Human Immunodeficiency Virus (HIV)

Question 1

Define HIV

Answer 1

Infection with human immunodeficiency virus (HIV)
HIV-1 is responsible for the global epidemic
HIV-2 is mostly restricted to West Africa

Question 2

What are the causes/risk factors of HIV?

Answer 2

Viral replication -> decline in CD4 count
HIV -> AIDS (acquired immunodeficiency syndrome) after ~10 years with CD4 count <200
• Sexual transmission – increased risk amongst gay men
• Blood and bodily fluids
- Vertical transmission (mother to child)
- IVDU
- Needle stick injury
- Blood transfusion
- Organ transplantation

Question 3

What are the signs and symptoms of HIV?

Answer 3

Seroconversion (2-6 weeks after exposure)
• Fever
• Night sweats
• Sore throat
• Diffuse maculopapular rash
• Myalgia
• Headache
• Diarrhoea
• Generalised lymphadenopathy
• Oral ulcers

Early
• Asymptomatic
• Persistent lymphadenopathy
• Rash
• Oral thrush
• Weight loss
• Malaise

AIDS (CD4 count <200 cells/ul)
Human papillomavirus
• Squamous cell carcinoma of cervix and anus
• HPV 16 & 18

Mucocutaneous candidiasis
• Oral, oesophageal or vaginal fungal infection
• White lesions or discharge
• Dysphagia/odynophagia
• Itching
• Dyspareunia

Hairy leukoplakia
• White lesions on side of tongue
• EBV infection

Pneumocystis carinii pneumonia (PCP)
• Pnemocystis jirovecii (fungus)
• Insidious onset SOB (especially on exertion)
• Non-productive cough
• Weight loss, night sweats
• Reticulonodular shadowing on CXR
• Ground glass appearance on HRCT

Toxoplasmosis
• Toxoplasma gondii
• Headache
• Confusion
• Seizures
• Motor weakness
• Fever
• Multiple ring enhancing lesions on imaging

Mycobacterium avium complex (MAC)
• Respiratory illness normally affecting birds
• Fever, fatigue, weight loss
• BM involvement: anaemia, neutropenia
• GI involvement: diarrhoea, abdominal pain

Question 4

What investigations are carried out for HIV?

Answer 4

• HIV antibodies (12 weeks after exposure)
• PCR for viral RNA
• CD4 count
• Viral load