Economic optimization of Wolbachia‐infected Aedes aegypti release to prevent dengue

• Published in: Pest management science Vol. 80; no. 8; pp. 3829 - 3838
• Main Authors: Hollingsworth, Brandon D., Cho, Chanheung, Vella, Michael, Roh, Hyeongyul, Sass, Julian, Lloyd, Alun L., Brown, Zachary S.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2024; Wiley Subscription Services, Inc
• Subjects: Aedes aegypti; Aquatic insects; Bacteria; Cities; Costs; Culicidae; Dengue fever; Differential equations; Disease transmission; Dynamic programming; Epidemics; Health risks; Mosquitoes; optimal control; Ordinary differential equations; Pest control; Population number; Public health; Stochasticity; Vector-borne diseases; Wolbachia; Wolbachia; optimal control; Aedes aegypti
• ISSN: 1526-498X; 1526-4998; 1526-4998
• DOI: 10.1002/ps.8086

BACKGROUND Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting ≈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 inelastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50–67% increase in optimal facility size. Furthermore, 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. Furthermore, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Releases of Wolbachia‐infected Aedes aegypti larvae (red bars) were modeled to minimize expected dengue damages and release costs. We simulated population dynamics (black lines) and Wolbachia prevalence (green lines) with optimal release, under different conditions for density dependence (subplot rows) and rearing facility capacity (subplot columns, grey dashed line).