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African swine fever in Europe State of play and future perspectives Franck C.J. Berthe Head of Animal and Plant Health
AFRICAN SWINE FEVER
African swine fever (ASF) is a highly contagious virus infection of domestic pigs, with the potential for very serious and rapid spread, irrespective of national borders ASF is transmitted through blood and ingestion of contaminated feed; but also through direct contacts between infected and uninfected animals and by certain tick species Different ASF virus strains differ in virulence, leading to acute, sub-acute and chronic forms of the disease European Wild boar are equally susceptible to ASF, which makes the control the infection very difficult if it becomes endemic in these populations ASF has serious socio-economic impact on people’s livelihoods, on trade of animals and animal products, and on food security in areas were many pigs are kept for self consumption
OVERVIEW OF EFSA’S ACTIVITY ON ASF
2009 2013 2014 2014
Urgent request for scientific advice on management options in wild boar populations
Request for a Risk assessment Risk for endemicity (RF and TCC) and introduction and endemicity (EU) DP and WB
Update on risk for endemicity (RF and TCC) Risk Assessment for endemicity (BY and UA) DP and WB
Request for epidemiological analysis, carriers, WB and tick population trends, WB management
2010: http://www.efsa.europa.eu/en/efsajournal/pub/1556.htm
2010: http://www.efsa.europa.eu/en/efsajournal/pub/1703
2014: http://www.efsa.europa.eu/en/efsajournal/pub/3628.htm
2014: http://www.efsa.europa.eu/en/efsajournal/pub/3616.htm
2015: http://www.efsa.europa.eu/en/efsajournal/pub/4163
http://www.efsa.europa.eu/en/topics/topic/africanswinefever
MILESTONES IN EFSA’S ADVICE ON ASF
March, EFSA assessed the risk of the disease remaining endemic in the countries neighboring the EU (Caucasian countries and Russia) – qualifying it as “moderate” – and the risk of introduction of the disease into the European Union July, EFSA concluded that ticks are important in maintaining the virus locally, but do not play an active role in its geographical spread March, in an urgent scientific advice following the outbreaks in Poland and Lithuania, EFSA concluded that hunting is not an effective tool to drastically reduce the size of the wild boar population in Europe. Also, artificial feeding of wild boar might increase it April, EFSA said that the risk of African swine fever becoming endemic in Georgia, Armenia and Russia had increased from moderate to high since 2010, when EFSA carried out its last risk assessment. In addition, the risk of the virus spreading further into unaffected areas from these countries through contaminated meat, animals or vehicles remained high EFSA recommended a combination of different management measures to reduce the spread of the disease among wild boar. These included targeted hunting, removal of carcasses in the wild and a strict feeding ban
2010 2014 2015
CONTROL MEASURES IN THE EU
Council Directive 2002/60/EC is the overarching piece of legislation providing the tool for the control of African swine fever in the EU Commission Decision 2003/422/EC provides a diagnostic manual for ASF Commission Implementing Decision 2014/709/EU amended by the Decision 2015/1783 included the specific regionalisation measures that have been taken with respect to evolution of the ASF situation in the EU A working document (SANTE/7112/2015) provides the principles and criteria for geographical and temporal definition of ASF regionalisation Guidelines on surveillance and control of ASF in feral pigs and preventive measures for pig holdings (SANCO/7138/2013) based on EFSA Scientific Opinions The EU goes beyond the OIE requirements and applies stricter standards
TERMS OF REFRENCE OF THE 2015 OPINION
Evaluate epidemiological data on ASF from Lithuania, Poland, Latvia and Estonia in order to obtain indications on the local behaviour of ASF in the wild boar population and its interaction with domestic pigs Assess the possible risk of spread of ASF-Genotype II strains/isolates currently or recently circulating in Europe, by pigs or wild boar becoming “carrier” that might play a role in virus transmission while remaining non- symptomatic Update previous Scientific Opinions on ASF, in particular regarding trends in wild boar population dynamics in the EU and its Eastern neighbouring territories, and distribution of vectors (soft ticks) Assess the best management options for wild boar both in infected areas and in the bordering risk areas, taking into account the local climatic conditions and wild boar ecology
