What is the typical etiology and treatment of Campylobacter infection in an otherwise healthy individual?

Campylobacter Infection: Etiology and Treatment

Etiology and Transmission

Campylobacter jejuni and C. coli are the primary causative agents of human campylobacteriosis, transmitted predominantly through contaminated poultry products, unpasteurized milk, and contaminated water. 1, 2

Primary Sources of Infection

• Poultry products represent the major source of human infections, with epidemiological studies demonstrating significant correlation between handling and consumption of undercooked chicken and Campylobacter enteritis 2, 3
• Raw or unpasteurized milk has caused multiple outbreaks 4, 3
• Contaminated water serves as an important transmission route 5, 3
• Sexual practices involving fecal-oral exposure increase infection risk 4
• International travel is the leading risk factor, particularly to Asia, Mexico, and South America 4, 2

High-Risk Exposures

• Barbecues present special hazards due to cross-contamination from raw meats to hands and other foods 3
• Contact with farm animals, particularly in petting zoos and agricultural settings 4
• Raw shellfish consumption 3

Clinical Presentation

The typical presentation includes bloody diarrhea, abdominal cramping, fever, and fecal leukocytes on stool examination. 1

Common Manifestations in Healthy Individuals

• Self-limited gastroenteritis with diarrhea (often bloody), abdominal pain, and fever lasting 3-7 days 4, 5
• Proctocolitis with bloody diarrhea as the most common presentation 1
• Fecal leukocytes are commonly present on stool examination 1
• Abdominal pain may mimic appendicitis 6

Severe Complications (Rare in Healthy Hosts)

• Bacteremia occurs primarily in immunocompromised patients 4, 6
• Toxic megacolon and intestinal perforation are rare but serious complications 1, 6
• Guillain-Barré syndrome develops in approximately 0.1% of cases, with C. jejuni accounting for 30% of all GBS cases worldwide 6, 5
• Reactive arthritis occurs in approximately 2% of cases 6, 5
• Post-infectious IBS can develop as a chronic sequela 6

Treatment Recommendations

Azithromycin is the first-line antibiotic for Campylobacter infection, with a single 1000 mg dose or 500 mg daily for 3 days achieving 96% clinical cure rates when initiated within 72 hours of symptom onset. 1

Antibiotic Selection

• Azithromycin (1000 mg single dose or 500 mg daily for 3 days) is the preferred agent with demonstrated 96% clinical cure rate 1, 2
• Erythromycin or clarithromycin are acceptable alternatives 2
• Fluoroquinolones should be avoided due to resistance rates exceeding 90% in many regions, with 33% clinical failure rates when isolates are resistant 4, 1

Critical Treatment Timing

• Initiate antibiotics within 72 hours of symptom onset for maximum benefit in reducing symptom duration 1
• Treat immunocompromised patients immediately, even with mild symptoms, due to high risk of bacteremia and systemic spread 1, 6

Fluoroquinolone Resistance Patterns

The evidence strongly demonstrates widespread fluoroquinolone resistance that makes these agents unsuitable for empiric therapy:

• 60% of travel-related Campylobacter infections in the United States are fluoroquinolone-resistant versus only 13% of domestic cases 4
• Thailand experienced rapid emergence with resistance increasing from 0% in 1990 to 84% in 1995 4
• Peru documented ciprofloxacin resistance of 73-90% in C. jejuni and 48-87% in C. coli 4
• Clinical failure occurred in 33% of patients prescribed fluoroquinolones when isolates were resistant 4

When Antibiotics Are Indicated

• Severe symptoms (high fever, bloody diarrhea, severe abdominal pain) 1
• Immunocompromised patients regardless of symptom severity 1, 6
• Symptoms present within 72 hours for maximum therapeutic benefit 1

Diagnostic Approach

Perform stool culture and check for fecal leukocytes in patients with bloody diarrhea and suspected infectious colitis. 1

Laboratory Testing

• Stool culture remains the gold standard for diagnosis 4
• Fecal leukocyte examination aids in diagnosis 1
• Blood cultures should be obtained in immunocompromised patients with fever and diarrhea due to increased bacteremia risk 4

Special Considerations

• Notify laboratory of suspected Campylobacter to ensure appropriate culture conditions for fastidious non-jejuni/non-coli species 4
• Consider colonoscopy or sigmoidoscopy if diagnosis is unclear or symptoms are severe 1

Prevention Strategies

Avoid raw or undercooked poultry, unpasteurized dairy products, and practice meticulous hand hygiene after handling raw meat or animals. 4

Food Safety Measures

• Cook poultry to internal temperature of 180°F (82°C) and red meats to 165°F (74°C) 4
• Avoid raw or undercooked eggs, unpasteurized dairy products, and raw shellfish 4
• Prevent cross-contamination during food preparation, especially at barbecues 3

Hygiene Practices

• Wash hands after handling raw meat, contact with animals, gardening, and before eating 4
• Use barriers during sexual practices that may involve fecal-oral exposure 4

Common Pitfalls to Avoid

• Do not use fluoroquinolones empirically for suspected Campylobacter—resistance is now widespread globally and associated with treatment failure 4, 1
• Do not delay treatment in immunocompromised patients even with mild symptoms—they require immediate systemic antibiotics due to bacteremia risk 1, 6
• Do not miss the 72-hour treatment window—antibiotic efficacy decreases significantly after this timeframe 1
• Do not overlook post-infectious complications—monitor for neurological symptoms (GBS), joint symptoms (reactive arthritis), and persistent GI symptoms (post-infectious IBS) in the weeks following acute infection 6