What is the recommended treatment for a patient with Campylobacter in their stool?

Treatment of Campylobacter Infection

Azithromycin is the first-line treatment for Campylobacter infections, with a dosing regimen of either 1000 mg as a single dose or 500 mg daily for 3 days. 1, 2

When to Treat vs. Observe

Most Campylobacter infections are self-limiting and resolve within 3-5 days without antibiotics in immunocompetent patients with mild symptoms. 2 However, antibiotic treatment is indicated for:

• Severe disease: bloody diarrhea, high fever (>101.5°F), or severe abdominal cramping 1, 2
• Prolonged symptoms: diarrhea lasting more than 1 week 2
• Immunocompromised patients: even with mild symptoms, due to risk of bacteremia and systemic spread (19% risk in cancer patients) 1, 2
• Early presentation: within 72 hours of symptom onset, when treatment is most effective 1, 2

First-Line Antibiotic Therapy

Azithromycin achieves a 96% clinical cure rate and reduces symptom duration from 50-93 hours to 16-30 hours when started within 72 hours. 1, 2 Dosing options:

• Single-dose regimen: 1000 mg once 1
• Multi-day regimen: 500 mg daily for 3 days 1, 2

The multi-day regimen is preferred for severe infections or immunocompromised patients. 1

Why Not Fluoroquinolones?

Fluoroquinolone resistance now exceeds 90% in Southeast Asia and has increased dramatically worldwide, with clinical failure occurring in 33% of patients when the isolate is resistant. 1, 2 Ciprofloxacin is FDA-approved for Campylobacter jejuni causing infectious diarrhea 3, but should only be used in areas with documented low fluoroquinolone resistance. 1 Using fluoroquinolones empirically without considering local resistance patterns leads to treatment failure and prolonged illness. 1, 2

Alternative Antibiotics

If azithromycin is unavailable:

• Erythromycin: 50 mg/kg/day divided every 6-8 hours for 5 days (pediatric dosing), though less effective than azithromycin 1, 4
• Ciprofloxacin: 500 mg twice daily for 3 days, only in regions with known low resistance 1, 3

Supportive Care Measures

Initial rehydration is critical, particularly for patients with severe diarrhea or signs of dehydration. 1, 2

• Use oral rehydration solutions (e.g., Ceralyte, Pedialyte) for most patients 1
• Administer IV fluids for patients with moderate to severe dehydration, fever, or vomiting 5, 1
• Continue age-appropriate feeding as tolerated 1, 2
• Avoid antimotility agents (loperamide, diphenoxylate) as they prolong bacterial shedding and worsen outcomes, particularly with bloody diarrhea or fever. 1, 2

Special Population: Immunocompromised Patients

Immunocompromised patients (cancer, HIV, hypogammaglobulinemia) should always receive antibiotics regardless of symptom severity due to high risk of bacteremia and systemic complications. 1, 2, 6 For severely ill cancer patients:

• Start azithromycin immediately 1
• Obtain complete blood count, electrolyte profile, and comprehensive stool work-up (culture for Campylobacter, C. difficile, Salmonella, E. coli) 5, 1
• Consider hospitalization for IV fluids and close monitoring 5, 1
• In refractory cases with severe diarrhea, octreotide 100-150 mcg subcutaneously three times daily may be considered, with dose escalation up to 500 mcg 5, 1

Recurrent infections may occur in immunocompromised patients despite standard therapy; prolonged treatment (up to 3 months with doxycycline) has been used in case reports. 6

Monitoring and Follow-Up

• Reassess at 48 hours: If no improvement or worsening symptoms, consider alternative antibiotics based on susceptibility testing 1, 2
• No routine follow-up stool cultures needed if symptoms resolve 1, 2
• Diarrhea persisting beyond 10-14 days warrants further evaluation to rule out complications or alternative diagnoses 7, 2

Critical Pitfalls to Avoid

• Delaying treatment beyond 72 hours reduces antibiotic effectiveness significantly 1, 2
• Discontinuing antibiotics before completing the full 3-5 day course leads to treatment failure 1, 2
• Using antimotility agents with bloody diarrhea or fever worsens outcomes and prolongs illness 5, 1, 2
• Failing to treat immunocompromised patients with mild symptoms risks bacteremia and systemic spread 1, 2

Post-Infectious Complications to Monitor

Be aware that Campylobacter is associated with subsequent development of:

• Guillain-Barré syndrome (most common infectious trigger) 1, 7, 8
• Reactive arthritis and Reiter's syndrome 1, 7, 8
• Hemolytic-uremic syndrome (rare) 1
• Toxic megacolon, perforation, bacteremia (rare but serious) 1

These complications can occur even after gastrointestinal symptoms resolve. 7