Identifying requirements for the invasion of a tick species and tick-borne pathogen through TICKSIM

Ticks and tick-borne diseases have been on the move throughout the UnitedState over the past twenty years. We use an agent-based model, TICKSIM,to identify the key parameters that determine the success of invasionof the tick and if that is successful, the succees of the tick-bornepathogen. We find that if an area has competent hosts, an initialpopulation of ten ticks is predicted to always establish a newpopulation. The establishment of the tick-borne pathogen depends onthree parameters: the initial prevalence in the ten founding ticks,the probability that a tick infects the longer-lived hosts and theprobability that a tick infects the shorter-lived hosts. These resultsindicate that the transmission rates to hosts in thenewly established area can be used to predict the potential risk ofdisease to humans.