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Hepatitis E virus (HEV) genotype 3 was first identified in swine raised on a Shanghai suburban pig farm in late 2006. To accurately determine the prevalence of HEV infections among Shanghai pig farms, 426 pig fecal samples were collected from 37 pig farms located in all 10 Shanghai suburban districts and tested for the presence of HEV RNA using RT-PCR. Genetic analysis based on an amplified 150-bp ORF2 fragment revealed 111 samples to be HEV positive, and the prevalence of HEV infection within the different districts varied between 0 and 41.7%. Thirty-two samples were sequenced, and phylogenetic analysis indicated that 10 isolates belonged to HEV genotype 4 and were most closely related to 3 human and 2 swine HEV strains, all of which had originally been isolated from Asian countries including Japan and China. The remaining 22 isolates belonged to genotype 3 and were most closely related to a strain of swine HEV, US-SW, isolated from pigs in the United States. Our data indicated that genotype 3 HEV was widespread among suburban Shanghai pig farms although further study is required to determine the source and zoonotic nature of the virus. 相似文献
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Berto A Mesquita JR Hakze-van der Honing R Nascimento MS van der Poel WH 《Zoonoses and public health》2012,59(7):477-481
This study represents the primary hepatitis E virus (HEV) surveillance in domestic pigs in Portugal, five pig farms were investigated in 5 different Portuguese regions, ten faecal samples were collected at four different stages of the production. All faecal samples were tested for hepatitis E virus by real-time RT-PCR. At least one sample from each farms of all age groups tested positive for HEV. The prevalence in the pig herds varied from 10% to 30% and the mean prevalence was 32% in weaners, 20% in growers, 32% in fatteners and 4% in adult dry sows. Phylogenetic analysis of the detected HEV sequences indicated that the circulating virus strains belong under the genotype 3. 相似文献
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Prevalence and genetic characterization of Hepatitis E virus in paired samples of feces and serum from naturally infected pigs 
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下载免费PDF全文 Salceda Fernndez-Barredo Carolina Galiana Angel García Maria Teresa Gmez-Muoz Santiago Vega Manuel A. Rodríguez-Iglesias Maria Teresa Prez-Gracia 《Canadian journal of veterinary research》2007,71(3):236-240
This study describes the distribution of Hepatitis E virus (HEV) in a naturally infected swine population and the genetic relatedness of HEV strains on swine farms in Spain. Of fecal and serum samples collected from 131 pigs and manure-ditch samples collected from 17 farms, HEV was detected in 16%, 14%, and 59%, respectively, for an overall prevalence rate of 23%. The maximum prevalence rates for feces and serum were in pigs 5 to 12 wk old. A high prevalence of the virus in feces (18%) was observed in sows. Gene sequencing was performed on 6 strains from feces, serum, and manure ditch: the nucleotide identities varied from 81.5% to 99% when compared with those of other strains of genotype 3 isolated from swine. This is the first study in Europe to show the variation in virus distribution by age in feces and serum in a naturally infected swine population. 相似文献
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Verocytotoxin-producing Escherichia coli O157:H7 (VTEC O157:H7) was detected in two of 2446 individual faecal samples collected from pigs slaughtered at five Swedish slaughterhouses, indicating a prevalence of 0.08 per cent, with a 95 per cent confidence interval from 0 to 0.16 per cent Four Swedish VTEC O157:H7-positive farms which kept ruminants and pigs were studied by repeated faecal sampling; VTEC O157:H7 was isolated from the ruminants and pigs on all the farms and the same strains were present in the pigs and the ruminants. On one of the farms, the organism persisted in the pig population for 11 months. On all four farms, management practices which might have influenced the isolation rate in pigs were identified. A group of young VTEC O157:H7-positive pigs was moved from one of the VTEC O157:H7-positive farms to a fattening herd where there were no ruminants. The number of VTEC O157:H7-positive faecal samples decreased gradually and after nine weeks the pigs were all negative; at slaughter none of the pigs was VTEC O157:H7-positive. 相似文献
