Campylobacter Species
Campylobacter species are Gram-negative bacteria that constitute the most common cause of bacterial gastroenteritis worldwide, with C. jejuni and C. coli responsible for the majority of human infections, while other species like C. fetus are associated with systemic infections particularly in immunocompromised hosts. 1
Taxonomy and Characteristics
Campylobacter is a diverse genus of bacteria with several clinically important species:
Major pathogenic species:
- C. jejuni (most common cause of human gastroenteritis)
- C. coli (second most common)
- C. fetus (associated with systemic infections)
Emerging species:
Campylobacter species are microaerophilic (require reduced oxygen levels), thermophilic (grow best at temperatures between 37-42°C), and typically appear as curved or spiral-shaped rods under microscopy 3.
Clinical Presentations
Campylobacter infections present in three main patterns:
Self-limited gastroenteritis - Most common presentation
- Symptoms: diarrhea (often bloody), abdominal pain, fever, nausea, vomiting
- Typically resolves within 1 week
Severe and prolonged diarrheal disease
- More common in immunocompromised patients
- Can persist for weeks to months
Systemic infection with extra-intestinal involvement
- Bacteremia, meningitis, endocarditis
- More common in immunocompromised hosts 1
Post-infectious Complications
- Guillain-Barré syndrome - Acute autoimmune neuropathy
- Reactive arthritis
- Post-infectious irritable bowel syndrome (PI-IBS) - Occurs in approximately 10% of cases 1, 2
Diagnosis
The Centers for Disease Control and Prevention (CDC) defines a confirmed case of Campylobacter infection as the isolation of Campylobacter from any clinical specimen 4, 1.
Diagnostic methods include:
Stool culture (gold standard)
- Requires special microaerophilic conditions
- Selective media
Molecular diagnostic panels
- Detect Campylobacter DNA
- May not distinguish viable from non-viable organisms
Blood cultures
- Important in patients with fever and diarrhea due to risk of bacteremia
- Particularly important in immunocompromised patients 1
Treatment
For severe Campylobacter infections:
First-line therapy: Azithromycin
- Adults: 1000 mg single dose or 500 mg daily for 3 days
- Children: 30 mg/kg as a single dose
- Preferred due to high fluoroquinolone resistance rates worldwide
Alternative antibiotics:
Special considerations:
- Immunocompromised patients may require longer treatment courses
- Chronic suppressive therapy may be needed for recurrent infections 1
Epidemiology and Transmission
Campylobacter naturally colonizes:
Transmission occurs through:
- Consumption of contaminated food (especially undercooked poultry)
- Unpasteurized dairy products
- Contaminated water
- Person-to-person spread (less common)
- Sexual practices with oral-fecal exposure 1, 6
Prevention
Key preventive measures include:
Food safety:
- Avoid raw/undercooked poultry, meat, and seafood
- Avoid unpasteurized dairy products and fruit juices
- Proper cooking temperatures for meat and poultry
Hand hygiene:
- Thorough handwashing after animal contact
- Proper food handling practices
Safe sexual practices:
- Avoiding unprotected sex practices that might result in oral exposure to feces 1
Travel precautions:
- Higher risk of resistant Campylobacter in Southeast Asia, Mexico, and South America 1
Public Health Importance
Campylobacter is a significant public health concern:
- One of the most common causes of bacterial gastroenteritis globally
- The CDC estimates over 300,000 infections per year are caused by drug-resistant Campylobacter in the US
- Requires a One Health approach (integrating human, animal, and environmental health) for effective control 5, 6
Campylobacter infections should be reported to public health authorities for surveillance and outbreak detection 4.