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Hepatitis E virus (HEV) infects humans and a wide variety of other mammalian hosts. Recently, HEV strains belonging to genotype 8 (G8) within the Orthohepevirus A species of the Hepeviridae family, were identified in Bactrian camels (Camelus bactrianus) in China. The Bactrian camel (also known as the Mongolian camel) is native to the steppes of Central Asia. However, the HEV strains of Mongolian camels have not been examined. Among 200 serum samples from domestic Bactrian camels raised on 6 farms, in 6 soums in 3 provinces; 71 (35.5 %) were positive for anti-HEV IgG, with prevalence differing by farm (soum) (4.2-75.0 %); and 2 camels (1.0 %) that had been raised in Bogd, Bayankhongor Province, which had the highest seroprevalence among the six studied areas, were positive for HEV RNA. The two HEV strains (BcHEV-MNG140 and BcHEV-MNG146) obtained from the viremic camels in the present study shared 97.7 % nucleotide identity. They were closest to the reported G8 Chinese camel HEV strains but differed from them by 13.9-14.3 % over the entire genome, with a nucleotide difference of 24.0-26.5 % from the reported G1-G7 HEV strains. A phylogenetic tree indicated that the BcHEV-MNG140 and BcHEV-MNG146 strains were located upstream of a clade consisting of the Chinese camel HEV strains and formed a cluster with them, with a bootstrap value of 100 %, suggesting that they may represent a novel subtype within G8. These results indicate a high prevalence of HEV infection in Mongolian camels and suggest that the variability of camel HEV genomes is markedly high., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In January 2012, Mongolia started a hepatitis A vaccination program, which has not yet been evaluated. The first occurrence of autochthonous acute hepatitis E in 2013, caused by genotype 4 hepatitis E virus (HEV), suggests the need for a routine study to monitor its prevalence. One hundred fifty-four consecutive patients who were clinically diagnosed with acute hepatitis between 2014 and 2015 in Ulaanbaatar, Mongolia were studied. By serological and molecular testing followed by sequencing and phylogenetic analysis, only one patient (0.6%) was diagnosed with acute hepatitis A, caused by genotype IA hepatitis A virus (HAV), and 32 (20.8%) patients were diagnosed with acute hepatitis E, caused by genotype 1 HEV. The 32 HEV isolates obtained in this study shared 99.5-100% nucleotide identity and were grouped into a cluster separated from those of subtypes 1a to 1f. Upon comparison of p-distances over the entire genome, the distances between one representative HEV isolate (MNE15-072) and 1a-1f strains were 0.071-0.137, while those between 1b and 1c were 0.062-0.070. In conclusion, the prevalence of acute hepatitis A has decreased in Mongolia since the start of the vaccination program, while the monophyletic genotype 1 HEV strain of a probably novel subtype has been prevalent., (© 2017 Wiley Periodicals, Inc.)

Despite the high endemicity of hepatitis A virus (HAV) in Mongolia, the genetic information on those HAV strains is limited. Serum samples obtained from 935 patients with acute hepatitis in Ulaanbaatar, Mongolia during 2004-2013 were tested for the presence of HAV RNA using reverse transcription-PCR with primers targeting the VP1-2B region (481 nucleotides, primer sequences at both ends excluded). Overall, 180 patients (19.3%) had detectable HAV RNA. These 180 isolates shared 94.6-100% identity and formed four phylogenetic clusters within subgenotype IA. One or three representative HAV isolates from each cluster exhibited 2.6-3.9% difference between clusters over the entire genome. Cluster 1 accounted for 65.0% of the total, followed by Cluster 2 (30.6%), Cluster 3 (3.3%), and Cluster 4 (1.1%). Clusters 1 and 2 were predominant throughout the observation period, whereas Cluster 3 was undetectable in 2009 and 2013 and Cluster 4 became undetectable after 2009. The Mongolian HAV isolates were closest to those of Chinese or Japanese origin (97.7-98.5% identities over the entire genome), suggesting the evolution from a common ancestor with those circulating in China and Japan. Further molecular epidemiological analyses of HAV infection are necessary to investigate the factors underlying the spread of HAV and to implement appropriate prevention measures in Mongolia., (© 2015 Wiley Periodicals, Inc.)

