HIV

Question 1

What type of virus?

Answer 1

Human retrovirus

Question 2

What cells does it infect?

Answer 2

Immune system cells and cause immunodeficiency

Question 3

Characteristics

Genome, enveloped etc

Answer 3

2 copies of positive single-stranded RNA
Enveloped

Question 4

What are the genotypes?

Answer 4

HIV-1
HIV-2

Question 5

Briefly describe how HIV infects cell

Answer 5

1. Attachment, entry, and uncoating
2. Reverse transcription and integration
3. Synthesis of viral parts
4. Assemebly and release

Question 6

Briefly describe the pathogenesis of untreated HIV

Primary infection -> Latency -> Progression to?

Answer 6

1. Primary infection (weeks)
   - Burst of viremia
   - Transient decline in CD4 cells
2. Latency (years)
   - Immune system fights off virus
   - Chronic low level viremia
3. Progression to AIDs
   - CD4 cell loss outweighs production (apoptosis, direct killing)

Question 7

What are the clinical features of primary infection?

Answer 7

Fever, cough, cervical lymphadenopathy, maculopapular rash, rash on chest

Question 8

What are the clinical features of latent infection?

Answer 8

Asymptomatic OR fever, malaise, loss of weight

Question 9

How to screen and diagnose?

Answer 9

1. PCR and culture: detect low levels of HIV DNA
2. HIV antibody tests: ELISA

Question 10

What is a confirmation test?

Answer 10

Western blot analysis

mandatory second test type

Question 11

What are AIDs-defining conditions marked by?

Answer 11

• CD4+ cell count of less than 200 cells per ul of blood
• Apperance of 1 or more of the typical opportunistic infections or cancers

Question 12

What are the clinical presentations of AIDs?

Answer 12

Oral thrush, cachexia, Kaposi’s sarcoma, Pneumocystis jiroveci pneumonia, Mycobacterium avium complex

Question 13

How is it transmitted?

Answer 13

• Mother to child
• Sexual transmission
• IV Drug users
• Health care staff

Question 14

What are some preventions?

Answer 14

• Advice to seropositive women
• Safer sexual practices
• Use of condoms
• Fewer partners
• Active treatment of other STDs
• Advice to stop injecting
• Do not share “works”
• Needle/syringe exchange programmes
• Advice on infection control
• Safe work practices

Question 15

What is the route of transmission?

Answer 15

Rectal and vaginal mucosa

Question 16

What is the first drug to reduce HIV risk? What is it?

Answer 16

Truvada
* Combination of 2 antiretroviral agents (emtricitabine and tenofovir)
* Protect uninfected high-risk person if drug is taken daily before and after exposure