The use of models in contingency planning - … · 13 DTU - VET Nordic-Baltic seminar, Vilnius 12....

Anette Boklund, DVM, ph.D.

The use of models in

contingency planning

12. October 2016 2 DTU - VET Nordic-Baltic seminar, Vilnius

Models – in relation to contingency

•Risk related to

– Import of disease to

• Herd

• Country

• Europe

–Spread

• Within a herd

• Between herds

• Between countries


Models – in relation to contingency

•Risk related to

–Import of disease to

• Herd

• Country

• Europe

–Spread

• Within herd

• Between herds

• Between countries


Risk of introduction


Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Risk of spread – within a herd

S I R


Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir


S I R


Risk of spread of spread between herds

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir


Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Herd-data ID-numbers Numbers of animals Coordinates Herd-types

Movement data - movements of live

animals - movements to

slaughter - milk tankers - distances

Data related to FMD - incubation period - time to clinical signs - spread time within herd

Danish contingency - probability to detect disease - probability of compliance - probability of reporting contacts

Risk of spread of spread between herds


Methods – DTU-DADS

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

All epidemics start on 1 herd

Several epidemics simulated


Methods – DTU-DADS

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

Local spread • 3km • incl. limited airborne spread • unregistered person contacts • rats, birds, cats, etc.


Control measures

• Surveillance

• Depopulation

• Movement restrictions

• Vaccination


Control measures

• Surveillance

• Depopulation

• Movement restrictions

• Vaccination

BASIC scenario

DEPOPULATION scenarios

VACCINATION scenarios

To live

To die


Results


Results

10 15

3 5


Export is driving the economics in DK


Ressource estimations


Used for contingency planning


DTU-DADS - ASF

• The DTU-DADS model has been further developed to also model spread of

– ASF


DTU-DADS - ASF


– ASF

– Including within-herd spread

– And residues from dead animals


DTU-DADS - ASF


– ASF

• Including within-herd spread


S I R

Infection process

Susceptible pig

Subclinical pig (μ) Clinical pig Residues of dead pigs (ε)


Infection process

Susceptible pig

Subclinical pig (μ) Clinical pig Residues of dead pigs (ε)

S I R


Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

DTU-DADS - ASF

• Within-herd spread, including residues from dead animals, are then used in a between-herd spread model similar to the FMD-model


Transport vehicle

Infected herd

Movements of pigs

Person contacts

Neighbouring herd

Semen

Semen

Abattoir

DTU-DADS - ASF



Risk of introduction - CSF

• Bronvoort et al. (2008)




– Returning livestock trucks highest risk for importing CSF

– Legal meat imports





– Legal meat imports in DK

• de Vos et al. (2004)

– Returning livestock trucks highest risk for importing CSF in NL


Risk of introduction - ASF

• Mur et al. (2012)

– Returning trucks Poland and Lithuania - HR

– Waste from international planes

– Waste from international ships

• Costard et al. (2013)

– Illegal import of pork and products


Risk of spread in HRP - ASF

• Nigsch et al. (2013)

– Spread from 1st infected herd 1st detection (HRP)

– HRP – 10, 20, 30, 40, 50, 60 days

– Limited numbers of infected herds (1-4)

– Super-spreader: DK, NL, LT, LV

– Super-recievers: DE, PL


• Dorea et al. (2016)

– DTU-DADS model

– simulating FMD

– Sweden

• Limited size and duration of Swedish outbreaks

• No additional effect of adding pre-emptive culling or vaccination

Ongoing and future work


• Simons et al. (2016)

– Modeling the spread of ASF in the Belgian pig livestock industry

– Using the DTU-DADS-ASF model

• The model is also being used in

– France - ASF

– Germany – FMD & ASF

Ongoing and future work


Thank you for your attention


References Boklund, A., Halasa, T., Christiansen, L.E., Enøe, C., 2013. Comparing control strategies against

foot-and-mouth disease: Will vaccination be cost-effective in Denmark? Preventive Veterinary Medicine 111, 206-219.

Costard, S., Jones, B.A., Martínez-López, B., Mur, L., de la Torre, A., Martínez, M., Sánchez-Vizcaíno, F., Sánchez-Vizcaíno, J.M., Pfeiffer, D.U., Wieland, B., 2013. Introduction of African Swine Fever into the European Union through Illegal Importation of Pork and Pork Products. PLoS One 8, e61104.

Halasa, T., Boklund, A., Bøtner, A., Toft, N., Thulke, H.H., 2016a. Simulation of Spread of African Swine Fever, Including the Effects of Residues from Dead Animals. Front Vet Sci 3, 6.

Halasa, T., Bøtner, A., Mortensen, S., Christensen, H., Toft, N., Boklund, A., 2016b. Simulating the epidemiological and economic effects of an African swine fever epidemic in industrialized swine populations. Veterinary Microbiology 193, 7-16.

Halasa, T., Toft, N., Boklund, A., 2015. Improving the effect and efficiency of FMD control by enlarging protection or surveillance zone. Frontiers in Veterinary Science 2.

Mur, L., Martínez-López, B., Sánchez-Vizcaíno, J., 2012. Risk of African swine fever introduction into the European Union through transport-associated routes: returning trucks and waste from international ships and planes. BMC Veterinary Research 8, 149.

Nigsch, A., Costard, S., Jones, B.A., Pfeiffer, D.U., Wieland, B., 2013. Stochastic spatio-temporal modelling of African swine fever spread in the European Union during the high risk period. Preventive Veterinary Medicine 108, 262-275.

The use of models in contingency planning - … · 13 DTU - VET Nordic-Baltic seminar, Vilnius 12....

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