1
|
Takahashi M, Kunita S, Nishizawa T, Ohnishi H, Primadharsini PP, Nagashima S, Murata K, Okamoto H. Infection Dynamics and Genomic Mutations of Hepatitis E Virus in Naturally Infected Pigs on a Farrow-to-Finish Farm in Japan: A Survey from 2012 to 2021. Viruses 2023; 15:1516. [PMID: 37515202 PMCID: PMC10385168 DOI: 10.3390/v15071516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Hepatitis E virus (HEV) causes acute or chronic hepatitis in humans. Pigs are the primary reservoir for zoonotic HEV genotypes 3 and 4 worldwide. This study investigated the infection dynamics and genomic mutations of HEV in domestic pigs on a farrow-to-finish pig farm in Japan between 2012 and 2021. A high prevalence of anti-HEV IgG antibodies was noted among pigs on this farm in 2012, when the survey started, and persisted for at least nine years. During 2012-2021, HEV RNA was detected in both serum and fecal samples, indicating active viral replication. Environmental samples, including slurry samples in manure pits, feces on the floor, floor and wall swabs in pens, and dust samples, also tested positive for HEV RNA, suggesting potential sources of infection within the farm environment. Indeed, pigs raised in HEV-contaminated houses had a higher rate of HEV infection than those in an HEV-free house. All 104 HEV strains belonged to subgenotype 3b, showing a gradual decrease in nucleotide identities over time. The 2012 (swEJM1201802S) and 2021 (swEJM2100729F) HEV strains shared 97.9% sequence identity over the entire genome. Importantly, the swEJM2100729F strain efficiently propagated in human hepatoma cells, demonstrating its infectivity. These findings contribute to our understanding of the prevalence, transmission dynamics, and genetic characteristics of HEV in domestic pigs, emphasizing the potential risks associated with HEV infections and are crucial for developing effective strategies to mitigate the risk of HEV infection in both animals and humans.
Collapse
Affiliation(s)
- Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Satoshi Kunita
- Center for Experimental Medicine, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Hiroshi Ohnishi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Putu Prathiwi Primadharsini
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Kazumoto Murata
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| |
Collapse
|
2
|
Identification of hepatitis E virus in wild sika deer in Japan. Virus Res 2022; 308:198645. [PMID: 34822952 DOI: 10.1016/j.virusres.2021.198645] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022]
Abstract
Hepatitis E virus (HEV) is a zoonotic agent mainly transmitted through the consumption of uncooked or undercooked meat products derived from infected animals. In Japan, domestic pigs and wild boars are the major animal reservoirs, and whether or not deer are an HEV reservoir remains controversial. We analyzed 395 serum and 199 liver samples from 405 sika deer (Cervus nippon) caught in the wild between 1997 and 2020 in 11 prefectures of Japan for markers of HEV infection. Overall, 17 deer had anti-HEV IgG (4.3%), while 1 (0.2%) had HEV RNA (genotype 3b), indicating the occurrence of ongoing HEV infection in wild deer in Japan. An analysis of the complete HEV genome (deJOI_14) recovered from a viremic deer in Oita Prefecture revealed only 88.8% identity with the first HEV strain in sika deer (JDEER-Hyo03L) in Japan, being closest (96.3%) to the HEV obtained from a hepatitis patient living in the same prefecture. Of note, the deJOI_14 strain was 8.7-9.0% different from the wild boar HEV strains obtained in the same habitat and the same year, suggesting that difference in infected HEV strains between boar and deer may be explained by the limited possibility of close contact with each other, although boars are a known source of HEV infection. Increased numbers of hepatitis E cases after consumption of raw or undercooked meat products of wild deer have been reported in Japan. These results suggest a low but nonnegligible zoonotic risk of HEV infection in wild deer in this country.
Collapse
|
3
|
Nishizawa T, Takahashi M, Tsatsralt-Od B, Nyamdavaa K, Dulmaa N, Osorjin B, Tseren-Ochir EO, Sharav T, Bayasgalan C, Sukhbaatar B, Nagashima S, Murata K, Okamoto H. Identification and a full genome analysis of novel camel hepatitis E virus strains obtained from Bactrian camels in Mongolia. Virus Res 2021; 299:198355. [PMID: 33662492 DOI: 10.1016/j.virusres.2021.198355] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 12/27/2022]
Abstract
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.
Collapse
Affiliation(s)
- Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan
| | - Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan
| | - Bira Tsatsralt-Od
- National Center for Communicable Diseases, Ministry of Health Mongolia, Ulaanbaatar, 210648, Mongolia
| | | | - Nyamkhuu Dulmaa
- National Center for Communicable Diseases, Ministry of Health Mongolia, Ulaanbaatar, 210648, Mongolia
| | | | - Erdene-Ochir Tseren-Ochir
- Department of Infectious Diseases and Microbiology, School of Veterinary Medicine, Mongolian University of Life Sciences, Ulaanbaatar, 17024, Mongolia
| | - Tumenjargal Sharav
- Department of Infectious Diseases and Microbiology, School of Veterinary Medicine, Mongolian University of Life Sciences, Ulaanbaatar, 17024, Mongolia
| | - Chimedtseren Bayasgalan
- Department of Infectious Diseases and Microbiology, School of Veterinary Medicine, Mongolian University of Life Sciences, Ulaanbaatar, 17024, Mongolia
| | - Boldbaatar Sukhbaatar
- Sector of Surveillance and Diagnosis of Infectious Diseases, State Central Veterinary Laboratory, Ulaanbaatar, 17024, Mongolia
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan
| | - Kazumoto Murata
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan.
| |
Collapse
|
4
|
Lee HS, Dao DT, Bui VN, Bui NA, Le TD, Nguyen-Viet H, Grace D, Thakur KK, Hagiwara K. Prevalence and phylogenetic analysis of hepatitis E virus in pigs in Vietnam. BMC Vet Res 2020; 16:333. [PMID: 32928220 PMCID: PMC7489210 DOI: 10.1186/s12917-020-02537-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/23/2020] [Indexed: 01/26/2023] Open
Abstract
Background Hepatitis E virus (HEV) is a zoonotic disease and has been reported around the world. The main objective of this study was to evaluate the sero-prevalence and phylogenetic analysis of HEV in Vietnam. Pig blood and fecal pooled samples were collected to assess the prevalence of HEV. We assessed the true prevalence (TP) of HEV from apparent prevalence (AP) by taking into account the sensitivity and specificity of diagnostic tests using a Bayesian approach. For phylogenetic analysis, the data compared with worldwide HEV reference strains including all eight genotypes (G1-G8) which were identified in previous study. Results A total of 475 sera and 250 fecal pooled samples were collected at slaughterhouses and pig farms from five provinces, in Viet Nam. Overall, the sero-AP of HEV was 58.53% (95% confidence interval: 53.95–62.70) while the sero-TP was slightly higher (65.43, 95% credible interval: 47.19–84.70). In terms of pooled samples, overall, the RNA-AP was 6.80% (95% confidence interval: 4.01–10.66). One strain in Hanoi, two strains in Dak Lak, seven strains in An Giang, four strains in Son La and two strains in Nghe An were isolated. The phylogenetic tree demonstrated that 19 Vietnamese strains were clustered into HEV 3 and 4. Conclusions This study provided evidence that HEV is circulating in domestic pigs in Vietnam. From a public health perspective, it is very important to raise public awareness for high-risk groups (e.g. slaughterhouse workers, pig traders, farmers and market sellers) who have more opportunities to come in contact with pig and contaminated meats.
Collapse
Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Regional Office for East and Southeast Asia, Room 301-302, B1 Building, Van Phuc Diplomatic Compound, 298 Kim Ma Street, Ba Dinh District, Hanoi, Vietnam.
| | - Duy Tung Dao
- National Institute of Veterinary Research, Hanoi, Vietnam
| | | | - Ngoc Anh Bui
- National Institute of Veterinary Research, Hanoi, Vietnam
| | - Thanh Duy Le
- National Institute of Veterinary Research, Hanoi, Vietnam
| | - Hung Nguyen-Viet
- International Livestock Research Institute (ILRI), Regional Office for East and Southeast Asia, Room 301-302, B1 Building, Van Phuc Diplomatic Compound, 298 Kim Ma Street, Ba Dinh District, Hanoi, Vietnam
| | - Delia Grace
- International Livestock Research Institute (ILRI), Nairobi, Kenya.,Natural Resources Institute, Chatham, UK
| | - Krishna K Thakur
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada
| | - Katsuro Hagiwara
- School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyodai, Ebetsu, Hokkaido, 069-8501, Japan.
| |
Collapse
|
5
|
Prevalence and genotype/subtype distribution of hepatitis E virus (HEV) among wild boars in Japan: Identification of a genotype 5 HEV strain. Virus Res 2020; 287:198106. [PMID: 32777387 DOI: 10.1016/j.virusres.2020.198106] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 02/06/2023]
Abstract
To further investigate the prevalence of hepatitis E virus (HEV) infection and characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 1880 boars captured in 17 prefectures in Japan from 2013 to 2019 were studied. Overall, anti-HEV IgG was detected in 8.9 % and HEV RNA was detected in 3.9 % of boars, which was comparable with our previous studies during 2003-2013 (10.3 % and 3.5 %, respectively). Among 74 boar HEV strains obtained from infected boars in the present study, 50 (68 %) were classified into genotype 3 (3a and 3b), 23 (31 %) were classified into genotype 4 (4i), and the remaining strain (wbJGF_19-1) was classified into genotype 5. The wbGF_19-1 strain shared 92.7 % identity over the entire genome with the prototype genotype 5 strain (JBOAR135-Shiz09). The identification of the second genotype 5 HEV strain in a place that is located only 100 km from the site at which JBOAR135-Shiz09 was identified, suggests that genotype 5 HEV circulates within a relatively close range in Japan. Genetically similar HEV strains forming a clade were identified from wild boars living in each area during the observation period of 11-13 years, although the nucleotide sequence changed gradually, accounting for up to 3.4-3.6 % within the 412-nucleotide ORF2 sequence. Eight groups of boars with a cluster of HEV infections were observed, consisting of two, three or four infected offspring, presumably born to the same mother or offspring with their mother. These results suggest that wild boars continue to be important reservoirs for HEV infection in humans in Japan.
