What are the symptoms and treatment options for Campylobacter infection, particularly in vulnerable populations such as young children, the elderly, and those with compromised immune systems?

Campylobacter Infection: Clinical Presentation and Management

Clinical Symptoms

Campylobacter infection typically presents with fever, diarrhea (often bloody), and abdominal pain after an incubation period of 1-7 days, with most cases being self-limited and resolving within 2-7 days. 1, 2

Gastrointestinal Manifestations

• Diarrhea is the hallmark symptom, frequently containing mucus and progressing to frank blood within a few days of onset 2, 3
• Abdominal pain and cramping occur commonly, sometimes severe enough to mimic appendicitis in children with mesenteric adenitis 4
• Fever is present in the majority of symptomatic cases 2, 3
• Significant vomiting and dehydration are uncommon compared to other bacterial enteritides 3
• Bloody stools occur in approximately 8% of cases, though heme-positive stools are found in 38-83% 4

Disease Severity Indicators

The presence of certain features should prompt more aggressive evaluation and treatment:

• Bloody or mucoid stools warrant stool testing for bacterial pathogens 4
• Severe abdominal cramping or tenderness indicates potential invasive disease 4
• Signs of sepsis require immediate blood cultures and empirical antimicrobial therapy 4
• Fecal white blood cells are present in 25-80% of cases, indicating colonic inflammation 4

Treatment Approach

When to Treat

Azithromycin is the first-line treatment for Campylobacter infections, particularly when initiated within 72 hours of symptom onset, reducing illness duration from 50-93 hours to 16-30 hours. 5, 6

Treatment is indicated for:

• Severe disease with bloody diarrhea, high fever, or severe abdominal pain 6
• Prolonged symptoms lasting more than 1 week 6
• Immunocompromised patients, even with mild infections, due to risk of bacteremia and systemic spread 5, 6
• Infants under 6 months who are at higher risk for severe disease and complications 5

Antimicrobial Therapy

Azithromycin dosing:

• 1000 mg single dose OR 500 mg daily for 3 days 5, 6
• Clinical cure rate of 96% with low resistance rates (approximately 4%) 5, 6

Alternative for children when azithromycin unavailable:

• Erythromycin 50 mg/kg/day divided every 6-8 hours for 5 days, though less effective 5, 6

Critical Pitfall: Fluoroquinolone Resistance

Fluoroquinolones should NOT be used empirically due to dramatic worldwide resistance increases, exceeding 90% in Southeast Asia and causing clinical failure in approximately 33% of resistant cases. 5, 6

• Resistance has increased from 0% to 84% in Thailand between 1990-1995 5
• Quinolone resistance can develop during treatment with symptomatic relapse 4
• Quinolones may worsen outcomes by eradicating competing normal flora 4

Supportive Care

• Oral rehydration solutions (e.g., Ceralyte, Pedialyte) are critical for patients with severe diarrhea or dehydration 5, 6
• Continue age-appropriate feeding as tolerated 5, 6
• Avoid antimotility agents as they may prolong bacterial shedding and worsen symptoms 5, 6

Special Population Considerations

Vulnerable Groups

Young children (0-4 years) have the highest incidence of campylobacteriosis 7

Immunocompromised patients:

• Always require antibiotic treatment, even for mild infections 5, 6
• Higher risk for bacteremia (occurring occasionally in high-risk groups) 1
• HIV-infected persons are at higher risk for non-jejuni non-coli Campylobacter species requiring specialized testing 6

Elderly patients should be evaluated for signs of systemic illness and dehydration 4

Post-Infectious Complications

Monitor for late complications that can occur weeks after initial infection:

• Guillain-Barré syndrome (occurs in approximately 1 in 1000 infections) 6, 8, 7
• Reactive arthritis and Reiter's syndrome 5, 6, 7
• Miller Fisher syndrome 7
• Rare severe complications include bacteremia, meningitis, cholecystitis, peritonitis, toxic megacolon, and perforation 5, 1, 2

Diagnostic Testing

Stool testing should be performed for Campylobacter in patients with fever, bloody or mucoid stools, severe abdominal cramping, or signs of sepsis. 4

• Direct phase-contrast microscopy of stools can provide rapid presumptive diagnosis during acute illness 3
• Culture requires selective medium with antibiotics and incubation under reduced oxygen tension at 42°C 3
• Organism persists in stools for 7-21 days untreated, sometimes up to 7 weeks 1, 3

Blood cultures should be obtained from:

• Infants <3 months of age 4
• Any patient with signs of septicemia 4
• Immunocompromised individuals 4

Follow-Up and Monitoring

• Reassess after 48 hours if no improvement or worsening symptoms occur; consider alternative antibiotics based on susceptibility testing 5, 6
• No routine follow-up stool cultures are needed if symptoms resolve 5, 6
• Diarrhea persisting beyond 10-14 days warrants further evaluation for parasitic infections or other causes 6
• Completing the full antibiotic course is essential; premature discontinuation leads to treatment failure 5, 6