{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T21:25:57Z","timestamp":1790717157351,"version":"4.1.0"},"reference-count":29,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,21]],"date-time":"2025-09-21T00:00:00Z","timestamp":1758412800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Cyclosporiasis, caused by Cyclospora cayetanensis, is a rare opportunistic infection, particularly in immunosuppressed patients with inflammatory bowel disease (IBD). Its clinical presentation may mimic IBD, with chronic diarrhea and anemia resistant to standard therapy. We report the case of a 24-year-old woman with ulcerative colitis (UC) and a history of liver transplantation, treated with vedolizumab and immunosuppressants. Despite endoscopic remission, she experienced persistent abdominal pain, diarrhea, and iron deficiency anemia. Escalation of biologic therapy was ineffective. After exclusion of bacterial and viral causes, stool testing identified Cyclospora cayetanensis. Treatment with nitazoxanide led to rapid clinical and laboratory improvement. Biologic therapy was temporarily discontinued and later resumed without recurrence of symptoms. This case shows that chronic diarrhea in IBD patients may not always result from the underlying disease. Immunosuppression increases the risk of opportunistic infections. Early diagnosis and specific treatment can improve outcomes and allow safe continuation of IBD therapy.<\/jats:p>","DOI":"10.3390\/microorganisms13092209","type":"journal-article","created":{"date-parts":[[2025,9,22]],"date-time":"2025-09-22T08:37:39Z","timestamp":1758530259000},"page":"2209","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Diagnostic Challenges of Cyclosporiasis in Chronic Diarrhea: A Case Study"],"prefix":"10.3390","volume":"13","author":[{"given":"Estera","family":"Banasik","sequence":"first","affiliation":[{"name":"Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences, University Clinical Hospital, 60-355 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3647-5070","authenticated-orcid":false,"given":"Agnieszka","family":"Dobrowolska","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences, University Clinical Hospital, 60-355 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucyna","family":"Wo\u017anicka-Le\u015bkiewicz","sequence":"additional","affiliation":[{"name":"Department of Family Medicine, Poznan University of Medical Sciences, 60-355 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9306-5038","authenticated-orcid":false,"given":"Piotr","family":"Eder","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences, University Clinical Hospital, 60-355 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,21]]},"reference":[{"key":"ref_1","first-page":"1027","article-title":"Chapter 83: Cyklosporoza","volume":"Volume IV","author":"Flisiak","year":"2020","journal-title":"Choroby Zaka\u017ane i Paso\u017cytnicze"},{"key":"ref_2","unstructured":"Heczko, P.B. (2000). Chapter 45. Cyklosporoza. Mikrobiologia i Choroby Zaka\u017ane, MedPharm."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1017\/S0031182019001471","article-title":"Cyclospora cayetanensis infection in humans: Biological characteristics, clinical features, epidemiology, detection method and treatment","volume":"147","author":"Li","year":"2020","journal-title":"Parasitology"},{"key":"ref_4","unstructured":"Kajfasz, P. (2025, September 16). Rzadkie Zespo\u0142y Biegunkowe Wywo\u0142ane Przez Pierwotniaki. Gastroenterologia Praktyczna. Available online: https:\/\/gastroenterologia-praktyczna.pl\/a2181\/Rzadkie-zespoly-biegunkowe-wywolane-przez-pierwotniaki-Cyklosporoza.html\/."},{"key":"ref_5","unstructured":"Paw\u0142owski, Z.S., and Stefaniak, J. (2004). Chapter 27: Cyklosporoza. Parazytologia Kliniczna w Uj\u0119ciu Wielodyscyplinarnym, PZWL."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/S0020-7519(02)00268-0","article-title":"Cyclospora cayetanensis: A review of an emerging parasitic coccidian","volume":"33","author":"Shields","year":"2003","journal-title":"Int. J. Parasitol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1548","DOI":"10.1056\/NEJM199705293362202","article-title":"An outbreak in 1996 of cyclosporiasis associated with imported raspberries. The Cyclospora Working Group","volume":"336","author":"Herwaldt","year":"1997","journal-title":"N. Engl. J. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1053\/j.gastro.2008.01.012","article-title":"Risk factors for opportunistic infections in patients with inflammatory bowel disease","volume":"134","author":"Toruner","year":"2008","journal-title":"Gastroenterology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2240","DOI":"10.3748\/wjg.v25.i18.2240","article-title":"Nested case-control study on risk factors for opportunistic infections in patients with inflammatory bowel disease","volume":"25","author":"Gong","year":"2019","journal-title":"World J. Gastroenterol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1007\/s00535-012-0686-9","article-title":"A prospective analysis of the incidence of and risk factors for opportunistic infections in patients with inflammatory bowel disease","volume":"48","author":"Naganuma","year":"2013","journal-title":"J. Gastroenterol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1097\/MIB.0b013e3182a827d2","article-title":"Opportunistic infections due to inflammatory bowel disease therapy","volume":"20","author":"Dave","year":"2014","journal-title":"Inflamm. Bowel Dis."