We can therefore think of disease transmission as a continuum. At one end, we have a situation where a single person – such as Mary Mallon – generates all of the cases. This is the most extreme example of superspreading, with one source responsible for 100 per cent of transmission. At the other end, we have a clockwork epidemic where each case generates exactly the same number of secondary cases. In most cases, an outbreak will lie somewhere between these two extremes.
