scholarly journals Prevalence of Hepatitis E Virus Antibodies in Canadian Swine Herds and Identification of a Novel Variant of Swine Hepatitis E Virus

2001 ◽  
Vol 8 (6) ◽  
pp. 1213-1219 ◽  
Author(s):  
Dongwan Yoo ◽  
Philip Willson ◽  
Yanlong Pei ◽  
M. Anthony Hayes ◽  
Anne Deckert ◽  
...  

ABSTRACT Swine hepatitis E virus is a newly identified potentially zoonotic virus from pigs of particular concern for possible direct transmission to a human xenotransplant recipient by organ transplantation. In the present study, prevalence of serum antibodies to hepatitis E virus was examined in Canadian swine herds. A total of 998 serum samples collected from 6-month-old healthy slaughter hogs were examined by enzyme immunoassay and Western blot analysis for antibodies to the recombinant open reading frame 3 (ORF3) protein of hepatitis E virus expressed in Escherichia coli. These samples represented more than 80 different swine production units from five major swine-producing provinces across Canada. From this study, 594 samples (59.4%) were found to be positive for hepatitis E virus antibody. The seroprevalence was higher in Quebec (88.8%) and Ontario (80.1%) than in Alberta and Saskatchewan (38.3%). By PCR using a pair of oligonucleotide primers deduced from the ORF2 sequence of human hepatitis E virus, a specific hepatitis E virus sequence was recovered from feces of pigs. The nucleotide sequence identity between the U.S. swine hepatitis E virus and the Canadian isolate (SK3) was only 85.8%, suggesting that genotypic variations may exist in swine hepatitis E virus in North America. Among 165 serum samples collected from humans in Saskatchewan, 2.4% were found to be positive for antibodies to the hepatitis E virus ORF3 protein. Our data indicate that hepatitis E virus is highly prevalent in commercial swine populations in Canada and support the suggestion that the swine hepatitis E virus may be an important zoonotic agent for humans.

2014 ◽  
Vol 62 (2) ◽  
pp. 243-256 ◽  
Author(s):  
Huanbin Liang ◽  
Heng Wang ◽  
Liangquan Zhang ◽  
Honglang Gu ◽  
Guihong Zhang

Hepatitis E virus (HEV) strains are classified into 4 genotypes by nucleotide sequencing. Genotypes 3 and 4 infect humans and animals via HEV-contaminated food or water. HEV RNA was detected by PCR and antibodies were detected by ELISA. Since human studies showed that HEV IgG antibodies in sera can persist for extended periods, diagnosis of HEV infection in swine or humans is mainly based on serological detection using commercial ELISA kits. However, there is no supplemental method to verify ELISA results. Hence, we developed a novel method used for mutual correction of these common processes. Here, a modified stable HepG2 cell line was transfected with pcDNA3.1-ORF3 to express the swine HEV ORF3 protein. Based on this cell line, a novel immunoperoxidase monolayer assay (IPMA) was developed to detect antibodies against HEV. The results show that this method has good specificity, sensitivity and repeatability. When used to investigate 141 porcine serum samples, the IPMA had a coincidence rate of 92.2% with a commercial ELISA kit. The established IPMA described herein is valuable as a supplemental method to ELISA and can differentiate infections by HEV and other viruses.


2005 ◽  
Vol 79 (11) ◽  
pp. 6680-6689 ◽  
Author(s):  
Judith Graff ◽  
Hanh Nguyen ◽  
Claro Yu ◽  
William R. Elkins ◽  
Marisa St. Claire ◽  
...  

ABSTRACT An infectious cDNA clone of hepatitis E virus was mutated in order to prevent synthesis of either open reading frame 2 (ORF2) protein or ORF3 protein. HuH-7 cells transfected with an ORF2-null mutant produced ORF3, and those transfected with an ORF3-null mutant produced ORF2. Silent mutations introduced into a highly conserved nucleotide sequence in the ORF3 coding region eliminated the synthesis of both ORF2 and ORF3 proteins, suggesting that it comprised a cis-reactive element. A mutant that was not able to produce ORF3 protein did not produce a detectable infection in rhesus macaques. However, a mutant that encoded an ORF3 protein lacking a phosphorylation site reported to be critical for function was able to replicate its genome in cell culture and to induce viremia and seroconversion in rhesus monkeys, suggesting that phosphorylation of ORF3 protein was not necessary for genome replication or for production of infectious virions.


