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World J Gastroenterol. Jul 7, 2019; 25(25): 3168-3182
Published online Jul 7, 2019. doi: 10.3748/wjg.v25.i25.3168
Epidemiology of hepatitis E in South-East Europe in the "One Health" concept
Anna Mrzljak, Petra Dinjar-Kujundzic, Lorena Jemersic, Jelena Prpic, Ljubo Barbic, Vladimir Savic, Vladimir Stevanovic, Tatjana Vilibic-Cavlek
Anna Mrzljak, Department of Medicine, Merkur University Hospital; School of Medicine, University of Zagreb, Zagreb 10000, Grad Zagreb, Croatia
Petra Dinjar-Kujundzic, Department of Medicine, Merkur University Hospital, Zagreb 10000, Grad Zagreb, Croatia
Lorena Jemersic, Jelena Prpic, Vladimir Savic, Croatian Veterinary Institute, Zagreb 10000, Grad Zagreb, Croatia
Ljubo Barbic, Vladimir Stevanovic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb 10000, Grad Zagreb, Croatia
Tatjana Vilibic-Cavlek, Department of Virology, Croatian Institute of Public Health; School of Medicine, University of Zagreb, Zagreb 10000, Grad Zagreb, Croatia
Author contributions: Mrzljak A and Dinjar-Kujundzic P made contributions to conception and design of the study, acquisition of the data, involved in drafting the manuscript. Jemersic L, Prpic J, Barbic L, Savic V and Stevanovic V made contributions in acquisition of the data, involved in drafting the manuscript. Vilibic-Cavlek T made contributions to design, involved in drafting and revising the manuscript critically. All authors read and approved the final manuscript.
Conflict-of-interest statement: No potential conflicts of interest. No financial support.
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/
Corresponding author: Anna Mrzljak MD, PhD, Assistant Professor, Department of Medicine, Merkur University Hospital, Zajceva 19, Zagreb 10000, Grad Zagreb, Croatia. anna.mrzljak@mef.hr
Telephone: +385-1-2431390 Fax: +385-1-2431393
Received: March 11, 2019
Peer-review started: March 11, 2019
First decision: May 9, 2019
Revised: May 16, 2019
Accepted: May 31, 2019
Article in press: June 1, 2019
Published online: July 7, 2019
Abstract

The significance of hepatitis E virus (HEV) as an important public health problem is rising. Until a decade ago, cases of HEV infection in Eur-ope were mainly confined to returning travelers, but nowadays, hepatitis E represents an emerging zoonotic infection in many European countries. The aim of this manuscript is to perform a systematic review of the published literature on hepatitis E distribution in humans, animals and environmental samples ("One Health" concept) in the South-Eastern European countries. Comparison of the available data showed that the anti-HEV seroprevalence in the South-Eastern Europe varies greatly, depending on the population studied, geographical area and methods used. The IgG seroprevalence rates in different population groups were found to be 1.1%-24.5% in Croatia, up to 20.9% in Bulgaria, 5.9-%17.1% in Romania, 15% in Serbia, up to 9.7% in Greece and 2%-9.7% in Albania. Among possible risk factors, older age was the most significant predictor for HEV seropositivity in most studies. Higher seroprevalence rates were found in animals. HEV IgG antibodies in domestic pigs were detected in 20%-54.5%, 29.2%-50%, 38.94%-50% and 31.1%-91.7% in Serbia, Bulgaria, Romania and Croatia, respectively. In wild boars seroprevalence rates were up to 10.3%, 30.3% and 31.1% in Romania, Slovenia and Croatia, respectively. A high HEV RNA prevalence in wild boars in some countries (Croatia and Romania) indicated that wild boars may have a key role in the HEV epidemiology. There are very few data on HEV prevalence in environmental samples. HEV RNA was detected in 3.3% and 16.7% surface waters in Slovenia and Serbia, respectively. There is no evidence of HEV RNA in sewage systems in this region. The available data on genetic characterization show that human, animal and environmental HEV strains mainly belong to the genotype 3.

Keywords: Hepatitis E virus, "One-Health", Humans, Animals, Environment, South-East Europe

Core tip: In South-East Europe, the hepatitis E virus (HEV) prevalence as in other parts of Europe varies greatly, depending on the studied population, geographical area and methods used. Seroprevalence rates were found to be 0%-36% in humans and 10.3%-54.5% in animals. Human studies showed sporadic detection of HEV RNA in patients with acute hepatitis and in transplant population. HEV RNA was detected in up to 31.6% pigs and 16.7% environmental samples. Studies on phylogenetic characterization in human, animal and environmental samples showed that HEV strains from the south-eastern European countries mainly belong to the genotype 3.