Epidemiology is the science of how disease develops in populations, with applications in
human, animal and plant diseases. For plant diseases, epidemiology has developed as a quantitative
science with the aims of describing, understanding and predicting epidemics, and intervening to
mitigate their consequences in plant populations. Although the central focus of epidemiology is
at the population level, it is often necessary to recognise the system hierarchies present by scaling
down to the individual plant/cellular level and scaling up to the community/landscape level. This is
particularly important for diseases caused by plant viruses, which in most cases are transmitted
by arthropod vectors. This leads to range of virus-plant, virus-vector and vector-plant interactions
giving a distinctive character to plant virus epidemiology (whilst recognising that some fungal,
oomycete and bacterial pathogens are also vector-borne). These interactions have epidemiological,
ecological and evolutionary consequences with implications for agronomic practices, pest and disease
management, host resistance deployment, and the health of wild plant communities. Over the last two
decades, there have been attempts to bring together these differing standpoints into a new synthesis,
although this is more apparent for evolutionary and ecological approaches, perhaps reflecting the
greater emphasis on shorter often annual time scales in epidemiological studies. It is argued here that
incorporating an epidemiological perspective, specifically quantitative, into this developing synthesis
will lead to new directions in plant virus research and disease management. This synthesis can serve
to further consolidate and transform epidemiology as a key element in plant virus research.