Lecture Notes: Human Immunodeficiency Virus
(HIV)
1. Introduction
HIV (Human Immunodeficiency Virus) is a retrovirus that attacks CD4+ T lymphocytes, leading to
progressive immunodeficiency. Untreated HIV leads to AIDS (Acquired Immunodeficiency
Syndrome).
2. History
First recognized in 1981 (opportunistic infections & Kaposi’s sarcoma). Virus identified in 1983 by
Luc Montagnier & Robert Gallo.
3. Virology
Family: Retroviridae, genus Lentivirus. Enveloped RNA virus with two copies of single-stranded
RNA. Enzymes: Reverse transcriptase, Integrase, Protease. Glycoproteins gp120, gp41. Types:
HIV-1 (worldwide, more pathogenic) and HIV-2 (West Africa, less transmissible).
4. Modes of Transmission
Sexual (unprotected intercourse), Bloodborne (transfusions, needles), Mother-to-child (pregnancy,
delivery, breastfeeding), Occupational exposure (needlestick).
5. Pathogenesis
HIV binds CD4 receptor + co-receptors (CCR5, CXCR4). Reverse transcription and integration into
host genome. CD4+ T-cell destruction → immunodeficiency. AIDS develops when CD4 <200
cells/µL or AIDS-defining illnesses appear.
6. Clinical Features
Acute infection (flu-like symptoms). Latency (asymptomatic or persistent lymphadenopathy). AIDS
(opportunistic infections, malignancies, neurological issues).
7. Diagnosis
Screening: ELISA (4th gen). Confirmatory: Western blot, Immunofluorescence, PCR. Monitoring:
CD4 count, Viral load.
8. Treatment
No cure but controlled with ART (Antiretroviral Therapy). Combination of ≥3 drugs from at least 2
classes. Classes: NRTIs, NNRTIs, Protease inhibitors, Integrase inhibitors, Entry inhibitors. Goals:
Suppress viral load, restore immunity, reduce transmission.
(HIV)
1. Introduction
HIV (Human Immunodeficiency Virus) is a retrovirus that attacks CD4+ T lymphocytes, leading to
progressive immunodeficiency. Untreated HIV leads to AIDS (Acquired Immunodeficiency
Syndrome).
2. History
First recognized in 1981 (opportunistic infections & Kaposi’s sarcoma). Virus identified in 1983 by
Luc Montagnier & Robert Gallo.
3. Virology
Family: Retroviridae, genus Lentivirus. Enveloped RNA virus with two copies of single-stranded
RNA. Enzymes: Reverse transcriptase, Integrase, Protease. Glycoproteins gp120, gp41. Types:
HIV-1 (worldwide, more pathogenic) and HIV-2 (West Africa, less transmissible).
4. Modes of Transmission
Sexual (unprotected intercourse), Bloodborne (transfusions, needles), Mother-to-child (pregnancy,
delivery, breastfeeding), Occupational exposure (needlestick).
5. Pathogenesis
HIV binds CD4 receptor + co-receptors (CCR5, CXCR4). Reverse transcription and integration into
host genome. CD4+ T-cell destruction → immunodeficiency. AIDS develops when CD4 <200
cells/µL or AIDS-defining illnesses appear.
6. Clinical Features
Acute infection (flu-like symptoms). Latency (asymptomatic or persistent lymphadenopathy). AIDS
(opportunistic infections, malignancies, neurological issues).
7. Diagnosis
Screening: ELISA (4th gen). Confirmatory: Western blot, Immunofluorescence, PCR. Monitoring:
CD4 count, Viral load.
8. Treatment
No cure but controlled with ART (Antiretroviral Therapy). Combination of ≥3 drugs from at least 2
classes. Classes: NRTIs, NNRTIs, Protease inhibitors, Integrase inhibitors, Entry inhibitors. Goals:
Suppress viral load, restore immunity, reduce transmission.
