An epidemic curve, also known as an epi curve or epidemiological curve, is a statistical chart used in epidemiology to visualise the onset of a disease outbreak. It can help with the identification of the mode of transmission of the disease. It can also show the disease's magnitude, whether cases are clustered or if there are individual case outliers, its trend over time, and its incubation period.[1][2] It can give outbreak investigators an idea as to whether an outbreak is likely to be from a point source (such as from a food handler), a continuous common source (with ongoing contamination), or a propagated source (that is transmitted primarily between people).[3][4]
Epidemic curves generally show the frequency of new cases compared to the date of disease onset.[2]