Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 21, 2021; 27(27): 4276-4297
Published online Jul 21, 2021. doi: 10.3748/wjg.v27.i27.4276
Viral infections in inflammatory bowel disease: Tips and tricks for correct management
Vincenzo Craviotto, Federica Furfaro, Laura Loy, Alessandra Zilli, Laurent Peyrin-Biroulet, Gionata Fiorino, Silvio Danese, Mariangela Allocca
Vincenzo Craviotto, Federica Furfaro, Laura Loy, Alessandra Zilli, Gionata Fiorino, Silvio Danese, Mariangela Allocca, Humanitas Clinical and Research Center, IRCCS, Rozzano 20089, Milano, Italy
Laurent Peyrin-Biroulet, Department of Hepato-Gastroenterology and Inserm U954, University Hospital of Nancy, Lorraine University, Nancy 54511, France
Gionata Fiorino, Silvio Danese, Mariangela Allocca, Department of Biomedical Sciences, Humanitas University, Pieve Emanuele 20090, Milano, Italy
Author contributions: Craviotto V and Allocca M conceived and designed the study; Craviotto V, Furfaro F and Zilli A collected the data; Craviotto V drafted the manuscript; all authors critically revised the manuscript and approved the final version.
Conflict-of-interest statement: MA received consulting fees from Nikkiso Europe, Mundipharma, Janssen, Abbvie and Pfizer; FF received consulting fees from Amgen, Abbvie and lecture fees from Janssen and Pfizer; LP-B reports personal fees from Merck, Abbvie, Janssen, Genentech, Mitsubishi, Ferring, Norgine, Tillots, Vifor, Hospira/Pfizer, Celltrion, Takeda, Biogaran, Boerhinger-Ingelheim, Lilly, HAC-Pharma, Index Pharmaceuticals, Amgen, Sandoz, Forward Pharma GmbH, Celgene, Biogen, Lycera, and Samsung Biosepsis; GF received consultancy fees from Ferring, MSD, AbbVie, Takeda, Janssen, Amgen, Sandoz, Samsung Bioepis, Celltrion; SD served as a speaker, consultant and advisory board member for Schering-Plough, Abbott (AbbVie) Laboratories, Merck, UCB Pharma, Ferring, Cellerix, Millenium Takeda, Nycomed, Pharmacosmos, Actelion, Alfa Wasserman, Genentech, Grunenthal, Pfizer, AstraZeneca, Novo Nordisk, Cosmo Pharmaceuticals, Vifor and Johnson and Johnson. VC, AZ and SB have no conflicts of interest to declare.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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:
Corresponding author: Mariangela Allocca, MD, PhD, Adjunct Professor, Humanitas Clinical and Research Center, IRCCS, Via Alessandro Manzoni, 56, Rozzano 20089, Milano, Italy.
Received: January 28, 2021
Peer-review started: January 28, 2021
First decision: March 6, 2021
Revised: April 1, 2021
Accepted: May 15, 2021
Article in press: May 15, 2021
Published online: July 21, 2021

Over the past decades, the treatment of inflammatory bowel diseases (IBD) has become more targeted, anticipating the use of immune-modifying therapies at an earlier stage. This top-down approach has been correlated with favorable short and long-term outcomes, but it has also brought with it concerns regarding potential infectious complications. This large IBD population treated with immune-modifying therapies, especially if combined, has an increased risk of severe infections, including opportunistic infections that are sustained by viral, bacterial, parasitic, and fungal agents. Viral infections have emerged as a focal safety concern in patients with IBD, representing a challenge for the clinician: they are often difficult to diagnose and are associated with significant morbidity and mortality. The first step is to improve effective preventive strategies, such as applying vaccination protocols, adopt adequate prophylaxis and educate patients about potential risk factors. Since viral infections in immunosuppressed patients may present atypical signs and symptoms, the challenges for the gastroenterologist are to suspect, recognize and diagnose such complications. Appropriate treatment of common viral infections allows us to minimize their impact on disease outcomes and patients’ lives. This practical review supports this standard of care to improve knowledge in this subject area.

Keywords: Inflammatory bowel diseases, Viral infections, Opportunistic infections, Standard of care, Crohn’s disease, Ulcerative colitis

Core Tip: The inflammatory bowel disease population treated with immune-modifying therapies is at increased risk of severe infections, including opportunistic infections sustained by viral agents. Of these opportunistic infections, 40% are due to viral pathogens, including hepatitis A virus, hepatitis C virus, hepatitis B virus, human papillomavirus, influenza virus, human immunodeficiency virus, herpes simplex virus, cytomegalovirus, varicella zoster virus, Epstein-Barr virus, and severe acute respiratory syndrome coronavirus 2 (causing coronavirus disease 19). A challenge for the gastroenterologist is to adopt preventive measures, recognize and treat common viral infections to minimize their impact on disease outcomes and patients' lives. This practical review supports this standard of care, aiming to bridge the gap of knowledge in this subject area.