The foremost reason any plague or pandemic spreads is due to lack of public sanitation, hygiene, and nutrition. These three factors relate directly to the health of our immune systems. Establishing the infrastructure for treated potable water and treated sanitation, along with good nutrition makes the plague and pandemics impossible in today's society. When fecal matter contaminates untreated public drinking supplies, and there is widespread poor nutrition that taxes the immune systems of so many, this is when the spread of disease becomes perilous.
The foremost reason any plague or pandemic spreads is due to lack of public sanitation, hygiene, and nutrition. These three factors relate directly to the health of our immune systems. Establishing the infrastructure for treated potable water and treated sanitation, along with good nutrition makes the plague and pandemics impossible in today's society. When fecal matter contaminates untreated public drinking supplies, and there is widespread poor nutrition that taxes the immune systems of so many, this is when the spread of disease becomes perilous.