| 1. |
- Widén, Frederik, et al.
(författare)
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Detection of herpesvirus DNA in Arctic foxes (Vulpes lagopus; syn. Alopex lagopus) with fatal encephalitis
- 2012
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Ingår i: Research in Veterinary Science. - : Elsevier BV. - 0034-5288 .- 1532-2661. ; 92, s. 509-511
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Tidskriftsartikel (refereegranskat)abstract
- A captive breeding programme for the Fennoscandian Arctic fox (Vulpes lagopus; syn. Alopex lagopus) failed due to fatal encephalitis. The aim of this study was to identify the causative agent. Viral nucleic acid was detected by PCR and in situ hybridization in the brain of affected foxes. The results suggest that a herpesvirus might be the causative agent. Whether this infection also occurs in free-living Arctic foxes is unknown. (C) 2011 Elsevier Ltd. All rights reserved.
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| 2. |
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| 3. |
- Emmoth, Eva, et al.
(författare)
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Inactivation of Viruses and Bacteriophages as Models for Swine Hepatitis E Virus in Food Matrices
- 2017
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Ingår i: Food and Environmental Virology. - : Springer Science and Business Media LLC. - 1867-0334 .- 1867-0342. ; 9, s. 20-34
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log(10) reductions of ae4.2, ae5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage I center dot X174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log(10). LA treatment at 2.2 M gave log(10) reductions in the viral spectrum of 0.29-2.1 for swine liver and 0.87-3.1 for ham, with I center dot X174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log(10) reductions of 1.6-2.8 for swine liver, 0.97-2.2 for ham and 1.3-2.3 for sausage, at 15-60 J cm(-2), with MS2 as the most stable microorganism. The HPP treatment gave significantly (p < 0.05) greater virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p < 0.05) greater than on ham for all microorganisms. The results presented here could be used in assessments of different strategies to protect consumers against virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested.
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| 4. |
- Gyarmati, Péter, et al.
(författare)
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Universal detection of hepatitis E virus by two real-time PCR assays : TaqMan((R)) and Primer-Probe Energy Transfer
- 2007
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Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 146:1-2, s. 226-235
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus (HEV) is a major cause of food- and waterborne diseases in countries with poor sanitation. Furthermore, travellers to such countries are also at risk of contracting the virus. Noteworthily, during the last decade an increasing number of non-travel-related cases were recorded even in countries with high sanitary standards. An alternative, direct route of infection, from animals to humans (zoonotic transmission) is suspected to be the cause of recent cases of hepatitis E. In order to provide rapid and sensitive methods for detecting the virus in various hosts, two real-time PCR methods were developed and compared: a TaqMan (R) and Primer-Probe Energy Transfer (PriProET) assay. These highly sensitive novel methods provide valuable diagnostic tools to investigate zoonotic transmission, to detect the virus in the food chain and in research related to the potential of hepatitis E virus to cross the species barrier. The results show that the two novel PCR assays are robust, highly sensitive and specific for broad range detection of the four genotypes of HEV. Compared to PriProET, the TaqMan (R) assay appears to perform slightly better, with higher fluorescence values for positive samples. However, the PriProET has the benefit of better tolerating the point mutations in the target nucleic acids. Thus, it provides a more powerful tool to detect new virus variants. These new molecular diagnostic assays are practical tools that can be employed in the area of public health, for disease diagnosis and for tracking outbreaks. In basic research the methods provide new tools to study HEV biology, including virus-host interactions and transmission between various host species.
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| 5. |
- Lin, Jay, et al.
