Asian Research Journal of Mathematics

Typhoid fever remains a significant public health challenge, particularly in developing countries with inadequate sanitation infrastructure. The emergence and spread of drug-resistant typhoid fever strains have complicated treatment, leading to prolonged illness, higher healthcare costs, and sustained transmission within communities. This growing resistance underscores the need for effective treatment approaches and disease control strategies. This study develops a mathematical model of typhoid fever transmission that incorporates antibiotic resistance. The model categorises infected individuals into drug-sensitive and drug-resistant typhoid fever strains. The impact of treatment modification through different therapeutic options is examined to assess its effect on the prevalence of both sensitive and resistant strains. The model is analysed qualitatively, and the basic reproduction number, R₀ , is derived as the sum of two reproduction numbers, R₀^s and R^r₀, representing the transmission contributions of the sensitive and resistant strains, respectively. Both local and global asymptotic stability conditions for disease-free and endemic equilibria are determined. Sensitivity analysis is conducted to identify the key parameters that influence typhoid fever transmission and persistence. Numerical simulations were performed to validate the analytical results, which demonstrated that typhoid vaccination, the use of appropriate treatment adjustment using first-line and second-line antibiotics, and improved hygiene and sanitation practices significantly reduce the prevalence of both drug-sensitive and drug-resistant strains, as well as the overall infection burden. These findings highlight the effectiveness of integrated prevention and treatment strategies in mitigating antibiotic resistance and enhancing typhoid fever control in the community