Can African swine fever be controlled through wild boar management?

Transcription

1 Can African swine fever be controlled through wild boar management?

2 African swine fever Despite the high mortality rates observed in naïve populations, not all infected animals die after short time. Indeed, both virus and antibodies are detected in affected animals, revealing the survival to infection of some individuals (Kurinov et al. 2012; Diagnosis of Lithuanian wild boar, 2014).

3 Remember the facts Expanding; high reproductive rate; low mortality Contact with pigs through sex & food Movements up to 250 km, increased by hunting Fences, rivers & highways are no barriers

4 Remember the facts

5 Aims of this presentation Review wild boar management tools Hunting Capturing Counting Discuss intervention options regarding ASF Biosafety Population control Other options 5

6 Aims of this presentation Review wild boar management tools Hunting Capturing Counting Discuss intervention options regarding ASF Biosafety Population control Other options 6

7 Hunting wild boar Driven hunt Stand hunt Stalking Several hunters With or without dogs Hunting site might be pre-baited One hunter Without dogs Hunting site must be pre-baited One hunter With or without dogs Key sites might be pre-baited REMEMBER: Hunting success (& fun) depends on wild boar abundance (i.e. hunters will not happily reduce their game) Baiting improves hunting success, but increases wild boar survival and reproduction Picture source: boarmasters.com

8 Trapping wild boar Capture specificity (wild boar) was 96.3% Capture effort was 16.5 days per wild boar Low pre-release mortality during capture and handling (6.5%) associated with trauma in corral traps Post-release monitoring by GPS-devices revealed no mortality due to anaesthesia

9 Trapping wild boar ASFORCE: Wild boar life-trapping in Sardinia, last week

10 Trapping wild boar REMEMBER: Trapping depends on baiting and can be counter-productive However, trapping is needed for tagging and research1 Few cases of real success in reducing a wild boar population by trapping2 1.- Barasona et al. BMCVM; 2.- Boadella et al PREVET

11 Estimating wild boar abundance Hunting data as relative abundance indicator Acevedo et al Acta Theriologica

12 Estimating wild boar abundance Ausencia A Presencia A A P A A A A Acevedo et al Epid & Infect

13 Wildlife monitoring: populations & diseases EU FP7 EMIDA ERA-NET

14 Aims of this presentation Review wild boar management tools Hunting Capturing Counting Discuss intervention options regarding ASF Biosafety Population control Other options 14

15 From disease discovery to disease control Barriers-biosafety Culling Habitat management Boadella et al EJWR

16 Integrated control options for shared diseases Vacunación del ganado V V Eliminación selectiva V + V + Vacunación del reservorio V + V V + Barreras Closed (biosafe) farm + Eliminación no selectiva Higiene V V V V Acceso a agua y comederos Open air farm Free-range Control de traslados

17 Biosecurity 2: Fences and barriers Vulnerable to elephants, suids Interfere with natur movements and migration Owens & Owens 1980 Afr. Wildlife, Sutmoller 2002 Ann. NY Acad. Sci., Jori 2011 PreVet, Schneider 2012 J.S. Afr. Vet. Assoc.

18 Biosecurity 2: Fences and barriers

19 Biosecurity 3: Carcasses and hunting remains Good! Wrong! Source: J. Vicente, IREC.

20 Wildlife population control

21 Population control 1: Random culling EXAMPLES WHERE RANDOM CULLING FAILED Red fox culling rabies Wild boar culling Aujeszky s disease Wild boar culling CSF M. Artois Culling reservoir populations to control the transmission of pathogens has proven disappointingly inefficient Culling could become a part of integrated control strategies ( ) contributing to increase their success likelihood, or reducing the total expenses M. Boadella Artois et al Rev. Sci. Tech. OIE; Boadella et al PreVet

22 Guidelines for ASF prevention through the control of wild boar populations MONITORING WILD BOAR & ASF 1.Current wild boar population monitoring in Europe is not enough. Efforts are needed towards the establishment of appropriate population monitoring tools. These tools cannot rely only on hunting results, since some populations are not hunted. 2.The surveillance of infectious agents including ASF should also be improved. Disease monitoring should consider both hunter-harvest sampling and non-invasive techniques such as oral fluid collection. BIOSAFETY 3.Contacts of wild boar with domestic pigs should be avoided enhancing the biosecurity and infrastructures of the pig holdings from the infected area (small scale fencing). Larger barriers to wild boar movements are unlikely to succeed and have undesirable consequences (large scale fencing). 4.Wild boar access to domestic pig/wild boar carcasses should be avoided. National carcass management schemes should be considered within the risk factors and as intervention options. 5.Wild boar translocations should be thoroughly monitored to avoid introduction at long distances. Illegal short- and long-distance wild boar translocations are known, but not their frequency. POPULATION CONTROL 6.Intense hunting (>50% of the estimated population) can reduce wild boar numbers locally, particularly in closed populations, but such an intense hunting pressure is difficult to maintain. In evenly distributed populations, reduction can be achieved in the long term if feeding is banned and the hunting pressure increased. 7.Hunting is a useful population management tool. However, two aspects need urgent European regulation from the animal health point of view: (1) the proper disposal of hunting offal/remains and (2) game baiting and feeding. 8.Future wild boar population control should consider control professionals and new methods, possibly including contraception. 22

23 Research needs 1. Basic parameters of ASFV maintenance within and between wild boar groups should be studied in selected ASF-affected wild boar populations to estimate basic parameters for transmission rate modelling. 2. Tools to control wild boar without hunting, for instance in protected areas and urban areas, are needed. Options to consider include refinements of trapping and contraception. 3. Ongoing control efforts (e.g. increased hunting pressure) offer an extraordinary opportunity to critically assess the success of current intervention. 23

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25 Management & Research Needs Monitor POPULATIONS and DISEASES (remember: nothing permanent, except change ) Set limits to OVERABUNDANCE and AGGREGATION Regulate feeding Increase hunting pressure Proper disposal of HUNTING REMAINS Set up and test innovative CONTROL tools