Colonic Spirochetes in a Patient With HIV

Abstract

Introduction: Spirochetosis of the colon was first reported in 1967 in a patient with chronic diarrhea. Since this first description, however, the clinical significance of spirochetosis has been controversial, as its relationship with human disease has remained unclear. Spirochetosis has been associated with abdominal pain, appendicitis, chronic diarrhea, and rectal bleeding in some cases, but in the majority of cases, spirochetosis is an incidental finding with no clear clinical correlates.The anaerobic intestinal spirochetes Brachyspira aalborgi and Brachyspira pilosicoli seem to be responsible for most cases of colonic spirochetosis. Treatment with metronidazole is advisable in patients with persistent symptoms. Case Report: We report a case of a 38-year-old African American male with HIV on HAART who presented with intermittent rectal pain, blood in the stool, and anal itching for 2 years. He underwent colonoscopy with multiple biopsies which revealed spirochetes in the colon. He was treated with a 10-day course of oral metronidazole with symptom resolution. Conclusion: A high degree of suspicion is required in cases presenting with abdominal pain, chronic diarrhoea, and/or hematochezia associated with a normal endoscopic examination, thus emphasizing the importance of multiple biopsies throughout the colon. Clinical recovery after drug therapy suggests that intestinal spirochetosis may play a pathogenic role in causing symptoms.Figure 1: Normal-appearing colonic mucosa.Figure 2: Warthin-Starry stain showing the surface coating by spirochetes.