The prevalence of human intestinal spirochetosis in Norway.

The prevalence of human intestinal spirochetosis (HIS) was determined histologically in 402 subjects from South Norway (Kristiansand) who had undergone colorectal resections during the period June 1991-June 1996. The figures were compared with those from a previous mid-Norwegian study (Trondheim) comprising 1205 patients with large bowel resections as well as colonoscopic mucosal biopsies examined in 1990. The studies showed a prevalence of HIS of 2.5% in mid-Norway and 3.0% in South Norway, and in both regions there was a considerable male predominance of HIS (70% and 75%, respectively). Furthermore, HIS was more often diagnosed by the pathologists in South Norway (25%) than in mid-Norway (6.5%).