system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
When was HIV virus discovered?
assistant
The correct answer is  Ans. is 'a' i.e., 1983(Ref: Harrison, 18th/e, p. 3146)* In 1983, human immunodeficiency virus (HIV) was isolated from a patient with lymphadenopathy, and by 1984 it was demonstrated clearly to the causative agent of AIDS.