HIV Flashcards
What is HIV?
Human Immunodeficiency Virus, a lentivirus in the Retroviridae family that causes AIDS by infecting and destroying immune system cells.
What are the major structural genes of HIV?
GAG (codes for structural proteins like p24), POL (codes for enzymes like reverse transcriptase), ENV (codes for envelope proteins like gp120 and gp41).
What are the key enzymes of HIV?
Reverse transcriptase, protease, and integrase.
What are the phases of HIV infection?
Viral transmission, primary infection, seroconversion, clinical latency, early symptomatic infection, AIDS.
What is the global prevalence of HIV?
As of 2015, 36.7 million people were living with HIV, with 76% in sub-Saharan Africa.
What is the main route of HIV transmission in Nigeria?
Heterosexual contact, accounting for 37% of new infections.
What is the window period for HIV testing?
The period after infection when antibodies are not yet detectable, ranging from 3-12 weeks depending on the test generation.
What are the main modes of HIV transmission?
Unprotected sex, exposure to infected blood, contaminated needles, and mother-to-child during pregnancy, birth, or breastfeeding.
What cells does HIV target?
CD4+ T-cells and cells with CCR5 or CXCR4 chemokine receptors.
What is the primary function of reverse transcriptase in HIV?
Converts viral RNA into DNA, enabling integration into the host genome.
What are the stages of HIV’s life cycle?
Entry, reverse transcription, integration, protein synthesis, maturation.
What is the significance of gp120 and gp41 in HIV?
Gp120 binds to CD4 receptors; gp41 facilitates fusion with the host cell membrane.
What are AIDS-defining illnesses?
Infections and malignancies strongly associated with immunocompromised states, such as Kaposi sarcoma and Pneumocystis pneumonia.
What are the types of HIV?
HIV-1 (most common worldwide) and HIV-2 (prevalent in West Africa).
What are the diagnostic tests for HIV?
Antibody detection (ELISA, Western blot), antigen detection (p24), viral nucleic acid (PCR), and disease monitoring (CD4 count, viral load).
What is the 4th-generation ELISA test?
A test combining p24 antigen detection and antibody detection, reducing the window period to 2 weeks.
What is the gold standard for HIV diagnosis?
PCR (Polymerase Chain Reaction), detecting viral nucleic acids.
What is HAART?
Highly Active Antiretroviral Therapy, a regimen to suppress HIV replication and prevent AIDS.
What are entry inhibitors?
Drugs preventing HIV entry into cells, e.g., enfuvirtide (blocks gp41) and maraviroc (blocks CCR5).
What are protease inhibitors?
Drugs blocking HIV protease, preventing maturation of new viral particles.
What are the primary prevention methods for HIV?
Safe sex practices, blood screening, use of sterile needles, and antiretroviral therapy for prevention (e.g., PrEP, PEP).
What is the significance of p24 antigen in HIV?
An early marker for HIV infection detectable within 2 weeks of exposure.
What is the main difference between 3rd and 5th-generation ELISA tests?
5th-generation ELISA differentiates HIV-1 antibodies, HIV-2 antibodies, and p24 antigen with separate results.
What is the importance of CD4 count in HIV management?
CD4 count helps monitor disease progression and determine the risk of opportunistic infections.
