A stochastic model of antibiotic misuse, economy, and drug resistance: relating mutant extinction probability to socioeconomic and epidemiological factors

Controlling antibiotic drug resistance requires understanding extinction and emergence mechanisms of emerging bacteria. Selective pressure from prolonged antibiotic misuse may cause high-level antimicrobial resistance. Self-medication and other socioeconomic factors reduce antibiotic use, accelerating the emergence and extinction of resistant pathogens through stochastic fluctuation. This continuous antibiotic self-medication exposes individuals and communities to antibiotic resistance, especially in low- and lower-middle-income countries, according to current literature. We developed a stochastic drug-resistance model that integrates socio-economic growth and antibiotic use to study extinction and strain establishment in this paper. We analytically derived the extinction threshold using the multi-type branching process and obtained pathogen extinction conditions that match numerical experiments. The model's sensitivity analysis identifies extinction dynamics' key parameters. Our results show that higher income, awareness, and lower antibiotic use may increase the chance of extinction by reducing antibiotic misuse, along with strain transmission potential. These analyses may help public health policymakers combat drug resistance.