Collapse
|
6
|
Dzierzon J, Oswaldi V, Merle R, Langkabel N, Meemken D. High Predictive Power of Meat Juice Serology on the Presence of Hepatitis E Virus in Slaughter Pigs. Foodborne Pathog Dis 2020; 17:687-692. [PMID: 32412857 DOI: 10.1089/fpd.2020.2797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Hepatitis E virus (HEV) as a zoonotic agent can be responsible for an acute hepatitis in humans, which is usually self-limiting. Progression toward a chronic stage is possible, especially in immunocompromised patients. In the past decade, the number of hepatitis E cases in humans in Germany has increased enormously to 3491 cases in 2018. Domestic pigs have been identified as a main animal reservoir and the consumption of raw and undercooked pork products, that is, livers or liver products, meat or meat products, is known as a potential risk of foodborne HEV infection. The aim of this study was to determine whether serological tests are appropriate to predict the occurrence of HEV in the liver and muscle of domestic pigs in Germany. In 2018, samples of meat juice, liver, and ham muscle were collected from 250 fattening pigs at an abattoir in North West Germany. Samples were analyzed for the presence of HEV antibodies using enzyme-linked immunosorbent assay respectively for the presence of HEV RNA using real-time reverse transcription-polymerase chain reaction. In total, 62% (155/250) of the meat juice samples were positive for HEV antibodies at a single animal basis. At herd level, 72% (18/25) of the herds were seropositive. The HEV prevalence in the liver was 17.2% (43/250). Each positive liver sample originated from seropositive herds respectively from HEV seropositive pigs. This study demonstrates for the first time the significant correlation between a positive HEV serology and the occurrence of HEV RNA in the liver of slaughter pigs (χ2 = 31.83; p < 0.001), highlighting the significant predictive power of positive serological results on the occurrence of HEV RNA in the liver.
Collapse
Affiliation(s)
- Janine Dzierzon
- Institute of Food Safety and Food Hygiene, Working Group Meat Hygiene, Freie Universität Berlin, Department of Veterinary Medicine, Berlin, Germany
| | - Verena Oswaldi
- Institute of Food Safety and Food Hygiene, Working Group Meat Hygiene, Freie Universität Berlin, Department of Veterinary Medicine, Berlin, Germany
| | - Roswitha Merle
- Institute for Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, Department of Veterinary Medicine, Berlin, Germany
| | - Nina Langkabel
- Institute of Food Safety and Food Hygiene, Working Group Meat Hygiene, Freie Universität Berlin, Department of Veterinary Medicine, Berlin, Germany
| | - Diana Meemken
- Institute of Food Safety and Food Hygiene, Working Group Meat Hygiene, Freie Universität Berlin, Department of Veterinary Medicine, Berlin, Germany
| |
Collapse
|
7
|
Motoya T, Umezawa M, Goto K, Doi I, Nagata N, Ikeda Y, Sakuta A, Sasaki N, Ishii K. High prevalence of hepatitis E virus infection among domestic pigs in Ibaraki Prefecture, Japan. BMC Vet Res 2019; 15:87. [PMID: 30866949 PMCID: PMC6416891 DOI: 10.1186/s12917-019-1816-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 02/21/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Hepatitis E virus (HEV) is prevalent in pigs and may serve as a reservoir for human infection. However, data on HEV infections in pigs in Ibaraki Prefecture, Japan, are limited. Here, we clarified the process and course of HEV in naturally infected pigs. Serum (n = 160) and liver (n = 110) samples were collected from pigs at the slaughterhouse. Furthermore, serum samples were collected from 45 breeding sows and serum and feces samples were collected from 7 piglets once a week (raised until 166 days of age). HEV antigen and antibodies were evaluated, and the genotype was identified based on molecular phylogenetic tree analysis. RESULTS The samples collected from the slaughterhouse revealed that few pigs were HEV carriers but most possessed anti-HEV antibodies. Most breeding sows possessed antibodies, and the piglets excreted HEV on the farm at approximately 10 weeks of age. One pig was initially infected, and in a few weeks, the other pigs living in the same sty became infected. CONCLUSIONS Most pigs in Ibaraki Prefecture were with HEV. On the farm, most piglets were infected with HEV by the time they reached slaughter age. We confirmed that HEV infection is successively transmitted among piglets living in the same sty.
Collapse
Affiliation(s)
- Takumi Motoya
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan. .,Laboratory of Laboratory Animal Science and Medicine, Faculty of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan.
| | - Masahiro Umezawa
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan
| | - Keiko Goto
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan
| | - Ikuko Doi
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan
| | - Noriko Nagata
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan
| | - Yoshiaki Ikeda
- Ibaraki Prefectural Institute of Public Health, Mito, Ibaraki, 310-0852, Japan
| | - Atsushi Sakuta
- Swine Laboratory, Ibaraki Prefectural Livestock Research Center, Inashiki, Ibaraki, Japan
| | - Nobuya Sasaki
- Laboratory of Laboratory Animal Science and Medicine, Faculty of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan
| | - Koji Ishii
- Department of Virology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan
| |
Collapse
|
8
|
Sasaki Y, Haruna M, Uema M, Noda M, Yamada Y. Prevalence and Phylogenetic Analysis of Hepatitis E Virus among Pigs in Japan. Jpn J Infect Dis 2018; 71:75-78. [DOI: 10.7883/yoken.jjid.2017.235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Yoshimasa Sasaki
- Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry and Fisheries
- Division of Biomedical Food Research, National Institute of Health Sciences
| | - Mika Haruna
- Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry and Fisheries
| | - Masashi Uema
- Division of Biomedical Food Research, National Institute of Health Sciences
| | - Mamoru Noda
- Division of Biomedical Food Research, National Institute of Health Sciences
| | - Yukiko Yamada
- Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry and Fisheries
| |
Collapse
|
9
|
Full-length genome of a novel genotype 3 hepatitis E virus strain obtained from domestic pigs in Japan. Virus Res 2017; 240:147-153. [DOI: 10.1016/j.virusres.2017.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 12/27/2022]
|
10
|
Ricci A, Allende A, Bolton D, Chemaly M, Davies R, Fernandez Escamez PS, Herman L, Koutsoumanis K, Lindqvist R, Nørrung B, Robertson L, Ru G, Sanaa M, Simmons M, Skandamis P, Snary E, Speybroeck N, Ter Kuile B, Threlfall J, Wahlström H, Di Bartolo I, Johne R, Pavio N, Rutjes S, van der Poel W, Vasickova P, Hempen M, Messens W, Rizzi V, Latronico F, Girones R. Public health risks associated with hepatitis E virus (HEV) as a food-borne pathogen. EFSA J 2017; 15:e04886. [PMID: 32625551 PMCID: PMC7010180 DOI: 10.2903/j.efsa.2017.4886] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatitis E virus (HEV) is an important infection in humans in EU/EEA countries, and over the last 10 years more than 21,000 acute clinical cases with 28 fatalities have been notified with an overall 10-fold increase in reported HEV cases; the majority (80%) of cases were reported from France, Germany and the UK. However, as infection in humans is not notifiable in all Member States, and surveillance differs between countries, the number of reported cases is not comparable and the true number of cases would probably be higher. Food-borne transmission of HEV appears to be a major route in Europe; pigs and wild boars are the main source of HEV. Outbreaks and sporadic cases have been identified in immune-competent persons as well as in recognised risk groups such as those with pre-existing liver damage, immunosuppressive illness or receiving immunosuppressive treatments. The opinion reviews current methods for the detection, identification, characterisation and tracing of HEV in food-producing animals and foods, reviews literature on HEV reservoirs and food-borne pathways, examines information on the epidemiology of HEV and its occurrence and persistence in foods, and investigates possible control measures along the food chain. Presently, the only efficient control option for HEV infection from consumption of meat, liver and products derived from animal reservoirs is sufficient heat treatment. The development of validated quantitative and qualitative detection methods, including infectivity assays and consensus molecular typing protocols, is required for the development of quantitative microbial risk assessments and efficient control measures. More research on the epidemiology and control of HEV in pig herds is required in order to minimise the proportion of pigs that remain viraemic or carry high levels of virus in intestinal contents at the time of slaughter. Consumption of raw pig, wild boar and deer meat products should be avoided.
Collapse
|
11
|
Pelosi E, Clarke I. Hepatitis E: a complex and global disease. EMERGING HEALTH THREATS JOURNAL 2017. [DOI: 10.3402/ehtj.v1i0.7069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- E Pelosi
- Department of Microbiology and Virology, Health Protection Agency, Southeast Regional Laboratory, Southampton General Hospital, Southampton, UK; and
| | - I Clarke
- Department of Molecular Microbiology, Southampton Medical School, Southampton General Hospital, Southampton, UK
| |
Collapse
|
12
|
Miura M, Inoue J, Tsuruoka M, Nishizawa T, Nagashima S, Takahashi M, Shimosegawa T, Okamoto H. Full-length genomic sequence analysis of new subtype 3k hepatitis E virus isolates with 99.97% nucleotide identity obtained from two consecutive acute hepatitis patients in a city in northeast Japan. J Med Virol 2016; 89:1116-1120. [PMID: 27922191 DOI: 10.1002/jmv.24743] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/27/2022]
Abstract
Full-length genomic sequences of hepatitis E virus (HEV) obtained from two consecutive cases of acute self-limiting hepatitis E in a city in northeast Japan were determined. Interestingly, two HEV isolates from each patient shared nucleotide identity of 99.97% in 7 225 nucleotides, and a phylogenetic analysis showed that they formed a cluster of Japanese isolates that is considered as a new HEV subtype 3k. The high similarity of HEV sequences of two isolates from these patients in this study suggested that a subtype 3k HEV strain had spread via a commonly distributed food in the city, possibly pig liver.