2000 ◽  
Vol 81 (12) ◽  
pp. 2885-2890 ◽  
Author(s):  
Harald C. Worm ◽  
George G. Schlauder ◽  
Herbert Wurzer ◽  
Isa K. Mushahwar

We isolated a novel hepatitis E virus (HEV-Au1) variant from a patient in Austria suffering from acute viral hepatitis, who had no known risk factors for acquiring hepatitis E. The clinical presentation and initial serological findings have been reported previously. In this paper we report the results of sequence and phylogenetic analysis of HEV products from viral RNA isolated from acute phase serum. The results show that HEV-Au1 is significantly divergent from other HEV isolates. The nucleotide identity of analysed fragments from the novel isolate ranges from 76·6 to 78·4% when compared to isolates from endemic regions and 84·6 to 87·9% when compared to isolates from non-endemic regions. Divergent results were obtained when serum samples taken from the convalescent phase of disease were tested with three different immunoassays (EIAs). An EIA based on United States isolate-specific peptides showed enhanced reactivity whereas EIAs based on recombinant proteins derived from prototype HEV strains from Burma and Mexico were unable to detect antibodies to HEV (anti-HEV) in late phase serum. The findings verify the presence of an additional HEV variant in an industrialized country and provide information about possible problems in detecting anti-HEV.


2010 ◽  
Vol 84 (18) ◽  
pp. 9059-9069 ◽  
Author(s):  
Suzanne U. Emerson ◽  
Hanh T. Nguyen ◽  
Udana Torian ◽  
Danielle Burke ◽  
Ronald Engle ◽  
...  

ABSTRACT Hepatitis E virus genotype 1 strain Sar55 replicated in subcloned Caco-2 intestinal cells and Huh7 hepatoma cells that had been transfected with in vitro transcribed viral genomes, and hepatitis E virions were released into the culture medium of both cell lines. Virus egress from cells depended on open reading frame 3 (ORF3) protein, and a proline-rich sequence in ORF3 was important for egress from cultured cells and for infection of macaques. Both intracellular ORF3 protein accumulation and virus release occurred at the apical membrane of polarized Caco-2 cells. ORF3 protein and lipids were intimately associated with virus particles produced in either cell line; ORF2 epitopes were masked in these particles and could not be immunoprecipitated with anti-ORF2.


Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 53 ◽  
Author(s):  
Sang-Hoon Han ◽  
Byung-Joo Park ◽  
Hee-Seop Ahn ◽  
Yong-Hyun Kim ◽  
Hyeon-Jeong Go ◽  
...  

Hepatitis E virus (HEV) is a quasi-enveloped, positive-sense single stranded RNA virus. HEV continually expands the host ranges across animal species. In this study, the possibility of cross-species infection with swine HEV-3 was investigated using rabbits. A total of fourteen 8-week old, specific pathogen-free rabbits were divided into three experimental groups. Four rabbits were used as negative controls, four rabbits were infected with rabbit HEV as positive controls, and six rabbits were inoculated with swine HEV-3. HEV RNA were detected from serum and fecal samples after viral challenge. The levels of anti-HEV antibodies, pro-inflammatory cytokines (IL-1, IL-6, TNF-α and IFN-α), and liver enzymes (alanine and aspartate aminotransferases) were determined in serum samples. Histopathological lesions were examined in liver tissues. Viral RNA and anti-HEV antibodies were identified in rabbits inoculated with swine HEV-3 demonstrating positive infectivity of the virus. However, pro-inflammatory cytokine and liver enzyme levels in serum were not significantly elevated, and only mild inflammatory lesions were detected in the liver tissues of rabbits infected with swine HEV-3. These results suggest that swine HEV-3 can engage in cross-species transmission to rabbits, but causes only mild inflammation of the liver.


2005 ◽  
Vol 86 (6) ◽  
pp. 1807-1813 ◽  
Author(s):  
Masaharu Takahashi ◽  
Tsutomu Nishizawa ◽  
Toshinori Tanaka ◽  
Bira Tsatsralt-Od ◽  
Jun Inoue ◽  
...  

