Mechanisms underlying the impact of environmental factors (physical, ecological, social) on infectious diseases.

The occurrence, transmission, and spread of infectious diseases are closely linked to environmental factors. As climate change intensifies, shifts in temperature, precipitation, and extreme weather events are modifying pathogen survival, vector ecology, and the geographical range of infectious diseases. At the same time, ecosystem degradation, land-use change, urbanization, poverty, and social unrest further shape population exposure, healthcare access, and disease vulnerability. This narrative review synthesizes the mechanisms by which physical, ecological, and social environmental factors influence infectious disease transmission. Unlike reviews that focus on single determinants, this review adopts an integrated framework to examine both individual mechanisms and cross-domain interactions. Guided by the One Health framework, we link these mechanisms to the human-animal-environment interface and highlight how environmental change can promote pathogen spillover, amplification, and spread. By clarifying these pathways, this review provides a theoretical basis for integrated infectious disease prevention, public health policy, and future research.