Assessment of the clinical significance of intestinal spirochaetosis

Spirochaetes are well known causative agents of diarrhoea in veterinary medicine. However, there is no agreement as to whether or not they have any clinical significance in humans.

To assess the symptoms associated with intestinal spirochaetosis, their response to treatment and the natural history of untreated cases.

A retrospective review of all cases of intestinal spirochaetosis identified within an eight year period in a single university teaching hospital was performed. A chart review and follow up telephone interview was performed to assess the indications for colonoscopy that led to the diagnosis, treatment received, and duration and nature of symptoms.

18 cases were identified. The indications for colonoscopy were diarrhoea in 50% and rectal bleeding in 16.7%; also investigation of constipation, anaemia and abdominal pain, and in two cases reassessment of chronic proctitis. Two subjects were treated with metronidazole and two were treated with aminosalicylates. 69% had complete resolution of symptoms at follow-up, 15% had persistent symptoms and 15% had intermittent symptoms. Of the two patients treated with metronidazole, one had resolution of symptoms and one has persistent abdominal pain.

Symptoms do not appear to parallel spirochaete persistence or eradication and therefore it seems appropriate to adopt a wait and see approach to treatment of patients in whom spirochaetes are identified, giving a trial of antimicrobial treatment only in those who have severe or persistent symptoms. Careful consideration of both host and pathogen should be undertaken.