An optimal control model for dengue dynamics with asymptomatic, isolation, and vigilant compartments

Prioritizing control implementation for dengue prevention and control for efficiency and cost benefits is crucial to the government, decision-makers, and policymakers, particularly in resource-limited communities where the disease is endemic. This study is primarily concerned with developing and analysing an optimal control model for dengue dynamics, which includes asymptomatic, isolation, and vigilant compartments in the human population with three time-varying functions. These functions represent personal protection using insecticide-treated bed nets and wearing long-sleeved clothes, treatment, and vector population control using insecticide spraying. Qualitative analysis of the model is carried out to minimize dengue spread and the control implementation costs using optimal control theory. By classifying all the possible combinations of control interventions into three distinct scenarios, single control intervention, double control intervention, and triple control interventions, the effect of implementing each control intervention in each scenario is illustrated through numerical simulations of the optimality system. The most efficient intervention in each scenario is identified by computing the efficiency index of each control intervention. In contrast, each scenario's most cost-effective control intervention strategy is obtained using infection averted ratio, average cost-effectiveness ratio, and incremental cost-effectiveness ratio approaches. Efficiency analysis reveals that combination of all the three optimal control interventions is the overall most efficient strategy, and thereby recommended for implementation to protect and control dengue transmission when resource allocations are readily available. In resource-limited communities, combination of optimal personal protection and treatment is regarded the overall most cost-effective strategy that can be implemented to guide against the spread of dengue according to the cost analysis.