AI Insight
This study develops a stochastic vector-host mathematical model to investigate how epidemiological parameters drive seasonal dengue epidemics and long-term transmission persistence. Using multivariate Sobol sensitivity analysis, the authors find that the vector-to-host population ratio and host recovery rate exert greater influence on epidemic dynamics than contact rates, suggesting that protecting infectious individuals from mosquito bites should be prioritized during seasonal outbreaks. Additionally, the model demonstrates that vertical transmission in mosquitoes lowers the threshold for dengue persistence, and that asynchronous covariance between host and vector populations at endemic equilibrium may explain the maintenance of viral reservoirs that seed new seasonal outbreaks.
Why it matters
These findings provide a quantitative basis for ranking public health intervention priorities in dengue-endemic regions, favoring personal protection measures over broad contact-reduction strategies. The framework is designed to be adaptable to field data, offering a practical tool for guiding context-specific dengue control programs.
arXiv:2605.21787v1 Announce Type: new
Abstract: We investigate how key epidemiological parameters shape both seasonal epidemics and the persistence of dengue transmission. Our findings confirm known mechanistic drivers of epidemic variability and introduce a ranking of parameter importance in our dengue model, which in turn informs the prioritization of public health policies. We propose a stochastic vector-host model with waning immunity, exogenous infection, and vertical transmission. To assess parameter influence, we first qualitatively analyze the macroscopic model. We then perform a multivariate Sobol sensitivity analysis of epidemic summary statistics, and examine the variance of the endemic equilibrium as a function of model parameters. We show that the macroscopic model is well posed, vertical transmission lowers the threshold for persistence, and low spatial coupling increases infectious endemic equilibria. The vector-host population ratio and host recovery rate have the largest first-order and total sensitivity indices, surpassing the contact rates; this implies that control measures during seasonal dengue should prioritize protecting infectious hosts from mosquito bites. Finally, we show that the covariance of hosts and vectors at the endemic equilibrium is asynchronous in the contact-rate plane. This robust pattern has epidemiological, ecological and evolutive interpretations. A dengue strain has two niches to exploit during the endemic regime, and coexisting strain have two niches each. Moreover, large fluctuations in a given strain during the endemic regime provide a mechanistic explanation for high vertical transmission, enabling viral reservoirs that can hatch and trigger outbreaks in the following season. We argue that our model and results can be adapted to address specific public health questions to guide dengue control using field data.