HIV

Question 1

risk factor groups of HIV

Answer 1

-heroin addicts
-homosexuals
-haemophiliacs
-haitains

Question 2

what type of virus is hiv

Answer 2

retrovirus OF THE LENTIVIRUS GENUS

Question 3

what cells does hiv attack

Answer 3

cd4+ receptors on cells such as macrophages, t helper cells and dendritic cells

Question 4

two types of HIV

Answer 4

HIV1- US and worldwide
HIV2- MORE RARE, western africa

Question 5

STRUCTURE OF HIV

Answer 5

Spherical in shape
- 2 copies of single stranded rna
- enclosed with a capsid of viral protein p24

Question 6

how can hiv be spread/ transmitted

Answer 6

• contact of infected bodily fluids
• sharing of IV needles
• medical procedures, skin grafts, organ donations
• pregnancy/ during delivery

Question 7

names of the stages of the viral replication

Answer 7

attachment
cell entry
interaction with host cells
replication
assembly
release

Question 8

describes the stages of HIV replication

Answer 8

-HIV attaches to cd4+ receptors using a co receptor such as gp120
-entry into cell and combines into host cells genome using viral integrase enzyme
- virus undergoes reverse transcription and sIngle strands of viral RNA are converted to double stranded DNA
- virion is then assembled, buds and leave the host cell ready to infect other cells

Question 9

main symptoms of acute HIV

Answer 9

• FEVER
  -oral candidiasis
  -swollen lymph nodes

Question 10

what is a lentivirus

Answer 10

represents a genus of slow viruses with a long incubation period

Question 11

what cells are mostly affected by hiv

Answer 11

CD4 T CELLS
macrophages
dendritic cells

Question 12

immune system response to HIV

Answer 12

• neutralises antibodies , but poor and slow to develop

cd8- cause an early decline in virus but virus escapes through mutations

Question 13

main immune system effect from hiv

Answer 13

progressive decline in number and function of CD4 LYMPHOCYTES

Question 14

mechanisms of cd4+ lymphocyte depletion

Answer 14

• direct cytotoxicity of directly infected cells
• activate induced death
• decrease in production
  -redistribution
• bystander cell killing

Question 15

socio-economic impact of
HIV/AIDS in Africa

Answer 15

• low life expectancty
• loss of economic workers
  -increased spending on healthcare
  -distortion of healthcare spending
• stigma of hiv

Question 16

When does HIV become AIDS

Answer 16

WHEN the cd4 is less than <200 cells per ml

Question 17

what problems arise when developing an immune response to HIV

Answer 17

• low neutralising antibodies and variability of gp120 means antibodies cant keep up with production
• glycoprotein envelope shows genetic diversity
• failure of cd4+ proliferation

Question 18

two markers used to monitor HIV infection

Answer 18

cd4+ cell count
HIV viral load

Question 19

what to do with patient with fever , rash + non specific symptoms

Answer 19

1- take a sexual history
2- think of hiv
3- tell lab and check for antigen

Question 20

how to prevent HIV

Answer 20

Circumcision - reduced ability of HIV to penetrate
STI control
Vaccines
HIV diagnosis

Question 21

types of hiv tests

Answer 21

point of care tests
venous blood samples
home testing kits

Question 22

treatments for HIV

Answer 22

Nucleoside reverse transcriptase inhibitors ( NRTI) and either a protease inhibitor or NNRTI

Question 23

what does HAART involve

Answer 23

act on different proteins in replication cycle to suppress viral replication

Question 24

two main methods that hiv develops drug resistance

Answer 24

non adherence
drug-drug interactions

Question 25

main immunological changes seen in progressive HIV

Answer 25

reduction in CD4 count
increase B2-microglobulin
decreased IL-2 production
polyclonal B-cell activation
decrease NK cell function
reduced delayed hypersensitivity responses

Question 26

Examples of an nnrti

Answer 26

nevirapine