ABSTRACT
In this and the next chapter we look at some of the
classic plagues which have afflicted human popu-
lations for many centuries. Just how long such dis-
eases have been part of the human condition remains
a matter of speculation but it seems likely that most
followed on from the invention of agriculture. Before
that revolution (around 5000 BC), hunter-gatherers
were constantly on the move in small groups. They
ate varied diets, were too small in numbers to provide
long-term disease reservoirs, and were seldom pres-
ent long enough to allow oral-faecal diseases to
flourish in contaminated water supplies. But with
agriculture came settlement and sedentism. Peoples
lived in large numbers, increasingly at high densities,
and often cheek by jowl with their domesticated ani-
mals. In these conditions, water teemed with
pathogens, waste piled up, diets narrowed, and the
preconditions for rapidly spreading epidemic diseases
were established. As urban populations grew and
interacted with each other through expanding trade,
so also did the ability to carry the burgeoning number
of disease strains around the world.
