Epidemiological drivers and control strategies for African swine fever transmission cycles at a wildlife-livestock interface

Abstract

Increasing reported outbreaks of African swine fever (ASF) at wildlife-livestock interfaces (where wild pigs and/or ticks interact with domestic pigs) have led to an increased interest in understanding the transmission dynamics and effective control strategies of the disease in these places. In such areas, the transmission cycles of ASF include a domestic pig cycle, a tick-domestic pig cycle, and a wild pig-tick-domestic pig cycle. A model that captures these cycles is used to explore the key parameters and control strategies (vaccination, isolation, and/or the use of an acaricide) for disease transmission. Using Latin hypercube sampling, the tick mortality and recruitment rates are found to be the key parameters for the spread of ASF. Numerical results show that early isolation of infected domestic pigs can be effective in controlling transmission only in the domestic pig cycle, whereas the use of an acaricide applied as a single strategy is not effective for any cycle. On the other hand, a strategy that combines these two strategies is effective in controlling transmission for all cycles, but its effectiveness is lower than that of the vaccination strategy. Thus, at a wildlife-livestock interface, vaccination is the best strategy, but where the vaccines are not yet available or affordable, a strategy that combines isolation and the use of an acaricide can be applied to control ASF transmission.