Fractional-order modeling and optimal control of lassa fever with non-pharmaceutical interventions

This paper presents a fractional-order model of Lassa fever transmission by applying the Atangana Baleanu Caputo (ABC) derivative which include the memory and hereditary effects in the disease dynamics. Human and rodent populations in the model, with non-pharmaceutical interventions, such as public enlightenment and quarantine as time-dependent control variables. Qualitative properties positivity, invariant region, equilibrium states, and the basic reproduction number R₀ are strictly examined. The disease-free and endemic equilibria are determined as stable with the help of the Lyapunov methods. A control framework is developed to optimize the costs of intervention and the infection burden and the conditions are obtained through the Maximum Principle of Pontryagin. Numerical simulations, performed through the Laplace Adomian Decomposition Method, illustrate the influence of memory effects in disease persistence and that combined control measures are effective in reducing the level of infection, length of an outbreak and the cost of the same. Sensitivity analysis determines transmission and intervention parameters to be important contributors of R₀. The findings emphasize the significance of awareness and the need to continue with quarantine at the early stage, and indicate the usefulness of the fractional-order modeling as a powerful tool to in the effective and resource-efficient epidemic control strategies.