(författare)
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High prevalence of hepatitis E virus in Swedish moose : A phylogenetic characterization and comparison of the virus from different regions
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hepatitis E virus (HEV) infects a range of species, including humans, pigs, wild boars and deer. Zoonotic transmission may contribute to the high HEV seroprevalence in the human population of many countries. A novel divergent HEV from moose (Alces alces) in Sweden was recently identified by partial genome sequencing. Since only one strain was found, its classification within the HEV family, prevalence in moose and zoonotic potential was unclear. We therefore investigated samples from 231 moose in seven Swedish counties for HEV, and sequenced a near complete moose HEV genome. Phylogenetic analysis to classify this virus within the family Hepeviridae and to explore potential host specific determinants was performed. Methods and Findings: The HEV prevalence of moose was determined by PCR (marker for active infection) and serological assays (marker of past infection) of sera and 51 fecal samples from 231 Swedish moose. Markers of active and past infection were found in 67 (29%) animals, while 34 (15%) were positive for HEV RNA, 43 (19%) were seropositive for anti-HEV antibodies, and 10 (4%) had both markers. The number of young individuals positive for HEV RNA was larger than for older individuals, and the number of anti-HEV antibody positive individuals increased with age. The high throughput sequenced moose HEV genome was 35-60% identical to existing HEVs. Partial ORF1 sequences from 13 moose strains showed high similarity among them, forming a distinct monophyletic clade with a common ancestor to HEV genotype 1-6 group, which includes members known for zoonotic transmission. Conclusions: This study demonstrates a high frequency of HEV in moose in Sweden, with markers of current and past infection demonstrated in 30% of the animals. Moose is thus an important animal reservoir of HEV. The phylogenetic relationship demonstrated that the moose HEV belonged to the genotype 1-6 group, which includes strains that also infect humans, and therefore may signify a potential for zoonotic transmission of this HEV. © 2015 Lin et al.
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| 6. |
- Persson, Sofia, et al.
(författare)
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Validation of an optimised method for quantitative detection of hepatitis E virus in pork sausage
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Hepatitis E virus (HEV) is an emerging zoonosis that can be transmitted to humans through the consumption of raw or undercooked pork meat products. Several methods for detecting the virus in food have been described, but there are still few robust data on qualitative and quantitative performance characteristics. In this study, we developed an optimised workflow for quantitative detection of HEV in pork sausage based on a combination of previously existing protocols. The protocol uses sample disruption and phase separation with tri-reagent and 1-bromo-3-chloropropane, followed by RNA concentration with isopropanol precipitation. We validated the protocol for use on reverse transcription quantitative real-time PCR (RT-qPCR) and reverse transcription droplet digital (RT-ddPCR). The 95% limit of detection and limit of quantification was 200 copies/g for both RT-qPCR and RT-ddPCR. The RT-ddPCR technology has previously shown promise as a more precise alternative to RT-qPCR. However, we found no evidence for improved performance using RT-ddPCR instead of RT-qPCR in this method. Furthermore, we also evaluated different combinations of RNA concentration methods and PCR detection strategies. This showed that isopropanol precipitation of viral RNA was more than twice as efficient as magnetic silica bead-based extraction when an inhibitor tolerant RT-PCR detection strategy was used. In conclusion, we present an efficient and well-characterised method for quantitative detection of HEV in pork sausage. Such methods are valuable to provide high quality data for risk assessments and food monitoring.
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| 7. |
- Roth, Anette, et al.
(författare)
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Markers for Ongoing or Previous Hepatitis E Virus Infection Are as Common in Wild Ungulates as in Humans in Sweden
- 2016
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Ingår i: Viruses-Basel. - : MDPI AG. - 1999-4915. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus (HEV) is a human pathogen with zoonotic spread, infecting both domestic and wild animals. About 17% of the Swedish population is immune to HEV, but few cases are reported annually, indicating that most infections are subclinical. However, clinical hepatitis E may also be overlooked. For identified cases, the source of infection is mostly unknown. In order to identify whether HEV may be spread from wild game, the prevalence of markers for past and/or ongoing infection was investigated in sera and stool samples collected from 260 hunted Swedish wild ungulates. HEV markers were found in 43 (17%) of the animals. The most commonly infected animal was moose (Alces alces) with 19 out of 69 animals (28%) showing HEV markers, followed by wild boar (Sus scrofa) with 21 out of 139 animals (15%), roe deer (Capreolus capreolus) with 2 out of 30 animals, red deer (Cervus elaphus) with 1 out of 15 animals, and fallow deer (Dama dama) 0 out of 7 animals. Partial open reading frame 1 (ORF1) of the viral genomes from the animals were sequenced and compared with those from 14 endemic human cases. Phylogenetic analysis revealed that three humans were infected with HEV strains similar to those from wild boar. These results indicate that wild animals may be a source of transmission to humans and could be an unrecognized public health concern.
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| 8. |
- Widén, Frederik, et al.
