A 20-year-old agricultural student had a self-limited febrile illness with myalgia two weeks ago. He now returns with headache, neck stiffness, and photophobia. CSF shows 80 cells/µL, predominantly lymphocytes, protein 70 mg/dL, glucose 55 mg/dL. He spent the intervening period working in flooded paddy fields. The most likely explanation for his current illness is:
- A Enteroviral meningitis acquired independently
- B Immune phase of leptospirosis with aseptic meningitis ✓
- C Tuberculous meningitis of subacute onset
- D Partially treated bacterial meningitis
Correct answer: B. Immune phase of leptospirosis with aseptic meningitis
Explanation
Leptospirosis classically runs a biphasic course. In the first leptospiraemic week the organism circulates in blood and CSF; by the second immune phase antibodies appear, leptospires clear from blood, and the patient may develop aseptic meningitis with lymphocytic CSF, uveitis or rash. Organisms are instead shed in urine during this phase. Normal CSF glucose excludes tuberculous and partially treated bacterial meningitis, and the occupational exposure plus preceding febrile illness points to leptospirosis.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.