Human Immunodeficiency Virus (HIV) and AIDS Vocabulary

Flashcards covering key definitions, viral enzymes, life cycle stages, clinical manifestations, diagnosis criteria, and treatment modalities for HIV and AIDS.

HIV

Human Immunodeficiency Virus; a retrovirus that targets and destroys CD4+ T cells, leading to immune system collapse if left untreated.

AIDS

Acquired Immune Deficiency Syndrome; severe immune system dysfunction caused by HIV, diagnosed when CD4+ cell count drops below $200\,\text{cells/mm}^3$ or an AIDS-defining condition is present.

HIV-1

The first discovered and most prevalent strain of the Human Immunodeficiency Virus worldwide.

HIV-2

A less pathogenic strain of the Human Immunodeficiency Virus that is largely confined to West Africa.

Retrovirus

A type of virus that utilizes the enzyme reverse transcriptase to translate its RNA genetic material into DNA.

Reverse transcriptase

A viral enzyme that makes a DNA copy from the HIV viral RNA genetic material.

HIV integrase

A viral enzyme that assists in inserting the viral DNA copy into the genetic material of the host cell.

HIV protease

A viral enzyme responsible for the final stages of virus production, assembling virus particles to be released to attack new cells.

Seven stages of HIV life cycle

The step-by-step process of viral replication: 1. Binding, 2. Fusion, 3. Reverse transcription, 4. Integration, 5. Replication, 6. Assembly, and 7. Budding.

Seroconversion

The phase in early HIV infection when anti-HIV antibodies become detectable in the blood, typically accompanied by flu-like symptoms for several weeks.

Stage 1: Early infection (Acute)

Initial stage characterized by rapid viral replication, lack of detection by traditional lab tests, absence of symptoms initially, followed by seroconversion.

Stage 2: Clinical latency (Chronic)

Stage where viral levels stabilize; lasts 3 to 12 years without treatment (or decades with treatment) and is generally asymptomatic or mild in symptoms.

Stage 3: Symptomatic HIV infection

Advanced stage marked by a persistent drop in CD4+ T cell count, increased viral load, ineffective immune defense, and progression to AIDS.

AIDS-defining conditions

Specific opportunistic illnesses or neoplasms (e.g., Kaposi's Sarcoma, Wasting Syndrome, Pneumocystis Jiroveci Pneumonia, pervasive candidiasis) required for an AIDS diagnosis.

HIV-associated dementia

Also known as AIDS dementia complex; a cognitive dysfunction causing memory loss, mental slowness, behavioral changes, word-finding difficulty, and motor/speech/balance problems.

Percutaneous needle-stick injury

An occupational blood exposure route for healthcare workers that carries an HIV transmission risk of less than $1\%$.

Antiretroviral therapy (ART)

Pharmacological treatment for HIV aimed at reducing viral load to undetectable levels, most commonly consisting of dual nucleosides plus a third agent.

NRTIs

Nucleoside Reverse Transcriptase Inhibitors; an ART drug class that inhibits reverse transcriptase to block viral RNA incorporation into host DNA, carrying a black box warning for lactic acidosis syndrome.

PrEP (Pre-exposure prophylaxis)

The use of antiretroviral medications prior to potential exposure, combined with condom use, which can lower HIV transmission risk by greater than $90\%$.

PEP (Post-exposure prophylaxis)

Emergency treatment consisting of ART taken for 28 days following potential exposure, accompanied by HIV testing initially and at 6 and 12 weeks.