Collapse
Affiliation(s)
- Masahito Miura
- Department of Gastroenterology, Omagari Kousei Medical Center, Omagari, Japan
| | - Jun Inoue
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mio Tsuruoka
- Department of Gastroenterology, Omagari Kousei Medical Center, Omagari, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Tooru Shimosegawa
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Japan
| |
Collapse
|
13
|
Morozov VA, Morozov AV, Rotem A, Barkai U, Bornstein S, Denner J. Extended Microbiological Characterization of Göttingen Minipigs in the Context of Xenotransplantation: Detection and Vertical Transmission of Hepatitis E Virus. PLoS One 2015; 10:e0139893. [PMID: 26466154 PMCID: PMC4605773 DOI: 10.1371/journal.pone.0139893] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 08/08/2015] [Indexed: 12/28/2022] Open
Abstract
Xenotransplantation has been proposed as a solution to the shortage of suitable human donors. Pigs are currently favoured as donor animals for xenotransplantation of cells, including islet cells, or organs. To reduce the xenotransplantation-associated risk of infection of the recipient the pig donor should be carefully characterised. Göttingen minipigs from Ellegaard are often used for biomedical research and are regularly tested by their vendor for the presence of numerous bacteria, fungi, viruses and parasites. However, screening for some pathogens transmittable to humans had not been performed.The presence of microorganisms was examined in Göttingen Minipigs by PCR methods. Since zoonotic transmission of porcine hepatitis E virus HEV to humans has been demonstrated, extended search for HEV was considered as a priority. RNA from sera, islet and other cells from 40 minipigs were examined for HEV using different real-time reverse transcription (RT)-PCRs, among them two newly established. In addition, sera were examined by Western blot analysis using two recombinant capsid proteins of HEV as antigens. HEV RNA was not detected in pigs older than one year including gilts, but it was detected in the sera of three of ten animals younger than 1 year. Furthermore, HEV was also detected in the sera of three sows six days after delivery and their offspring, indicating vertical transmission of the virus. PCR amplicons were cloned, sequenced and the viruses were found to belong to the HEV genotype (gt) 3/4. Anti-HEV immunoglobulins G were detected in one sow and maternal antibodies in her six day old piglet. Since Göttingen minipigs were negative for many xenotransplantation-relevant microorganisms, they can now be classified as safe. HEV may be eliminated from the Ellegaard herd by selection of negative animals and/or by treatment of the animals.
Collapse
Affiliation(s)
| | | | - Avi Rotem
- Beta-O2 Technologies Ltd., Rosh Haain, Israel
| | | | - Stefan Bornstein
- Center Internal Medicine, University Clinics Carl Gustav Carus, Technical University, Dresden, Germany
| | - Joachim Denner
- Robert Koch Institute, Berlin, Germany
- * E-mail: (VAM); (JD)
| |
Collapse
|
14
|
Liu X, Saito M, Sayama Y, Suzuki E, Malbas FF, Galang HO, Furuse Y, Saito M, Li T, Suzuki A, Oshitani H. Seroprevalence and molecular characteristics of hepatitis E virus in household-raised pig population in the Philippines. BMC Vet Res 2015; 11:11. [PMID: 25622684 PMCID: PMC4312430 DOI: 10.1186/s12917-015-0322-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 01/12/2015] [Indexed: 01/21/2023] Open
Abstract
Background Hepatitis E virus (HEV) infection is a significant public health concern in Asia, and swine is an important source of sporadic HEV infection in human. However, no epidemiological data are available regarding HEV infection among the swine or human population in the Philippines. To assess the HEV infection status among pigs in rural areas, we investigated the molecular characteristics and seroprevalence of HEV among household-raised pigs in San Jose, Tarlac Province, the Philippines. Result Serum and rectal swab samples were collected from 299 pigs aged 2–24 months from 155 households in four barangays (villages) between July 2010 and June 2011. Enzyme-linked immunosorbent assay (ELISA) revealed that 50.3% [95% confidence interval (CI) 44.5–56.2%] and 22.9% (95% CI 18.2–28.1%) of pigs tested positive for anti-HEV IgG and IgM, respectively. HEV RNA was detected in the feces of 22 pigs (7.4%, 95% CI 4.7–10.9%). A total of 103 households (66.5%, 95% CI 58.4–73.8%) had at least one pig that tested positive for anti-HEV IgG or IgM or HEV RNA. The prevalence of anti-HEV IgG and IgM in breeding pig (8–24 months) were higher than that in growing pigs (2–4 months) (p < 0.0001 and p = 0.008, respectively). HEV RNA was more frequently detected in 2–4-month-old pigs (9.2%, 95% CI 5.4–14.6%) than in ≥5-month-old pigs (4.8%, 95% CI 1.1–8.5%) without statistical significance (p = 0.142). HEV RNA showed 0–27.6% nucleotide difference at the partial ORF2 gene among the detected viruses, and a majority of them belonged to subtype 3a (20/22, 90.9%). Conclusion We found a high prevalence of HEV antibodies in the household-raised pig population in rural areas of the Philippines, which indicates the potential risk of HEV infection among local residents. Only genotype 3 of HEV was observed, and genetically diverse strains of HEV were found to be circulating in pigs in this study. Electronic supplementary material The online version of this article (doi:10.1186/s12917-015-0322-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xiaofang Liu
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Mariko Saito
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. .,Tohoku-RITM Collaborating Research Center on Emerging and Reemerging Infectious Diseases, RITM compound, FCC, Alabang, Muntinlupa City, 1781, Philippines.
| | - Yusuke Sayama
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Ellie Suzuki
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Fedelino F Malbas
- Research Institute for Tropical Medicine, FCC, Alabang, Muntinlupa City, 1781, Philippines.
| | - Hazel O Galang
- Research Institute for Tropical Medicine, FCC, Alabang, Muntinlupa City, 1781, Philippines.
| | - Yuki Furuse
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Mayuko Saito
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Tiancheng Li
- Depatment of Virology II, National Institute of Infectious Diseases, 4-7-1Gakuen, Musashimurayama-shi, Tokyo, 208-0011, Japan.
| | - Akira Suzuki
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Hitoshi Oshitani
- Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. .,Tohoku-RITM Collaborating Research Center on Emerging and Reemerging Infectious Diseases, RITM compound, FCC, Alabang, Muntinlupa City, 1781, Philippines.
| |
Collapse
|
15
|
Pujols J, Rodríguez C, Navarro N, Pina-Pedrero S, Campbell JM, Crenshaw J, Polo J. No transmission of hepatitis E virus in pigs fed diets containing commercial spray-dried porcine plasma: a retrospective study of samples from several swine trials. Virol J 2014; 11:232. [PMID: 25539662 PMCID: PMC4304624 DOI: 10.1186/s12985-014-0232-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 12/18/2014] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Hepatitis E virus (HEV) has been reported in the human population and pigs are a recognized reservoir for HEV and a possible source of HEV transmission to humans. Spray-dried porcine plasma (SDPP) is an ingredient commonly used in feed for pigs around the world. Even though processing conditions used to produce SDPP should be adequate to inactivate HEV, it was of interest to analyze commercial SDPP samples for presence of genome and antibodies (AB) against HEV and to retrospectively analyze serum samples collected from pigs used in past experiments that had been fed diets containing either 0% or 8% SDPP to detect potential transmission of HEV as determined by seroconversion. RESULTS Eighty-five commercial SDPP samples were analyzed by ELISA and 100% of them contained AB against HEV, while 22.4% (11 of 49 samples analyzed) were positive for HEV RNA. Frozen sera samples (n = 140) collected from 70 pigs used in past experiments that had been fed diets containing either 0% or 8% commercial SDPP was analyzed by ELISA for AB against HEV. Age of pigs at sera sampling ranged from 3 to 15 weeks and feeding duration of diets ranged from approximately 4 to 9 weeks. One lot of SDPP used in one experiment was analyzed and confirmed to contain HEV RNA. Regardless of the diet fed, some sera samples collected at the beginning of an experiment contained AB titer against HEV. These sera samples were collected from weaned pigs prior to feeding of the experimental diets and the HEV titer was probably from maternal origin. However, by the end of the experiments, HEV titer was not detected or had declined by more than 50% of the initial titer concentration. CONCLUSIONS To our knowledge, this is the first study reporting presence of HEV AB titer and RNA in SDPP. Retrospective analysis of serum collected from pigs fed diets with SDPP revealed no indication of seroconversion to HEV. The results indicate that feeding SDPP in diets for pigs does not represent a risk of transmitting HEV, even though HEV genome may be detected in SDPP.
Collapse
Affiliation(s)
- Joan Pujols
- Centre de Recerca en Sanitat Animal (CReSA), Fundación UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain. .,Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Barcelona, Spain.
| | - Carmen Rodríguez
- APC EUROPE, S.A. Avda, Sant Julià 246-258, Pol. Ind. El Congost, E-08400, Granollers, Spain.
| | - Nuria Navarro
- Centre de Recerca en Sanitat Animal (CReSA), Fundación UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
| | - Sonia Pina-Pedrero
- Centre de Recerca en Sanitat Animal (CReSA), Fundación UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
| | - Joy M Campbell
- APC Inc., 2425 SE Oak Tree Court, Ankeny, IA, 50021, USA.
| | - Joe Crenshaw
- APC Inc., 2425 SE Oak Tree Court, Ankeny, IA, 50021, USA.
| | - Javier Polo
- APC EUROPE, S.A. Avda, Sant Julià 246-258, Pol. Ind. El Congost, E-08400, Granollers, Spain. .,APC Inc., 2425 SE Oak Tree Court, Ankeny, IA, 50021, USA.
| |
Collapse
|
16
|
Abstract
The prevalence of anti-HEV isotype-specific antibodies and viraemia were investigated in serum samples collected from slaughter-age pigs (aged 22-24 weeks) from 23 farms in Scotland. Of 176 serum samples tested, 29·0% (n = 51) were anti-HEV IgG positive, 36·9% (n = 65) anti-HEV IgA positive and 29·0% (n = 51) anti-HEV IgM positive. Overall seroprevalence (anti-HEV IgG+ and/or IgA+ and/or IgM+) was 61·4% (n = 108). HEV RNA was detected in 72/162 serum samples (44·4%). Partial sequence of ORF2 (98 nt) was obtained from eight HEV RNA-positive samples and phylogenetic analysis confirmed that they were all of genotype 3. This is the first report on the prevalence of HEV in pigs in Scotland. Given the increasing incidence of locally acquired HEV infection in the UK, evidence that HEV is a foodborne zoonosis emphasizes the need for surveillance in pigs.
