What is the antibiotic of choice for Campylobacter (C.) jejuni infection?

Antibiotic of Choice for Campylobacter jejuni

Azithromycin is the antibiotic of choice for Campylobacter jejuni infection, with a recommended dosing of either 1000 mg as a single dose or 500 mg daily for 3 days. 1

First-Line Treatment Recommendation

• The Infectious Diseases Society of America and American College of Physicians recommend azithromycin as the preferred first-line treatment due to its superior efficacy (96% clinical cure rate) and persistently low resistance rates (approximately 4% for travel-related infections). 1, 2

• Macrolide resistance in C. jejuni remains low and stable in most regions, with resistance rates of only 2-4% reported in multiple surveillance studies, making azithromycin highly reliable. 3, 4

• Early treatment within 72 hours of symptom onset is critical, as azithromycin can reduce symptom duration from 50-93 hours to 16-30 hours when initiated promptly. 1, 2

Dosing Regimens

• For severe cases or dysentery: Azithromycin 1000 mg single dose 2

• For less severe cases: Azithromycin 500 mg daily for 3 days 1, 2

• Both regimens demonstrate equivalent efficacy, with the single-dose option offering superior adherence and convenience. 5

Why Fluoroquinolones Are No Longer First-Line

• Fluoroquinolone resistance in C. jejuni has reached epidemic proportions globally, with resistance rates exceeding 90% in Southeast Asia and 60% in travel-related infections in the United States. 6, 1

• Clinical failure occurs in approximately 33% of patients treated with fluoroquinolones when the isolate is resistant, directly impacting morbidity and prolonging illness. 6, 1

• Fluoroquinolone resistance emerged earlier in Campylobacter (1990s) than in other enteric pathogens, with Thailand showing an increase from 0% to 84% resistance between 1990-1995. 6

• Fluoroquinolones (ciprofloxacin 500 mg twice daily for 3 days or levofloxacin 500 mg daily for 3 days) should only be considered in geographic areas with documented low fluoroquinolone resistance rates. 1, 2

Special Populations Requiring Treatment

• Immunocompromised patients must always receive antibiotic treatment, even for mild infections, due to the risk of systemic dissemination and increased mortality. 1, 2

• Infants under 6 months are at higher risk for severe disease and complications, warranting prompt azithromycin treatment. 1

• For pediatric patients when azithromycin is unavailable, erythromycin 50 mg/kg/day divided every 6-8 hours for 5 days may be used as an alternative, though it is less effective. 1

Supportive Care Measures

• Initial rehydration is critical for patients with severe diarrhea or dehydration signs, with oral rehydration solutions (Ceralyte, Pedialyte) recommended for most patients. 1

• Maintain adequate hydration with 8-10 large glasses of clear liquids daily. 2

• Avoid antimotility agents (loperamide) as they may prolong bacterial shedding and worsen symptoms. 1

Critical Pitfalls to Avoid

• Using fluoroquinolones empirically without considering local resistance patterns leads to treatment failure in one-third of cases and significantly prolongs illness duration. 1, 2

• Delaying antibiotic treatment beyond 72 hours substantially reduces effectiveness and extends symptom duration. 1, 2

• Discontinuing antibiotics prematurely before completing the full course can result in treatment failure. 1

• Do not administer azithromycin simultaneously with aluminum or magnesium-containing antacids, as they reduce drug absorption. 5

When to Escalate Care

• Presence of blood in stool or severe abdominal pain requires immediate medical attention. 2

• Fever >38.5°C or symptoms persisting beyond 48 hours despite treatment warrant reassessment and consideration of alternative antibiotics based on susceptibility testing. 1, 2

• Signs of significant dehydration (decreased urination, dizziness, dry mouth) require prompt medical evaluation. 2

• Macrolide resistance, though rare at 4%, is significantly associated with increased risk of hospitalization when present. 6

FDA-Approved Indication

• Ciprofloxacin is FDA-approved for infectious diarrhea caused by Campylobacter jejuni when antibacterial therapy is indicated, though resistance patterns now limit its clinical utility. 7