Economic Optimization of Wolbachia-infected Aedes aegypti release to prevent dengue.

BACKGROUND: Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting approximately 3.83 billion people worldwide. Recent releases of Wolbachia-transinfected Ae. aegypti in several cities worldwide have shown that it can reduce dengue transmission. However, these releases are costly, and, to date, no framework has been proposed for determining economically optimal release strategies that account for both costs associated with disease risk and releases.

RESULTS: We present a flexible stochastic dynamic programming framework for determining optimal release schedules for Wolbachia-transinfected mosquitoes that balances the cost of dengue infection with the costs of rearing and releasing transinfected mosquitoes. Using an ordinary differential equation model of Wolbachia and dengue in a hypothetical city loosely describing areas at risk of new dengue epidemics, we determined that an all-or-nothing release strategy that quickly brings Wolbachia to fixation is often the optimal solution. Based on this, we examined the optimal facility size, finding that it was less than unitary elastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50-67% increase in optimal facility size. Further, we found that these results are robust to mosquito life-history parameters and are mostly determined by the mosquito population size and the fitness costs associated with Wolbachia.

CONCLUSIONS: These results reinforce that Wolbachia-transinfected mosquitoes can reduce the cost of dengue epidemics. Further, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. This article is protected by copyright. All rights reserved.