Collapse
|
17
|
Okano H, Takahashi M, Isono Y, Tanaka H, Nakano T, Oya Y, Sugimoto K, Ito K, Ohmori S, Maegawa T, Kobayashi M, Nagashima S, Nishizawa T, Okamoto H. Characterization of sporadic acute hepatitis E and comparison of hepatitis E virus genomes in acute hepatitis patients and pig liver sold as food in Mie, Japan. Hepatol Res 2014; 44:E63-E76. [PMID: 23927634 DOI: 10.1111/hepr.12216] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 07/30/2013] [Accepted: 07/31/2013] [Indexed: 02/06/2023]
Abstract
AIM To characterize hepatitis E in Mie prefecture and to investigate whether raw pig liver sold as food in Mie is contaminated with hepatitis E virus (HEV) strains similar to those recovered from patients. METHODS Seventeen patients with sporadic acute hepatitis E treated from 2004 to 2012 were studied. A total of 243 packages of raw pig liver from regional grocery stores were tested for the presence of HEV RNA. The partial genomic sequences of human and swine HEV isolates were determined and subjected to the phylogenetic analyses. RESULTS The HEV isolates recovered from the 17 patients segregated into genotype 3 (n = 15) and genotype 4 (n = 2), and 15 genotype 3 isolates further segregated into 3e (n = 11) and 3b (n = 4). Pig liver specimens from 12 (4.9%) of the 243 packages had detectable HEV RNA. All 12 swine HEV isolates were grouped into genotype 3 (3a or 3b). Although no 3e strains were isolated from pig liver specimens, two 3b swine strains were 99.5-100% identical to two HEV strains recovered from hepatitis patients, within 412-nt partial sequences. CONCLUSION The 3e HEV was prevalent among hepatitis E patients. HEV RNA was detected in approximately 5% of pig liver sold as food. The presence of identical HEV strains between hepatitis patients and pig liver indicated that pigs play an important role as reservoirs for HEV in humans in Mie. Further studies are needed to clarify the source of 3e HEV in the animal and environmental reservoirs.
Collapse
Affiliation(s)
- Hiroshi Okano
- Department of Gastroenterology, Suzuka General Hospital, Suzuka, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Thiry D, Mauroy A, Saegerman C, Thomas I, Wautier M, Miry C, Czaplicki G, Berkvens D, Praet N, van der Poel W, Cariolet R, Brochier B, Thiry E. Estimation of hepatitis E virus (HEV) pig seroprevalence using ELISA and Western blot and comparison between human and pig HEV sequences in Belgium. Vet Microbiol 2014; 172:407-14. [PMID: 24975642 DOI: 10.1016/j.vetmic.2014.06.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 05/26/2014] [Accepted: 06/03/2014] [Indexed: 01/16/2023]
Abstract
Zoonotic transmission of hepatitis E virus (HEV) is of special concern, particularly in high income countries were waterborne infections are less frequent than in developing countries. High HEV seroprevalences can be found in European pig populations. The aims of this study were to obtain prevalence data on HEV infection in swine in Belgium and to phylogenetically compare Belgian human HEV sequences with those obtained from swine. An ELISA screening prevalence of 73% (95% CI 68.8-77.5) was determined in Belgian pigs and a part of the results were re-evaluated by Western blot (WB). A receiver operating characteristic curve analysis was performed and scenarios varying the ELISA specificity relative to WB were analysed. The seroprevalences estimated by the different scenarios ranged between 69 and 81% and are in agreement with the high exposure of the European pig population to HEV. Pig HEV sequences were genetically compared to those detected in humans in Belgium and a predominance of genotype 3 subtype f was shown in both swine and humans. The high HEV seroprevalence in swine and the close phylogenetic relationships between pig and human HEV sequences further support the risk for zoonotic transmission of HEV between humans and pigs.
Collapse
Affiliation(s)
- Damien Thiry
- Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - Axel Mauroy
- Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Science (UREAR-ULg), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - Isabelle Thomas
- National Reference Centre for Hepatitis viruses, Viral Diseases, Operational Directorate Communicable and Infectious Diseases, Scientific Institute of Public Health, B-1050 Brussels, Belgium
| | - Magali Wautier
- National Reference Centre for Hepatitis viruses, Viral Diseases, Operational Directorate Communicable and Infectious Diseases, Scientific Institute of Public Health, B-1050 Brussels, Belgium
| | - Cora Miry
- Veterinary Pathology, Dierengezondheidszorg Vlaanderen, B-8820 Torhout, Belgium
| | - Guy Czaplicki
- Department of Animal Health, Regional Agency for Animal Health and Identification, B-4431 Loncin, Belgium
| | - Dirk Berkvens
- Unit of Veterinary Helminthology, Department of Biomedical Sciences, Institute of Tropical Medicine, B-2000 Antwerp, Belgium
| | - Nicolas Praet
- Unit of Veterinary Helminthology, Department of Biomedical Sciences, Institute of Tropical Medicine, B-2000 Antwerp, Belgium
| | - Wim van der Poel
- Division Virology, Central Veterinary Institute, Wageningen University Research, NL-8200 AB Lelystad, the Netherlands
| | - Roland Cariolet
- Department of Production of Specific Pathogen-Free Decontaminated Pigs and Experimentation, Ploufragan/Plouzané Laboratory, Anses, BP 53, F-22440 Ploufragan, France
| | - Bernard Brochier
- National Reference Centre for Hepatitis viruses, Viral Diseases, Operational Directorate Communicable and Infectious Diseases, Scientific Institute of Public Health, B-1050 Brussels, Belgium
| | - Etienne Thiry
- Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium.
| |
Collapse
|
19
|
Takahashi M, Okamoto H. Features of hepatitis E virus infection in humans and animals in Japan. Hepatol Res 2014; 44:43-58. [PMID: 23721425 DOI: 10.1111/hepr.12175] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/23/2013] [Accepted: 05/27/2013] [Indexed: 02/08/2023]
Abstract
In Japan, hepatitis E had long been considered to be a rare liver disease which can be accidentally imported from endemic countries in Asia and Africa, where the sanitation conditions are suboptimal. However, since the identification of the first autochthonous hepatitis E case and hepatitis E viremic domestic pigs in Japan in 2001, our understanding of hepatitis E virus (HEV) infection in this country has been changing markedly. This has largely been due to the development of serological and gene-based diagnostic assays, the accumulation of molecular epidemiological findings on HEV infection in humans and animals (as potential reservoirs for HEV in humans) and the recognition of the importance of zoonotic food-borne and other routes of transmission of HEV, including blood-borne transmission. Although it is now evident that autochthonous hepatitis E in Japan is far more common than was previously thought, clinical and subclinical HEV infections indigenous to Japan remain underdiagnosed and their prevalence is still underestimated due to the presence of unknown transmission routes and a low awareness of the infection status by many physicians in Japan. This review focuses on the features of HEV infection in humans and animals, as definitive or potential reservoirs for HEV, in Japan, and updates the current knowledge on the routes of transmission, including zoonotic routes, which are important for the maintenance and spread of HEV in Japan.
Collapse
Affiliation(s)
- Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | | |
Collapse
|
20
|
Takahashi M, Nishizawa T, Nagashima S, Jirintai S, Kawakami M, Sonoda Y, Suzuki T, Yamamoto S, Shigemoto K, Ashida K, Sato Y, Okamoto H. Molecular characterization of a novel hepatitis E virus (HEV) strain obtained from a wild boar in Japan that is highly divergent from the previously recognized HEV strains. Virus Res 2013; 180:59-69. [PMID: 24370869 DOI: 10.1016/j.virusres.2013.12.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 01/16/2023]
Abstract
Although a consensus classification system for hepatitis E virus (HEV) genotypes is currently unavailable, HEV variants (JBOAR135-Shiz09 and wbJOY_06) from wild boars (Sus scrofa leucomystax) have provisionally been classified into two novel genotypes (5 and 6). While performing a survey of HEV infections among 566 wild boars that were captured in Japan between January 2010 and August 2013, we found 24 boars (4.2%) with ongoing HEV infections: 13 had genotype 3 HEV, 10 had genotype 4 HEV and the remaining boar possessed a novel HEV variant (designated wbJNN_13). The entire wbJNN_13 genome comprised 7247 nucleotides excluding the poly(A) tail, and was highly divergent from known genotype 1 to 4 HEV isolates derived from humans, swine, wild boars, deer, mongoose and rabbits by 22.4-28.2%, JBOAR135-Shiz09 and wbJOY_06 by 19.6-21.9% and rat, ferret, bat and avian HEV isolates by 40.9-46.1% over the entire genome. Phylogenetic trees confirmed that wbJNN_13 is distantly related to all known HEV isolates. A Simplot analysis revealed no significant recombination among the existing HEV strains. These results indicate the presence of at least three genetic lineages of presumably boar-indigenous HEV strains. Further studies to fully understand the extent of the genomic heterogeneity of HEV variants infecting wild boars are warranted.
Collapse
Affiliation(s)
- Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan
| | - Suljid Jirintai
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan
| | - Manri Kawakami
- Hepatology Research Center, Okayama Saiseikai General Hospital, Okayama-shi, Okayama 700-8511, Japan
| | | | | | - Shogo Yamamoto
- Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki-shi, Miyazaki 889-2155, Japan
| | | | - Kozo Ashida
- Division of Internal Medicine, Okayama University Hospital Misasa Medical Center, Misasa, Tottori 682-0122, Japan
| | - Yukihiro Sato
- Kamiichi General Hospital, Kamiichi, Toyama 930-0391, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
| |
Collapse
|
21
|
Mulyanto, Suparyatmo JB, Andayani IGAS, Khalid, Takahashi M, Ohnishi H, Jirintai S, Nagashima S, Nishizawa T, Okamoto H. Marked genomic heterogeneity of rat hepatitis E virus strains in Indonesia demonstrated on a full-length genome analysis. Virus Res 2013; 179:102-12. [PMID: 24231359 DOI: 10.1016/j.virusres.2013.10.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/30/2013] [Accepted: 10/30/2013] [Indexed: 12/26/2022]
Abstract
Rat hepatitis E virus (HEV) strains have recently been isolated in several areas of Germany, Vietnam, the United States, Indonesia and China. However, genetic information regarding these rat HEV strains is limited. A total of 369 wild rats (Rattus rattus) captured in Central Java (Solo) and on Lombok Island, Indonesia were tested for the presence of rat HEV-specific antibodies and RNA. Overall, 137 rats (37.1%) tested positive for rat anti-HEV antibodies, while 97 (26.3%) had rat HEV RNA detectable on reverse transcription-PCR with primers targeting the ORF1-ORF2 junctional region. The 97 HEV strains recovered from these viremic rats were 76.3-100% identical to each other in an 840-nucleotide sequence and 75.4-88.4% identical to the rat HEV strains reported in Germany and Vietnam. Five representative Indonesian strains, one from each of five phylogenetic clusters, whose entire genomic sequence was determined, were segregated into three genetic groups (a German type, Vietnamese type and novel type), which differed from each other by 19.5-23.5 (22.0 ± 1.7)% over the entire genome. These results suggest the presence of at least three genetic groups of rat HEV and indicate the circulation of polyphyletic strains of rat HEV belonging to three distinct genetic groups in Indonesia.
