Case Presentation: A 24-year-old man with ADHD and chronic low back pain under rheumatologic evaluation for possible axial spondyloarthritis presented with six days of fever (to 100.9°F), fatigue, myalgias, nausea/vomiting, and inability to tolerate oral intake. Admission labs showed platelets 86 × 10³/μL, creatinine 2.04 mg/dL, AST 82 U/L, ALT 120 U/L; CT brain/abdomen and chest X-ray were unremarkable. CSF revealed 20 nucleated cells (50% neutrophils), glucose 70 mg/dL, protein 29 mg/dL; respiratory viral panel was positive for rhinovirus/enterovirus; CSF and blood cultures showed no growth to date. Empiric vancomycin and ceftriaxone were initiated for possible bacterial meningitis, despite CSF findings favoring a viral process.The differential included viral meningitis (enterovirus) due to CSF profile, seasonality, and babysitting exposure; and anaplasmosis/ehrlichiosis and leptospira given thrombocytopenia, transaminitis, fever, and epidemiologic risks from visiting Westchester County and swimming in a Vermont river. TTP was unlikely without hemolysis or schistocytes. NSAID use and doxycycline intolerance complicated management. EBV PCR was low-level with negative CSF EBV; CMV, hepatitis screens, and anaplasma/ehrlichia PCR were negative.By day 4, fever resolved and headache improved and by day 5, platelets and creatinine normalized and LFTs stabilized/downtrended, prompting antimicrobial de-escalation. On day 6, AST/ALT rose close to 1000 U/L with normal bilirubin, raising concern for severe hepatocellular injury. Leptospira IgM returned positive the same day; penicillin G was initiated for suspected Weil’s syndrome. LFTs began to downtrend on day 7; repeat MRI was unremarkable on day 8. He completed an 8-day antibiotic course (ceftriaxone followed by penicillin G) and was discharged on day 9 with normalized platelets, resolving LFTs, and improved renal function.
Discussion: This case highlights leptospirosis (Weil’s syndrome) as a diagnostic challenge in hospital medicine, mimicking viral meningitis, tickborne infections, and hematologic emergencies. The patient’s aseptic meningitis, AKI, thrombocytopenia, and transaminitis prompted broad empiric treatment. Diagnostic stewardship—including smear assessment, culture, and targeted PCR—enabled refocused care. A sharp rise in liver enzymes, with negative viral and tickborne tests, led to reconsideration of zoonotic exposures, confirming leptospirosis via serology and guiding therapy. Hospitalists balanced antimicrobial decisions (penicillin G selection, avoiding doxycycline due to intolerance) while addressing confounders like viral symptoms and potential NSAID-related liver injury. The case underscores the importance of exposure history, organ involvement reassessment, and antimicrobial stewardship.
Conclusions: Leptospirosis should be considered in hospitalized patients with febrile illness, aseptic meningitis, AKI, thrombocytopenia, and severe hepatocellular injury, even in non-tropical regions with freshwater exposure. Hospitalist-led diagnostic stewardship—early empiric therapy, timely de-escalation, and focused serologic testing—supports accurate diagnosis and better outcomes. Medication intolerance (e.g., doxycycline) and potential drug-induced liver injury can complicate management; targeted therapy with penicillin G led to rapid improvement in this case.