Malaria, Viral Haemorrhagic Fevers, and Arboviral Illnesses — WACS Viva & Clinical Scenarios (Infectious and Tropical Diseases)

Exam-style malaria, viral haemorrhagic fevers, and arboviral illnesses viva scenarios with examiner probes and model answers for Internal Medicine candidates.

Scenarios covered

• SCENARIO 1: A 28-year-old male farmer from an endemic community presents with a 3-day history of high-grade fever, jaundice, dark tea-coloured urine, and altered consciousness (Glasgow Coma Scale 9/15). Thick blood film demonstrates Plasmodium falciparum ring forms with 14% hyperparasitaemia. Serum creatinine is 320 µmol/L and blood glucose is 2.1 mmol/L. Outline your immediate emergency resuscitation, antiparasitic regimen, and complications surveillance protocol.
• SCENARIO 2: A 32-year-old resident doctor presents with sudden-onset fever, severe pharyngitis, retro-sternal pain, conjunctival injection, and facial puffiness 8 days after resuscitating an acutely bleeding febrile patient. Outline the biosafety triage, personal protective equipment requirements, diagnostic confirmation pathway, and specific therapeutic protocol for suspected Lassa fever.
• SCENARIO 3: A 45-year-old commercial driver presents with acute high fever, severe retro-orbital headache, breakthrough arthralgia, and petechial eruptions on the extremities. On day 5, defervescence is accompanied by intense abdominal pain, persistent vomiting, a haematocrit spike from 38% to 50%, and severe thrombocytopenia (platelet count 35 x 10⁹/L). Formulate the diagnostic classification, dynamic fluid titration protocol, and vital organ monitoring strategy for severe dengue infection.
• SCENARIO 4: Discuss the molecular mechanisms of Plasmodium falciparum cytoadherence, endothelial activation, and rosette formation. Contrast these microvascular phenomena with the pathogenesis of endothelial barrier breakdown and coagulopathy in Filovirus infections (Ebola and Marburg virus diseases).
• SCENARIO 5: Compare the pharmacological properties, dosing regimens, toxicities, and safety in special populations (pregnancy and renal impairment) of parenteral artesunate, intravenous quinine infusion, and 8-aminoquinolines (primaquine and tafenoquine).