http://www.efsa.europa.eu/sites/default/files/scientific_output/files/main_documents/4163.pdf
MONTHLY NUMBER OF NOTIFICATIONS IN EU MS
4 1 1 1
12
26 27
86 85
4
40 37
31
22
15
23
16
20 21 19
35
55
141
105
2 2 5 5 5
11
18
8 8 5 6
9 6
16 16
2 2 2
7
3 1
4 5 6 3
6 9
11
7
3
7
2 0
20
40
60
80
100
120
140
160
Jan Feb May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
2014 2015
Estonia
Latvia
Lithuania
Poland
TOR 1. ASF-BEHAVIOUR IN WB POPULATION
Evaluate the epidemiological data on ASF from Lithuania, Poland, Latvia and Estonia in order to obtain indications on the local behaviour of ASF in the wild boar population and its interaction with domestic pigs
Assessment was based on:
• Chronological description of the ASF outbreaks
in Lithuania, Poland, Latvia and Estonia
• Spatio-temporal observations
• Wild boar-domestic pig interface
• Short and long distance spread of ASFV
• Clustering of ASF notifications
• Laboratory surveillance (PCR, Ab)
• Expert opinion on factors contributing to further spread of ASFV between sub-populations of a wild boar meta-population
Spread of ASFV to new areas which could not be related to wild boar movement occurred mostly during periods of outbreaks in domestic pig populations
ASF spreads locally in the wild boar population, independent of outbreaks in domestic pigs
The low biosecurity level appeared to be the source of virus introduction in the backyard farms; yet, direct contact between pigs and wild boar was not reported
All primarily ASF outbreaks in pig holdings or cases in wild boar were found by passive surveillance
TOR 1. CONCLUSIONS
There is a high likelihood that contact of susceptible wild boar with infectious material (e.g. blood, carcass or excreta from an infected animal) in the environment will lead to further spread of ASFV
There is a moderate to high likelihood that direct contact between wild boar will lead to further spread of ASFV, especially in places where animals are gathered, such as feeding places
Very intense and frequent drive hunts during depopulation campaigns are important factors leading to the movement of wild boar and possible spread of ASFV
TOR 1. CONCLUSIONS BASED ON EXPERT OPINION
An assessment of the possible risk of spread of ASF-Genotype II strains/isolates currently or recently circulating in Europe, and specially in Russia or the Baltic States, by pigs or wild boar becoming "carrier" that might play a role in virus transmission while remaining non-symptomatic
Assessment was based on:
• Description of experimental infections
with ASFV genotype II strains currently
circulating in Eastern European countries
• Observations on possible shedding of
ASFV by experimentally infected animals
TOR 2. CARRIERS: EVIDENCE - ROLE IN SPREAD?
The Genotype II ASFV strain is highly virulent and induces an acute form of ASF with a high lethality in both wild and domestic pigs. As yet, no scientific data has demonstrated the presence of carrier pigs in the Eastern European Union
Intermittent viraemia following survival from experimental inoculation with Genotype II ASF has been observed in one animal and DNA could be identified in tissues for 61 days post infection
Even if there are no carriers, there are several mechanisms that can lead to long-term circulation of ASFV in pig or wild boar populations
ASF virus presence in tissues has been demonstrated to persist up to 6 months and can be infectious for susceptible animals fed with it
TOR 2. CONCLUSIONS
Where new data is available, provide an update of previous Scientific Opinions on ASF, in particular
i. describe identifiable relevant trends in wild boar population dynamics in the EU and its Eastern neighbouring territories;and
ii. provide an updated distribution of ASF competent vectors (soft ticks) and its possible role on ASF epidemiology specially in Russia or the Baltic States
Assessment was based on:
• Relatively abundance of wild boar in
the Eastern European countries
• Temporal trends in harvested wild boar
• Systematic literature review
TOR 3. TRENDS IN WILD BOAR POPULATION DYNAMICS
There is an increase in the number of harvested wild boar in most European countries, likely to reflect increased numbers of wild boar
There is a decrease in the number of hunters in most European countries
There is no indication that the population growth will slow down in the next few years.