Collapse
Affiliation(s)
- Mulyanto
- West Nusa Tenggara Hepatitis Laboratory, Mataram, Indonesia; Immunobiology Laboratory, Faculty of Medicine, University of Mataram, Mataram, Indonesia
| | | | | | - Khalid
- Immunobiology Laboratory, Faculty of Medicine, University of Mataram, Mataram, Indonesia
| | - Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | - Hiroshi Ohnishi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | - Suljid Jirintai
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan.
| |
Collapse
|
22
|
Hepatitis E virus: foodborne, waterborne and zoonotic transmission. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:4507-33. [PMID: 24071919 PMCID: PMC3823334 DOI: 10.3390/ijerph10104507] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/20/2013] [Accepted: 09/03/2013] [Indexed: 02/07/2023]
Abstract
Hepatitis E virus (HEV) is responsible for epidemics and endemics of acute hepatitis in humans, mainly through waterborne, foodborne, and zoonotic transmission routes. HEV is a single-stranded, positive-sense RNA virus classified in the family Hepeviridae and encompasses four known Genotypes (1–4), at least two new putative genotypes of mammalian HEV, and one floating genus of avian HEV. Genotypes 1 and 2 HEVs only affect humans, while Genotypes 3 and 4 are zoonotic and responsible for sporadic and autochthonous infections in both humans and several other animal species worldwide. HEV has an ever-expanding host range and has been identified in numerous animal species. Swine serve as a reservoir species for HEV transmission to humans; however, it is likely that other animal species may also act as reservoirs. HEV poses an important public health concern with cases of the disease definitively linked to handling of infected pigs, consumption of raw and undercooked animal meats, and animal manure contamination of drinking or irrigation water. Infectious HEV has been identified in numerous sources of concern including animal feces, sewage water, inadequately-treated water, contaminated shellfish and produce, as well as animal meats. Many aspects of HEV pathogenesis, replication, and immunological responses remain unknown, as HEV is an extremely understudied but important human pathogen. This article reviews the current understanding of HEV transmission routes with emphasis on food and environmental sources and the prevalence of HEV in animal species with zoonotic potential in humans.
Collapse
|
23
|
Owolodun OA, Giménez-Lirola LG, Gerber PF, Sanford BJ, Feagins AR, Meng XJ, Halbur PG, Opriessnig T. Development of a fluorescent microbead-based immunoassay for the detection of hepatitis E virus IgG antibodies in pigs and comparison to an enzyme-linked immunoassay. J Virol Methods 2013; 193:278-83. [PMID: 23773809 DOI: 10.1016/j.jviromet.2013.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/31/2013] [Accepted: 06/06/2013] [Indexed: 01/27/2023]
Abstract
Swine hepatitis E virus (HEV) is a zoonotic virus and pigs are considered as an important reservoir. Swine HEV infection is widespread and most pig herds are infected. Humans can be infected with swine HEV via consumption of undercooked pork or through direct contact with infected pigs. To minimize the risk of zoonotic transmission, sensitive tools to assess the HEV infection status of pigs and pork products are needed. The objective of this study was to develop a fluorescent microbead-based immunoassay (FMIA) for the detection of IgG antibodies against swine HEV and compare it to an in-house enzyme-linked immunoassay (ELISA). Three sets of samples were utilized: (A) samples from pigs infected experimentally with different strains of HEV (positive controls, n=72), (B) samples from known HEV-negative pigs (negative controls, n=62) and (C) samples from pigs of unknown HEV infection status (n=182). All samples were tested by both ELISA and FMIA. The results on the experimental samples with known HEV exposure indicate that both assays have a specificity of 100% while the sensitivity ranges from 84.6% (ELISA) to 92.3% (FMIA). The overall prevalence of HEV IgG antibodies in field samples from pigs with unknown HEV exposure was 21.9% (40/182) for the ELISA and 21.4% (39/182) for the FMIA. The two assays had an almost perfect overall agreement (Kappa=0.92).
Collapse
Affiliation(s)
- Olajide A Owolodun
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; Department of Biochemistry and Applied Molecular Biology, National Veterinary Research Institute, Vom, Plateau State, Nigeria
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Jirintai S, Jinshan, Tanggis, Manglai D, Mulyanto, Takahashi M, Nagashima S, Kobayashi T, Nishizawa T, Okamoto H. Molecular analysis of hepatitis E virus from farm rabbits in Inner Mongolia, China and its successful propagation in A549 and PLC/PRF/5 cells. Virus Res 2012; 170:126-37. [PMID: 23041252 DOI: 10.1016/j.virusres.2012.09.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/25/2012] [Accepted: 09/26/2012] [Indexed: 01/05/2023]
Abstract
Rabbit hepatitis E virus (HEV) strains have recently been isolated in several areas of China and in the US and France. However, the host range, distribution and zoonotic potential of these HEV strains remain unknown and their propagation in cultured cells has not yet been reported. A total of 211 4-month-old rabbits raised on a farm in Inner Mongolia were tested for the presence of anti-HEV antibodies and HEV RNA. Overall, 121 rabbits (57.3%) tested positive for anti-HEV antibodies, and 151 (71.6%) had detectable HEV RNA. The 174 HEV strains recovered from these viremic rabbits, including two distinct strains each from 23 rabbits, differed from each other by up to 13.6% in a 412-nucleotide (nt) sequence within ORF2, and were 89.3-95.9% identical to the reported rabbit HEV strains in other provinces of China. Three representative Inner Mongolian strains, one each from three phylogenetic clusters, whose entire genomic sequences were determined, shared 79.6-96.7% identities with reported rabbit HEV strains within the entire or 242- to 1349-nt partial genomic sequence. Rabbit HEV strains recovered from liver tissues of rabbits with a high HEV load propagated efficiently in human cell lines (A549 and PLC/PRF/5 cells), suggesting the potential zoonotic risk of rabbit HEV.
Collapse
Affiliation(s)
- Suljid Jirintai
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi-Ken 329-0498, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Mulyanto, Depamede SN, Sriasih M, Takahashi M, Nagashima S, Jirintai S, Nishizawa T, Okamoto H. Frequent detection and characterization of hepatitis E virus variants in wild rats (Rattus rattus) in Indonesia. Arch Virol 2012; 158:87-96. [PMID: 22983110 DOI: 10.1007/s00705-012-1462-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 07/22/2012] [Indexed: 02/02/2023]
Abstract
One hundred sixteen rats (Rattus rattus) captured in Indonesia from 2011 to 2012 were investigated for the prevalence of hepatitis E virus (HEV)-specific antibodies and HEV RNA. Using an ELISA based on HEV genotype 4 with an ad hoc cutoff value of 0.500, 18.1 % of the rats tested positive for anti-HEV IgG. By nested RT-PCR, 14.7 % of the rats had rat HEV RNA, and none were positive for HEV genotype 1-4. A high HEV prevalence among rats was associated with lower sanitary conditions in areas with a high population density. Sixteen of the 17 HEV isolates obtained from infected rats showed >93.0 % nucleotide sequence identity within the 840-nucleotide ORF1-ORF2 sequence and were most closely related to a Vietnamese strain (85.9-87.9 % identity), while the remaining isolate differed from known rat HEV strains by 18.8-23.3 % and may belong to a novel lineage of rat HEV. These results suggest a wide distribution of rat HEV with divergent genomes.
Collapse
Affiliation(s)
- Mulyanto
- Immunobiology Laboratory, Faculty of Medicine, University of Mataram, Mataram, Indonesia
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Nidaira M, Takahashi K, Ogura G, Taira K, Okano S, Kudaka J, Itokazu K, Mishiro S, Nakamura M. Detection and phylogenetic analysis of hepatitis E viruses from mongooses in Okinawa, Japan. J Vet Med Sci 2012; 74:1665-8. [PMID: 22850461 DOI: 10.1292/jvms.11-0520] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hepatitis E virus (HEV) infection has previously been reported in wild mongooses on Okinawa Island; to date however, only one HEV RNA sequence has been identified in a mongoose. Hence, this study was performed to detect HEV RNA in 209 wild mongooses on Okinawa Island. Six (2.9%) samples tested positive for HEV RNA. Phylogenetic analysis revealed that 6 HEV RNAs belonged to genotype 3 and were classified into groups A and B. In group B, mongoose-derived HEV sequences were very similar to mongoose HEV previously detected on Okinawa Island, as well as to those of a pig. This investigation emphasized the possibility that the mongoose is a reservoir animal for HEV on Okinawa Island.
Collapse
Affiliation(s)
- Minoru Nidaira
- Department of Biological Sciences, Okinawa Prefectural Institute of Health and Environment, 2085 Ozato, Nanjo, Okinawa 901-1202, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Pérez-Gracia MT, Mateos-Lindemann ML. [Hepatitis E. Current perspectives]. Med Clin (Barc) 2012; 139:404-11. [PMID: 22538059 DOI: 10.1016/j.medcli.2012.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Revised: 02/14/2012] [Accepted: 02/23/2012] [Indexed: 01/19/2023]
Abstract
Infection with hepatitis E virus (HEV) is highly prevalent in developing countries and the WHO estimates one third of the world population has had contact with the virus. Its diagnosis and epidemiology are well known in endemic countries but, recently, there have been sporadic cases in developed countries in patients with no history of travel. Currently in these countries, hepatitis E is considered a zoonosis yet there remain to be known other routes of transmission. Another interesting aspect is that HEV can cause chronic hepatitis in transplanted patients, other immunocompromised patients and even in immunocompetent people. There have also been reported cases of fulminant hepatitis and other extrahepatic manifestations. The diagnosis is based on serological studies and detection of viral RNA in blood and feces. The vaccine is a good option to prevent this infection that affects a large number of people in deprived geographical areas but unfortunately it is not available yet.
