A pyramid of human ecology of disease for pandemic preparedness

The emergence of zoonotic infectious diseases and its potential threat to future health security highlights the need to re-examine how we conceptualize the impact of human-environment interactions on health. Traditionally, social scientists, epidemiologists, and ecologists have used the human ecology frameworks to understand disease dynamics, framing health outcomes as the result of interactions between population, habitat, and behaviour. However, they fall short in capturing the fluid, evolving nature of social-biological interactions across time and space particularly during epidemics. To capture this dynamic nature, we combine the triangle of human ecology and the triangle of disease ecology into a unified pyramid model. This integrated framework brings together four domains, namely pathogen, population, behaviour, and the environment. Domains like population and environment, which are featured in both triangle frameworks, are integrated, while non-overlapping domains such as pathogen and behaviour are added, reflecting their joint importance in disease emergence and spread. Together, these four domains interact and shift over time and across three key phases of an epidemic, defined by emergence, spread, and responses. We apply this framework to the COVID-19 pandemic, from the initial outbreak in late 2019 into the major phases of global response before 2023. We demonstrate how the four domains help map evolving interactions that shape spillover, transmission pathways, and the effectiveness of public health response. By incorporating sociopolitical and behavioural domains, our framework addresses a critical gap in conventional pandemic preparedness tools. Our framework supports scientists, public health practitioners, and policymakers in tracing emerging epidemic risks from increasing social and environmental disruptions, such as growing inequalities in cities and anthropogenic land-use change. We argue that addressing these imbalances calls for a collaborative effort to build societal resilience, where prioritising biodiversity conservation, socio-environmental equity, and participatory decision-making will be key to strengthening preparedness against future pandemic crises.