Modeling the effects of vector species composition and temperature on the risk of dengue virus

The risk of vector-borne disease is highly dependent on the local community composition of hosts and vectors, as well as the means by which disease is introduced into a susceptible population. The mosquito species Aedes aegypti and Aedes albopictus are both vectors of dengue virus, but differ in their biting preferences and ability to transmit the disease. The two species compete for habitat at the larval stage and their spatial distributions are highly heterogeneous, due in part to variability in factors such as temperature and resource quality affecting the outcome of competition and the resulting abundance of each species. In addition to affecting vector population dynamics, temperature also strongly affects multiple aspects of the disease transmission process. We present the basic reproduction number $R_0$ for a deterministic temperature-dependent transmission model between humans, Ae. aegypti, and Ae. albopictus, then develop a stochastic continuous-time Markov chain transmission model and determine the probability of disease extinction $P_0$ for introduction by exposed or infectious humans, Ae. aegypti, or Ae. albopictus. We explore how both $R_0$ and $P_0$ depend on a number of variables, including temperature, vector species composition, vector-host ratio, and mosquito biting behavior. We discuss our results in the context of changes in climate and neighborhood-level spread of mosquito populations and dengue.