Severe Human Intestinal Spirochetosis: An Unusual Cause of Diffuse Colonic Ulcerations in a Patient Living With HIV

Abstract

Colonic ulceration in HIV infected individuals is commonly attributed to infectious colitis (viral, bacterial and fungal) and inflammatory bowel disease. Among bacterial causes, pathogens like salmonella, shigella, campylobacter, Yersinia and Neisseria gonorrhea predominate. Intestinal spirochetosis is however gaining clinical significance as an infectious cause of colonic ulceration in this population. Normal colonic mucosa is visualized in most cases and data on cases with colonic ulcerations remains sparse. Herein, we present a unique case of a HIV-infected male with diffuse colonic ulcerations attributed solely to intestinal spirochetosis. A 30-year-old male with a medical history of HIV infection, not on ARTs, and irritable bowel syndrome presented with a 2-week history of left lower abdominal pain and severe watery diarrhea. He initially had 4 stools daily, which were non-bloody, but became bloody one day prior to his presentation with an increased frequency of 10-12 stools. No identifiable precipitating factor. Colonoscopy done 2 years prior was normal. On admission, his vital signs were: BP 111/88 mmHg, HR 101 bpm and Temp 37.4 ° C. He had dry oral mucous membranes and a tender left lower abdominal quadrant. The rest of his exam was unremarkable. He was admitted for volume resuscitation. Stool ova and parasite, Clostridium difficile toxin, stool culture, RPR, Cryptosporidium, rotavirus and Giardia antigens were all negative. No leukocytosis or anemia. CD4 count was 246. An abdominopelvic CT scan was unrevealing. Colonoscopy was performed which revealed severe diffuse punctate ulcerations involving entire colon but worse in left colon (Figure 1, 2). Pathologic analysis of biopsy specimens revealed intestinal spirochetes in the entire colon and rectum, forming a false brush border over surface epithelium (Figure 3). No other pathogen was identified. A diagnosis of intestinal spirochetosis was made. He received ARTs and a 14-day course of oral Metronidazole. His clinical course was marked by complete resolution of diarrhea and abdominal pain. Repeat colonoscopy was not pursued given symptom resolution. Our patient had severe diffuse colonic ulcerations, a colonic pathology less commonly described in Intestinal spirochetosis. Interestingly, severity of ulcerations correlated with symptom severity. Hence, intestinal spirochetosis should be considered in cases of colonic ulcerations in HIV infected patients after excluding alternate causes.1608_A Figure 1. Colonoscopy showing diffuse severe colon ulcerations1608_B Figure 2. Colonoscopy showing diffuse severe colon ulcerations1608_C Figure 3. Intestinal spirochetes forming false brush border over surface epithelium and staining red with Treponema Pallidum immunostain