(författare)
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Development of improved analytical methods for use in animal health and in foodborne disease surveillance for source attribution
- 2013
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Ingår i: Revue Scientifique et Technique- Office International des Epizooties. - 0253-1933 .- 1608-0637. ; 32, s. 549-558
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Tidskriftsartikel (refereegranskat)abstract
- Considering the 'One Health' principles, the links between animal and human health are very strong. Both domestic and wild animals are sources of infectious agents that cause diseases in humans. Poor animal health may also indirectly affect human health, through reduced access to food. A large number of infectious diseases of animals,the transboundary animal diseases, spread rapidly across borders. Robust and accurate diagnostic assays are needed to detect the infectious agents rapidly and to limit their spread. A large arsenal of novel assays has been developed during the last three decades, with a tremendous impact on the detection of infectious agents. The new diagnostic methods are mostly laboratory-based and expensive, requiring sophisticated equipment and special skills. However, rapid and cheap field-based assays have also been developed. Herein, the authors give several examples of the development of novel assays, with special focus on the 'One Health' principles.
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| 9. |
- Widén, Frederik
(författare)
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ENDEMIC HEPATITIS E IN TWO NORDIC COUNTRIES
- 2009
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Ingår i: Eurosurveillance. - 1560-7917. ; 14, s. 20-28
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies against hepatitis E virus (anti-HEV) were found in 248 Swedish and Danish patients between 1993 and 2007. Most patients were symptomatic and tested for anti-HEV due to travel abroad. Among patients with known country of infection, most were infected in Asia, mainly on the Indian subcontinent. However, 29 patients were infected in Europe, nine of these had HEV IgM and/or HEV RNA in serum. In sera from 65 of 141 tested patients HEV RNA could be detected, and 63 strains could be typed by limited sequencing within ORF2. HEV RNA was found in sera from 71% of the patients with HEV IgM and IgG and in 18% of the patients with only detectable HEV IgG. It was also found up to three weeks after the onset of disease in 67% of the patients with known date of onset. Patients infected in Europe were infected by genotype 3, and were older than those infected by genotype 1 (mean age 55.3 vs 30 years, p<0.001). Since it is known that genotype 3 can infect domestic pigs, HEV strains from 18 piglets in 17 herds in Sweden and Denmark were sequenced. Phylogenetic analyses of the genotype 3 strains showed geographical clades and high similarity between strains from patients and pigs from the same area. There are thus autochthonous hepatitis E cases in Scandinavia, and there are probably many undiagnosed ones. Patients with hepatitis of unknown etiology should therefore be investigated for anti-HEV even if they have not been outside Europe, since infections acquired from pigs or other animals should be taken into consideration.
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| 10. |
- Widén, Frederik
(författare)
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Hepatitis E as a Zoonosis
- 2016
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Ingår i: Hepatitis E Virus. - Dordrecht : Springer Netherlands. - 9789402409406 ; 948:948, s. 61-71
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Bokkapitel (refereegranskat)abstract
- Hepatitis E (HE) virus infection is not limited to spread from human to human but also occurs between animals and more importantly as zoonotic spread from animals to humans. Genotyping of strains from hepatitis E virus-infected patients has revealed that these infections are not all caused by genotypes 1 or 2 but often by genotypes 3 or 4. Therefore, it is important to understand the striking difference between the spread of genotypes 1 and 2 in countries with poor sanitary standards and the spread of genotypes 3 and 4 in countries with good sanitary standards. The number of animal species known to be infected with HEV is expanding rapidly. The finding of HEV in new host species always raises the question regarding the zoonotic potential of these newfound strains. However, as new strains are found, the complexity increases.Certain genotypes are known to have the ability of zoonotic spread from certain animal species and these animals may even constitute an infection reservoir. Some animal species may contribute to zoonotic infections albeit on a smaller scale, while others are believed to be of minor or no importance at all. This chapter reviews possible sources of zoonotic hepatitis E virus infection.
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| 11. |
- Widén, Frederik, et al.
