For a given probability of transmission, the equilibrium population size first decreases with disease death rate, then increases .
(the equilibrium population size; decreases then; T:For a given probability of transmission; T:first) (the equilibrium population size; increases; T:first; T:then)
the equilibrium population size the equilibrium population size
decreases then increases
T:For a given probability of transmission T:first
T:first T:then