ENDOSCOPIC DIAGNOSIS OF HUMAN INTESTINAL SPIROCHETOSIS: A CASE SERIES

Aims: Human intestinal spirochetosis (HIS) is defined by the presence of a layer of spirochetes attached by one end ofthe cell to the colorectal epithelium. Brachyspira pilosicoli and Brachyspira aalborgi are the etiologic agents of HIS. While many patients with HIS have no symptoms, some have symptoms such as chronic diarrhea and bloody stool. There is little known about pathogenicity of HIS, and awareness is still low. We investigated the characteristics of patients treated for HIS.

Methods: We retrospectively reviewed the clinicopathological features of 71 patients with HIS seen from January 2008 to December 2018. HIS was diagnosed in all patients by colonoscopic biopsy.

Results: There were 59 males and 12 females with an average age of 58 (30 ~ 79) years. There were no symptoms in 44 patients, and 27 had symptoms. The most common symptom was diarrhea. There were various endoscopic findings including normal mucosa, erythema, erosions, ulcers and intestinal spirochetes attached to a polyp. Bacterial cultures were performed in some cases. B. pilosicoli was identified and isolated in five patients and B. aalborgi in six. Drug susceptibility was performed using the E-test. Organisms were sensitive to metronidazole and tetracycline. Eradication therapy using metronidozole was given to 29 patients. Nine patients with no symptoms and other gastrointestinal diseases were excluded. Symptoms improved in 15/20 patients.

Conclusions: In this study, HIS has no characteristic endoscopic features. Not all patients with HIS have symptoms. However, in patients with symptoms, eradication therapy was effective. If there are no other causes of gastrointestinal symptoms, symptomatic patients with HIS should undergo eradication. We think that asymptomatic patients do not need treatment.