Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
BMC Biol. 2024 Nov 21;22(1):269. doi: 10.1186/s12915-024-02070-1.
Wolbachia incompatible insect technique (IIT) programs have been shown in field trials to be highly effective in suppressing populations of mosquitoes that carry diseases such as dengue, chikungunya, and Zika. However, the frequent and repeated release of Wolbachia-infected male mosquitoes makes such programs resource-intensive. While the need for optimization is recognized, potential strategies to optimize releases and reduce resource utilization have not been fully explored.
We developed a process-based model to study the spatio-temporal metapopulation dynamics of mosquitoes in a Wolbachia IIT program, which explicitly incorporates climatic influence in mosquito life-history traits. We then used the model to simulate various scale-down and redistribution strategies to optimize the existing program in Singapore. Specifically, the model was used to study the trade-offs between the intervention efficacy outcomes and resource requirements of various release program strategies, such as the total number of release events and the number of mosquitoes released. We found that scaling down releases in existing sites from twice a week to only once a week yielded small changes in suppression efficacy (from 87 to 80%), while requiring 44% fewer mosquitoes and release events. Additionally, redistributing mosquitoes from already suppressed areas and releasing them in new areas once a week led to a greater total suppressive efficacy (83% compared to 61%) while also yielding a 16% and 14% reduction in the number of mosquitoes and release events required, respectively.
Both scale-down and redistribution strategies can be implemented to significantly reduce program resource requirements without compromising the suppressive efficacy of IIT. These findings will inform planners on ways to optimize existing and future IIT programs, potentially allowing for the wider adoption of this method for mosquito-borne disease control.
已在田间试验中证明，沃尔巴克氏体不相容昆虫技术（IIT）项目在抑制携带登革热、基孔肯雅热和寨卡病毒等疾病的蚊子种群方面非常有效。然而，频繁和重复释放携带沃尔巴克氏体的雄性蚊子使得此类项目资源密集。虽然认识到需要进行优化，但尚未充分探索潜在的优化释放和减少资源利用的策略。
我们开发了一个基于过程的模型来研究沃尔巴克氏体 IIT 项目中蚊子的时空复合种群动态，该模型明确将气候对蚊子生活史特征的影响纳入其中。然后，我们使用该模型模拟了各种缩小规模和重新分配策略，以优化新加坡现有的计划。具体来说，该模型用于研究各种释放计划策略的干预效果和资源需求之间的权衡，例如释放事件的总数和释放的蚊子数量。我们发现，将现有地点的释放频率从每周两次减少到每周一次，对抑制效果的影响很小（从 87%降至 80%），而所需的蚊子和释放事件数量减少了 44%。此外，将蚊子从已经得到抑制的地区重新分配到新地区，并每周释放一次，可使总抑制效果更大（83%相比 61%），同时所需的蚊子和释放事件数量分别减少了 16%和 14%。
无论是缩小规模还是重新分配策略，都可以显著减少项目资源需求，而不会影响 IIT 的抑制效果。这些发现将为规划者提供优化现有和未来 IIT 计划的方法，可能会促使更广泛地采用这种方法来控制蚊媒疾病。
