Double Trouble: Intestinal Spirochetosis in an HIV-Positive Patient 1598

• Published in: The American journal of gastroenterology Vol. 113; no. Supplement; p. S919
• Main Authors: Faruqui, Saamia, Matthews, Lindsay A., Peters, Cacey, Glover, Porter, Affronti, John P.
• Format: Journal Article
• Language: English
• Published: New York Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins 01.10.2018
• Subjects: Biopsy; Diarrhea; Gastroenterology; HIV; Human immunodeficiency virus; Infections; Patients; Syphilis
• ISSN: 0002-9270; 1572-0241
• DOI: 10.14309/00000434-201810001-01598

This case highlights an uncommon but important etiology of diarrhea in HIV-infected patients, intestinal spirochetosis (IS). The spirochetes in this infection are different than the more commonly known organisms causing syphilis and Lyme disease, and are found at a higher rate in the HIV-positive population compared to the general population. Intestinal spirochetosis can pose diagnostic and therapeutic challenges for clinicians. A 31 year-old man diagnosed with HIV infection two years ago, well controlled on antiretrovirals, presented to the outpatient GI clinic for evaluation of a several-month history of morning nausea, with associated generalized abdominal pain. He also reported clear liquid emesis, and diarrhea several times per day, without blood. His pain was not associated with eating or having a bowel movement. He also reported a 20-pound unintential weight loss. He underwent an outpatient EGD and colonoscopy for evaluation of his persistent nausea and diarrhea. Biopsies were taken from the duodenum and terminal ileum, as well as random colon biopsies. Upon histologic examination, the biopsies showed intestinal spirochetosis, confirmed by positive staining of organisms with Warthin-Starry stain, PAS stain, and spirochete immunostain. Serum RPR was negative in the patient and his male partner. The prevalence of IS varies globally; a large Japanese cohort had an overall prevalence of 1.7%; the prevalence was 5.5% among the HIV-positive population studied. The predominant species are Brachyspira aalborgi and Brachyspira pilosicoli, notably different from the most commonly known spirochete, Treponema palllidum. The clinical significance of intestinal infection by these organisms is unknown, but it has been postulated that invasion of spirochetes beyond the surface epithelium causes symptoms. It has been found that HIV-infected individuals are more likely to experience symptoms regardless of invasion through the epithelium, and the utility of treatment with metronidazole for symptomatic individuals is still unknown. The chronic inflammation and the prolonged duration of symptoms in these patients may be misdiagnosed as IBD; therefore, histopathology remains the cornerstone for diagnosis of IS, as serum studies for syphilis, the most common spirochete, are often negative. The diagnosis of IS may pose clinical challenges for clinicians, and in cases of diarrhea of unknown origin in HIV-positive patients, intestinal spirochetosis should be considered.