Systemic Bacterial, Fungal, and Zoonotic Infections — WACS Viva & Clinical Scenarios (Infectious and Tropical Diseases)

Exam-style systemic bacterial, fungal, and zoonotic infections viva scenarios with examiner probes and model answers for Internal Medicine candidates.

Scenarios covered

• SCENARIO 1: A 28-year-old male presents with a three-week history of step-ladder fever, persistent headache, dry cough, and progressive abdominal distension followed by acute, severe generalized abdominal pain and altered sensorium. Clinical examination reveals toxic facies, relative bradycardia (Faget sign), marked abdominal rigidity with absent bowel sounds, and hepatosplenomegaly. Discuss the differential diagnosis, diagnostic bacteriological pathway, and emergency multidisciplinary management of complicated enteric fever with suspected ileal perforation.
• SCENARIO 2: A 34-year-old immunocompromised adult presents with a four-week history of low-grade fever, progressive weight loss, drenching night sweats, multiple non-tender lymphadenopathies, and fluctuating cranial neuropathies. Cerebrospinal fluid analysis demonstrates lymphocytic pleocytosis, significantly elevated protein, and low CSF-to-plasma glucose ratio. Contrast neuroimaging demonstrates basal meningeal enhancement. Detail the diagnostic strategy to differentiate disseminated tuberculous meningitis from cryptococcosis and African histoplasmosis, including laboratory staining, antigen detection,
• SCENARIO 3: A 42-year-old farmer from an agricultural community presents with multiple hypopigmented, anaesthetic skin macules on the trunk and limbs, bilateral thickened, tender ulnar and common peroneal nerves, and progressive weakness of the intrinsic muscles of both hands. Recently, he developed high fever, widespread painful erythematous subcutaneous nodules, and acute iridocyclitis. Formulate the clinical classification according to Ridley-Jopling criteria, diagnose the acute reactional state, and outline the therapeutic regimen and nerve function monitoring protocol.
• SCENARIO 4: A 45-year-old roadside construction worker presents five days following a puncture injury to the foot with inability to open his mouth (trismus), painful neck stiffness, dysphagia, and unprovoked generalized reflex spasms triggered by auditory and visual stimuli. He demonstrates autonomic lability with fluctuating blood pressures (180/100 mmHg to 85/50 mmHg), diaphoresis, and sinus tachycardia (140 beats per minute). Outline the clinical staging according to the Ablett classification, immediate airway and critical care stabilization, neutralization of unbound toxin, and targeted management of
• SCENARIO 5: A 38-year-old abattoir worker presents with persistent undulating fever, profuse drenching nocturnal sweats with a characteristic mouldy odour, arthralgias, and severe lower back pain refractory to analgesics. Examination reveals spinal tenderness at L4-L5 and mild splenomegaly. Magnetic resonance imaging demonstrates spondylodiscitis. Detail the diagnostic investigation strategy for chronic zoonotic infection and define the evidence-based antimicrobial regimens recommended for systemic Brucella infection with osteoarticular involvement.