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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Sep 24, 2016; 6(3): 460-471
Published online Sep 24, 2016. doi: 10.5500/wjt.v6.i3.460
Cryptosporidium infection in solid organ transplantation
Diana F Florescu, Uriel Sandkovsky
Diana F Florescu, Uriel Sandkovsky, Transplant Infectious Diseases Program, Division of Infectious Diseases, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5400, United States
Diana F Florescu, Division of Transplant, Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198-3285, United States
Author contributions: Florescu DF and Sandkovsky U contributed equally in the design, data collection, interpretation, drafting and final approval of the article.
Conflict-of-interest statement: Dr. Diana Florescu received a grant from Chimerix Inc.; grant from CLS Behring; consulting for Chimerix Inc. and CLS Behring. Dr. Uriel Sandkovsky received a research grants from from CLS Behring, ViiV healthcare, GSK, Pfizer; consulting for Rib-X pharmaceuticals.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Diana F Florescu, MD, Transplant Infectious Diseases Program, Division of Infectious Diseases, Department of Internal Medicine, University of Nebraska Medical Center, 985400 Nebraska Medical Center,Omaha, NE 68198-5400, United States. dflorescu@unmc.edu
Telephone: +1-402-5598650 Fax: +1-402-5595581
Received: February 10, 2016
Peer-review started: February 12, 2016
First decision: April 15, 2016
Revised: April 22, 2016
Accepted: June 14, 2016
Article in press: June 16, 2016
Published online: September 24, 2016
Processing time: 226 Days and 14.7 Hours
Abstract

Diarrhea is a common complication in solid organ transplant (SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.

Keywords: Cryptosporidium; Solid organ transplantation; Diarrhea; Nitazoxanide; Antiparasitic drugs

Core tip: Diarrhea caused by Cryptosporidium is a serious and underrecognized cause of diarrhea in solid organ transplant recipients. The most important diagnostic challenge is low index of suspicion, since many new diagnostic methods have improved detection of the parasite. Treatment can be challenging as the disease may cause severe dehydration and antiparasitic drugs have modest activity. Electrolyte and fluid replacement, reduction of immunosuppression and antiparasitic therapy are the cornerstones of management. Newer antiparasitic drugs and vaccines may help manage the disease in the future.