Asymptomatic Intestinal Spirochetosis Found Incidentally in Endoscopic Specimens

Abstract

Intestinal spirochetosis is a zoonotic infection caused by gram-negative bacteria of the genus Brachyspira. In Japan, several cases have been reported since Nakamura et al. first reported the disease in 1998, and although it has been recognized by pathologists, there have only been a handful of reports on the disease. In this study, we investigated an incidence of intestinal spirochetosis in samples obtained through colonoscopic biopsy, polypectomy, and EMR. Ten patients (6 men and 4 women) were diagnosed with intestinal spirochetosis and had been infected with Brachyspira aalborgi among 537 patients (318 men and 219 women). Ages ranged from 49 to 73 years. The overall incidence was 1.9%, and the incidence in men (1.88%) and women (1.82%) was almost equal. In past reports, intestinal spirochetes was more common among men, although only one report examined the sex-specific incidence of this disease. Our results suggested that a similar number of infections occur in women, but the infection route is not clear.