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旨在调查四川地区藏猪戊型肝炎病毒（hepatitis E virus,HEV）的流行情况和遗传演化,作者用RT-PCR法对2018—2020年采集自四川省甘孜藏族自治州和阿坝藏族自治州的22个藏猪场332份藏猪粪便样本进行HEV检测,并对阳性样本进行基因分型。RT-PCR检测结果表明HEV核酸阳性率为20.48%（68/332,95% CI=16.3%~25.2%）,22个规模藏猪场中HEV猪场阳性率为77.27%（17/22,95% CI=54.6%~92.2%）,健康样本阳性率为2.86%（3/105,95% CI=0.6%~8.1%）,腹泻样本阳性率为28.63%（65/227,95% CI=22.8%~35.0%）,系统进化分析显示所有阳性株均为G4型。为了进一步研究该地区流行毒株的演化过程,以贝叶斯进化分析软件进行分歧时间估算,结果表明,藏猪流行毒株的分歧时间最早为1999年,最晚为2016年。并分别从每年的样本中挑选1份阳性样本得到全基因组序列,核酸序列相似性为89.5%~93.1%。通过对3条全基因组重组分析发现SWU/301/2019存在重组现象,SWU/301/2019重组区域位于ORF1的3 746—4 655 bp。本研究首次对四川地区藏猪源HEV进行调查,结果表明四川藏猪中存在一定程度的HEV感染,为四川地区对藏猪感染HEV的防治以及深入研究四川藏猪源HEV遗传变异及生物学特性提供了参考依据。 相似文献
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Salceda Fernández-Barredo Carolina Galiana Angel García Santiago Vega María Teresa Gómez María Teresa Pérez-Gracia 《Journal of veterinary diagnostic investigation》2006,18(5):462-465
The aim of this study was to determine at which production stages hepatitis E virus (HEV) is shed by the highest number of pigs and to estimate the relative risk associated with each stage. For this purpose, 146 fecal samples of pigs from 21 farms were studied. In addition, 1 sample from the manure ditch and another sample of drinking water, collected directly from the trough located in the pen, were taken from 16 farms. HEV RNA was detected in fecal samples from 34 pigs (23.29%). The production stages in which most pigs excreted HEV were weaners (41.7%) and pigs in the first month of feeding (60%). The results of the statistical analysis showed that the principal significant risk stage in HEV shedding was the first month of feeding (odds ratio [OR] 19.5, 95% CI 3.59-106.07, P = 0.001) followed by the weaners stage (OR 9.3, 95% CI .78-48.42, P = 0.008). In 8 out of 16 farms tested (50%) HEV RNA was detected in raw manure and in the water trough of only 1. Detection of HEV in manure ditches raises the concern of how to deal with manure of swine origin, because it is used as soil fertilizer. 相似文献
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Marconni Victor da Costa Lana Noemi Rovaris Gardinali Raquel Aparecida Sales da Cruz Letícya Lerner Lopes Gustavo Sousa Silva João Garcia Caramori Júnior Anderson Castro Soares de Oliveira Marcos de Almeida Souza Edson Moleta Colodel Amauri Alcindo Alfieri Caroline Argenta Pescador 《Tropical animal health and production》2014,46(2):399-404
The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n?=?5) or family-scale farms (n?=?5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State. 相似文献
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Rose N Lunazzi A Dorenlor V Merbah T Eono F Eloit M Madec F Pavio N 《Comparative immunology, microbiology and infectious diseases》2011,34(5):419-427
The importance of the domestic pig reservoir for Hepatitis E virus (HEV) was assessed by estimating the seroprevalence and prevalence of HEV contaminated livers in French slaughter-aged pigs. 6565 sera and 3715 livers were randomly sampled from 186 pig farms throughout the country. Taking the sampling design into account, the farm-level seroprevalence was 65% (95% CI 57–74) and 31% (95% CI 24–38) of the slaughter-aged pigs had antibodies against HEV. The individual prevalence of HEV RNA positive livers was 4% (95% CI 2–6) and 24% (95% CI 17–31) of the farms had at least 1 positive liver. Most isolates were of genotype 3f (76.7%) with smaller amounts of 3c (18.6%) and 3e (4.6%). The high prevalence of HEV in pigs and the similarities between HEV subtypes from pigs and humans corroborates the possible zoonotic origin of some HEV autochthonous infections. 相似文献
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One hundred and thirteen finishing pig units and 74 sow units in Catalonia, Spain, were examined to determine the prevalence of salmonella infections and the factors that could be associated with them. Pooled faecal samples were taken from the finishing units, and samples of faeces were collected from individual sows. The Salmonella isolates were serotyped, phage typed and examined for their antimicrobial susceptibility to 18 common antimicrobial drugs. In addition, blood samples from pigs on 141 farms were analysed by ELISA. In both the bacteriological and serological surveys, a questionnaire with 84 questions was completed for each farm. Salmonella species were isolated from 20 per cent of the finishing units and 24 per cent of the sow units; 14 serotypes were detected in the finishing pigs and 11 in the sows. More than 30 per cent of the strains were resistant to tetracycline, sulphonamides, ampicillin or streptomycin, and 69 per cent of the strains were resistant to three or more agents up to 10 compounds. Seventy-seven per cent of the farms had at least one seropositive animal, and 26 per cent of these farms had an individual seroprevalence of 50 per cent or more. The factors associated (P<0.05) with the excretion of Salmonella species in the finishing units were the practice of raising livestock other than pigs (odds ratio [OR]=6.18), the herd size (OR=5.87), and a past history of clinical salmonellosis (OR=4.97). For the sows, the factors associated (P<0.05) with the excretion of Salmonella species were having open-flushed drainage of sewage (OR=34.48), a lack of rodent control measures (OR=0.05) and the number of sows in the unit (OR=9.26). Factors associated with seropositivity in the finishing units were a lack of bird-proof nets (OR=0.30) and the use of water from private wells (OR=3.64). 相似文献