(författare)
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Molecular epidemiology of hepatitis E virus in humans, pigs and wild boars in Sweden
- 2011
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 139, s. 361-371
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E infections in humans are usually acquired in endemic countries in Asia or Africa. In Sweden 17 cases infected in Europe, between 1993 and 2009, were identified. All had clinical hepatitis E with unknown source of infection. Hepatitis E virus (HEV) was identified in faecal samples from 63 piglets in 12 pig farms in Sweden. HEV was also identified in blood from 13 out of 159 investigated Swedish wild boars from nine counties. Partial HEV genomes from humans, pigs and wild boars were sequenced and compared by phylogeny. The results showed close relatedness between HEY strains from piglets from the same farm and from wild boars from the same county. HEV strains from humans showed relatedness with strains from pigs and wild boars from the same county. This study showed that HEY strains form geographical clusters in the phylogenetic tree. The methods used in this study may thus be used for tracing the origin of an infecting strain. Furthermore, this study indicated that there are endemic sources of human HEY infections in Sweden.
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| 12. |
- Widén, Frederik, et al.
(författare)
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PCR detection and analyzis of potentially zoonotic Hepatitis E virus in French rats
- 2014
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Ingår i: Virology Journal. - 1743-422X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hepatitis E virus has been detected in a wide range of animals. While Genotypes 1-2 of this virus infect only humans, 3-4 can spread from animals to humans and cause sporadic cases of human disease. Pig, and possibly also rats, may act as a reservoir for virus. From a public health perspective it is important to clarify the role of rats for infection of humans. Rats often live close to humans and are therefore of special interest to public health. Rats live of waste and inside the sewage system and may become infected. Reports of hepatitis E virus in rats have been published but not from France. The possibility that rats in an urban area in France were Hepatitis E virus infected, with which type and relationship to other strains was investigated. This study provides information important to public health and better understanding the occurrence of hepatitis E virus in the environment. Eighty one rats (Rattus Norvegicus) were captured, euthanized, sampled (liver and faeces) and analyzed by real-time RT-PCR's, one specific for Hepatitis E virus in rats and one specific for genotype 1-4 that that is known to infect humans. Positive samples were analyzed by a nested broad spectrum RT-PCR, sequenced and compared with sequences in Genbank.Findings: Twelve liver and 11 faeces samples out of 81 liver and 81 faeces samples from 81 captured rats were positive in the PCR specific for Hepatitis E virus in rats and none in the PCR specific for genotype 1-4. Comparison by nucleotide BLAST showed a maximum of 87% similarity to Hepatitis E virus previously detected in rats and significantly less to genotype 1-4.Conclusions: This is the first study demonstrating that rats in France carries hepatitis E virus and provide information regarding its relation to other virus strains previously detected in rats and other host animals world-wide. Genotype 1-4 was not detected.
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| 13. |
- Xia, Hongyan, et al.
(författare)
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Differentiation of Classical Swine Fever Virus Infection from CP7_E2alf Marker Vaccination by a Multiplex Microsphere Immunoassay
- 2015
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Ingår i: Clinical and Vaccine Immunology. - 1556-6811 .- 1556-679X. ; 22, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Classical swine fever (CSF) is a highly contagious viral disease of pigs that has a tremendous socioeconomic impact. Vaccines are available for disease control. However, most industrialized countries are implementing stamping-out strategies to eliminate the disease and avoid trade restrictions. These restrictions can be avoided through the use of marker vaccines such as CP7_ E2alf. Marker vaccines have to be accompanied by reliable and robust discriminatory assays. In this context, a multiplex microsphere immunoassay for serological differentiation of infected from vaccinated animals (DIVA) was developed to distinguish CSF virus (CSFV)-infected animals from CP7_ E2alf-vaccinated animals. To this end, three viral proteins, namely, CSFV E2, CSFV E-rns, and bovine viral diarrhea virus (BVDV) E2, were produced in insect cells using a baculovirus expression system; they were used as antigens in a microsphere immunoassay, which was further evaluated by testing a large panel of pig sera and compared to a well-characterized commercial CSFV E2 antibody enzyme-linked immunosorbent assays (ELISAs) and a test version of an improved CSFV E-rns antibody ELISA. Under a cutoff median fluorescence intensity value of 5,522, the multiplex microsphere immunoassay had a sensitivity of 98.5% and a specificity of 98.9% for the detection of antibodies against CSFV E2. The microsphere immunoassay and the CSFV E-rns ELISA gave the same results for 155 out of 187 samples (82.8%) for the presence of CSFV E-rns antibodies. This novel multiplex immunoassay is a valuable tool for measuring and differentiating immune responses to vaccination and/or infection in animals.
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