What is the treatment for suspected leptospirosis?

Treatment for Suspected Leptospirosis

For suspected leptospirosis, treatment should be initiated immediately with doxycycline or penicillin, without waiting for laboratory confirmation, as early treatment is critical for preventing complications. 1

Clinical Presentation and Diagnosis

• Leptospirosis presents as a biphasic illness characterized by fever, headache, chills, myalgia, and conjunctival suffusion 2
• The disease can be classified into two main clinical forms:
  • Mild to moderate form with flu-like symptoms (most common) 1
  • Severe form (Weil's disease) characterized by hemorrhage, jaundice, and hepato-renal failure (occurs in 5-10% of cases) 1
• The septicemic or bacteremic phase lasts 4-7 days with high fever, diffuse myalgias (especially in the calves), headache, and conjunctival suffusion 1
• Conjunctival suffusion is a suggestive clinical sign that should prompt consideration of leptospirosis 2
• Laboratory findings may include proteinuria, hematuria, leukocytosis, anemia, elevated bilirubin with mild elevation of transaminases, and alterations in renal function 1

Treatment Algorithm

For Mild to Moderate Leptospirosis:

1. Start treatment as soon as possible without waiting for confirmation 1
2. Recommended antibiotics:
   • Doxycycline (first-line) 1, 3
   • Penicillin (alternative) 1, 3
3. Standard course of therapy is 7 days 1

For Severe Leptospirosis (Weil's disease):

1. Initiate antibiotics immediately within the first hour of recognition 1
2. Do not delay treatment while waiting for laboratory confirmation 1
3. Recommended antibiotics:
   • Penicillin (first-line for severe disease) 1, 3
   • Doxycycline (alternative) 1
4. Treatment duration: 7-10 days (extend to 10 days in patients with slow clinical response) 1
5. Consider ICU admission for patients with:
   • Persistent or worsening tissue hypoperfusion despite initial fluid resuscitation 1
   • Respiratory failure 4
   • Renal failure requiring hemofiltration 4

Supportive Care

• Fluid resuscitation targeting systolic arterial blood pressure >90 mmHg in adults 1
• Continuous observation and frequent clinical examinations 1
• Monitor for development of crepitations indicating fluid overload or impaired cardiac function 1
• For severe respiratory failure, consider early respiratory ECMO support 4
• Hemodialysis or hemofiltration may be required for acute renal failure 5

Common Pitfalls and Caveats

• Leptospirosis may be misdiagnosed as viral hepatitis in patients with fever and jaundice 1
• It can also be misdiagnosed as pulmonary-renal syndrome when presenting with diffuse alveolar hemorrhage and acute renal failure 6
• Treatment initiated after 4 days of symptoms may be less effective, highlighting the need for prompt therapy 1
• Avoid discontinuing antibiotics too early; complete the full course even with clinical improvement 1
• Diagnosis can be confirmed by:
  • Isolation of Leptospira from clinical specimen
  • Fourfold increase in Leptospira agglutination titer between acute and convalescent serum specimens
  • Demonstration of Leptospira in clinical specimen by immunofluorescence 2
• Blood cultures should be taken in the first 5 days, before antibiotics, for optimal yield 1

Remember that early antibiotic administration is critical for preventing progression to severe disease and reducing mortality in leptospirosis 1, 7.