haem

Question 1

HIV definition (G)

Answer 1

HIV is a lentovirus (in retrovirus family) that infects CD4 T helper cells resulting progressive destruction of the immune system and onset of AIDS

AIDS (acquired autoimmune deficiency syndrome) is opportunistic infections due to reduced immune response (typically takes 8-10 years to develop)

Question 2

HIV epidemiology (G)

Answer 2

-HIV-1 most prevalent in the UK, HIV-2 most prevalent in West Africa
-UK have reached 90 90 90 target (90% of positive cases diagnosed, 90% of these on antiretroviral treatment, 90% of these with viral suppression)
-global decline in recent years

Question 3

HIV aetiology (G)

Answer 3

-bodily fluids (sexual intercourse)
-blood (IVDU, needlestick injury)
-vertical transmission

Question 4

HIV risk factors (G)

Answer 4

-MSM
-unprotected penile-vaginal, oral, anal sex
-sex workers
-IVDU
-sharing needles

Question 5

HIV pathophysiology (G)

Answer 5

-HIV gp120 binds to CD4 T helper cells
-endocytosis of HIV RNA , reverse transcriptase and viral proteins into the cell
-reverse transcriptase converts HIV RNA > DNA, this travels across the nucleus and integrase integrates it into the host DNA
-protein synthesis: new copies of RNA and viral proteins
-these move to the cell membrane to assemble an immature HIV
-immature HIV exits the cell and viral protease forms mature infectious HIV
-results in an increase in HIV viral copies, decrease in CD4 T helpers
-CD4 under 200 is AIDS

Question 6

HIV stages and presentation (G)

Answer 6

1. seroconversion (primary/ acute infection)- glandular fever like symptoms
   -maculopapular rash
   -mouth ulcers
   -mild lymphadenopathy