  In numerous contexts, individuals may decide whether they take actions to
mitigate the spread of disease, or not. Mitigating the spread of disease
requires an individual to change their routine behaviours to benefit others,
resulting in a 'disease dilemma' similar to the seminal prisoner's dilemma. In
the classical prisoner's dilemma, evolutionary game dynamics predict that all
individuals evolve to 'defect.' We have discovered that when the rate of
cooperation within a population is directly linked to the rate of spread of the
disease, cooperation evolves under certain conditions. For diseases which do
not confer immunity to recovered individuals, if the time scale at which
individuals receive information is sufficiently rapid compared to the time
scale at which the disease spreads, then cooperation emerges. Moreover, in the
limit as mitigation measures become increasingly effective, the disease can be
controlled, and the rate of infections tends to zero. Our model is based on
theoretical mathematics and therefore unconstrained to any single context. For
example, the disease spreading model considered here could also be used to
describe social and group dynamics. In this sense, we may have discovered a
fundamental and novel mechanism for the evolution of cooperation in a broad
sense.
