Dr. Robert, from internet based search I have found that HIV was recognized on 1st of December, 1981. But when HTLV-III was recognized? Or HTLV I-II as initially they were considered to be the same as HTLV-III or HIV?
This gets a bit confusing, but I'll try to explain.
HTLV-I is an abbreviation for human t-cell lymphotropic virus type 1. It was discovered in 1977 in Japan. It is implicated in several illnesses, including adult T-cell leukemia/lymphoma. HTLV-II is a very closely related virus (70% genomic homology, which means very similar structures). It is found in IV drug users, Native Americans and also in some Caribbean and South American Indian groups. It has not been clearly linked to any diseases yet. HTLV-III was one of the initial names for HIV-1. In addition, HIV also used to be referred to as LAV: lymphadenopathy associated virus. These names were discontinued when the formal name HIV was adopted. HTLV-IV is an outdated name for HIV-2.
More recently HTLV-III and HTLV-IV have been used to describe recently characterized viruses that were discovered in Cameroon in 2005.