Hepatitis E is considered to be a worldwide public health problem. Although the prevalence of hepatitis E virus (HEV) antibodies in healthy individuals is noted to be 11%, no patients with acute hepatitis E have previously been identified in Mongolia. Three hundred two consecutive patients (183 males and 119 females; median age of 22.0 [Interquartile range: 18.3-25.0] years) who were clinically diagnosed with sporadic acute hepatitis during 2012-2013 in Ulaanbaatar, Mongolia, were studied. By serological and/or molecular approaches, 77 (25.5%), 93 (30.8%), 19 (6.3%), 48 (15.9%), and 12 (4.0%) of the patients were diagnosed with acute hepatitis of types A, B, C, D (superinfection of hepatitis delta virus on a background of chronic hepatitis B virus infection) and E, respectively, while the cause of hepatitis was unknown in the remaining 53 patients (17.5%). The 12 hepatitis E patients had no history of travel abroad in the 3 months before the onset of disease, and lived separately in fixed or movable houses with water supplied via pipe, tank or well, denying transmission from a common water supply. The 12 HEV isolates obtained from the patients showed high nucleotide identities of 99.7-100%, and a representative HEV isolate, MNE13-227, was closest to the Chinese isolates of genotype 4, with the highest identity of 97.3% in the 304-nt ORF2 sequence and 92.1% over the entire genome. The present study revealed the occurrence of autochthonous acute hepatitis E in Mongolia, caused by a monophyletic genotype 4 HEV strain., (© 2015 Wiley Periodicals, Inc.)

Viral hepatitis is one of the major health concerns worldwide, particularly in Asian countries. Mongolia, which is located in northern Asia, between Russia and China, is confronting various infectious diseases, such as viral hepatitis and tuberculosis. As for healthy individuals in Mongolia, the reported prevalence of hepatitis B surface antigen (HBsAg) was 9 or 10% and the reported prevalence of anti-hepatitis C virus ranged from 11 to 25%. We reported a markedly high prevalence of hepatitis D virus RNA (83%) among apparently healthy individuals with HBsAg in Ulaanbaatar. Also due to lack of proper mechanisms to handle sewerage, disinfection, and lack of clean water supply across the country, hepatitis A is endemic in Mongolia. Moreover, Mongolia ranked in the high-prevalence zone for hepatitis B, D, and C., How to Cite This Article: Tsatsralt-Od B. Viral Hepatitis in Mongolia: Past, Present, and Future. Euroasian J Hepato-Gastroenterol 2016;6(1):56-58., Competing Interests: Source of support: Nil Conflict of interest: None

Mongolia which is located in Northern Asia between Russia and China is endowed with one of lowest population density in the world. Acute hepatitis due all types of hepatitis virus has been reported in Mongolia. Also, dual and triple hepatitis viruses, HBV, HDV and HCV are highly prevalent among patients with chronic liver disease living in Mongolia. Due to these facts, liver cancer is the leading cause of cancer mortality in Mongolia. The national immunization program including vaccination against hepatitis B was started in 1991 and screening of blood donations for HBsAg and anti-HCV was introduced in 1993 and 1997 respectively. The incidence of hepatitis viruses showing a downhill course in some parts of Mongolia, but comprehensive efforts are needed to control hepatitis viruses and containment of hepatitis related liver diseases and liver cancer in Mongolia., How to Cite This Article: Tsatsralt OB. Epidemiology of Viral Hepatitis and Liver Diseases in Mongolia. Euroasian J Hepato-Gastroenterol 2015;5(1):37-39., Competing Interests: Source of support: Nil Conflict of interest: None

Although no outbreaks of hepatitis E have been reported in Mongolia, a significant proportion of the general population had antibodies to hepatitis E virus (HEV). To investigate whether pigs are possible reservoirs of HEV in Mongolia, serum samples obtained from 243 2- or 3-month-old pigs on four swine farms surrounding Ulaanbaatar, the capital city of Mongolia, were tested for the presence of anti-HEV antibodies and HEV RNA. Overall, 223 pigs (91.8%) tested positive for anti-HEV, while 89 pigs (36.6%) had detectable HEV RNA. The 89 HEV isolates obtained from the viremic pigs were 78.7-100% identical to each other, and 80.9-85.9% similar to the prototype genotype 3 HEV isolate (US1) in the 412-nucleotide (nt) sequence within open reading frame 2. They were classified into two novel phylogenetic groups within genotype 3, differing by 16.4-21.3%. The swMN06-A1288 and swMN06-C1056 isolates, representing each of the two clusters within genotype 3, had a genomic length of nucleotides (nt) 7,222 nt and 7,223 nt, respectively, excluding the poly(A) tail, and shared only 81.6% over the entire genome. Upon comparison with the 25-reported genotype 3 HEV isolates over the entire genome, swMN06-A1288 had identities of merely up to 84.9%, while swMN06-C1056 of only up to 85.9%. Phylogenetic analysis confirmed the remote relatedness of the Mongolian swine isolates to the genotype 3 HEV isolates reported thus far. These results indicate that farm pigs in Mongolia are frequently infected with presumably indigenous HEV strains of genotype 3 and could be a source of HEV infections in humans in Mongolia.

