HIV/AIDS: Transmission, Pathogenesis, Opportunistic Infections, and Modern Management

HIV (human immunodeficiency virus) → AIDS (acquired immunodeficiency syndrome) if untreated.

Transmission

• Sexual (vaginal, anal, oral — receptive higher risk)
• Blood: needle sharing, transfusion (rare screened), occupational
• Perinatal: pregnancy, delivery, breastfeeding
• NOT: casual contact, saliva, sweat, tears, insects, surfaces

Pathogenesis

• CD4+ T-cell depletion → immune collapse
• Viral replication → chronic immune activation → inflammation, comorbidities

Stages

1. Acute seroconversion (flu-like, high viremia)
2. Clinical latency (years, ongoing replication)
3. AIDS: CD4 <200 or OI

Opportunistic Infections (AIDS-defining)

• PCP (Pneumocystis pneumonia)
• MAC (Mycobacterium avium complex)
• Cryptococcal meningitis
• Toxoplasmosis encephalitis
• Kaposi sarcoma (HHV-8)
• Cervical cancer (HPV)
• Wasting syndrome

Modern Management

• ART (antiretroviral therapy): 2+ drug classes, lifelong.
• Goal: viral suppression (<50 copies/mL) → immune recovery, U=U.
• First-line: INSTI-based (bictegravir, dolutegravir) + 2 NRTIs.
• PrEP (pre-exposure): TDF/FTC or TAF/FTC or cabotegravir LA.
• PEP (post-exposure): 28-day ART within 72h.

With ART, HIV is a manageable chronic condition. Life expectancy near normal if diagnosed early and treated.