The optimal strategy of incompatible insect technique (IIT) using Wolbachia to control Malaria

For decades, techniques to control vector population with low environmental impact have been widely explored in both field and theoretical studies. The incompatible insect method (IIT) using Wolbachia, based on cytoplasmic incompatibility, is a technique that Wolbachia-infected male mosquitoes are incapable of producing viable offspring after mating with wildtype female mosquitoes. While the IIT method experimentally ensured its effectiveness in several field works, the failure of female mosquito population control owing to the accidental contamination of Wolbachia-infected female mosquitoes has been a concern and an obstacle in implementing the IIT method in nature. In this study, we developed a population-based IIT mathematical model using cytoplasmic incompatibility and evaluated the effectiveness of the IIT method in scenarios where contamination was present or absent. In addition, by extending the model to assess the disease infection status of the human population with malaria, we evaluated the optimal release strategy and cost for successful disease control. Our study proves that IIT could be a promising method to control mosquito-borne diseases without perfect eradication of vector mosquito population regardless of contamination.