. Taking into account the diverse rate of spread in Poland, this review aims to present and discuss the current state of knowledge on ASF including its epidemiology, pathology, transmission, and perspectives of control.

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African Swine Fever Outbreak Investigation on Large Commercial Pig Farm in Serbia

Acta veterinaria ◽

10.2478/acve-2021-0019 ◽

2021 ◽

Vol 71 (2) ◽

pp. 219-229

Author(s):

Milijana Nešković ◽

Bojan Ristić ◽

Rade Došenović ◽

Siniša Grubač ◽

Tamaš Petrović ◽

...

Keyword(s):

African Swine Fever ◽

Farming Systems ◽

Wild Boars ◽

Key Points ◽

Risk Period ◽

Pig Farms ◽

Pig Farm ◽

Sources Of Infection ◽

In The Beginning ◽

The City

Abstract The first confirmed case of African Swine Fever (ASF) in Serbia occurred in 2019. Since then, numerous outbreaks in domestic pigs and wild boars have been reported. Until April 2021, all the detected ASF cases were in backyard pigs. Beside backyard and smallholders farming systems as a dominant pig production system in Serbia, large commercial pig farms can also be found, located mostly in villages. In the beginning of April 2021, a large commercial farrow-to-finish pig farm in Serbia with almost 19,000 animals was affected with the ASF virus. The pig farm analysed in this paper is located in an area where ASF was confirmed earlier in both backyard and wild boars. In this study, we describe the overall epidemiological course of the ASF outbreak. Epidemiological investigation using a hypothesis-based approach was conducted in order to reconstruct the disease course until the official notification. All the available data from the farm were analysed with the aim to determine the high-risk period (HRP). Some of the key points to consider when it comes to the sources of infection and entry route of ASF are the following: contamination of the area in the immediate vicinity of the farm, risky human activities, irregularities and some omissions in the external farm biosecurity and immediate proximity of the city waste-yard where the communal waste is disposed of. It was concluded that when commercial pig farms are surrounded by villages with a large number of backyards, hence the anthropogenic factor is the key risk factor for ASF spreading.

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Risk Assessment of African Swine Fever Virus Exposure to Sus scrofa in Japan Via Pork Products Brought in Air Passengers’ Luggage

Pathogens ◽

10.3390/pathogens9040302 ◽

2020 ◽

Vol 9 (4) ◽

pp. 302

Author(s):

Satoshi Ito ◽

Jaime Bosch ◽

Cristina Jurado ◽

José Manuel Sánchez-Vizcaíno ◽

Norikazu Isoda

Keyword(s):

Risk Assessment ◽

Wild Boar ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Domestic Pigs ◽

Pork Products ◽

Risk Assessment Models ◽

Annual Probability ◽

Virus Exposure ◽

Stochastic Risk

In recent years, African swine fever (ASF) has become prevalent in many areas, including Asia. The repeated detection of the ASF virus (ASFV) genome in pork products brought in air passenger’s luggage (PPAP) was also reported from Japanese airports. In the present study, the risk of ASFV exposure to susceptible hosts in Japan via three different pathways was assessed. Two quantitative stochastic risk assessment models were built to estimate the annual probability of ASFV exposure to domestic pigs, which could be attributed to foreign job trainees or foreign tourists. A semi-quantitative stochastic model was built to assess the risk of ASFV exposure to wild boar caused by foreign tourists. The overall mean annual probability of ASFV exposure to domestic pigs via PPAP carried by foreign job trainees was 0.169 [95% confidence interval (CI): 0.000–0.600], whereas that by foreign tourists was 0.050 [95% CI: 0.000–0.214], corresponding to approximately one introduction every 5.9 and 20 years, respectively. The risk of ASFV exposure to domestic pigs was dispersed over the country, whereas that of wild boar was generally higher in the western part of Japan, indicating that the characteristics of the potential ASF risk in each prefecture were varied.

