Modeling the invasion and establishment of a tick-borne pathogen

Area of Science:

• Ecology
• Epidemiology
• Mathematical Biology

Background:

• Tick-borne diseases pose significant public health and ecological challenges.
• Understanding pathogen transmission dynamics within tick populations is crucial for effective control strategies.

Purpose of the Study:

• To develop and analyze a discrete-time tick-host-pathogen model.
• To investigate the invasion and establishment dynamics of diseases in hard-bodied ticks.
• To quantify the impact of various parameters on disease spread and prevalence.

Main Methods:

• Developed a discrete-time model incorporating tick developmental stages, host availability, and pathogen transmission routes.
• Analyzed the disease-free system's global dynamics.
• Applied the model to *Borellia burgdorferi* and *Anaplasma phagocytophila* in *Ixodes ricinus* ticks.
• Utilized Monte Carlo simulations to calculate disease metrics and parameter elasticities.

Main Results:

• Increased tick survival facilitates disease invasion, reduces establishment time, and increases prevalence.
• Disease invasion is sensitive to tick-to-host transmission and searching efficiency.
• Disease prevalence and establishment time are not sensitive to transmission efficiency or searching efficiency.

Conclusions:

• Tick survival is a critical factor influencing the establishment and prevalence of tick-borne diseases.
• Modeling approaches are essential for understanding disease dynamics beyond initial invasion, including transitional and long-term phases.
• The developed model provides a framework for studying complex tick-host-pathogen interactions.