HIV and hep B

Question 1

A patient is said to have aids when the CD4 T cell count falls below how many cells/micrlitre?

Answer 1

200

Question 2

How does the infection of HIV take place?

Answer 2

HIV primarily infects cells with CD4 receptor molecules
Virus binds to CD4 using gp120 - binding causes release of gp41 which facilitates the fusion of viral envelope with cell membrane and the core is released into the cytoplasm
Once in cytoplasm, RNA genome is released and reverse transcribed into cDNA
cDNA travels to nucleus where it is integrated with cell genome becoming provirus

Question 3

How is Hep B spread?

Answer 3

By infected blood and bodily fluids, e.g. semen, vaginal secretions, saliva

Question 4

Hep B is a non-retroviral virus. True or false?

Answer 4

True

Question 5

Jaundice and light-coloured stools are symptoms of which viral infection?

Answer 5

Hep B

Question 6

Describe the life cycle of Hep B

Answer 6

Attachment and entry
cDNA -> cccDNA
cccDNA is a template for transcription of 4 viral RNAs
DNA and core proteins released into cytoplasm
replication
4 viral RNAs are processed further and become virions
release of mRNA to cytoplasm

Question 7

What is the best way to be protected against Hep B?

Answer 7

Vaccination

Question 8

Hep B primarily interferes with the functions of which major organ?

Answer 8

Liver

Question 9

Hep B does not usually require treatment. Why?

Answer 9

Because most adults clear the infection spontaneously

Question 10

Drugs to minimise liver damage caused by Hep B can be taken. What is an indicator of significant amount of liver damage?

Answer 10

elevated serum alanine aminotransferase

Question 11

Lamivudine is used for liver damage caused by Hep B. True or false?

Answer 11

True