Mongolia is highly endemic for hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections among apparently healthy adults. However, the age-specific prevalence of ongoing HBV, HCV, and HDV infections among children in Mongolia remains unknown. Therefore, samples obtained from a total of 655 apparently healthy children of 0.3-15 years of age (307 boys and 348 girls; age, mean +/- standard deviation [SD], 8.4 +/- 4.2 years) living in Mongolia, between October 2005 and January 2006, were tested for serological and molecular markers of HBV, HCV, and HDV infections. Although 88.7% of the 655 children studied were immunized against hepatitis B, 64 (9.8%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA and 13 (2.0%) for HDV RNA. Twenty-seven children (4.1%) had detectable HCV RNA. Collectively, 82 (12.5%) were viremic for one or more of these viruses, including eight children with dual viremia of HBV/HCV and one child with triple HBV/HCV/HDV viremia. When children without anti-HBc, anti-HCV and anti-HDV IgG (n = 510) served as a control, a history of hospitalization was significantly associated with HBV viremia (P < 0.0001), anti-HBc positivity (P < 0.0001), and HCV viremia (P = 0.0001). HBsAg mutation was found in 18 (31.6%) of the 57 children with viremia, including those at amino acid position 126, 127, 129, 131, 134, 143 or 144. There were no significant differences in the frequency of HBsAg mutation in relation to age, sex, and hepatitis B vaccination status of the children, suggesting that HBsAg mutation plays a limited role in failure of vaccination in Mongolia.

To compare the epidemiologic profiles of hepatitis A virus (HAV) and hepatitis E virus (HEV) infections in children in Mongolia, the prevalence of HAV and HEV infections was investigated serologically and molecularly among 717 apparently healthy individuals of 0-20 years of age (mean +/- standard deviation, 8.6 +/- 4.9 years) using serum samples obtained between October 2005 and January 2006. Total antibody against HAV (anti-HAV [total]) was detected in 494 (68.9%) of the 717 subjects, while IgG antibody against HEV (anti-HEV IgG) was detected in only five subjects (0.7%) (P < 0.0001). All five subjects who had anti-HEV IgG, were negative for anti-HEV IgM and HEV RNA. Anti-HAV was detectable in 24 (75.0%) of the 32 infants aged 7 days to 6 months, but not in any of the 8 infants aged 7 to <12 months. The prevalence of anti-HAV was 19.5% (17/87) in the age group of 1-3 years, and it increased to 50.0% (69/138) in the age group of 4-6 years, and further to 81.4% (105/129) in the age group of 7-9 years. Of note, 97.2% of the subjects in the age group of 16-20 years had anti-HAV. The presence of HAV RNA was tested in all 717 subjects, and three children of 1, 4, or 8 years of age were found to have detectable HAV RNA (subgenotype IA). No subject had a history of hepatitis or jaundice. In conclusion, HEV infection was uncommon, but HAV infection lacking overt clinical features was prevalent among children in Mongolia.

One hundred ten consecutive patients (60 males and 50 females; age, mean +/- standard deviation [SD], 22.6 +/- 6.4 years; range 16-48 years) who were clinically diagnosed with sporadic acute hepatitis between December 2004 and January 2005 in Ulaanbaatar, Mongolia, were studied. IgM antibodies to hepatitis A virus were detected in 18 patients (16.4%), IgM antibodies to hepatitis B core (anti-HBc IgM) in 38 patients (34.5%) including two patients with concurrent hepatitis delta virus (HDV) infection, and hepatitis C virus RNA in nine patients (8.2%). There were 30 hepatitis B virus (HBV) carriers who had detectable hepatitis B surface antigen and antibodies to HDV but were negative for anti-HBc IgM, suggesting that they acquired type D acute hepatitis due to superinfection of HDV on a background of chronic HBV infection. None had IgM antibodies to hepatitis E virus (HEV). Consequently, 16.4, 32.7, 6.4, 1.8, and 27.3% of the patients were diagnosed as having acute hepatitis of type A, B, C, type B + D (HBV/HDV coinfection), and type D (superinfection of HDV), respectively. The cause of hepatitis was not known in the remaining 17 patients (15.5%). All 18 HAV isolates were genotyped as IA, all 9 HCV isolates were genotyped as 1b, and all 32 HDV isolates were classified into genotype I. The distribution of HBV genotypes among the 67 HBV isolates was A (1.5%, n = 1) and D (98.5%, n = 66). The present study indicates that de novo infections of HAV, HBV, HCV, and HDV are prevalent among young adults in Mongolia., (Copyright 2006 Wiley-Liss, Inc.)

