MBBS OSCE · Infectious Diseases
OSCE — HIV / AIDS
Eight-minute OSCE station on HIV / AIDS: focused history, examination priorities, investigations, emergency and definitive management.
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Brief (to candidate)
You will assess a patient with a presentation consistent with HIV / AIDS.
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.
Clinical context
HIV is a retrovirus (lentivirus) that infects and depletes CD4+ T-helper lymphocytes, producing progressive cell-mediated immunodeficiency. AIDS is the advanced stage, defined by CD4 under 200 cells/uL, a CD4 percentage below 14%, or any AIDS-defining illness (PJP, toxoplasmosis, CMV, MAC, Kaposi sarcoma, CNS lymphoma, etc.). Transmitted by sexual contact, blood/blood products, needle-sharing, and mother-to-child. Acute infection is a mononucleosis-like illness 2 to 4 weeks after exposure, followed by years of clinical latency, then opportunistic infections and tumours as CD4 falls. Diagnosis: 4th-generation Ag/Ab combo assay (p24 + antibody) confirmed by HIV-1/2 differentiation; staging by
Candidate tasks
- Clarify onset, severity, associated features, and red-flag symptoms.
- State focused examination priorities.
- List first-line investigations and any named score/criteria.
- Give immediate resuscitation steps.
- Outline definitive management with doses/routes where standard.
- Name complications and disposition (ward / HDU / theatre / discharge safety-net).
- Mention one special-population modifier (pregnancy, child, elderly, CKD).
Examiner checklist
| Domain | Pass behaviours |
|---|---|
| Definition | Correct working diagnosis language |
| Assessment | Focused, prioritised, red flags sought |
| Investigations | Appropriate first-line + interpretation |
| Emergency care | ABC / time-critical actions first |
| Definitive care | Specific drugs/procedures, not generic phrases |
| Safety | Mononucleosis-like illness with fever, rash, lymphadenopathy, mucosal ulcers 2 t |
| Safety | Known HIV with CD4 under 200 and subacute dyspnoea, dry cough, fever, hypoxia ou |
| Safety | HIV with CD4 under 100 and new focal neurology, headache, seizure, ring-enhancin |
| Communication | Clear plan and safety-netting |
Model outline
Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use guideline-standard therapy with named agents and doses. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays critical care for non-urgent imaging.