Optimal control and cost-effectiveness of the control strategies chlamydiosis

Chlamydiosis is a prevalent sexually transmitted infection affecting both men and women. Despite some modeling studies exploring its transmission dynamics, limited knowledge exists on the optimal combination of available controls for the disease. This paper presents a mathematical model with time-dependent variables to investigate the optimal control and cost-effectiveness of a combination of environmental hygiene, public health education, and vaccination control measures. The goal was to reduce the number of infections caused by contact with the infected individuals and contaminated environment while minimizing the cost associated with implementing control efforts. The necessary conditions and the existence of an optimal control problem were examined using Pontryagin’s Maximum Principle. The numerical simulations of the optimal control problem were carried out using a forward and backward-in-time fourth-order Runge–Kutta scheme. Findings from optimal control show that the scenario that incorporates all three control interventions yields superior results out of the seven control scenarios examined in this study. Also, cost-effectiveness analyses indicated that the combination of vaccination and sanitation effectively controls the spread of the disease at affordable costs. Therefore, this strategy is recommended for implementation due to its health benefits and cost-effectiveness.