Final answer:
The higher the subsistence strategies, the higher the spread of epidemic disease. Agricultural practices and urban densification contribute to increased disease spread, coupled with socio-economic factors affecting vulnerability to outbreaks. Diseases that don't provide lasting immunity in survivors have a greater capacity for recurrence and can lead to higher mortality over time.
Step-by-step explanation:
The higher the subsistence strategies, the higher the spread of epidemic disease. As the size and density of human populations increase, often due to agricultural practices, the likelihood of an epidemic spreading also increases. This is attributable to several factors: higher contact rates among people, greater dependency on a single food source that can be compromised, and an environment that aids in the proliferation of disease vectors. Additionally, pathogens that do not confer long-lasting immunity in survivors can spread more widely and recur, posing a constant threat to the population.
Historically, large urban areas and agricultural communities saw frequent epidemics due to factors like high human and animal waste accumulation, heightened disease vectors such as rodents or insects, and socio-economic variables influencing the distribution of disease. Super-spreading events, often seen in diseases like the plague, are more likely to occur in high-density environments where human traffic and disease vectors intersect.
Furthermore, certain infectious diseases cannot sustain themselves without a sufficiently large host population. For example, the measles virus requires a large contiguous population to continue its existence. In smaller, hunter-gatherer societies, diseases like measles would have likely died out after affecting the group due to limited hosts and consequent immunity in survivors.