19. HIV and AIDS – Flashcards
Unlock all answers in this set
Unlock answersquestion
| What are retroviruses? |
answer
| - Viruses that carry their genetic material in the form of RNA - Have reverse transcriptase which allows transcription of RNA to DNA |
question
| What are some subfamilies of retroviruses? |
answer
| - Oncoviruses (HTLV-1, HTLV-2) - Lentiviruses (HIV-1, HIV-2) |
question
| HIV is a ___, AIDS is a _____ diagnosis. |
answer
| virus, clinical |
question
| Who is considered as having AIDS? |
answer
| people who are HIV positive and have less than 200 CD4 cells, or have an AIDS indicator disease |
question
| Describe retroviruses |
answer
| - enveloped - positive-strand RNA virus - encodes reverse transcriptase |
question
| Retroviruses replicate through a ___ ___. |
answer
| DNA intermediate |
question
| A retrovirus' DNA copy is integrated into the __ ___ to become a cellular gene |
answer
| host chromosome |
question
| Gallo and Montagnier discovered which retrovirus in 1981? (duh) |
answer
| HIV-1 |
question
| How many people are living with HIV? |
answer
| 33 million |
question
| How many people with HIV die each year? |
answer
| 3 million |
question
| How many new infections of HIV occur per year? What about in children? |
answer
| 7 million 580,000 in children |
question
| Two-third of world HIV infections occur in _____ |
answer
| Sub-Saharan Africa |
question
| 1 out of ____ sexually active adults in the world have HIV |
answer
| 100 |
question
| The prevalence of HIV is highest in which group? |
answer
| Men who have sex with men |
question
| How can HIV be transmitted? (how likely is it for each way) |
answer
| - blood (or fluids contaminated by blood and serum) --> 99% chance you'll get it - Semen - vaginal fluids - oral sex (but it is difficult for it to be transmitted this way) |
question
| What host related factors increase infectiousness? |
answer
| primary infection (highest risk due to peak in viral load) late infection genital tract infections ulcers |
question
| What is the risk probability of transmitting HIV from a needle stick? |
answer
| 1 in 200-300, so .3% |
question
| What is the risk probability of transmitting HIV from mother to infant? |
answer
| 1 in 4, or 1 in 25 with treatment |
question
| Describe how HIV initiates replication |
answer
| - gp120 of HIV interacts with the CD4 surface molecule expressed on T helper lymphocytes - this leads to fusion of the viral membrane and the cell membrane and viral genetic material enters in the host cell |
question
| Once HIV releases its genetic material in the T cells, what happens?! |
answer
| - reverse transcriptase synthesizes a complementary DNA strand - then, a copy of the DNA strand is produced - it becomes integrated into our genome by integrase |
question
| Once the retroviruses DNA copy gets integrated into our genome what happens? |
answer
| - viral DNA is transcribed like other host genes - each copy contains approx. five error or mutation |
question
| Why does it matter that viruses have sloppy polymerase? |
answer
| When there's a bunch of mutations going on, the virus may be changed such that drugs normally used to treat the virus can no longer bind. The virus may become resistant... solution is to use a cocktail of drugs |
question
| What effect does HIV have on CD4 lymphocytes? |
answer
| It results in cell death by direct effect or by triggering apoptosis |
question
| Antibodies against p120 may produce ___ ___ ___ |
answer
| antibody dependent cytotoxicity |
question
| CD4s are primarily responsible for which areas of the immune response? |
answer
| delayed type hypersensitivity cell mediated immunity |
question
| Why are people with HIV at higher risk of opportunistic infection and malignancies? |
answer
| CD4 cells also help B cells... defect in B cells BAD |
question
| When does the peak of HIV in blood occur? |
answer
| around 6 weeks after clinical latency it increases until death (6 to 10 years) |
question
| What is the trend of CD4 T cell count with HIV? |
answer
| steep decline from 0-6 weeks, increase from 6 to 12 weeks followed by a slow decline until death at 11 years |
question
| Describe the trend of antibody against HIV |
answer
| rises slowly until about 1 year then decreases until 8.5 years (before death) |
question
| List some opportunistic infections characteristic of AIDS |
answer
| -Oral candidas -Toxoplasmosis -Cryptococcal meningitis -Severe herpes -Cytomegalovirus -TB -Pneumocystis pneumonia |
question
| What are some malignancies associated with AIDS? |
answer
| Kaposi's sarcoma Lymphoma Cervical cancer |
question
| What are other clinical syndromes associated with AIDS? |
answer
| AIDS related dementia wasting syndrome |
question
| Above 400 CD4/mm^3, what develops? |
answer
| lymphoma |
question
| At 400 CD4/mm^3, what develops? |
answer
| CNS disorders |
question
| Below 200 CD4/mm^3, what develops? |
answer
| Wasting of HIV |
question
| Describe serology test for HIV |
answer
| - It involves a screening test for antibodies to a number of viral antigens by enzyme immunoassay - Confirmation is done using a western blot |
question
| Briefly explain a western blot |
answer
| - you use an antibody to detect a protein... so wherever there is a protein, antibody will bind to it - you run it on a gel because that separates the proteins by either structure or length of the polypeptide - then you stain it with antibody specific to the target protein |
question
| What type of immunologic studies are used in the lab to detect, stage or monitor HIV? |
answer
| CD4 counts |
question
| What other lab aspects are used to examine HIV? |
answer
| - Viral load testing - Resistance genotyping (to see if sequences of genes in HIV have mutations that cause resistance) |
question
| Hi . If you are reading this please go look at slide 17 of the HIV lecture. |
answer
| thank you ma'am |
question
| What are important points to touch on in pre/post test HIV counselling? |
answer
| - What is HIV - how it's spread - pros and cons of being tested - how the test is done - explain accuracy of the test (false positives) - how results will be obtained - meaning of a positive result |
question
| Name some anti-retrovirals. (It'll be so fun!! woo) |
answer
| - Nucleoside analogs (reverse transcriptase inhibitors) - Non-nucleoside reverse transcriptase inhibitors - Protease inhibitors - Fusion inhibitrs - Integrase inhibitors |
question
| Was is HAART? |
answer
| highly active anti retroviral therapy |
question
| What are some problems with the treatment of HIV/AIDS? |
answer
| -Side effects -Compliance -Resistance -Cost |
question
| When should you start therapy for HIV/AIDS? |
answer
| Controversy!! - Some say early on so that high viral loads aren't achieved... avoid transmission - Some say only when patient is socially, emotionally stable to avoid issues such as cost and compliance |
question
| Why did the rate of HIV disease decline significantly since 1996? |
answer
| HAART |
question
| The mortality rate associated with HIV is similar to that of ___ or __ |
answer
| chronic liver disease or diabetes |
question
| The risk of infection upon needle stick exposure depends on: |
answer
| The stage of the patient's disease --> viral load How much blood --> hollow vs solid needle, gauge of the needle and was it aspiration vs. injection |
question
| What should you do if you've have a needle stick? |
answer
| -Confirm the patient's HIV status -Document your status (with occupational health) -Begin antiviral prophylaxis |
question
| Who might be considered for pre-exposure prophylaxis? |
answer
| - MSM with high risk sexual activity - Heterosexuals with multiple partners in areas of high HIV risk - partners of people with HIV (who have high viral loads) - IVDU |
question
| What is the prophylaxis drug called? |
answer
| Tenofovir + emtricitabine Tuvada |
