Lecture 19: HIV Flashcards
What are the subfamilies of retroviruses
Oncoviruses (HTLV-1, HTV-2)
Lentiviruses (HIV-1, HIV-2)
What are characteristics of aids
HIV positive, less than 200 CD4 indicator disease
Can you have HIV without aids
if you have HIV it does not mean that you have aids, aids is a syndrome you contract after becoming infected with HIV and become suspetable to the infection (immune system has to become compromised as virus has replicated and destroyed your CD4 cells doesn’t happen to everyone who contracts HIV if they are on appropriate management
What are characteristics of retroviruses
enveloped, positive-strand RNA virus, encodes reverse transcriptase
Replicate through a DNA intermediate, then back into RNA
The DNA copy is integrated (why it was so hard to treat) into the host chromosome to become a cellular gene
Who discovered retroviruses
HIV-1 was discovered in 1918 by Gallo and Montagnier
Subsequently, HIV-2 was isolated in West Africa
____ of HIV+ live in Africa
67% (7.5% of world)
What is HIV presented in
blood (or fluids contaminated by blood and serum)
Semen
Vaginal fluids
What are factors that increase infectiousness in HIV
Primary infection: high viral load
Late-stage: high viral load
Genital tract infections: mucosal breech and recruitment of inflammatory cells
What is the biggest determinate of HIV
Host related factors
Estimated ____ of people dont know they are infected with HIV
25%
What are the top risks of acquiring HIV
blood transfusion
mother to infant: 1 in 4 (with no treatment)
mother to infant with treatment
needle-sharing with IV drug use
anal
needle stick injury
How does HIV replicate
The mushroom shaped gp120 (protein on surface of HIV virus) of HIV interacts with the CD4 receptor surface molecule expressed on T-helper lymphocytes and cells of the macrophage lineage. through binding and fusion
- Reverse transcription: synthesizes a complementary DNA
- Integration: into our genome by integrate; Once integrated, viral DNA is transcribed like other host genes
- Replication: each copy contains approximately five errors or mutation
- Assembly
- Budding
How does HIV enter
by fusion with the cellular envelope
HIV infection of CD4 lymphocytes results in
cell death
___ are primarily responsible for cell mediated immunity
CD4s
As CD$ cells are lost, ____ and ____
opportunistic infections and malignancies occur
What is the course of aids with no treatment
High HIV load in blood
When does aids develop when
any of a number of signs of CD4 depletion occur
What are lab aspects of HIV
- Serology:
- screening tests for antibodies to a number of viral antigens by enzyme immunoassay
- confirmation using western blot - Immunologic studies: CD4 counts
- Viral load testing: PCR quantification of RNA in plasma
- Resistance genotyping:L looking at the sequences of the genes in the HIV to see if there are mutation that cause resistance
what is a BioRad Geenius
Differentiates HIV1 and HIV2
Removes subjectivity
rapid (30 min)
What are the goals of HIV therapy
Maximal and durable suppression viral load
Restoration or preservation of immune function
Improvement in quality of life
Reduction of HIV morbidity and mortality
Preservation of future treatment options
Why is it important to suppress the viral load in HIV
now with some therapies we can drop someones viral load to the point where it is undetectable, if you are undetectable it is not sensitive enough to be picked up on a lab test and you cant transmit the virus when you are undetectable
Why is it important to preserve future treatment options for HIV
get simple, less drugs, less time a day makes people compliant to stay on drugs if they come off they could become resistant
What is the treatment for HIV
anti retro-virals
specifically nucleoside analogs (reverse transcriptase inhibitors)
lots more options now too ex. protease, fusion and integrate inhibitors
What did treatment for HIV look like in the past
there were only 3 types of nucleoside analogs
(ALT, 3CT, DDI)
do you treat right away: only 3 options could become resistant if not compliant
so often would wait for them to absolutely need to the drug
What is HAART
highly active anti retroviral therapy
When was there a big drop in HIV
1997 as appropriate therapy (HAART)
What does the risk of infection in a needle stick exposure depend on
stage of patients disease (primary is worst, or terminal without management)
How much blood (hollow (blood inside) vs. solid, gauge of needle, aspiration vs. injection)
What to do if you have a needle stick exposure
report to occupational health
Confirm patients status
document your status (for insurance purposes, prove that you weren’t hurt before exposure)
begin antiviral phorphylaxis (take with 72 hours of exposure)
