The impact of isolation of identified active tuberculosis cases on the number of latently infected individuals

Abstract

Isolation, quarantine, disinfection, inoculation, education have been the five important preventive control measures used to control an epidemic. Isolation, which is aimed at restricting the spread to susceptibles by restricting the movements of infectious cases, tops the list. Identifying and isolating patients with active tuberculosis could be effective as control measure. In order to minimize the transmission of the disease and to break the transmission chain of the Mycobacterium tuberculosis and thus the sterilization of the source of infection, we consider an optimal control strategy associated with isolation of infectious individuals who spread the disease. The existence of an optimal control for an objective functional that takes into account both the number of infectious individuals and the cost of isolation strategy, the characterization of the optimal control, and the uniqueness of the optimality system are proved. The optimality system is solved numerically using the Forward-Backward Sweep method. The numerical results showed that isolation strategy will considerably reduce the number of latently infected individuals. © 2011 Springer-Verlag.