Collapse
Affiliation(s)
- María Teresa Pérez-Gracia
- Departamento de Microbiología, Facultad de Ciencias de la Salud, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain.
| | | |
Collapse
|
28
|
A549 and PLC/PRF/5 cells can support the efficient propagation of swine and wild boar hepatitis E virus (HEV) strains: demonstration of HEV infectivity of porcine liver sold as food. Arch Virol 2011; 157:235-46. [DOI: 10.1007/s00705-011-1153-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 10/15/2011] [Indexed: 01/06/2023]
|
29
|
Geng J, Wang L, Wang X, Fu H, Bu Q, Liu P, Zhu Y, Wang M, Sui Y, Zhuang H. Potential risk of zoonotic transmission from young swine to human: seroepidemiological and genetic characterization of hepatitis E virus in human and various animals in Beijing, China. J Viral Hepat 2011; 18:e583-90. [PMID: 21914080 DOI: 10.1111/j.1365-2893.2011.01472.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The aim of this study was to further investigate the prevalence of infection and genotype of hepatitis E virus (HEV) among different species of animals, people whose works are related to pigs and the general population in the suburb of Beijing, China. Serum and faecal samples were collected from 10 animal species and humans. Anti-HEV was detected by enzyme immunoassays (EIA); HEV RNA was amplified by reverse transcription-nested polymerase chain reaction (RT-nPCR) method. PCR products were cloned and sequenced. The isolated swine HEV sequences were analysed phylogenetically. The positive rates of serum anti-HEV in swine, cattle, milk cow, horse, sheep, donkey, dog, duck, chicken, pig farm workers and slaughterhouse workers, and general population were 81.17% (802/988), 25.29% (66/261), 14.87% (40/269), 14.29% (40/280), 9.30% (53/514), 0 (0/25), 0 (0/20), 2.53% (8/316), 3.03% (7/231), 58.73% (37/63), 35.87% (66/184) and 20.06% (538/2682), respectively. The anti-HEV prevalence in adult swine (≥ 6 months) and younger swine (≤ 3 months) was 91.49% (591/646) and 61.7% (211/342), respectively. The positive rate of HEV RNA in young swine faeces was 47.94% (93/194). All 93 isolates from the younger swine shared 87.8-100% nucleotide homology with each other and had identities of 75.6-78.9%, 73.9-76.1%, 76.4-80.6% and 83.1-95.0% with the corresponding regions of genotypes 1-4 HEV, respectively. Phylogenetic analysis showed that all HEV isolates belong to genotype 4, subgenotype 4d. These results suggest a potential risk of zoonotic transmission of HEV from younger swine to farmers who rear pigs.
Collapse
Affiliation(s)
- J Geng
- Department of Microbiology, Peking University Health Science Center, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Serological diagnostics of hepatitis E virus infection. Virus Res 2011; 161:84-92. [PMID: 21704091 DOI: 10.1016/j.virusres.2011.06.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/03/2011] [Accepted: 06/07/2011] [Indexed: 12/15/2022]
Abstract
Development of accurate diagnostic assays for the detection of serological markers of hepatitis E virus (HEV) infection remains challenging. In the course of nearly 20 years after the discovery of HEV, significant progress has been made in characterizing the antigenic structure of HEV proteins, engineering highly immunoreactive diagnostic antigens, and devising efficient serological assays. However, many outstanding issues related to sensitivity and specificity of these assays in clinical and epidemiological settings remain to be resolved. Complexity of antigenic composition, viral genetic heterogeneity and varying epidemiological patterns of hepatitis E in different parts of the world present challenges to the refinement of HEV serological diagnostic assays. Development of antigens specially designed for the identification of serological markers specific to acute infection and of IgG anti-HEV specific to the convalescent phase of infection would greatly facilitate accurate identification of active, recent and past HEV infections.
Collapse
|
31
|
Okamoto H. Efficient cell culture systems for hepatitis E virus strains in feces and circulating blood. Rev Med Virol 2011; 21:18-31. [PMID: 21294213 DOI: 10.1002/rmv.678] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Attempts have been made to propagate hepatitis E virus (HEV) in primary hepatocyte culture and various other cultured cells. However, the replication ability of HEV recovered from culture media remains extremely low. Recently, efficient culture systems have been established in PLC/PRF/5 (hepatocellular carcinoma) and A549 (lung cancer) cell lines for HEV strains of genotypes 3 and 4 in our laboratory. They originated in fecal extracts from patients containing HEV RNA in extremely high-titers (10(7) copies/ml), and named the JE03-1760F (genotype 3) and HE-JF5/15F (genotype 4) strains, respectively. HEV RNA in culture supernatants reached 10(8) copies/ml in titer, and were transmitted successively through many passages. An infectious HEV cDNA clone (pJE03-1760F/wt) was constructed that has replication activity comparable to that of the wild-type JE03-1760F in feces. The ORF3 protein is indispensable for shedding HEV particles from cells in the reverse genetics system. HEV recovered from culture media, as well as circulating HEV, possess ORF3 proteins on the surface and are covered with cellular membranes, and therefore, ORF2 epitopes are buried in these particles. In contrast, HEV excreted into feces are naked nucleocapsids without a lipid layer or surface expression of the ORF3 protein. HEV in sera of patients with acute hepatitis E can infect and replicate in PLC/PRF/5 and A549 cells, with efficiency comparable to the circulating HEV RNA levels. High-efficiency cell culture systems for infectious viruses, thus developed, are expected to open up a new era and resolve many mysteries in the epidemiology, molecular biology, and treatment of HEV.
Collapse
Affiliation(s)
- Hiroaki Okamoto
- Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke-Shi, Tochigi, Japan.
| |
Collapse
|
32
|
A systematic review/meta-analysis of primary research investigating swine, pork or pork products as a source of zoonotic hepatitis E virus. Epidemiol Infect 2011; 139:1127-44. [DOI: 10.1017/s0950268811000677] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
SUMMARYThe objectives of our study were to identify and categorize primary research investigating swine/pork as a source of zoonotic hepatitis E virus (HEV) using the relatively new technique of scoping study, and to investigate the potential association between human exposure to swine/pork and HEV infection quantitatively using systematic review/meta-analysis methodology. From 1890 initially identified abstracts, 327 were considered for the review. Five study design types (cross-sectional, prevalence, genotyping, case-report and experimental transmission studies) were identified. A significant association between occupational exposure to swine and human HEV IgG seropositivity was reported in 10/13 cross-sectional studies. The association reported between pork consumption and HEV IgG seropositivity was inconsistent. The quantification of viral load in swine and retail pork, viral load required for infection in primates, cohort and case-control studies in humans, and formal risk assessment are recommended before specific public-health policy actions are taken.
Collapse
|
33
|
Sato Y, Sato H, Naka K, Furuya S, Tsukiji H, Kitagawa K, Sonoda Y, Usui T, Sakamoto H, Yoshino S, Shimizu Y, Takahashi M, Nagashima S, Jirintai, Nishizawa T, Okamoto H. A nationwide survey of hepatitis E virus (HEV) infection in wild boars in Japan: identification of boar HEV strains of genotypes 3 and 4 and unrecognized genotypes. Arch Virol 2011; 156:1345-58. [PMID: 21475985 DOI: 10.1007/s00705-011-0988-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 03/21/2011] [Indexed: 12/14/2022]
Abstract
To investigate the nationwide prevalence of hepatitis E virus (HEV) infection and to characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 578 boars captured in 25 prefectures from 2003 to 2010 were studied. Anti-HEV IgG was detected in 8.1%, and HEV RNA in 3.3% of boars. Among the 19 boar HEV isolates obtained from infected boars, 14 isolates (74%) were classified as genotype 3, 4 isolates (21%) as genotype 4, and the remaining isolate (wbJOY_06) was distantly related to all known HEV isolates of genotypes 1-4, differing by 18.4-25.0% and 18.0-24.3% within the 412-nucleotide sequence of ORF1 and ORF2, respectively. A genotype 4 boar HEV isolate (wbJGF_08-1) obtained herein shared 98.6% identity over the entire genome with a human HEV isolate obtained from a patient who developed acute hepatitis after consuming undercooked wild boar meat, suggesting that wild boars are also reservoirs for genotype 4 HEV in humans.
Collapse
Affiliation(s)
- Yukihiro Sato
- Kamiichi General Hospital, Kamiichi, Toyama, 930-0391, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
PURPOSE OF REVIEW To discuss recent advances in characterising viral Hepatitis E (HEV) in nonendemic regions, with a special focus on epidemiology in high-income countries, different clinical aspects of the disease, possible zoonotic origin of these cases and the improvement of Hepatitis E diagnosis. RECENT FINDINGS In high-income countries, most cases of Hepatitis E are acquired locally and not imported from endemic regions. Different genotypes are involved in indigenous cases than those in endemic regions. Particular population groups, such as transplant recipients, can be persistently infected by hepatitis E and develop chronic diseases. Viral hepatitis E is frequently observed in people in animal care occupations. Indeed, HEV has a large animal reservoir and this emerging disease in developed countries has probably a zoonotic origin. SUMMARY Recent studies on viral Hepatitis E have shown that the epidemiology of the disease differs between endemic and nonendemic regions. Several lines of evidence suggest that Hepatitis E is more frequent than was suspected and that it has a possible animal origin. Particular attention must be paid to the possible chronic evolution of various forms of the disease. Surveillance of human cases and animal reservoirs must be developed further.
Collapse
|
35
|
Xia H, Wahlberg N, Belák S, Meng XJ, Liu L. The emergence of genotypes 3 and 4 hepatitis E virus in swine and humans: a phylogenetic perspective. Arch Virol 2010; 156:121-4. [PMID: 20927637 DOI: 10.1007/s00705-010-0818-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 09/21/2010] [Indexed: 01/18/2023]
Abstract
To investigate whether there is any phylogenetic evidence to support the hypothesis that swine is the natural host of HEV genotypes 3 and 4, Bayesian analysis of 80 full-length genomic sequences of HEV was performed. The results showed that the strains of genotypes 3 and 4 from swine are paraphyletic with regard to strains of human origin, which are thus phylogenetically nested among the swine strains. Recognition of HEV genotypes 3 and 4 as viruses from swine or swine HEV can provide an evolutionary explanation to the observation of cross-species infection by genotypes 3 and 4 HEV.
