HIV

Question 1

Natural hx of HIV

Answer 1

ACUTE INFECTION (SEROCONVERSION) - ASYMPTOMATIC - HIV RELATED ILLNESS - AIDS DEFINING ILLNESS - DEATH

over the course of the infection = CD4 count falls + HIV viral load rises - increasing risk of developing infections + tumours

Question 2

HIV prevention

Answer 2

• BEHAVIOUR CHANGE + CONDOMS
  
  • CIRCUMCISION
  • Rx as PREVENTION: UNDETECTABLE VIRAL LOAD = UNTRANSMISSABLE
  • PRE-EXPOSURE PROPHYLAXIS (PrEP)
  • POST-EXPOSURE PROPHYLAXIS for SEXUAL EXPOSURE (PEP)

Question 3

Primary HIV Presentation

Answer 3

ABRUPT ONSET 2 - 4 WEEKS POST-EXPOSURE + SELF-LIMITING 1 - 2 WEEKS

SYMPTOMS = GENERALLY NON-SPECIFIC + DDx incl. RANGE of COMMON CONDITIONS

* FLU-LIKE ILLNESS
* FEVER
* MALAISE + LETHARGY
* PHARYNGITIS
* LYMPHADENOPATHY
* TOXIC EXANTHEMA - widespread rash

Question 4

Pneumocystis jirovci (hx, investigations, management)

Answer 4

OPPORTUNITISTIC INFECTION = CD4 < 200 usually

CLASSICAL Hx: DRY COUGH + INCREASING SOB OVER SEVERAL WEEKS (when walking on flat ground?)

INVESTIGATIONS: CXR + INDUCED SPUTUM/BRONCHOSCOPY for PCR

MANAGEMENT: CO-TRIMOXAZOLE, PENTAMIDINE

PROPHYLAXIS until CD4 > 200

Question 5

HIV Investigations

Answer 5

Diagnosis = antigen/antibody testing (4th gen test window period is 1 month)

Managing infection = HIV viral load (effectiveness of rx), HIV resistance testing (baseline resistance, sub-optimal response to rx, failing rx, want to change rx), avidity testing, subtype determination, tropism testing, drug lvls

Question 6

HIV Management

Answer 6

• MONITORING DISEASE = HIV VIRAL LOAD, CD4 LYMPHOCYTE COUNT, CLINICAL FEATURES

	○ BLOOD TESTS = PRIOR to STARTING Rx + AFTER 1 MONTH + then EVERY 3 MONTHS

* PRIMARY + SECONDARY CHEMOPROPHYLAXIS to PREVENT INFECTIONS
* VACCINATIONS: HEP B, PNEUMOCCOCAL DISEASE, H. INFLUENZAE TYPE B, poss. INFLUENZA + HEP A
* LIFE-LONG ANTIVIRALS = COMBINATION 3 IN 1 PILL STARTED at DIAGNOSIS - needs to be adhered to, to prevent resistance

Question 7

Classes of HIV Anti-virals

Answer 7

• NUCLEOSIDE REVERSE TRANSCRIPTADE INHIBITORS = MARROW TOXICITY, NEUROPATHY, LIPODYSTROPHY
  
  • NON-NUCLEOSIDE REVERSE TRANSCRIPASE INHIBITORS = SKIN RASHES, HYPERSENSITIVITY, DRUG INTERACTIONS, NEUROPSYCHIATRIC EFFECTS
  • INTEGRASE INHIBITORS = RASHES, DISTURBED SLEEP
  • PROTEASE INHIBITORS = DRUG INTERACTIONS, DIARRHOEA, LIPODYSTROPHY, HYPERLIPIDAEMIA

Question 8

Challenges in HIV care

Answer 8

• OSTEOPOROSIS
• COGNITIVE IMPAIRMENT
• MALIGNANCY
• CEREBROVASCULAR DISEASE
• RENAL DISEASE
• IHD
• DM

Question 9

Spread of HIV infection

Answer 9

• SEXUAL TRANSMISSION
  
  • INJECTION DRUG MISUSE
  • BLOOD PRODUCTS
  • VERTICAL TRANSMISSION (mother - child)
  • ORGAN TRANSPLANT

Question 10

HIV virus + immunology

Answer 10

• HIV-1 + HIV-2 (2 distinct viruses) - predominantly HIV-1 globally
  
  • HIV INFECTS + DESTROYS IMMUNE CELLS esp. T-HELPER CELLS○ CD4 RECEPTORS NOT EXCLUSIVE to LYMPHOCYTES = also present on surface of macrophages + monocytes, cells in brain, skin, many other sites
    1. ATTACHES to CELLS w/ CD4 on SURFACE w/ CERTAIN CHEMOKINE RECEPTORS
    2. RETROVIRUSES = RNA - DNA using REVERSE TRANSCRIPTASE (makes lots of errors, thus leading to lots of inaccuracy during replication + VIRUS DIVERSITY); PERSISTENT INFECTION of CELL (provides ongoing opportunity to transmit)
    3. INTEGRASE facilitates INTEGRATION INTO HOST CELL DNA
    4. Contains PROTEASE ENZYME for MATURE VIRUS PROGENY

Question 11

Occupational exposure to HIV

Answer 11

1. WHAT ARE THE RISKS of TRANSMISSION
   
   2. WHAT IMMEDIATE ACTIONS SHOULD be TAKEN
   3. WHAT HAPPENS NEXT
   4. HOW CAN RISK of EXPSOURE be DECREASED
   5. TESTING for HIV, HEPATITIS B + C

First aid - assess risk - PEP

Question 12

Symptomatic infestion/HIV-illness

Answer 12

NON-SPECIFIC CONSTITUTIONAL SYMPTOMS:

* FEVER
* NIGHT SWEATS
* DIARRHOEA
* WGT. LOSS

MINOR OPPORTUNITISTIC INFECTIONS:

	• ORAL CANDIDA
	• ORAL HAIRY LEUKOPLAKIA
	• HERPES ZOSTER
	• RECURRENT HERPES SIMPLEX
	• SEBORRHOEIC DERMATITIS
TINEA INFECTIONS