Evolving behavioral dynamics and environmental risk in cholera epidemics

Cholera, an infectious disease transmitted by water, is a harmful and sometimes life-threatening public health issue in a significant number of poor and middle-income nations all over the world, where inadequate water and sanitation infrastructure, together with noticeable climate variability, contribute to regular and frequently severe outbreaks. Consequently, it is important to understand the interplay between environmental risks and human decision-making in exacerbating the disease burden in our society. This work develops and analyzes a seasonally driven cholera model that integrates with an aquatic bacterial reservoir (leading to indirect transmission), temperature, and hydrological conditions, and shows how these factors change regularly, reflecting recurring alterations in bacterial survival and exposure risk throughout the year. To address these characteristics of the environment, we consider human behavior which is integrated through an evolutionary game-theoretic (EGT) framework, wherein individuals decide protective and non-protective strategies (such as purifying drinking water, utilizing safe sources, or enhancing hygiene, treatment, and vaccination) and adjust their choices by emulating strategies that provide greater perceived benefits, thus balancing the costs of prevention against the health and economic repercussions of infection and treatment. The interaction between behavior and transmission influences the effective force of infection from the environment and significantly changes the magnitude, duration, and temporal dynamics of outbreaks. Our findings suggest that rapid and vast implementation of preventive measures, combined with moderate vaccination and timely treatment, markedly decreases both the average incidence and the seasonal peak size. In addition, excessive prevention costs or inadequate risk perception keep the system in a high-burden state, even while treatments are available. Therefore, efficient cholera control in seasonal contexts requires improvements in water and sanitation infrastructure, alongside policies that align individual incentives with communal benefits, including subsidies for household water treatment, targeted risk communication, and vaccination strategies informed by behavioral insights. We expect the outcomes of our study to assist policymakers in developing a comprehensive plan to stop other water-borne diseases.