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Malignant Otitis Externa Monitoring — SCE Infectious Diseases MCQ

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HardRespiratory InfectionMalignant Otitis Externa MonitoringSCE Infectious Diseases

A patient develops fever, conjunctival suffusion, jaundice and acute kidney injury 8 days after freshwater exposure in a rat-infested warehouse. A blood leptospiral PCR taken on illness day 2 was negative. Which diagnostic action now best reflects UKHSA specimen timing?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — Send urine for leptospiral PCR and serum for IgM testing, providing onset and exposure details to the reference laboratory

Explanation lettering: B = shown as A · A = shown as B · E = shown as D · D = shown as E

A is correct. Leptospiral DNA is most readily detected in blood early, whereas urine remains PCR-positive for longer; IgM becomes useful later, so day 8 favours urine PCR plus serology and full timing and exposure information. B chooses the specimen whose molecular yield is falling. C tests the wrong anatomical site. D overinterprets an early negative result. E substitutes insensitive, non-reference microscopy for validated PCR and serology.

Reference: UKHSA: leptospirosis: https://www.gov.uk/guidance/leptospirosis