Collapse
Affiliation(s)
- Hongyan Xia
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | | | | | | |
Collapse
|
36
|
Molecular and serological survey of hepatitis E virus infection among domestic pigs in Inner Mongolia, China. Arch Virol 2010; 155:1217-26. [PMID: 20512514 DOI: 10.1007/s00705-010-0706-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 04/30/2010] [Indexed: 12/17/2022]
Abstract
To evaluate the prevalence and characteristics of swine hepatitis E virus (HEV) infection in Inner Mongolia, China, serum samples obtained from 356 2- to 4-month-old pigs on 14 farms in Inner Mongolia were tested for the presence of anti-HEV antibodies and HEV RNA. Overall, 186 pigs (52%) tested positive for anti-HEV antibodies, while 30 pigs (8%) had detectable HEV RNA levels. The 30 HEV isolates recovered from the viremic pigs were phylogenetically classified into genotype 4 and differed from each other by up to 15.3% in a 412 nt sequence within ORF2. The Inner Mongolian swine HEV strains were most similar to human or swine HEV strains isolated in the other provinces of China but differed by 15.9-18.9% from those in Mongolia (formerly known as Outer Mongolia). These results indicate that farm pigs in Inner Mongolia are frequently infected with markedly divergent genotype 4 HEV strains that may be indigenous to China.
Collapse
|
37
|
Pavio N, Meng XJ, Renou C. Zoonotic hepatitis E: animal reservoirs and emerging risks. Vet Res 2010; 41:46. [PMID: 20359452 PMCID: PMC2865210 DOI: 10.1051/vetres/2010018] [Citation(s) in RCA: 259] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 04/01/2010] [Indexed: 12/23/2022] Open
Abstract
Hepatitis E virus (HEV) is responsible for enterically-transmitted acute hepatitis in humans with two distinct epidemiological patterns. In endemic regions, large waterborne epidemics with thousands of people affected have been observed, and, in contrast, in non-endemic regions, sporadic cases have been described. Although contaminated water has been well documented as the source of infection in endemic regions, the modes of transmission in non-endemic regions are much less known. HEV is a single-strand, positive-sense RNA virus which is classified in the Hepeviridae family with at least four known main genotypes (1–4) of mammalian HEV and one avian HEV. HEV is unique among the known hepatitis viruses, in which it has an animal reservoir. In contrast to humans, swine and other mammalian animal species infected by HEV generally remain asymptomatic, whereas chickens infected by avian HEV may develop a disease known as Hepatitis-Splenomegaly syndrome. HEV genotypes 1 and 2 are found exclusively in humans while genotypes 3 and 4 are found both in humans and other mammals. Several lines of evidence indicate that, in some cases involving HEV genotypes 3 and 4, animal to human transmissions occur. Furthermore, individuals with direct contact with animals are at higher risk of HEV infection. Cross-species infections with HEV genotypes 3 and 4 have been demonstrated experimentally. However, not all sources of human infections have been identified thus far and in many cases, the origin of HEV infection in humans remains unknown.
Collapse
Affiliation(s)
- Nicole Pavio
- Ecole Nationale Vétérinaire d'Alfort, 94704 Maisons-Alfort, France.
| | | | | |
Collapse
|
38
|
Takahashi M, Tamura K, Hoshino Y, Nagashima S, Yazaki Y, Mizuo H, Iwamoto S, Okayama M, Nakamura Y, Kajii E, Okamoto H. A nationwide survey of hepatitis E virus infection in the general population of Japan. J Med Virol 2010; 82:271-81. [PMID: 20029817 DOI: 10.1002/jmv.21678] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To investigate nationwide the prevalence of hepatitis E virus (HEV) infection in the general population of Japan, serum samples were collected from 22,027 individuals (9,686 males and 12,341 females; age, mean +/- standard deviation: 56.8 +/- 16.7 years; range: 20-108 years) who lived in 30 prefectures located in Hokkaido, mainland Honshu, Shikoku, and Kyushu of Japan and underwent health check-ups during 2002-2007, and were tested for the presence of IgG, IgM, and IgA classes of antibodies to HEV (anti-HEV) by in-house ELISA and HEV RNA by nested RT-PCR. Overall, 1,167 individuals (5.3%) were positive for anti-HEV IgG, including 753 males (7.8%) and 414 females (3.4%), the difference being statistically significant (P < 0.0001). The prevalence of anti-HEV IgG generally increased with age and was significantly higher among individuals aged >or=50 years than among those aged <50 years (6.6% vs. 2.7%, P < 0.0001). Although 13 individuals with anti-HEV IgG also had anti-HEV IgM and/or anti-HEV IgA, none of them had detectable HEV RNA. The presence of HEV RNA was further tested in 50 or 49-sample minipools of sera from the remaining 22,014 individuals, and three individuals without anti-HEV antibodies tested positive for HEV RNA. The HEV isolates obtained from the three viremic individuals segregated into genotype 3 and were closest to Japan-indigenous HEV strains. When stratified by geographic region, the prevalence of anti-HEV IgG as well as the prevalence of HEV RNA or anti-HEV IgM and/or anti-HEV IgA was significantly higher in northern Japan than in southern Japan (6.7% vs. 3.2%, P < 0.0001; 0.11% vs. 0.01%, P = 0.0056; respectively).
Collapse
Affiliation(s)
- Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Tochigi-Ken, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Johne R, Plenge-Bonig A, Hess M, Ulrich RG, Reetz J, Schielke A. Detection of a novel hepatitis E-like virus in faeces of wild rats using a nested broad-spectrum RT-PCR. J Gen Virol 2009; 91:750-8. [DOI: 10.1099/vir.0.016584-0] [Citation(s) in RCA: 259] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
|
40
|
Zhang S, Tian D, Zhang Z, Xiong J, Yuan Q, Ge S, Zhang J, Xia N. Clinical significance of anti-HEV IgA in diagnosis of acute genotype 4 hepatitis E virus infection negative for anti-HEV IgM. Dig Dis Sci 2009; 54:2512-8. [PMID: 19117132 DOI: 10.1007/s10620-008-0657-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 11/28/2008] [Indexed: 12/09/2022]
Abstract
Anti-HEV IgM is a diagnostic for recent or ongoing HEV infection. However, some patients with acute hepatitis E (AHE) negative for anti-HEV IgM in acute period were often observed in clinical practice. In this study, we constructed the anti-HEV IgA indirect ELISA assay to evaluate the significance of anti-HEV IgA. The specificity of anti-HEV IgA was 99.6%. Among 245 AHE patients, 84 samples from 84 patients were positive for HEV RNA. The positive rate of anti-HEV IgA, anti-HEV IgM and anti-HEV IgG in 84 samples positive for HEV RNA was 96.3, 97.6, and 88.1%, respectively, and no sample was negative for anti-HEV IgA and anti-HEV IgM simultaneously. Among 245 AHE patients, we found nine samples collected from nine patients in acute period were negative for anti-HEV IgM but positive for anti-HEV IgA and two samples were positive for HEV RNA. Detection of anti-HEV IgA can be a useful supplement for diagnosis of acute HEV infection especially in patients negative for anti-HEV IgM.
Collapse
Affiliation(s)
- Shujun Zhang
- Department of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Kaba M, Davoust B, Marié JL, Barthet M, Henry M, Tamalet C, Raoult D, Colson P. Frequent transmission of hepatitis E virus among piglets in farms in Southern France. J Med Virol 2009; 81:1750-9. [PMID: 19697419 DOI: 10.1002/jmv.21553] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study aimed to assess whether hepatitis E virus (HEV) is present in domestic pigs in Southern France, and to determine the relationship between HEV sequences detected from pigs and from humans. Two hundred fifteen sera, 207 stools, and 107 bile samples were collected from 3- or 6-month-old pigs from different regions of Southern France. Pig IgG anti-HEV antibodies testing was performed using a commercial ELISA kit with minor modifications. Pig HEV RNA was tested by real-time PCR and sequencing assays using "in-house" protocols. Forty percent of pigs were HEV-seropositive. Sixty-five percent of 3-month-old pigs and none of 6-month-old pigs were HEV RNA-positive. HEV RNA was significantly more frequently detected from stools than from sera (65% vs. 22%; P < 0.001). Phylogenetic analysis showed that pig HEV sequences belonged to genotype 3 and formed two clusters of genotype 3f and 3e. Nucleotide homology between pig HEV sequences of each cluster was high (>97%), and clusters were correlated with the geographical origin of pigs and with their repartition into pens and buildings in the pig farm. Based on analysis of 331 nucleotides, pig HEV sequences were close genetically to HEV sequences found from humans or pigs in Europe, and one showed complete nucleotide identity with an HEV sequence obtained in France from a human. The present data indicate that 3-month-old pigs from Southern France might represent a potential source of HEV transmission to humans, and stress the potential of HEV to cause epizootic infections in population of farm pigs.
Collapse
Affiliation(s)
- Mamadou Kaba
- URMITE CNRS-IRD UMR 6236, Facultés de Médecine et de Pharmacie, Université de la Méditerranée Aix-Marseille-II, Marseille, France
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Analysis of the helicase gene of Korean swine hepatitis E virus isolates and trends in viral infection. Arch Virol 2009; 154:1361-4. [DOI: 10.1007/s00705-009-0447-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 06/24/2009] [Indexed: 10/20/2022]
|
43
|
Sakano C, Morita Y, Shiono M, Yokota Y, Mokudai T, Sato-Motoi Y, Noda A, Nobusawa T, Sakaniwa H, Nagai A, Kabeya H, Maruyama S, Yamamoto S, Sato H, Kimura H. Prevalence of hepatitis E virus (HEV) infection in wild boars (Sus scrofa leucomystax) and pigs in Gunma Prefecture, Japan. J Vet Med Sci 2009; 71:21-5. [PMID: 19194072 DOI: 10.1292/jvms.71.21] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The prevalence of hepatitis E virus (HEV) infection in wild boars and pigs in Gunma Prefecture, Japan, was serologically and genetically examined. The positive detection rates of anti-HEV IgG and HEV RNA in the wild boars were 4.5% (4/89) and 1.1% (1/89), whereas those in the pigs were 74.6% (126/169) and 1.8% (3/169), respectively. The positive rates of anti-HEV IgG and HEV RNA on the 17 pig farms in the present study ranged from 20% to 100%, respectively. One male wild boar approximately 5 years of age was positive for HEV RNA but was negative for anti-HEV IgG. Three pigs from 2 farms were positive for HEV RNA; 2 of these pigs were negative for HEV IgG, and the other was positive. A phylogenetic analysis revealed that all of the HEV ORF1 genes detected in the present study belonged to genotype III. In Gunma Prefecture, HEV is highly prevalent and widespread, and uncooked wild boar and pig meat may have the potential to transmit HEV to humans.