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Impaired T‐cell responses in domestic pigs and wild boar upon infection with a highly virulent African swine fever virus strain

Transboundary and Emerging Diseases ◽

10.1111/tbed.13678 ◽

2020 ◽

Vol 67 (6) ◽

pp. 3016-3032 ◽

Cited By ~ 2

Author(s):

Jane Hühr ◽

Alexander Schäfer ◽

Theresa Schwaiger ◽

Laura Zani ◽

Julia Sehl ◽

...

Keyword(s):

T Cell ◽

Wild Boar ◽

Virus Strain ◽

African Swine Fever Virus ◽

African Swine Fever ◽

T Cell Responses ◽

Fever Virus ◽

Domestic Pigs ◽

Cell Responses ◽

Highly Virulent

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Comparative Pathology of Domestic Pigs and Wild Boar Infected with the Moderately Virulent African Swine Fever Virus Strain “Estonia 2014”

Pathogens ◽

10.3390/pathogens9080662 ◽

2020 ◽

Vol 9 (8) ◽

pp. 662

Author(s):

Julia Sehl ◽

Jutta Pikalo ◽

Alexander Schäfer ◽

Kati Franzke ◽

Katrin Pannhorst ◽

...

Keyword(s):

Wild Boar ◽

Viral Antigen ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus ◽

Kinetic Experiment ◽

Domestic Pigs ◽

Hunting Bag ◽

North Eastern ◽

The Baltic

Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led to a higher number of clinically healthy, antibody-positive animals in the hunting bag of North-Eastern Estonia. Experimental characterization showed high virulence in wild boar but moderate virulence in domestic pigs. Putative pathogenic differences between wild boar and domestic pigs are unresolved and comparative pathological studies are limited. We here report on a kinetic experiment in both subspecies. Three animals each were euthanized at 4, 7, and 10 days post infection (dpi). Clinical data confirmed higher virulence in wild boar although macroscopy and viral genome load in blood and tissues were comparable in both subspecies. The percentage of viral antigen positive myeloid cells tested by flow cytometry did not differ significantly in most tissues. Only immunohistochemistry revealed consistently higher viral antigen loads in wild boar tissues in particular 7 dpi, whereas domestic pigs already eliminated the virus. The moderate virulence in domestic pigs could be explained by a more effective viral clearance.

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African Swine Fever Status in Europe

Viruses ◽

10.3390/v11040310 ◽

2019 ◽

Vol 11 (4) ◽

pp. 310 ◽

Cited By ~ 34

Author(s):

Przemyslaw Cwynar ◽

Jane Stojkov ◽

Klaudia Wlazlak

Keyword(s):

Eastern Europe ◽

Wild Boar ◽

Western Europe ◽

African Swine Fever ◽

Disease Spread ◽

Wild Boar Population ◽

Domestic Pig ◽

Domestic Pigs ◽

In The Wild ◽

Virus Spreading

African Swine Fever (ASF) is a highly contagious disease that affects the domestic pig and wild boar population. The aim of this study was to describe the introduction and spread of the ASF virus in Western Europe (1960–1995) and in Eastern Europe (2007–2018), with particular emphasis on the current ASF situation in Poland and its challenges and future perspectives. The first ASF outbreak in Europe was reported in Portugal in 1957, with the virus spreading over most of Western Europe over the next 30 years. In Eastern Europe, the virus was first observed in Georgia in 2007, from where the disease spread quickly to other neighboring countries, reaching Poland in 2014. Since then, there have been 3341 confirmed cases in the wild boar population in Poland. Although there have been no confirmed cases of wild boars coming into contact with domestic pigs, the first notified case concerning domestic pigs was reported in July 2014. Since then, there have been a total of 213 confirmed outbreaks of ASF on Polish pig farms. Given the virulence of the ASF virus and the myriad of transmission routes across Europe, the monitoring of this disease must be a priority for Europe.

