Heavy Rain Wielding Weil Disease: A Rare Case of Leptospirosis in Baltimore, Maryland

Introduction: Weil disease, characterized by jaundice, renal failure and hemorrhage, is caused by the pathogenic Leptospira spirochete. Transmission to humans occurs via exposure to animals or contaminated urine. Most United States cases occur in tropical states, such as Puerto Rico and Hawaii. However, recent literature suggests that climate change may impact our previous understanding of Leptospira’s geographic predilection.

We present a rare case of Leptospirosis in Baltimore, Maryland, in a patient presenting with pulmonary-renal syndrome who lacked obvious risk factors.


Description: A 44-year-old man with no medical history presented for 3 days of vomiting, diarrhea, myalgias and anuria. The family noted rodent sightings in their Baltimore suburb. He was admitted for abnormal blood work: acute kidney injury, thrombocytopenia, mild transaminitis and direct hyperbilirubinemia. Initially stable, he had rapid clinical deterioration requiring intubation, vasopressors and continued renal replacement therapy. Evidence of urine red blood cell casts and diffuse alveolar hemorrhage (DAH) on bronchoalveolar lavage led to high-suspicion of autoimmune pulmonary-renal syndrome. He was treated with early pulse-dose methylprednisolone and empiric antibiotics.

Workup for immunodeficiency and autoimmune disease was unrevealing. Renal biopsy showed acute tubular necrosis without vasculitis; steroids were discontinued. Leptospirosis IgM was positive. His clinical status improved with treatment for Leptospirosis, ultimately leading to liberation from the ventilator and vasopressors.


Discussion: Our patient had classic symptoms for Weil disease but no clear exposure history. Testing and treatment for Leptospirosis should be promptly considered in the presence of possible pulmonary-renal syndrome even without a clear exposure history on thorough exploration.

In our literature search, this is the first case of Leptospirosis in Baltimore since 2020. Although the exact source of our patient’s infection is unclear, heavy rainfall in July 2025 may have increased the risk of transmission from rats in the patient’s neighborhood. Since Leptospirosis has not been a reportable CDC disease since 1994, we must remain vigilant and aware of evolving disease incidence as our external environment changes.