Modeling cholera transmission dynamics with antibiotic resistance and mutation: A case study in Zimbabwe

Cholera remains a significant cause of morbidity and mortality worldwide. Although antibiotic use can reduce transmission, misuse, overuse, or incomplete treatment can foster the emergence of antibiotic resistance. Selective pressure plays a crucial role in shaping the dynamics of resistance in Vibriocholerae, particularly by increasing the mutation rate that transforms antibiotic-sensitive strains into resistant ones. In this study, we develop a novel mathematical model to investigate the impact of antibiotic resistance on cholera transmission dynamics. We establish the existence and stability of equilibria and fit the model to cholera outbreak data from Zimbabwe. Our results reveal a critical interplay between mutation rates and strain fitness: when resistant strains have low reproductive fitness, increased mutation rates alone fail to establish their dominance; however, when resistance carries a fitness advantage, higher mutation rates trigger a regime shift to resistant strain dominance-a newly identified phenomenon with implications for resistance management. We further demonstrate that incomplete treatment (lower recovery rates) exacerbates resistance by prolonging antibiotic exposure. Crucially, our findings underscore that judicious antibiotic use can simultaneously curb resistance emergence and outbreak spread in Zimbabwe, offering actionable insights for public health strategies.