title: Simulation of Spread of African Swine Fever, Including the Effects of Residues from Dead Animals.
abstract: To study the spread of African swine fever (ASF) within a pig unit and the impact of unit size on ASF spread, a simulation model was created. In the model, an animal can be in one of the following stages: susceptible, latent, subclinical, clinical, or recovered. Animals can be infectious during the subclinical stage and are fully infectious during the clinical stage. ASF virus (ASFV) infection through residues of dead animals in the slurries was also modeled in an exponentially fading-out pattern. Low and high transmission rates for ASFV were tested in the model. Robustness analysis was carried out in order to study the impact of uncertain parameters on model predictions. The results showed that the disease may fade out within the pig unit without a major outbreak. Furthermore, they showed that spread of ASFV is dependent on the infectiousness of subclinical animals and the residues of dead animals, the transmission rate of the virus, and importantly the unit size. Moreover, increasing the duration of the latent or the subclinical stages resulted in longer time to disease fade out. The proposed model is a simple and robust tool simulating the spread of ASFV within a pig house taking into account dynamics of ASFV spread and the unit size. The tool can be implemented in simulation models of ASFV spread between herds.
authors: National Veterinary Institute, Technical University of Denmark , Copenhagen , Denmark.
authors: Tariq
authors: T
authors: Halasa
authors: National Veterinary Institute, Technical University of Denmark , Copenhagen , Denmark.
authors: Anette
authors: A
authors: Boklund
authors: National Veterinary Institute, Technical University of Denmark , Copenhagen , Denmark.
authors: Anette
authors: A
authors: Bøtner
authors: National Veterinary Institute, Technical University of Denmark , Copenhagen , Denmark.
authors: Nils
authors: N
authors: Toft
authors: Department of Ecological Modeling, Helmholtz Center for Environmental Research (UFZ) , Leipzig , Germany.
authors: Hans-Hermann
authors: HH
authors: Thulke
keywords: ASF; African swine fever; model; simulation; virus