What is the recommended diagnosis and treatment for jejunitis caused by Campylobacter (C.) jejuni?

Diagnosis of Jejunitis Caused by Campylobacter jejuni

Stool culture remains the gold standard for diagnosing C. jejuni jejunitis, though molecular PCR testing on stool or biopsy specimens offers superior sensitivity and should be considered when culture is negative but clinical suspicion remains high. 1, 2

Diagnostic Approach

Clinical Presentation to Recognize

• Typical presentation includes diarrhea (watery and/or bloody), fever, and severe abdominal cramps that may mimic appendicitis 3, 4
• Symptoms develop after consumption of undercooked poultry, raw milk, contaminated water, or cross-contaminated ready-to-eat foods 5
• Severe abdominal pain warrants imaging to exclude surgical complications including appendicitis, perforation, or toxic megacolon 3

Laboratory Diagnosis

Stool Culture:

• Conventional stool culture is the traditional diagnostic method but has significant limitations, with false-negative rates reaching 28% in prospective studies 2
• Culture results take several days and are prone to false negatives from loss of bacterial viability during transport, overgrowth of other fecal flora, and poor growth of certain Campylobacter species on traditional media 2
• Despite these limitations, obtaining stool culture is recommended to confirm diagnosis and guide antibiotic selection based on susceptibility testing 6

Molecular Testing (PCR):

• PCR targeting the mapA gene (specific to C. jejuni) can be performed on routinely processed stool specimens or colon biopsy tissue, offering superior sensitivity to culture 1
• In patients with focal active colitis on biopsy, PCR detected C. jejuni DNA in 19% of cases, demonstrating its utility when culture is negative 1
• Five non-culture methods (including enzyme immunoassay and molecular methods) showed 100% agreement in identifying positive specimens, while culture misidentified 28% 2
• PCR on fixed, routinely processed colon biopsies is an excellent diagnostic method, particularly when culture fails or in patients already undergoing colonoscopy 1

Histopathology

• Colon biopsy typically shows focal active colitis (FAC) characterized by focal cryptitis with preservation of crypt architecture 1
• This pattern is nonspecific and can indicate infection or adverse drug effects, but presence of C. jejuni DNA by PCR suggests current or recent infection 1
• Consider biopsy with PCR testing in patients presenting with diarrhea, gastrointestinal bleeding, or incidental FAC findings on colonoscopy 1

When to Obtain Microbiologic Testing

• Microbiologic testing is recommended in returning travelers with severe or persistent symptoms to guide treatment and prevent prolonged illness 7
• Testing is particularly important in immunocompromised patients, those with bloody diarrhea, high fever, severe abdominal pain, or symptoms persisting beyond one week 6

Imaging Evaluation

• Abdominal ultrasound or CT scan is warranted when clinical deterioration occurs to detect thickened bowel wall, ileus, or toxic megacolon 3
• Plain abdominal X-ray can identify intestinal perforation (rare complication) or toxic megacolon 3
• Imaging should be obtained promptly in patients with severe abdominal pain mimicking appendicitis to rule out surgical complications 3

Critical Diagnostic Pitfalls

• Culture has a 28% misidentification rate (primarily false negatives), so negative culture does not exclude C. jejuni infection when clinical suspicion is high 2
• Random loss of bacterial viability during specimen handling in transport media significantly reduces culture sensitivity 2
• Diarrhea persisting beyond 10-14 days warrants further evaluation for complications or alternative diagnoses 6
• In immunocompromised patients and pregnant women, maintain high suspicion for bacteremia and consider blood cultures, as these populations are at risk for systemic spread and serious complications 3, 6

Post-Diagnostic Monitoring

• Monitor for neurological symptoms (ascending weakness, areflexia) in the weeks following acute infection, as Guillain-Barré syndrome typically develops 1-3 weeks post-infection and occurs in approximately 30% of all GBS cases worldwide 3, 4
• Assess for joint symptoms indicating reactive arthritis, which develops in approximately 2% of cases and can cause persistent impaired joint movement 3
• Evaluate persistent gastrointestinal symptoms beyond 10-14 days for possible post-infection IBS, which is an established complication with long-lasting changes in gut microbiota and intestinal motility 8, 3