Fighting typhoid fever: Modeling antibiotic resistance and antibiotic switching

Abstract

Typhoid fever continues to be a major public health concern, particularly in developing countries where the sanitation infrastructure is inadequate. The rise in resistance to typhoid drugs has made treatment increasingly challenging, resulting in longer recovery times and continued transmission of the disease within households and communities. This growing resistance underscores the urgent need for improved treatment strategies and public health intervention. In this study, we presented a mathematical model of typhoid fever that incorporates antibiotic resistance and the implementation of antibiotic switching as a control strategy. The model considers individuals infected with typhoid antibiotic sensitive strains and typhoid antibiotic resistant strain. The effects of antibiotic switching, which involves transitioning patients between different antibiotics, are modeled to study its impact on the prevalence of resistant and sensitive strains. The model is analyzed and the model reproduction number, $R_0$, is found to be the sum of two reproduction numbers $R_s$ and $R_r$ representing the contribution of the sensitive and resistant strains, respectively. The stability analysis indicates that the disease-free equilibrium is stable when the model reproduction number is less than one, suggesting the possibility of eradicating the disease under effective control measures. In contrast, the endemic equilibrium remains stable when the reproduction number exceeds one, indicating persistent infection levels. Sensitivity analysis is performed to identify critical parameters that influence the persistence of typhoid in the population. Numerical simulations are performed to support the theoretical findings. The results obtained demonstrate that antibiotic switching can reduce the prevalence of resistant and sensitive strains and overall infection levels, highlighting their potential as an effective strategy to manage antibiotic resistance in typhoid fever.