As it is usually a solo hunter it must select its prey well. The cheetah, just as any hunter or predator, usually selects the unhealthy, the injured, the weary, the starved, and the young. These animals are least apt to be able to protect themselves from the cheetah by fleeing. The cheetah's body is designed to help it run fast for short lengths of time to catch its prey. The cheetah has very little genetic diversity.
Most cheetahs are almost identical.
It has been shown that often the reason species of animals are disease resistant is because they have a diversity in their genetics from blood types to tissue types. This is what gives difficulties in blood transfusions and in organ or tissue donations. One has to find somone who is very close genetically so the body does not see that donation of tissue as being foreign such that it rejects it. This is one indication of the lack of genetic diversity in the cheetah for it is able to accept donor tissue from almost any other cheetah. Each time a pathogen enters the body of any species it learns that system better.