To evaluate the usefulness of detection of antibodies to hepatitis E virus (HEV) to screen for viraemic pigs, serum samples obtained from 1425 1–6-month-old pigs in Japan were tested for swine HEV RNA and IgG, IgM and IgA classes of anti-HEV antibody. Fifty-five (5 %) of the 1071 2–5-month-old pigs were positive for swine HEV RNA, but none of 218 1-month-old pigs or 136 6-month-old pigs had detectable HEV RNA. The prevalence of anti-HEV IgG among the viraemic pigs (67 %, 37/55) was similar to that among the non-viraemic pigs (55 %, 757/1370) and the prevalence of anti-HEV IgM among the viraemic pigs and non-viraemic pigs was 7 and 3 %, respectively. However, anti-HEV IgA was detected significantly more frequently among viraemic pigs than among non-viraemic pigs (55 vs 10 %, P<0·0001). These results suggest that anti-HEV IgA is more useful than anti-HEV IgM to screen for viraemic pigs.


1999 ◽  
Vol 37 (12) ◽  
pp. 3828-3834 ◽  
Author(s):  
Sen-Yung Hsieh ◽  
Xiang-Jin Meng ◽  
Ying-Hua Wu ◽  
Shih-Tung Liu ◽  
Albert W. Tam ◽  
...  

Recently, we found that more than 10% of the cases of acute non-A, non-B, non-C hepatitis in Taiwan were caused by a novel strain of hepatitis E virus (HEV). Since none of these patients had a history of travel to areas where HEV is endemic, the source of transmission remains unclear. The recent discovery of a swine HEV in herd pigs in the United States has led us to speculate that HEV may also circulate in herd pigs in Taiwan and may serve as a reservoir for HEV in Taiwan. Of 275 herd pigs obtained from 10 pig farms in Taiwan, 102 (37%) were seropositive for serum anti-HEV immunoglobulin G (IgG). A 185-bp genomic sequence within the ORF-2 of the HEV genome was amplified and cloned from serum samples of an anti-HEV positive pig and subsequently from serum samples of a patient with acute hepatitis E. Sequence comparison revealed that the swine and human isolates of HEV share 97.3% identity. Phylogenetic analyses further showed that the Taiwan swine and human isolates of HEV form a distinct branch divergent from all other known strains of HEV, including the U.S. swine strain. To examine the potential risk of cross-species transmission of swine HEV to humans, the seroprevalences of anti-HEV IgG in 30 swine handlers, 20 pork dealers, and 50 control subjects were assessed and were found to be 26.7, 15, and 8%, respectively (for swine handlers versus controls,P = 0.048). Our findings may help provide an understanding of the modes of HEV transmission and may also raise potential public health concerns for HEV zoonosis.


2005 ◽  
Vol 76 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Takehiro Mitsui ◽  
Yukie Tsukamoto ◽  
Shigeru Suzuki ◽  
Chikao Yamazaki ◽  
Kazuo Masuko ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1329
Author(s):  
Mohammad Sultan Khuroo

The adverse relationship between viral hepatitis and pregnancy in developing countries had been interpreted as a reflection of retrospectively biased hospital-based data collection by the West. However, the discovery of hepatitis E virus (HEV) as the etiological agent of an epidemic of non-A, non-B hepatitis in Kashmir, and the documenting of the increased incidence and severity of hepatitis E in pregnancy via a house-to-house survey, unmasked this unholy alliance. In the Hepeviridae family, HEV-genotype (gt)1 from genus Orthohepevirus A has a unique open reading frame (ORF)4-encoded protein which enhances viral polymerase activity and viral replication. The epidemics caused by HEV-gt1, but not any other Orthohepevirus A genotype, show an adverse relationship with pregnancy in humans. The pathogenesis of the association is complex and at present not well understood. Possibly multiple factors play a role in causing severe liver disease in the pregnant women including infection and damage to the maternal-fetal interface by HEV-gt1; vertical transmission of HEV to fetus causing severe fetal/neonatal hepatitis; and combined viral and hormone related immune dysfunction of diverse nature in the pregnant women, promoting viral replication. Management is multidisciplinary and needs a close watch for the development and management of acute liver failure. (ALF). Preliminary data suggest beneficial maternal outcomes by early termination of pregnancy in patients with lower grades of encephalopathy.


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