HIV Lab Testing Flashcards
(19 cards)
How many HIV viruses are there?
HIV 1 and HIV 2
distinct viruses
How many HIV/AIDS patients are present in sub-saharan africa compared to the rest of the world?
2/3 of total HIV/AIDS cases
What is the predominant HIV virus worldwide?
HIV 1
What enzyme do retroviruses use to convert RNA to DNA?
Reverse transcriptase
What group of retroviruses does HIV belong?
Lentiviruses
What enzyme does HIV use to integrate its DNA with that of the host cell?
Integrase
Name the 4 groups of HIV 1
Which group is responsible for the global HIV epidemic?
Group M
Group N
Group O
Group P
HIV 1 Group M is the strain responsible
How many subtypes of HIV 1 Group M are there?
Why are these subtypes important?
10
Different treatment for different subtypes
What lab tests can you use to diagnose HIV?
Antigen/ Antibody tests
4th generation ELISA assays are the big ones
-Allow simultaneous detection of antibody and antigen
What lab tests can you use to manage HIV infection?
Viral Load HIV resistance testing Subtype determination Tropism testing Drug levels
What do we mean by the diagnostic window period?
Why is this important?
Time during which markers of infection are not detectable
Testing during this period can result in false negatives
(Varies between individuals)
What is Viral load testing used for?
Used to monitor the effectiveness of HIV treatment
Used for diagnoses in presence of maternal antibody
What is important to remember about viral load and transmission?
Can still transmit with an undetectable viral load
What does HIV resistance testing involve?
Very basic terms
Sequencing of the polymerase and protease genes
Identification of specific mutations that confer resistance to antiretroviral drugs
What is HIV resistance Testing used for?
4 points
Baseline at diagnosis
Suboptimal treatment response
Treatment failing
Want to change treatment for another reason
What is tropism testing?
What does it do and why do we do it?
Which co-receptor does the virus use to enter CD4 cells, required before using a CCR5 antagonist
Why might we test drug levels in a HIV patient?
Compliance
When will a patient have to inform work of their HIV diagnosis?
Only if they require you to have a HIV test
(May need a HIV test to work abroad)
(If involved in healthcare will need to avoid exposure prone procedures (EPPs))
How do you monitor HIV infection?
CD4 lymphocyte count
HIV viral load
Clinical features