Wild boars have never been found infested by Ornithodoros spp. because wild boar normally do not rest inside burrows, but on the ground surface
In Europe, ticks of the O. erraticus complex have been reported in some countries around the Mediterranean Basin (Portugal, Spain and Italy and Turkey), the Black sea (Moldavia, Romania, Georgia), and in Armenia and Azerbaijan
There is no report indicating the occurrence of Ornithodoros spp. in the 4 affected Member States
TOR 3. CONCLUSIONS
Assessment of the suitability, effectiveness and the practical aspects of implementation of the main wild boar management measures in ASF infected areas and bordering risk areas
Assessment was based on:
• quantitative information on the efficacy
of different wild boar management options
(literature review)
expert consultation organized to obtain
unpublished information
• epidemiological simulation model
TOR 4. MANAGEMENT OPTIONS
As yet, a reduction below 60% of the wild boar population has never been documented in Europe with conventional hunting methods
Frequent and intense drive hunts can lead to adaptive behaviour among hunted wild boar, compensatory growth of the population, influx of wild boar from adjacent areas and extensive movements of wild boar outside of the focal area
To reduce wild boar populations, feeding should be prohibited and hunting rates increased for several consecutive years especially for females, as all age classes of females are highly reproductive
TOR 4. CONCLUSIONS
Currently there is not enough evidence to state the exact quantitative threshold separating baiting and feeding amounts of supplied feed resources
Required baiting quantities may differ greatly between different habitats and hunting practices and the type of feed provided. However, the experts agreed that baiting has to avoid the increased survival and reproduction in the populations
The model demonstrated that measures such as depopulation attempts for more than 70 % of the wild boar populations would be, theoretically, effective to control ASF but practically they are impossible to be achieved in one hunting season
TOR 4. CONCLUSIONS
On the other hand, conventional management strategies, such as implementing a feeding-ban or targeted hunting of females, can effectively prevent the spread of ASF in the control area only after multiple years of application
The model predicted that the combination of different tools, such as the exclusion of contact to carcasses and the intensification of conventional hunting, reducing reproduction in the following year by 30-40%, were effective to stop the spread of ASF in wild boar
TOR 4. CONCLUSIONS
ONGOING ACTIVITY WITH MEMBER STATES
http://www.efsa.europa.eu/en/events/event/151123
Joint initiative between the 3 Baltic states and Poland to better understand the epidemiology of the disease in wild boars September 2015: preparatory meeting to define the needs of the EU member states affected by ASF 23-25 November 2015: technical workshop to be held in Parma, to standardise the collection of epidemiological data on the disease
African swine fever has rapidly spread since the 2007 outbreaks in trans-Caucasian countries and the Russian Federation, irrespective of national borders
There has been a shift over time towards more focus on the role of wild boars in the dynamic of African Swine Fever
However, spread to new areas which could not be related to wild boar movement occurred mostly during periods of ASF detection in domestic pigs or related to human activity
TAKE HOME MESSAGE
2009. Anette Bøtner, Agustin Estrada Peña, Alessandro Mannelli, Barbara Wieland, Carsten Potzsch, Cristiana Patta, Emanuel Albina, Ferdinando Boinas, James Michael Sharp, Linda Dixon, Mo Salman, Sánchez Vizcaíno, Sandra Blome, Vittorio Guberti, Milen Georgiev, Jordi Tarres, Tilemachos Goumperis
2013. Sergei Khomenko, Liisa Sihvonen, Hans-Herman Thulke, José Manuel Vizcaino, Andrey Gogin, Maria Luisa Arias, Daniel Beltran-Alcrudo, Sandra Blome, Klaus Depner, Vittorio Guberti, Claire Guinat, Anton Karaulov, Anette Bøtner, Jonna Kyyrö, Tigran Markosyan, Iwona Markowska-Daniel, Dmitry Morozov, Külli Must, Carsten Potzsch, Dietrich Rassow, Mikheil Sokhadze
2014. Andrea Bau, Alessandro Broglia, Andrea Gervelmeyer, Andrey Gogin, Jane Richardson, Frank Verdonck, Didier Verloo
2014. Carola Sauter-Louis, Sergei Khomenko, Andrey Gogin, Alessandro Broglia, Anna de la Torre, Hans-Herman Thulke, Vittorio Guberti, Jose Manual Vizcaino, Sandra Blome, Claire Guinat, Maria Luisa Arias, Mary Louise Penrith, Iwona Markowska-Daniel, Tomasz Podgórski, Janis Ozolins, Giovanni Massei, András Náhlik
2015. Luisa Arias Maria, Sandra Blome, Ana De La Torre, Vittorio Guberti, Claire Guinat, Sergei Khomenko, Frank Koenen, Iwona Markowska-Daniel, Giovanna Massei, Andras Nahlik, Mary Louise Penrith, Tomasz Podgorski, Carola Sauter-Louis, Hans-Hermann Thulke and Jose Manuel Vizcaino
Special thank to Sofie Dhollander and Andrey Gogin
ACKNOWLEDGEMENTS