Miscellaneous

Question 1

H.I.V

Epidemiology?

Answer 1

Male : Female 3:1
UK prevalence about 100k
Incidences falling due to antivirals

Question 2

H.I.V

What is the CD4 count of AIDs and name a common Aids defining illness

Answer 2

• CD4 count <200/mm3
  1) GP120 on virus bonds to CD4 on Th cell and reduces its function

Pneumocystis Pneumonia (PCP)- global lung issue where all alveoli are affected

Question 3

HI.V

Aetiology?

Answer 3

• sexual intercourse
• mother to child trans-placental/ breast feeding
• contaminated blood
• contaminated needles

Question 4

H.I.V

Pathophysiology?

Answer 4

1) decline in T cells = dysregualtion of B cells
2) Dysregulation of Ab production = dysregulation of Antigen response
3) Unable to respond to infection

Question 5

H.I.V

Signs and Symptoms?

Answer 5

• fever
• night sweats
• diarrhoea
• weight loss

Signs

Opportunistic infections such as recurrent herpes simplex and oral Candida

Question 6

H.I.V

Complications? These may be called ‘Aids defining illnesses’

Answer 6

Kaposi sarcoma

Candidiasis

HSV

TB

Recurrent pneumonia

Question 7

H.I.V

Diagnostic test?

Answer 7

Adults- serum HIV Ab levels

Babies-(before 18 months)- HIV Ab level test inaccurate because maternal Ab might be present

So INSTEAD: perform PCR or viral culture for diagnosis

Question 8

H.I.V

Treatment? (Non medical)

Answer 8

• Sex education
• avoid concomitant sexual partners
• pre and post exposure prophylaxis
• partner notification

Question 9

H.I.V

Medical treatment?

Answer 9

• Highly Active Anti- Retroviral Therapy (HAART)

This is not a cure but it suppresses HIV RNA concentration below limit of detection and restores immune function

Question 10

H.I.V

How do we monitor HIV?

Answer 10

• CD4 cell count
• HIV RNA
• Serum U&E and LFT

Question 11

H.I.V

Describe the 6 parts of the Physiology of the virus beginning with Attachment?

Answer 11

1) ATTACHMENT- viral receptors (GP120 to CD4)
2) CELL ENTRY- only the viral core enters host cell
3) INTERACTION WITH HOST CELL- uses cell materials for their replication
4) REPLICATION- may localise in nucleus/ cytoplasm- production of viral nucleic acid and proteins
5) ASSEMBLY- occurs in nucleus (herpesvirus), cytoplasm (poliovirus) or cell membrane (influenza)
6) RELEASE- by lysis of the cell or by exocytosis from the cell over a period of time

Question 12

What age group accounts for 50% of new infections?

Answer 12

19-24 yrs