Why are there no doented cases of AIDS in Africa until 1982 even though in America it goes back to 1979?

Doentation is unreliable in Africa. It is a known fact that HIV is common in species of monkey that live in Africa, and that African tribes hunt monkeys for food (so called bush meat). It doesn't take a genius to realize that a cross species jump occurred because someone in Africa must have eaten monkey flesh raw or perhaps even drank the blood of the monkey.