DDT 18- Human Immonodeficiency Virus Infection

Question 1

where does HIV originate from

Answer 1

SIV Simian immunodeficiency virus but mutated and infected humans

Question 2

2 types of HIV

Answer 2

HIV 1 - most common worldwide

HIV 2 - West Africa, mozambique and Angola

Question 3

HIV 1 strains are related to

Answer 3

SIVcpz/s, from the

Chimpanzee subspecies Pan troglodytes

Question 4

HIV 2 strains are related to

Answer 4

SIVsmm, from Sooty
Mangabey monkeys (Cercocebus atys)

Question 5

how is it believed that HIV crossed species

Answer 5

possibly crossed species. through butchering bush meat trade

Question 6

How is HIV transmitted

Answer 6

Blood
Semen
Saliva to a lesser degree

Question 7

HIV

Answer 7

Human Immunodeficiency Virus

Question 8

AIDS

Answer 8

Aacquired Immuno Deficiency Syndrome

Question 9

HIV as a retrovirus

Answer 9

RNA nucleic acid

RNA-DNA-RNA replication

Question 10

how does HIV attack immune system

Answer 10

Invades and destroys T helper cells

Question 11

how is HIV released

Answer 11

Released by budding

Question 12

what macromolecules, enzymes and nucleic acid does HIV contain

Answer 12

Viral RNA
• Reverse trancriptase
• Integrase
• Protease
• Docking glycoprotein
GP120

Question 13

what does HIV need to do once a host is infected with HIV

Answer 13

needs to convert its RNA using Reverse transcriptase into DNA
It then incorporates into the DNA of the host cell

Question 14

HIV propagates in host cell

Answer 14

envelope protein binds to receptors of plasma membrane of host cell
envelope protein fuses with plasma membrane and HIV enters cytoplasm - capsid is removed
Reverse transcriptase converts RNA into single stranded DNA then double stranded DNA which enters the host’s nucleus and is integrated into the host’s chromosomes
Chromosome now transcribes viral RNA
Viral RNA leaves nucleus and synthsizes viral proteins on host ribosomes
These proteins will produce new viruses and virus leaves host cell using host plasma membrane as viral envelope

Question 15

where does early infection of HIV begin in the body

Answer 15

lymph nodes

Question 16

what cells are infected with HIV what is this event followed by

Answer 16

T helper cells are infected and destroyed

this is followed by a latent period - asymptomatic

Question 17

HIV transmission

Answer 17

During sexual contact
During pregnancy, childbirth, breastfeeding
Injection substance use
Blood transfusion with infected blood or organ transplant
Occupational exposure

Question 18

HIV drugs

Answer 18

drus that will mimic receptors of T helper cells and prevent virus from binding to T helper
Drugs that prevent integration

Question 19

HIV control

Answer 19

protease inhibitors

AZT - azidothymidine

Question 20

protease inhibitors

Answer 20

Block viral enzyme protease. Resulting in viral copies that cannot infect new cells

Question 21

Azidothymidine

Answer 21

inhibits reverse transcriptase
crosses blood brain barrier
Blocks RNA conversion to DNA
Prone to evasion by mutated viral strains

Question 22

HAART

Answer 22

Highly Active Antiretroviral Therapy - combination of several antiretroviral medicines to slow the rate at which HIV makes copies of itself

Question 23

How did the prevalence of HIV in pregnant women in Uganda captial

Answer 23

increased at over 30%

Question 24

HIV prevention programs

Answer 24

practice safe sex w/ condoms
sterile needles for people addicted to intravenous drugs
Screening and treatment for other STIs
Substance abuse screening

Question 25

main symptoms of AIDS

Answer 25

Encephalitis meningitis 
retinitis 
pneumocystis
kaposi's disease, tumours
esophagitis

Question 26

AIDS defining bacterial infections

Answer 26

Mycoplasma pneumoniae
• Streptococcus pneumoniae
• Treponema pallidum
• Candida albicans

Question 27

AIDS defining cancers

Answer 27

Kaposi’s sarcoma from HHV-8 / KSV (20-30%, only in male homosexuals)
• cervical carcinoma from some HPV types
• non-Hodgkin’s lymphomas