Carriage of intestinal spirochaetes by humans: epidemiological data from Western Australia

The purpose of this study was to investigate carriage of intestinal spiroch aetes by selected population groups in Western Australia. Stool specimens f rom 293 rural patients with gastrointestinal disorders, and from 227 health y migrants from developing countries were cultured. Spirochaete isolates we re identified using PCR, and typed by pulsed field gel electrophoresis (PFG E). Brachyspira aalborgi was not isolated. Brachyspira pilosicoli was recov ered from 15 rural patients, all Aboriginal. Prevalence was 9.9% in 151 Abo riginals and 0% in 142 non-Aboriginals. Carriage of B. pilosicoli amongst m igrants was 10.6% (24/227). Carriage was significantly increased in Aborigi nal children aged 2-5 years (P = 0.0027) and in migrant individuals from th e Middle East and Africa (P = 0.0034). Carriage was significantly associate d with detection of faecal protozoa in both Aboriginals (P = 0.0021) and mi grants (P = 0.012). PFGE results indicated that the B. pilosicoli strains w ere genetically diverse.