Blood Borne Viruses / CRP

Question 1

Classify HIV.

Answer 1

Single strand, enveloped, +ve RNA virus. It is a retrovirus.

Question 2

What are the types of HIV?

Answer 2

HIV-1: most common around the world (originally from chimpanzees). HIV-2: confined to W. Africa, less virulent.

Question 3

How can HIV-1 be further divided?

Answer 3

Group M: Subtypes: A-D, F-H, J-K; Group N, O, P; A - Sub-Saharan Africa; B - Europe, Americas; Most research goes into HIV-1 Type B despite Type A being the most prevalent in the world.

Question 4

How is HIV transmitted?

Answer 4

Sexually transmitted, Blood and bodily fluids (semen, saliva), Vertical transmission.

Question 5

What are the significant parts of the HIV virus?

Answer 5

p24 which is an antigen/antibody that can be detected.
Reverse transcriptase allows the virus to replicate.

Question 6

How does HIV cause disease?

Answer 6

Viral RNA is transcribed to single-strand DNA and integrates into the host genome.

Question 7

What is seroconversion? How long will this take in the case of HIV?

Answer 7

The point when a specific antibody (HIV p24-antibody) is detectable in the blood. This happens around 2 weeks after infection (the incubation period), i.e. when symptoms may appear (glandular fever-like) although many are asymptomatic.

Question 8

How does HIV progress in patients?

Answer 8

Incubation period of ~2 weeks Then POSSIBLE symptoms: fever, malaise, myalgia, pharyngitis rarely meningoencephalitis. Then dormant only apparent through testing (HIV p24 antigen/antibody test). Progressive loss of T4 cells leading to immunodeficiency (AIDS) - patient is susceptible to opportunistic infections, Kaposi sarcoma and malignancies.