Taxonomy of HIV: To which Retroviridae subfamily does human immunodeficiency virus (HIV) belong?

Introduction / Context:
Viral taxonomy reflects biological behavior. HIV is a lentivirus—characterized by long incubation periods, persistent infection, and progressive immunopathology—placing it within the Retroviridae subfamily Lentivirinae.

Given Data / Assumptions:

• Family: Retroviridae (reverse-transcribing RNA viruses).
• Ask: correct subfamily designation for HIV.
• Compare with other retroviral subgroups.

Concept / Approach:
Lentiviruses (e.g., HIV-1, HIV-2, SIV, FIV) cause slowly progressive diseases. Oncovirinae historically included oncogenic retroviruses (now Orthoretrovirinae subfamilies like Gammaretrovirus/Deltaretrovirus), while Spumavirinae covers foamy viruses (Spumaretrovirinae).

Step-by-Step Solution:
Match pathogen (HIV) → clinical behavior (slow, persistent) → Lentivirinae. Exclude oncogenic (HTLV) and foamy virus groupings. Select “Lentivirinae.”

Verification / Alternative check:
Standard virology texts and ICTV classifications list HIV under Lentivirinae.

Why Other Options Are Wrong:
Oncovirinae corresponds to tumor-associated retroviruses; Spumavirinae are foamy viruses; “None of these” is incorrect.

Common Pitfalls:
Confusing HIV (lentivirus) with HTLV (deltaretrovirus/oncogenic category).

Final Answer:
Lentivirinae.