L13-HIV

Question 1

What are four classical signs of AIDS

Answer 1

Oral thrush
Kaposi’s sarcoma
Pneumocystis pneumonia (PCP)
malignancies

Question 2

Is HIV more common in men or women in the UK?

Answer 2

Men

Question 3

What kind of virus is HIV?

Answer 3

A ssRNA retrovirus

Question 4

What cells does HIV affect?

Answer 4

CD4+ T cells

Question 5

Fill out the following steps on how HIV infected CD4+ T cells

Answer 5

1) HIV binds CD4+ receptor on T cell and a coreceptor (CCR5)
2) HIV penetrates cell and empties its contents
3) ssRNA converted to dsDNA using RT
4) viral DNA is incorporated into cells DNA via integrase
5) cell divides and replicated the protein
6) protein buds out of cell and is cleaved to active form

Question 6

Name three ways in which HIV can be transmitted

Answer 6

Sexual contact 
Contact of bodily fluids with blood/broken skin 
Transfusion
Contaminated needles
Vertical transmission

Question 7

Account for the slight peak seen in the CD4+ count after its initial decline

Answer 7

It’s the immune systems attempt to overcome the virus

Question 8

Below what number of CD4+ T cells is the disease considered AIDS?

Answer 8

200

Question 9

Describe some early symptoms of HIV?

Answer 9

Patients often falling ill with
Fever
Weight loss
Pharyngitis 
Lymphadenopathy

Later symptoms may include
Rash 
Vomiting
Myalgia 
Oesophageal sores

Question 10

Describe some factors affecting the likelihood of successful HIV transmission

Answer 10

Anal intercourse
High viral load 
Breaches of the skin 
Lack of condom use
Presence of other STI’s

Question 11

What is the life expectancy of an otherwise healthy individual with HIV. And what factors are important for keeping their viral load down?

Answer 11

78 years
Early detection
Treatment and adherence to said treatment
Healthy living e.g. alcohol and smoking

Question 12

Describe the three diagnostic tests for HIV and the pros and cons of each

Answer 12

Serology - looks for the viral antigen and the HIV antibody.
-same day result but chance of false negative

PCR - highly sensitive, used to confirm HIV diagnosis, takes a while

Rapid tests
Less than an hour. Can show false positives

Question 13

What is the main aim of anti-retroviral drugs?

Answer 13

To reduce viral load - this also means transmission is near impossible if viral load is undetectable

Question 14

Where do the three main classes of anti-retrovirals act?

Answer 14

Prevent entry of virus to cell
Protease inhibitors to prevent activation of protein
Reverse transcriptase inhibitors

Often used in combination to prevent resistance developing