[Mathematical modelling of an infectious disease in a prison setting and optimal preventative control strategies]

A mathematical model was constructed for modelling transmission dynamics and the evolution of an infectious disease in a prison setting, considering asymptomatic infectious people, symptomatic infectious people and isolated infectious people. The model was proposed as a nonlinear differential equation system for describing disease epidemiology. The model's stability was analysed for including a preventative control strategy which would enable finding a suitable basic reproduction number-based control protocol. A cost function related to the system of differential equations was formulated to minimise infectious populations and intervention costs; such function was minimised by using the Pontryagin maximum principle which determines optimum preventative control strategies by minimising both infectious populations and associated costs. A numerical analysis of the model was made, considering preventative control effectiveness levels and different control weighting constants. Conclusions were drawn. The basic reproduction number characterises system stability and leads to determining clear control criteria; a preventative control threshold was defined, based on the controlled basic reproduction number which enabled deducing that disease control requires uniform preventative control involving high rates of effectiveness.