A spatial simulation model for dengue virus infection in urban areas

Area of Science:

• Epidemiology
• Mathematical Modeling
• Vector-borne Diseases

Background:

• Dengue infections affect 80-100 million globally, with transmission expanding to new regions.
• The Aedes aegypti mosquito is a primary vector, and Cairns, Australia, frequently experiences dengue outbreaks.
• Understanding dengue spread is crucial for public health interventions.

Purpose of the Study:

• To develop and validate a spatially-explicit, individual-based mathematical model for dengue transmission.
• To investigate factors contributing to dengue outbreaks, particularly large-scale epidemics.
• To assess the model's utility for dengue control planning and optimization.

Main Methods:

• A coupled mathematical model integrating mosquito population dynamics, human movement, virus transmission, and vector control.
• Utilized high-quality outbreak, mosquito trapping, vegetation coverage, and census data for calibration and validation.
• Spatially-explicit and individual-based approach to simulate disease spread.

Main Results:

• The model accurately reproduced a 2003 dengue outbreak in Cairns and simulated the 2008/2009 epidemic.
• Warmer weather and increased human movement had minimal impact on virus spread.
• A shorter extrinsic incubation period for the dengue virus strain was identified as a significant factor in the 2008/2009 epidemic's explosive nature.

Conclusions:

• The simulation model serves as a proof-of-concept for understanding dengue spread dynamics.
• The model can inform dengue control strategies, including vector population reduction and vaccination program assessment.
• The model's framework is adaptable for other vector-borne viral diseases like chikungunya.