C0441 - Case of Concomitant Cryptosporidiosis and Ulcerative Colitis

Amberly Vaughan, BS¹, Kyler Kozacek, DO², Tudor Oroian, MD², Dawn Torres, MD^2
1Uniformed Services University of the Health Sciences, Hebert School of Medicine, North Bethesda, MD; ²Walter Reed National Military Medical Center, Bethesda, MD

Introduction: Cryptosporidiosis is a parasitic infection of gastrointestinal epithelia that presents primarily as acute watery diarrhea. In patients with inflammatory bowel disease (IBD), cryptosporidiosis can be mistaken for a flare. We present a case of an active duty service member with positive Cryptosporidium PCR on workup of what appeared to be an ulcerative colitis (UC) flare.

Case Description/Methods: A forty-three year-old male presented after two weeks of acutely worsening diarrhea, rectal pressure, blood with wiping, and bloating. Testing for Cryptosporidium was negative by routine histology and Giemsa and GMS stains of duodenal biopsies but was positive on a stool PCR panel. Both calprotectin and CRP were elevated. Colonoscopy showed inflammation to 30cm with friability, spontaneous hemorrhage, and ulceration. He was started on nitazoxanide for Cryptosporidium and oral mesalamine and a prednisone taper for UC flare. He improved symptomatically, with less frequent cramping and bowel movements and more formed stools.

Discussion: This case resembles documented cases of cryptosporidiosis in IBD patients but is unique in that most other cases were in Crohn’s patients 2-5,7-9. Our patient’s improvement on the three medications makes it difficult to definitively attribute the patient’s symptoms to either cryptosporidiosis or UC flare. Combining nitazoxanide with immunosuppression has not worsened his disease severity, which is also reflected in literature 9. It is possible, however, that nitazoxanide alone would have resolved his symptoms and obviated steroid use 3. The decision whether to test for Cryptosporidium in suspected UC flare should be based on pre-test probability and type of testing available. As seen in our case, less sensitive tests like Giemsa and GMS staining may result in false negatives. Stool PCR is the gold standard for detecting Cryptosporidum. PCR does not depend on fecal oocyst shedding, unlike modified Ziehl-Neelsen acid fast stain, direct immunofluorescence antibody testing, and stool microscopy 1,6. The weakness of stool PCR is that it also detects nonviable Cryptosporidium, and a positive test does not necessarily confirm an infectious cause of diarrhea. Lessons from this case include the importance of correct diagnosis to guide treatment, consideration of Cryptosporidium testing in cases of suspected UC flare, and the range of sensitivities among Cryptosporidium tests.


Disclosures:


Amberly Vaughan, BS¹, Kyler Kozacek, DO², Tudor Oroian, MD², Dawn Torres, MD². C0441 - Case of Concomitant Cryptosporidiosis and Ulcerative Colitis, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.