Human intestinal spirochetosis mimicking ulcerative colitis

Abstract

Human intestinal spirochetosis (HIS) is a colorectal infection caused by the Brachyspira species of intestinal spirochetes, whose pathogenicity in humans remains unclear owing to the lack of or mild symptoms. We monitored the 5-year clinical course of a woman diagnosed with HIS in whom ulcerative colitis (UC) had been suspected. Following a positive fecal occult blood test, she underwent a colonoscopic examination at a local clinic where she was diagnosed with "right-sided" UC concomitant with incidentally detected HIS, and was referred to our hospital. Colonoscopic, histopathological, and cytological examination revealed localized erosive colitis in the ascending and the right transverse colon concomitant with HIS resembling skip lesions of UC. Initially, we chose the wait-and-watch approach; however, she gradually developed bloody diarrhea. Metronidazole improved her abdominal symptoms, as well as her colonoscopic and histopathological findings, suggesting that HIS was responsible for her colorectal inflammation. This case reveals (1) a possible pro-inflammatory role of HIS, (2) difficulties in diagnosing HIS in chronic proctocolitis, and (3) a possible inclusion of some HIS cases in "UC". HIS could mimic UC and might be included in differential diagnoses for UC. Antibiotic administration is necessary following the detection of HIS, particularly in patients demonstrating an atypical presentation of UC.

Unusual intra-rectal “laterally spreading tumour” in immunosuppressed patient with ulcerative colitis

“…Delayed diagnosis may lead, among other complications, to expose patients to unnecessary drug therapy, which, in this case, probably favoured the occurrence of this intra-rectal condyloma. invasion of spirochetosis beyond the surface epithelium may be associated with gastrointestinal symptoms, such as chronic mucosal diarrhea, rectal bleeding, abdominal pain and weight loss, mimicking IBD as in the present case (16,17). Individuals without any invasion are in principle asymptomatic (16), but, for unknown reason, homosexual and HIV-positive men as well as children are more likely to be symptomatic with a single colonisation (16).…”

“…The treatment usually involves 5 to 10 days of metronidazole but symptomatic improvement with the use of other antibiotics (such as clindamycin or macrolides) (16) and spontaneous resolution has also been reported (18), which could explain clinical improvement of this patient without metronidazole. Some authors are suggesting the existence of a possible relationship (overlap) between HIS and UC (17). The links between HIS and UC are close but complex with 3 possible groups: (1) UC accompanied temporally or incidentally by HIS, (2) UC associated with HIS and (3) HIS mimicking UC.…”

Severe Colitis with Portal Venous Gas Caused by <i>Brachyspira pilosicoli</i> Infection

“…If patients are symptomatic after ruling out of other diseases, eradication therapy should be considered. It is common to use metronidazole or amoxicillin as therapeutic agents (1,11,23), but in recent years, the efficacy of penicillin has decreased due to an increase in β-lactamase-producing strains (24).…”

Mucosal eosinophilic infiltration may be a characteristic of human intestinal spirochetosis

“…Therefore, most cases are found incidentally by histological examination of specimens taken endoscopically during (a) annual check-up in healthy persons, (b) further investigation after positive results for fecal occult blood, or (c) follow-up after polypectomy/surgery for tumorous lesions [ 2 ]. However, some HIS cases manifest a significant degree of mucosal inflammation [ 4 , 5 ] or exacerbated inflammaton of accompanying ulcerative colitis [ 6 ], and thus the pathogenesis of HIS is considered uncertain. Histologically, mucosal inflammation in HIS has been reported to be mild or non-specific [ 1 ], but mucosal eosinophilia was indicated in a recent report [ 7 ].…”