Modelling the dynamics of antimicrobial-resistant typhoid infection with environmental transmission

Abstract The emergence of treatment-induced acquired resistance is considered one of the most significant challenges in managing typhoid infection. A deterministic nonlinear mathematical model describing the transmission dynamics of antimicrobial-resistant typhoid infection is developed and analyzed. The basic reproduction number is computed for the model. The condition for the existence of possible equilibria and their stability has been discussed. The sensitivity analysis shows that the direct transmission rates of two strains and the consumption rate of bacteria in environmental transmission strongly impacts the basic reproduction number R 0 . The parameter p , related to treatment-induced acquired resistance, does not affect R 0 , but numerical simulations reveal that it enhances the load of resistant strain in a co-existence equilibrium state. Although the resistant strain has lower transmissibility than the sensitive strain, the resistant strain alone can persist in a community due to re-infection. The study suggests that access to safe drinking water combined with improved sanitation and hygiene practices can reduce the emergence and global spread of antimicrobial-resistant S. Typhi strains.