Mission of the Community Veterinary Emergency Team to LITHUANIA SCOPE of the mission: African Swine Fever in wild boar in Lithuania at the border with Belarus (27 31 January 2014)
Terms of Reference To provide scientific, technical, managerial and practical on-the-spot assistance on the development of the most suitable control and eradication measures for African swine fever (ASF) under local conditions To support the Lithuanian authorities to elaborate a plan on the surveillance and possible eradication of ASF
Lithuania: places visited - Vilnius: Central Veterinary Office - Alytus and Varena Region Belarus
Epidemiological background On 24.1.2014 two wild boar tested positive for ASFV (one was hunted, the other was found dead) Both animals were hunted/found dead on 20.1.2014 The wild boar found dead was located about 40 km north from the border to Belarus, the other hunted about 5 km from the border. The distance between the two animals is about 36 km.
Infected Area (art 15 CD 2002/60) districts of: Trakai, Lazdijai, Varėna, Alytus, Druskininkai, Šalčininkai. Belarus
The Virus: The Lithuanian ASFV 100% sequence homology with the ASFV detected in Belarus in 2013 (Grodno region) Belarus Lithuania Grodno ASF outbreak
From the epidemiological background and the lab testing results it can be concluded that: most probably the infection of the wild boar found dead took place around 12 January while the other around 15 January due to the large distance (>30 km) between the two infected animals and the fact that the infection took place more or less at the same time, it is very unlikely that the animals infected each other by direct contact; however, it cannot be excluded that undetected ASF cases in wild boar occurred already in the period November 2013 January 2014.
Potential sources of infection Three working hypothesis: movement of infected wild boar from other infected areas (Belarus) Infection of wild boar by uptake of infected material available in the area (e.g. infected kitchen waste disposed in the forest or near the villages) Infection of wild boar coming from domestic pigs, particularly from the back yard sector.
Hypothesis I: Movement of infected wild boar from other infected areas (Belarus) Conclusion: In Alytus due to the hard winter conditions hunters are feeding wild boar, surviving dependend on the feeding provided by hunters. Movement of wild boar more than 5 km at this time of the year is highly unlikely; ASF infected wild boar showing symptoms of disease are very reluctant to move from one place to another. Therefore, hypothesis I could not be proven
Hypothesis II: Infection of wild boar by uptake of infected material available in the area In the infected areas a very close human-wildlife connection is given In searching food wild boar may easily access land settlements or resting places looking for kitchen waste which might be contaminated with ASFV This hypothesis could neither be proven nor excluded but the close vicinity of wild boar habitat and human settlements is favoring Hypothesis II.
Hypothesis III: Infection of wild boar coming from domestic pigs, back yard On the basis of the information available this hypothesis appeared to be unlikely. In fact, no evidence has been found that domestic pigs in the back yard sector were affected by ASF. This finding is also supported by the laboratory investigations conducted
Conclusions and recommendations: general recommendations An expert group shall be established (Article 15 2002/60/EC). Veterinarians, epidemiologists, wildlife biologist and hunters trans-boundary cooperation at local level between veterinarians from Lithuania and Belarus should be intensified. The Lithuania s NRL uses internationally validated tests and reference standards for ASF diagnosis appropriated to provide a confident diagnosis of ASF. However increased cooperation and coordination between the different departments involved in the ASF diagnosis should be established.
Council Directive 2002/60/EC 27 June 2002 Article 15: as soon as a MS confirms a primary case of ASF in a feral pig population: "The MS should establish an expert group including veterinarians, hunters, wildlife experts and epidemiologists. The expert group shall assist in: studying the epidemiological situation defining the infected area and to implement the eradication plan." Then, within 90 days the eradication plan Article 16
Conclusions and recommendations surveillance: Domestic Pigs All pig holdings under strict health programme: a.s. 1 a week All sick or dead pigs, for which other causes cannot be excluded on clinical grounds, should be examined for ASF Ante-post mortem exam pig slaughtering home consumption Wild Boar All WB found dead/sick/hunted shall be inspected by vets and tested for ASF and CSF. Places at specified high risk (places where WB are gathered) under strict surveillance
Conclusions and recommendations preventive measures (SANCO/7138/2013): Standstill and movement control Carcasses disposal Swill feeding Biosecurity Awareness campaign Hunting
Hunting WB- necessary for sampling purposes however: hunting may be counter-productive, it may increase the size of the home-range of wild boar metapopulations there is little evidence that hunting is an efficient tool in controlling the disease (population dynamics) due to the characteristics of ASF, the lethality induced by the disease is normally higher than the one achievable by hunting In case the disease is detected in a small size population of wild boar it would appear more prudent to monitor the evolution of the disease without increasing hunting pressure.