Treatment of Pasteurella Infections
Penicillin or amoxicillin is the first-line treatment for Pasteurella infections, with alternatives including doxycycline, fluoroquinolones, or trimethoprim-sulfamethoxazole for penicillin-allergic patients. 1, 2, 3
First-Line Treatment Options
Penicillin derivatives:
Treatment duration:
- 5-7 days for uncomplicated infections
- Longer duration may be required for severe infections, immunocompromised patients, or deep tissue involvement 1
Alternative Treatments (for penicillin-allergic patients)
- Doxycycline: 100 mg twice daily 5, 4
- Fluoroquinolones (e.g., ciprofloxacin): Effective against Pasteurella with very low MICs 3, 6
- Trimethoprim-sulfamethoxazole: Effective alternative with good in vitro activity 3, 6
- Clindamycin: 300-450 mg three times daily (though not optimal for Pasteurella specifically) 1
Clinical Considerations
Source of Infection
Animal bite wounds: Most common source of Pasteurella infections, particularly from cats (72%) and dogs (28%) 7
- Wounds should be thoroughly irrigated and debrided 1
- Antibiotic prophylaxis is recommended for:
- Deep puncture wounds (especially cat bites)
- Wounds on hands, feet, face, or near joints
- Immunocompromised patients
- Wounds with delayed presentation (>8 hours)
Respiratory infections: Second most common presentation, may be occupational in animal handlers 4
Special Populations
- Children: Avoid doxycycline in children under 8 years due to risk of tooth discoloration
- Pregnant women: Avoid doxycycline in third trimester
- Immunocompromised patients: May require longer treatment duration and broader coverage
Monitoring and Follow-up
- Most patients should show clinical improvement within 48-72 hours of appropriate antibiotic therapy
- If no improvement after 72 hours, consider:
- Reevaluation of diagnosis
- Changing antibiotic therapy
- Possible surgical drainage if abscess has formed
Common Pitfalls
- Delayed recognition: Pasteurella infections typically develop rapidly (within 24 hours of animal bite)
- Inadequate wound care: Thorough irrigation and debridement are essential
- Inappropriate antibiotic selection: Using antibiotics with poor activity against Pasteurella (e.g., first-generation cephalosporins, macrolides)
- Overlooking deep tissue involvement: Pasteurella can cause osteomyelitis and joint infections if not properly treated
Complications
- Without proper treatment, Pasteurella infections can progress to:
- Tenosynovitis
- Septic arthritis
- Osteomyelitis
- Bacteremia (rare, but more common in immunocompromised patients)
Early recognition and appropriate antibiotic therapy are essential for preventing these complications and ensuring good outcomes.