Fever after Floodwaters

A 42-year-old previously healthy man presents to the emergency department with 5 days of high-grade fevers, severe myalgias, and progressive jaundice. He reports intense headache, photophobia, and nausea over the past 48 hours.

He works as a rice farmer in rural Thailand and recalls wading through floodwaters two weeks prior while repairing irrigation canals. He owns several dogs that roam freely around his property and notes that rodents are common in the fields. He has no recent travel outside his province, no sick contacts, and no history of blood transfusions or intravenous drug use.

On examination, he appears ill and jaundiced. Vital signs show temperature 39.2°C, heart rate 112 bpm, blood pressure 90/60 mmHg, respiratory rate 22/min, oxygen saturation 96% on room air. Notable findings include bilateral conjunctival suffusion without purulent discharge, mild neck stiffness, and tender hepatomegaly. There is no rash, lymphadenopathy, or focal neurologic deficits.

Laboratory studies reveal total bilirubin 8.5 mg/dL (direct 6.2 mg/dL), AST 120 U/L, ALT 95 U/L, alkaline phosphatase 210 U/L. Serum creatinine is 3.8 mg/dL (baseline 0.9 mg/dL), BUN 48 mg/dL. Complete blood count shows leukocytosis (14.2×10³/μL) with left shift, thrombocytopenia (85×10³/μL), and normocytic anemia. Creatine kinase is elevated at 850 U/L. Urinalysis demonstrates proteinuria (2+), granular casts, and microscopic hematuria. Cerebrospinal fluid analysis shows mild lymphocytic pleocytosis (25 cells/μL) with normal glucose and protein. Chest radiograph is unremarkable.