Collapse
Affiliation(s)
- Chieko Sakano
- Gunma Prefectural Meat Inspection Laboratory, 305-7 Higoshi, Tamamura, Sawa, Gunma, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Ward P, Poitras E, Leblanc D, Letellier A, Brassard J, Plante D, Houde A. Comparative analysis of different TaqMan real-time RT-PCR assays for the detection of swine Hepatitis E virus and integration of Feline calicivirus as internal control. J Appl Microbiol 2009; 106:1360-9. [PMID: 19187137 DOI: 10.1111/j.1365-2672.2008.04104.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIMS The aim of this study was to compare the performance of four TaqMan RT-PCR assays with a commonly used nested RT-PCR and to include the Feline calicivirus (FCV) as an internal control. METHODS AND RESULTS RNA extracted from 87 swine faecal samples and 103 swine blood samples was subjected to different detection systems. Faecal samples naturally contaminated with Hepatitis E virus (HEV) and negative samples were artificially inoculated with 3.2 x 10(3) PFU of FCV. Detection results obtained on faecal and plasma samples were 35.6% and 4.9% with the nested RT-PCR assay, 8.0% and 0%, 0% and 0%, 13.8% and 0% and 36.8% and 3.9% with TaqMan systems A, B, C and D respectively. The Ct means obtained with the multiplex TaqMan assay were 30.11 and 30.43 for the detection of FCV with HEV contaminated samples and negative samples. CONCLUSIONS The TaqMan system D was more suitable for the detection of swine HEV strains than the three others and FCV was integrated successfully as an internal control. SIGNIFICANCE AND IMPACT OF THE STUDY FCV was demonstrated as an efficient control to monitor the RNA extraction process and HEV amplification procedure in a multiplex HEV/FCV TaqMan assay. This control would be helpful in limiting false negative results.
Collapse
Affiliation(s)
- P Ward
- Agriculture and Agri-Food Canada, Food Research and Development Centre, St-Hyacinthe, QC, Canada
| | | | | | | | | | | | | |
Collapse
|
45
|
Toyoda K, Furusyo N, Takeoka H, Murata M, Sawayama Y, Hayashi J. Epidemiological study of hepatitis E virus infection in the general population of Okinawa, Kyushu, Japan. J Gastroenterol Hepatol 2008; 23:1885-90. [PMID: 19120876 DOI: 10.1111/j.1440-1746.2008.05568.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM The aim of this study was to investigate the prevalence of hepatitis E virus (HEV) infection in the general population of Japan by determining presence of the antibody to HEV (anti-HEV). METHODS The prevalence of HEV infection was determined by positivity of serum antibody to HEV (anti-HEV). RESULTS On retrospective analysis, a significant decrease in anti-HEV prevalence was found in Okinawa healthy residents from 1995 (15.8%) to 2005 (5.5%) (P < 0.0001). In 2005, the anti-HEV prevalence was significantly higher in Okinawa wild boar hunters (25.3%) than in the residents (male 7.7% and female 4.1%) (P < 0.0001). A significant difference was found in the history of consumption of undercooked or raw boar meat between anti-HEV positive and negative hunters (100% vs 64.3%) (P = 0.0018). CONCLUSIONS In conclusion, the anti-HEV prevalence has decreased in the residents of this area, but HEV infection has continued at a high rate in the hunters through the custom of eating undercooked or raw boar meat.
Collapse
Affiliation(s)
- Kazuhiro Toyoda
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | |
Collapse
|
46
|
Pelosi E, Clarke I. Hepatitis E: a complex and global disease. EMERGING HEALTH THREATS JOURNAL 2008; 1:e8. [PMID: 22460217 PMCID: PMC3167588 DOI: 10.3134/ehtj.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 03/12/2008] [Accepted: 04/10/2008] [Indexed: 12/13/2022]
Abstract
Thirty years after its discovery, the hepatitis E virus (HEV) continues to represent a major public health problem in developing countries. In developed countries, it has emerged as a significant cause of non-travel-associated acute hepatitis. HEV infects a wide range of mammalian species and a key reservoir worldwide appears to be swine. Genomic sequence similarity between some human HEV genotypes and swine HEV strains has been identified and we know that humans can acquire HEV infection from animals. Although for the most part the clinical course of HEV infection is asymptomatic or mild, significant risk of serious disease exists in pregnant women and those with chronic liver disease. In addition, there are data on the threat of chronic infections in immunocompromised patients. Beyond management of exposure by public health measures, recent data support that active immunisation can prevent hepatitis E, highlighting the need for vaccination programmes. Here we review the current knowledge on HEV, its epidemiology, and the management and prevention of human disease.
Collapse
Affiliation(s)
- E Pelosi
- Department of Microbiology and Virology, Health Protection Agency, Southeast Regional Laboratory, Southampton General Hospital, Southampton, UK
| | | |
Collapse
|
47
|
Serological and molecular evidence of hepatitis E virus in swine in Brazil. Vet J 2008; 182:474-80. [PMID: 18805029 DOI: 10.1016/j.tvjl.2008.08.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 07/08/2008] [Accepted: 08/09/2008] [Indexed: 12/11/2022]
Abstract
Active hepatitis E virus (HEV) infections in two Brazilian swine herds were investigated. In study 1, 26 piglets born to five anti-HEV positive sows were monitored from birth to post-partum week 22. Serum samples were screened for the detection of anti-HEV antibodies and a nested RT-PCR used to examine the HEV genome. Passive transfer of immunity was confirmed. At week 22, 23/26 (88.4%) of the piglets had seroconverted. Genome amplification was achieved in a feces pool from one holding pen and in one serum sample, both from 13-week-old animals. Histology was suggestive of a potential HEV infection. In the second study, 47 piglets born to six anti-HEV-positive sows were monitored after weaning. Seroconversion was determined in eight animals at 6-8 weeks of age. HEV RNA was detected in two pools from a holding pen for 12-16-week-old animals. Brazilian isolates were classified as genotype 3. This is the first molecular evidence of HEV infection in Brazilian pig herds.
Collapse
|
48
|
de Deus N, Casas M, Peralta B, Nofrarías M, Pina S, Martín M, Segalés J. Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm. Vet Microbiol 2008; 132:19-28. [PMID: 18562132 DOI: 10.1016/j.vetmic.2008.04.036] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 04/10/2008] [Accepted: 04/17/2008] [Indexed: 11/18/2022]
Abstract
The objective of the present study was to determine the pattern of Hepatitis E virus (HEV) infection in a naturally infected, farrow-to-finish herd. For that purpose, a prospective study was conducted in randomly selected 19 sows and 45 piglets. Blood samples were collected from sows at 1 week post-farrowing and from piglets at 1, 3, 6, 9, 12, 15, 18 and 22 weeks of age. Furthermore 3 or 5 animals were necropsied at each bleeding day (but at 1 week of age), and serum, bile, liver, mesenteric lymph nodes and faeces taken. HEV IgG, IgM and IgA antibodies were determined in serum and viral RNA was analysed in all collected samples by semi-nested RT-PCR. Histopathological examination of mesenteric lymph nodes and liver was also conducted. From 13 analysed sows, 10 (76.9%) were positive to IgG, one to IgA (7.7%) and two to IgM (15.4%) antibodies specific to HEV. In piglets, IgG and IgA maternal antibodies lasted until 9 and 3 weeks of age, respectively. IgG seroconversion occurred by 15 weeks of age while IgM and IgA at 12. On individual basis, IgG was detectable until the end of the study while IgM and IgA antibody duration was of 4-7 weeks. HEV RNA was detected in serum at all analysed ages with the highest prevalence at 15 weeks of age. HEV was detected in faeces and lymph nodes for the first time at 9 weeks of age and peaked at 12 and 15 weeks of age. This peak coincided with the occurrence of hepatitis as well as with HEV detection in bile, liver, mesenteric lymph nodes and faeces, and also with highest IgG and IgM OD values at 15 weeks. Finally, different HEV sequences from this farm were obtained, which they clustered within 3 different groups, together with other Spanish sequences, all of them of genotype 3. Moreover, the present study also indicates that the same pig can be infected with at least two different strains of HEV during its productive life. This is the first study characterizing HEV infection in naturally infected pigs with chronological virus detection and its relationship with tissue lesions throughout the productive life of the animals.
Collapse
Affiliation(s)
- Nilsa de Deus
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | | | | | | | | | | | | |
Collapse
|
49
|
Bouwknegt M, Frankena K, Rutjes SA, Wellenberg GJ, de Roda Husman AM, van der Poel WHM, de Jong MCM. Estimation of hepatitis E virus transmission among pigs due to contact-exposure. Vet Res 2008; 39:40. [PMID: 18367077 DOI: 10.1051/vetres:2008017] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Accepted: 03/19/2008] [Indexed: 12/13/2022] Open
Abstract
Locally acquired hepatitis E in humans from industrialized countries has been repeatedly suggested to originate from pigs. Pigs may serve as a reservoir of hepatitis E virus (HEV) for humans when a typical infected pig causes on average more than one newly infected pig, a property that is expressed by the basic reproduction ratio R(0). In this study, R(0) for HEV transmission among pigs was estimated from chains of one-to-one transmission experiments in two blocks of five chains each. Per chain, susceptible first-generation contact pigs were contact-exposed to intravenously inoculated pigs, subsequently susceptible second-generation contact pigs were contact-exposed to infected first-generation contact pigs, and lastly, susceptible third-generation contact pigs were contact-exposed to infected second-generation contact pigs. Thus, in the second and third link of the chain, HEV-transmission due to contact with a contact-infected pig was observed. Transmission of HEV was monitored by reverse transcriptase polymerase chain reaction (RT-PCR) on individual faecal samples taken every two/three days. For susceptible pigs, the average period between exposure to an infectious pig and HEV excretion was six days (standard deviation: 4). The length of HEV-excretion (i.e. infectious period) was estimated at 49 days (95% confidence interval (CI): 17-141) for block 1 and 13 days (95% CI: 11-17) for block 2. The R0 for contact-exposure was estimated to be 8.8 (95% CI: 4-19), showing the potential of HEV to cause epidemics in populations of pigs.
Collapse
Affiliation(s)
- Martijn Bouwknegt
- Laboratory for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
50
|
Lorenzo FR, Tsatsralt-Od B, Ganbat S, Takahashi M, Okamoto H. Analysis of the full-length genome of hepatitis E virus isolates obtained from farm pigs in Mongolia. J Med Virol 2007; 79:1128-37. [PMID: 17597486 DOI: 10.1002/jmv.20905] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
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.
Collapse
Affiliation(s)
- Felipe R Lorenzo
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Tochigi-Ken, Japan
| | | | | | | | | |
Collapse
|