HIV

Question 1

HIV is known as a reterovirus, why?

Answer 1

“Backwards virus” because it converts ssRNA to DNA and then back to ssRNA using reverse transcription

Question 2

Which receptors does HIV need to bind to order to enter the cell?

Answer 2

Binds to CD4 receptor

AND a co-receptor (either CCr5 or CXCR4)

Question 3

Without CD4 cells, which cells are unable to carry out their function of killing virally infected cells?

Answer 3

CD8 + T cells (cytotoxic)

Question 4

Once inside the cell, how does HIV replicate?

Answer 4

Uses reverse transcription and integrates the transcribed DNA into the host DNA- the viral proteins are then transcribed and the cell dies and proteins go on to infect more cells

Question 5

How is HIV transmitted?

Answer 5

Through the blood:
Sexual contact 
Transfusion 
Contaminated needles 
Perinatal transmission

Question 6

How is HIV diagnosed?

Answer 6

Blood tests- serology for Ag and Ab- risk of false negative and PCR to follow up
Rapid tests can be used in urgent situations - finger prick/oral

Question 7

What treatment is used for HIV?

Answer 7

3 antiretroviral drugs (to prevent resistance)
A nucleotide reverse transcriptase inhibitor

A non-nucleotide reverse transcriptase inhibitor OR protease inhibitor

An integrase inhibitor

Question 8

What is the aim of the antiretroviral drugs used to treat HIV?

Answer 8

To get viral load to an undetectable level to reduce transmission and progression of HIV to AIDS

Question 9

During the infection progression of HIV, what happens a few weeks after primary infection?

Answer 9

Viral load increases exponentially
CD4+ cells temporarily drop
Seroconversion
Flu-like symptoms, rash, fever

Question 10

What happens during the latent infection period of HIV progression?

Answer 10

Viral load decreases to very low levels
Asymptomatic
The lower the viral load the more likely the patient will the healthy longer
10-15 years, can be shorter

Question 11

What happens during symptomatic period of infection by HIV?

CD4 + cells are at which level?

Answer 11

Coughs, colds, psoriasis, dermatitis, TB become apparent

CD4+ cell count around 350cells/microL

Question 12

At stage 4 of HIV progression, the patient is said to have what?
How does this present?

Answer 12

Severe infection/ AIDS (CD4+ cells <200per microL) 
PCP
Toxoplasmosis 
CMV
Lymphoma