Complexity of host-vector dynamics in a two-strain dengue model

Area of Science:

• Epidemiology
• Mathematical Biology
• Infectious Disease Dynamics

Background:

• Dengue fever is a significant global health concern, transmitted by mosquitoes.
• Understanding the dynamics of multiple dengue virus strains is crucial for effective control strategies.
• Previous models often simplify host-vector interactions or strain competition.

Purpose of the Study:

• To develop and analyze a compartmental host-vector model for dengue with two viral strains.
• To investigate conditions for strain displacement or co-existence.
• To explore the impact of temporary cross-immunity and secondary infections on disease dynamics.

Main Methods:

• Utilized a slow-fast system approach to model host and vector epidemiological time scales.
• Applied geometric singular perturbation techniques for model dimension reduction.
• Conducted numerical bifurcation analysis using literature-derived parameter values.

Main Results:

• Identified conditions for endemic equilibria where one dengue strain dominates or both co-exist.
• Demonstrated the utility of quasi-steady state approximation for vector dynamics in simplifying the model.
• Compared the bifurcation structure of the host-vector model with simpler host-only models.

Conclusions:

• The host-vector model provides a more realistic framework for studying dengue transmission dynamics.
• Dimension reduction techniques effectively capture essential disease dynamics.
• The findings offer insights into the complex interplay of multiple dengue strains and host immunity.