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Maribel Casas Raquel Cortés Sonia Pina Bibiana Peralta Alberto Allepuz Martí Cortey Jordi Casal Marga Martín 《Veterinary microbiology》2011
Hepatitis E is a zoonotic disease and is highly prevalent in European swine livestock. There is a need to compare the infection dynamics of hepatitis E virus (HEV) between herds with the same production system and determine the percentage of animals that could arrive infected at slaughter age. Therefore, a longitudinal study was performed in six Spanish farrow-to-finish affected farms. Twenty piglets per farm were monitored from nursery to slaughter. RT-PCR and serology techniques were applied to analyze longitudinally collected sera and/or faecal samples. Liver and bile samples were also taken at the abattoir. Anti-HEV IgM were firstly detected at 7 weeks of age in 5 farms whereas at 13 weeks of age in 1 farm (farm 2). At slaughter age 50–100% of pigs had seroconverted to anti-HEV IgG in the former 5 farms whereas in the other herd only 5% of pigs were IgG seropositive (farm 2). Six out of 96 livers and 5 out of 80 biles analyzed were HEV positive at the abattoir (total percentage of infected animals: 11.5%). All these positive animals had already seroconverted except 2 pigs of farm 2. Hence, pigs can be seronegative at slaughter age being infected during the latest fattening period. Manipulation of HEV-infected livers or other organs from pigs could be considered a possible route of transmission in Spanish abattoirs. This study represents the first longitudinal survey on swine HEV infection dynamics conducted in different herds. 相似文献
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为了解广西猪群中戊型肝炎病毒(HEV)基因型,利用套式RT-PCR用对南宁周边猪场采集到的104份新鲜猪粪便进行HEV检测、分离并成功扩增和克隆了11株阳性毒株的ORF2基因部分保守片段.序列测定结果表明,11株HEV ORF2序列自身核苷酸同源性为97.7%~100%,推导编码的氨基酸同源性为97.9%~100%;与4型HEV代表毒株Ch-S-1、Ch-T11、swGX40等的核苷酸同源性为84.6%~90.6%,而与其他各型之间的同源性较低.系统发育进化树结果表明,11株HEV广西株为基因4型,其中,10株HEV为4a亚型,1株毒株为4e亚型.结果表明,广西猪群中流行的HEV均为基因4型,且以4a亚型为优势流行毒株. 相似文献
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Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm 总被引：1，自引：0，他引：1
de Deus N Casas M Peralta B Nofrarías M Pina S Martín M Segalés J 《Veterinary microbiology》2008,132(1-2):19-28
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. 相似文献
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Castro-Hermida JA Delafosse A Pors I Ares-Mazás E Chartier C 《The Veterinary record》2005,157(20):623-627
During the kidding season between January and April 2003, 10 farms were selected and divided into two groups of five. The farms in group A had had serious diarrhoeal illness and losses in neonatal kids the previous year, and there were Cryptosporidium parvum infections in kids associated with diarrhoea during the survey. On the farms in group B, there was no history of diarrhoeal disease the previous year and neither C parvum oocysts nor diarrhoea were detected in neonatal kids during the survey. Faecal samples were collected once from 10 adult goats aged between one and seven years on each farm. To assess more accurately the pattern of output of oocysts of C parvum and cysts of Giardia duodenalis by periparturient adult goats, one farm was selected from each group, faecal samples were collected weekly before and after kidding from 12 goats on the farm in group A and from 10 goats on the farm in group B. There was no significant difference in the prevalence of G duodenalis cysts between the group A farms (14 per cent) and the group B farms (12 per cent), and the numbers of cysts excreted ranged from 143 to 400 cysts per gram of faeces (cpg) on the group A farms and 72 to 334 cpg on the group B farms. There was a significant difference (P=0.03) in the prevalence of C parvum oocysts at the group level between the group A farms (20 per cent) and the group B farms (6 per cent). All the adult goats excreted cysts and oocysts at some date around the kidding period; the number of animals excreting cysts of G duodenalis or oocysts of C parvum increased when they gave birth, and seven to 10 times more cysts and oocysts were shed in the three weeks around kidding than in the period more than three weeks from kidding (P<0.001). 相似文献