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Pathogenesis of African swine fever in domestic pigs and European wild boar

Virus Research ◽

10.1016/j.virusres.2012.10.026 ◽

2013 ◽

Vol 173 (1) ◽

pp. 122-130 ◽

Cited By ~ 119

Author(s):

Sandra Blome ◽

Claudia Gabriel ◽

Martin Beer

Keyword(s):

Wild Boar ◽

African Swine Fever ◽

Domestic Pigs ◽

European Wild Boar

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Towards risk-based surveillance of African Swine Fever in Switzerland

10.1101/2021.05.17.444420 ◽

2021 ◽

Author(s):

Maria Elena Vargas-Amado ◽

Luís Pedro Carmo ◽

John Berezowski ◽

Claude Fischer ◽

Maria João Santos ◽

...

Keyword(s):

High Risk ◽

Wild Boar ◽

Disease Transmission ◽

Forest Cover ◽

Disease Risk ◽

Animal Health ◽

African Swine Fever ◽

Early Disease ◽

Domestic Pig ◽

Domestic Pigs

African Swine Fever (ASF) has emerged as a disease of great concern to swine producers and government disease control agencies because of its severe consequences to animal health and the pig industry. Early detection of an ASF introduction is considered essential for reducing the harm caused by the disease. Risk-based surveillance approaches have been used as enhancements to early disease epidemic detection systems in livestock populations. Such approaches may consider the role wildlife plays in hosting and transmitting a disease. In this study, a novel method is presented to estimate and map the risk of introducing ASF into the domestic pig population through wild boar intermediate hosts. It makes use of data about hunted wild boar, rest areas along motorways connecting ASF affected countries to Switzerland, outdoor piggeries, and forest cover. These data were used to compute relative wild boar abundance as well as to estimate the risk of both disease introduction into the wild boar population and disease transmission to domestic pigs. The way relative wild boar abundance was calculated adds to the current state of the art by considering the effect of beech mast on hunting success and the probability of wild boar occurrence when distributing relative abundance values among individual grid cells. The risk of ASF introduction into the domestic pig population by wild boar was highest near the borders of France, Germany, and Italy. On the north side of the Alps, areas of high risk were located on the unshielded side of the main motorway crossing the Central Plateau, which acts as a barrier for wild boar. The results of this study can be used to focus surveillance efforts for early disease detection on high risk areas. The developed method may also inform policies to control other diseases that are transmitted by direct contact from wild boar to domestic pigs.

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Comparative Pathology of Domestic Pigs and Wild Boar Infected with the Moderately Virulent African Swine Fever Virus Strain “Estonia 2014”

10.20944/preprints202007.0747.v1 ◽

2020 ◽

Author(s):

Julia Sehl ◽

Jutta Pikalo ◽

Alexander Schäfer ◽

Kati Franzke ◽

Katrin Pannhorst ◽

...

Keyword(s):

Wild Boar ◽

Viral Antigen ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus ◽

Kinetic Experiment ◽

Domestic Pigs ◽

Hunting Bag ◽

North Eastern ◽

The Baltic

Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led to a higher number of clinically healthy, antibody-positive animals in the hunting bag of North-Eastern Estonia. Experimental characterization showed high virulence in wild boar but moderate virulence in domestic pigs. Putative pathogenic differences between wild boar and domestic pigs are unresolved and comparative pathological studies are limited. We here report on a kinetic experiment in both subspecies. Three animals each were euthanized at 4, 7 and 10 days post infection (dpi). Clinical data confirmed higher virulence in wild boar although macroscopy and viral genome load in blood and tissues were comparable in both subspecies. The percentage of viral antigen positive myeloid cells tested by flow cytometry did not differ significantly in most tissues. Only immunohistochemistry revealed consistently higher viral antigen loads in wild boar tissues in particular 7 dpi, whereas domestic pigs already eliminated the virus. The moderate virulence in domestic pigs could be explained by a more effective viral clearance.

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