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1324","DOI":"10.1016\/j.cgh.2020.02.009","article-title":"Predicting, preventing, and managing treatment-related complications in patients with inflammatory bowel diseases","volume":"18","author":"Beaugerie","year":"2020","journal-title":"Clin. Gastroenterol. Hepatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1053\/j.gastro.2018.04.012","article-title":"Risk of serious and opportunistic infections associated with treatment of inflammatory bowel diseases","volume":"155","author":"Kirchgesner","year":"2018","journal-title":"Gastroenterology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.rdc.2016.09.005","article-title":"Opportunistic Infections in Biological Therapy, Risk and Prevention","volume":"43","author":"Bryant","year":"2017","journal-title":"Rheum. Dis. Clin. N. Am."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1016\/j.crohns.2013.12.013","article-title":"Second European evidence-based consensus on the prevention, diagnosis, and management of opportunistic infections in inflammatory bowel disease","volume":"8","author":"Rahier","year":"2014","journal-title":"J. Crohn\u2019s Colitis"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1093\/ecco-jcc\/jjab052","article-title":"ECCO Guidelines on the Prevention, Diagnosis, and Management of Infections in Inflammatory Bowel Disease","volume":"15","author":"Kucharzik","year":"2021","journal-title":"J. Crohns Colitis"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.cgh.2019.02.044","article-title":"Comparative risk of serious infections with biologic and\/or immunosuppressive therapy in patients with inflammatory bowel diseases: A Systematic Review and Meta-Analysis","volume":"18","author":"Singh","year":"2020","journal-title":"Clin. Gastroenterol. Hepatol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1093\/ecco-jcc\/jjz137","article-title":"The Safety Profile of Vedolizumab in Ulcerative Colitis and Crohn\u2019s Disease: Four years of global post-marketing data","volume":"14","author":"Cohen","year":"2020","journal-title":"J. Crohns Colitis"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.crohns.2009.02.010","article-title":"The European (ECCO) consensus on opportunistic infections in IBD","volume":"3","author":"Rahier","year":"2009","journal-title":"J. Crohns Colitis"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3451","DOI":"10.1017\/S0950268815000370","article-title":"2013 multistate outbreaks of Cyclospora cayetanensis infections associated with fresh produce: Focus on the Texas investigations","volume":"143","author":"Abanyie","year":"2015","journal-title":"Epidemiol. Infect."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1136\/gutjnl-2015-311079","article-title":"The safety of vedolizumab for ulcerative colitis and Crohn\u2019s disease","volume":"66","author":"Colombel","year":"2017","journal-title":"Gut"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"699","DOI":"10.1056\/NEJMoa1215734","article-title":"Vedolizumab as induction and maintenance therapy for ulcerative colitis","volume":"369","author":"Feagan","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1016\/j.crohns.2012.09.002","article-title":"Second European evidence-based consensus on the diagnosis and management of ulcerative colitis","volume":"6","author":"Dignass","year":"2012","journal-title":"J. Crohns Colitis"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"649","DOI":"10.1093\/ecco-jcc\/jjx008","article-title":"Third European Evidence-based Consensus on Diagnosis and Management of Ulcerative Colitis. Part 1: Definitions, diagnosis, extra-intestinal manifestations, pregnancy, cancer surveillance, surgery, and ileo-anal pouch disorders","volume":"11","author":"Magro","year":"2017","journal-title":"J. Crohns Colitis"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1093\/ecco-jcc\/jjab178","article-title":"ECCO guidelines on the therapeutics in ulcerative colitis: Medical treatment","volume":"16","author":"Raine","year":"2022","journal-title":"J. Crohns Colitis."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1185","DOI":"10.1097\/00042737-199910000-00019","article-title":"The histopathology of coeliac disease: Time for a standardized report scheme for pathologists","volume":"11","author":"Oberhuber","year":"1999","journal-title":"Eur. J. Gastroenterol. Hepatol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"558","DOI":"10.1016\/j.jhep.2019.10.003","article-title":"The gut\u2013liver axis in liver disease: Pathophysiological basis for therapy","volume":"72","author":"Albillos","year":"2020","journal-title":"J. Hepatol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1016\/S0140-6736(19)31266-8","article-title":"The evolution of the use of faecal microbiota transplantation and emerging therapeutic indications","volume":"394","author":"Allegretti","year":"2019","journal-title":"Lancet"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1180","DOI":"10.1093\/ecco-jcc\/jjx063","article-title":"Faecal microbiota transplantation for inflammatory bowel disease: A systematic review and meta-analysis","volume":"11","author":"Paramsothy","year":"2017","journal-title":"J. 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