Shrestha A, Basnet S, KC S. Subclinical hepatitis E virus genotype 1 infection: The concept of “dynamic human reservoir”. World J Hepatol 2024; 16(4): 506-510 [PMID: 38689746 DOI: 10.4254/wjh.v16.i4.506]
Corresponding Author of This Article
Sudhamshu KC, PhD, Professor, Department of Hepatology, National Academy of Medical Sciences, Mahabouddha, Kathmandu 44600, Nepal. sudhamshu.liver@gmail.com
Research Domain of This Article
Gastroenterology & Hepatology
Article-Type of This Article
Editorial
Open-Access Policy of This Article
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/
World J Hepatol. Apr 27, 2024; 16(4): 506-510 Published online Apr 27, 2024. doi: 10.4254/wjh.v16.i4.506
Subclinical hepatitis E virus genotype 1 infection: The concept of “dynamic human reservoir”
Ananta Shrestha, Suresh Basnet, Sudhamshu KC
Ananta Shrestha, Department of Hepatology, Alka Hospital, Kathmandu 44600, Nepal
Suresh Basnet, Department of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
Sudhamshu KC, Department of Hepatology, National Academy of Medical Sciences, Kathmandu 44600, Nepal
Author contributions: Shrestha A developed the core concept, reviewed literature, drafted the manuscript; KC S contributed to improvising the concept, reviewed literature, drafted manuscript; Basnet S contributed by literature review, improvement and critical review of the manuscript.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Sudhamshu KC, PhD, Professor, Department of Hepatology, National Academy of Medical Sciences, Mahabouddha, Kathmandu 44600, Nepal. sudhamshu.liver@gmail.com
Received: December 28, 2023 Peer-review started: December 28, 2023 First decision: February 6, 2024 Revised: February 22, 2024 Accepted: March 28, 2024 Article in press: March 28, 2024 Published online: April 27, 2024 Processing time: 117 Days and 23.7 Hours
Abstract
Hepatitis E virus (HEV) is hyperendemic in South Asia and Africa accounting for half of total Global HEV burden. There are eight genotypes of HEV. Among them, the four common ones known to infect humans, genotypes 1 and 2 are prevalent in the developing world and genotypes 3 and 4 are causing challenge in the industrialized world. Asymptomatic HEV viremia in the general population, especially among blood donors, has been reported in the literature worldwide. The clinical implications related to this asymptomatic viremia are unclear and need further exploration. Detection of viremia due to HEV genotype 1 infection, apparently among healthy blood donors is also reported without much knowledge about its infection rate. Similarly, while HEV genotype 3 is known to be transmitted via blood transfusion in humans and has been subjected to screening in many European nations, instances of transmission have also been documented albeit without significant clinical consequences. Epidemiology of HEV genotype 1 in endemic areas often show waxing and waning pattern. Occasional sporadic occurrence of HEV infection interrupted by outbreaks have been frequently seen. In absence of known animal reservoir, where HEV exists in between outbreak is a mystery that needs further exploration. However, occurrence of asymptomatic HEV viremia due to HEV genotype 1 during epidemiologically quiescent period may explain that this phenomenon may act as a dynamic reservoir. Since HEV genotype 1 infection cannot cause chronicity, subclinical transient infection and transmission of virus might be the reason it sustains in interepidemic period. This might be the similar phenomenon with SARS COVID-19 corona virus infection which is circulating worldwide in distinct phases with peaks and plateaus despite vaccination against it. In view of existing evidence, we propose the concept of “Dynamic Human Reservoir.” Quiescent subclinical infection of HEV without any clinical consequences and subsequent transmission may contribute to the existence of the virus in a community. The potential for transmitting HEV infection by asymptomatic HEV infected individuals by fecal shedding of virus has not been reported in literature. This missing link may be a key to Pandora's box in understanding epidemiology of HEV infection in genotype 1 predominant region.
Core Tip: Epidemiology of hepatitis E virus (HEV) is yet to be known and unraveled. HEV genotype 1 outbreaks tend to reoccur in periodic fashion in certain endemic areas. The virus often disappears even during conducible seasons and living conditions in between these outbreaks. There are no known animal reservoirs for human HEV genotype 1. Occurrence of asymptomatic viremia and transmission during epidemic quiescence in endemic areas may show humans acting as transient reservoir keeping the virus viable in the community. We propose this phenomenon as “Dynamic Human Reservoir” and emphasize the need for further research and data on this area for better understanding of HEV epidemiology.
