but they have been proven a zillion times over for HIV.
there are at least 2 lymphotrophic viruses. there is now another one in africa, which causes wasting but is antibody negetive, because it does not cross react with the b type abbot antibody. but its readily picked up by pcr.
its estimated that there have been about 5 different zoonosis from the bush to man and back again
a good site is the aaron diamond hiv research center in manhatten