Mongolia is known for its high endemicity for hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections among apparently healthy individuals. However, there are little or no data on the prevalence and genotype distribution of HBV, HCV, and HDV among patients with chronic liver disease in Mongolia. Therefore, serum samples obtained in 2004 from 207 patients (age, mean+/-standard deviation, 51.0+/-11.9 years) including those with chronic hepatitis (n=90), liver cirrhosis (n=41), and hepatocellular carcinoma (n=76) were tested for serological and molecular markers of HBV, HCV, and HDV infections. Of the 207 patients, 144 (69.6%), 106 (51.2%), and 117 (56.5%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA, HCV RNA, and HDV RNA, respectively. Collectively, 172 patients (83.1%) were viremic for one or more of these viruses, including dual viremia of HBV/HDV (26.6%) or HBV/HCV (7.7%) and triple HBV/HCV/HDV viremia (30.0%). Of note, triple ongoing infection was significantly more frequent among patients with hepatocellular carcinoma than among those with chronic hepatitis (63.2% vs. 14.4%, P<0.0001). One hundred sixty patients (77.3%) had a history of blood transfusion and/or surgery. The distribution of HBV genotypes among the 116 HBV-viremic patients was: A (0.9%), B (0.9%), C (6.0%), D (88.8%), and C plus D (3.4%). All 117 HDV isolates were classified into genotype I. The 106 HCV RNA-positive samples were typed as genotype 1b (92.5%), 2a (0.9%), or 1b plus 2a (6.6%); mixed infection of two distinct HCV genotypes was found exclusively in the patients with hepatocellular carcinoma., (Copyright (c) 2005 Wiley-Liss, inc.)

Subclinical hepatitis E virus (HEV) infection among healthy individuals was studied serologically and molecularly. Serum samples collected at screening between March and April 2004 (or just before retirement) from 266 medical staff members (35 males, 231 females) who had been working for 8.8 +/- 8.5 (mean +/- standard deviation, range, 0.3-35.1) years in a city hospital in Japan and serum samples that had been collected from these staff members at the start of employment were tested for IgA, IgM, and IgG antibodies to HEV (anti-HEV) by in-house enzyme-linked immunosorbent assays. Overall, six subjects (2.3%) tested positive for anti-HEV IgG at the screening; among them, four subjects (1.5%) had already been positive for anti-HEV IgG at the start of employment and two subjects (0.8%) seroconverted after initiation of employment. Periodic serum samples that had been collected from the two seroconverted subjects were tested for HEV antibodies and HEV RNA. The two subjects became positive for anti-HEV IgG in 1978 or 2003, respectively, with no discernible elevation in alanine aminotransferase (ALT) level, and continued to be seropositive up through the screening date. Although anti-HEV IgM was not detectable in the two subjects, one was infected transiently with Japan-indigenous HEV strain of genotype 3 and the other was positive transiently for anti-HEV IgA. The present study indicates that even an individual with subclinical HEV infection had evidence of transient viremia in the absence of ALT elevation and that anti-HEV IgA detection may be useful for serological diagnosis of recent subclinical HEV infection., ((c) 2005 Wiley-Liss, Inc.)

To evaluate the usefulness of detection of antibodies to hepatitis E virus (HEV) to screen for viraemic pigs, serum samples obtained from 1425 1-6-month-old pigs in Japan were tested for swine HEV RNA and IgG, IgM and IgA classes of anti-HEV antibody. Fifty-five (5 %) of the 1071 2-5-month-old pigs were positive for swine HEV RNA, but none of 218 1-month-old pigs or 136 6-month-old pigs had detectable HEV RNA. The prevalence of anti-HEV IgG among the viraemic pigs (67 %, 37/55) was similar to that among the non-viraemic pigs (55 %, 757/1370) and the prevalence of anti-HEV IgM among the viraemic pigs and non-viraemic pigs was 7 and 3 %, respectively. However, anti-HEV IgA was detected significantly more frequently among viraemic pigs than among non-viraemic pigs (55 vs 10 %, P<0.0001). These results suggest that anti-HEV IgA is more useful than anti-HEV IgM to screen for viraemic pigs.