Intestinal Spirochetosis as a Presenting Symptom of Undiagnosed HIV Infection

Abstract

Purpose: A 47-year-old male presented with a 2-month history of diarrhea, averaging 3-20 bowel movements per day. The stools were watery, non-mucoid, malodorous, and primarily postprandial in nature. There was no fecal urgency, tenesmus, or incontinence. He developed rectal bleeding and he reported chronic, generalized abdominal pain following meals. Despite an excellent appetite, he had frequent nausea and lost approximately 40 pounds in weight over the preceding two months. He had no fever, but did note night sweats. He denied any history of pancreatic disease, exotic travel, antibiotic use, sick contacts, or anal intercourse. Stools studies were unrevealing for fecal leukocytes, C. difficile toxin, bacterial culture (including AFB), ova and parasite examination (including Giardia antigen), Cryptosporidium/Isospora, and qualitative fecal fat. Stool pH was 6.5, arguing against carbohydrate malabsorption. Celiac serologies, B12, folate, zinc, and fat-soluble vitamin levels were all normal. CBC demonstrated pancytopenia. HIV serology and confirmatory Western blot were positive. EGD with duodenal biopsies was normal. Colonoscopy revealed subtle erythema in the ascending and descending colon, with biopsies demonstrating active colitis and colonic spirochetosis. Results: Histological findings of intestinal spirochetosis are often an incidental finding on colonic biopsies. Intestinal spirochetes constitute a heterogeneous group of bacteria predominantly associated with low socioeconomic status, especially in developing countries. HIV infected individuals and homosexuals are at increased risk of colonization by these organisms. In the United States and other developed countries, 30-40% of cases have been reported in HIV/AIDS patients, as well as in Hepatitis C patients. The clinical course typically includes prolonged bouts of watery diarrhea, weight loss, and vague crampy abdominal pain occasionally associated with rectal bleeding. Symptoms are notably relieved with fasting. Conclusion: Definitive diagnosis of spirochetosis is histologic. Treatment is supportive in most cases, however in patients with severe symptoms, a 2 week course of metronidazole has been proven to be effective.Figure. 60X: Silver Stain showing spiral shaped organisms coating the colonic mucosa consistent with Brachyspira.