What is the treatment for leptospirosis, including medications to order and supportive care?

Leptospirosis Management: SOAP and Orders

Subjective (History)

Start treatment immediately upon clinical suspicion—do not wait for laboratory confirmation, as delay increases mortality. 1

Key Historical Features to Elicit:

• Exposure history within past 2-20 days: 2

  • Contact with flood water or contaminated fresh water 2, 1
  • Recreational water sports in fresh water 1
  • Occupational exposure to animals (rats, dogs, cattle) or contaminated water 2, 1
  • Agricultural work, especially in flooded fields 3

• Symptom pattern (biphasic course): 2

  • Initial bacteremic phase (4-7 days): high fever (≥39°C), severe myalgias especially in calves, headache 2, 1
  • Immune phase (1-3 days later): recurrent fever, jaundice, hemorrhage, renal failure 2

Objective (Physical Examination)

Critical Physical Findings:

• Conjunctival suffusion (highly suggestive) 2, 1
• Jaundice (indicates severe disease/Weil's disease) 2, 1
• Signs of hemorrhage (petechiae, ecchymoses) 2
• Hepatomegaly 2
• Signs of respiratory distress or hypoxemia 1
• Hemodynamic instability (hypotension, tachycardia) 1

Assessment (Diagnostic Workup)

Immediate Laboratory Orders:

Basic Labs:

• Complete blood count (expect polymorphonuclear leukocytosis, thrombocytopenia, anemia if hemorrhage) 2, 1
• Comprehensive metabolic panel (elevated bilirubin with mild transaminase elevation, renal dysfunction) 2, 1
• Urinalysis (proteinuria, hematuria) 2, 1
• Coagulation studies (often normal despite bleeding due to capillary fragility) 2

Diagnostic Confirmation:

• Blood cultures (3 sets, at least 1 hour apart): Must be obtained within first 5 days before antibiotics if possible, but do not delay treatment >45 minutes 2, 1
• Keep blood cultures at room temperature for reference laboratory 2
• Serology: IgM ELISA (positive 6-10 days after symptom onset) 2, 1
  • IgM titer >1:320 is diagnostic 2, 1
  • Titer 1:80-1:160 suggests early infection 2, 1
• Convalescent serology: Repeat >10 days after symptom onset with microscopic agglutination test (MAT) 2

Note: Urine is NOT suitable for leptospira isolation 2

Plan (Treatment)

Severity Classification and Antibiotic Selection:

MILD TO MODERATE DISEASE (outpatient or hospitalization without organ failure):

Doxycycline 100 mg orally twice daily for 7 days is the treatment of choice 1, 4, 5

• Reduces illness duration by 2 days 5
• Prevents leptospiruria 5
• 76.8% protective efficacy demonstrated 6

Alternative for mild disease:

• Azithromycin (promising but less data) 4
• Penicillin (traditional choice but less convenient) 4, 7

SEVERE DISEASE (Weil's disease with jaundice, hemorrhage, renal failure, or respiratory compromise):

Ceftriaxone 2g IV daily for 7 days is the preferred regimen 4, 8

• Superior convenience and safety profile compared to penicillin 8
• 95% recovery rate in severe cases 8
• May extend to 10 days if slow clinical response 1

Alternative for severe disease:

• Penicillin G 1.5 million units IV every 6 hours 2, 4
• Cefotaxime 4

Critical timing: Start antibiotics within 1 hour of recognizing severe disease—each hour of delay increases mortality 1

Supportive Care Orders:

For Severe Disease:

• Fluid resuscitation: Target systolic BP >90 mmHg, normal heart rate 1
• Monitor for fluid overload (crepitations indicating pulmonary edema) 1
• ICU admission if persistent hypoperfusion despite fluids 1
• Continuous monitoring—never leave patient alone 1

For Respiratory Complications:

• Methylprednisolone 0.5-1.0 mg/kg IV daily for 1-2 weeks if hypoxemia or significant respiratory distress develops 2

Renal Support:

• Prepare for dialysis if progressive renal failure 2

Monitoring:

• Daily reassessment of antibiotic regimen 1
• Complete full 7-day course even with clinical improvement 1

Special Populations:

Children <8 years:

• Avoid doxycycline due to permanent tooth discoloration risk 6
• Use penicillin or ceftriaxone instead 6

Prophylaxis (post-flood exposure):

• Doxycycline 200 mg single dose orally provides 76.8% protection 6
• Reserve for high-risk settings with attack rates >10 per 100 person-years 6

Common Pitfalls to Avoid:

• Do not wait for serological confirmation before starting antibiotics—serology is often negative in first week 2, 1
• Do not mistake for viral hepatitis in patients with fever and jaundice 1
• Do not discontinue antibiotics early despite clinical improvement 1
• Do not use urine for culture 2
• Treatment after 4 days of symptoms may be less effective 1