Epidemiology

Most commonly found in tropical climates

Etiology

• Pathogen: Leptospira (especially L. interrogans sensu lato), a genus of gram-negative spirochete with hook-shaped ends
  • Spirochetes cannot be visualized using Gram staining and require specialized staining methods.
• Transmission
  • Sources
    • Urine, blood, or tissue of an infected animal (most commonly rats)
    • Environmental contamination (e.g., water contaminated with urine of infected animals)
  • Entry points: broken skin or exposed mucous membranes (e.g., conjunctiva, oral mucosa)
  • Risk factors
    • Occupations that involve direct or indirect contact with animals (e.g., agricultural or sewage workers)
    • Freshwater recreational activities (e.g., canoeing, swimming, windsurfing)

Pathophysiology

Clinical features

• Mostly asymptomatic or mild/self-limited
• Abrupt-onset fever, rigors, myalgia, headache
• Nausea, vomiting, diarrhea
• Classic examination finding: conjunctival hyperemia (suffusion)

Diagnostics

Treatment