辽宁省猪圆环病毒2型血清学调查与分析

为了解辽宁省猪圆环病毒2型（PCV2）感染情况，对来自辽宁省14个市的59个规模化商品猪场的734份血清、17个种猪场的329份血清、45户农村散养户的146份血清，采用ELISA（酶联免疫吸附试验）方法进行PCV2抗体检测。结果显示，59个规模化猪场中有51个为阳性，阳性率86.4%（51/59），其734份样品中有351份为阳性，样品阳性率为47.8%（351/734）；17个种猪场中有15个为阳性，阳性率为88.2%（15/17），其种猪群样品阳性率为47.6%（81/170），仔猪群样品阳性率为29.6%（47/159）；45户散养户中有23户为阳性，阳性率为51.1%（23/45），检测的146份样品有58份阳性，样品阳性率39.7%（58/146）。可见，PCV2在辽宁省各地的感染已经很普遍，并且种猪群感染率高于仔猪群，规模场的感染率高于农村散养户。     

西宁市猪圆环病毒2型感染的流行病学调查

用酶联免疫吸附试验（ELISA）检测了西宁市8个规模养殖场和部分散养户的161份猪血清样品的猪圆环病毒2型（PCV2）抗体。结果显示，所有被检猪场均有PCV2抗体阳性猪存在，161份血清样品中PCV2抗体阳性率为86．95％。从上述样品中随机抽取28份样品，用PCR方法检测了PCV2ORF1基因；结果，从13份血清中扩增到了特异性PCV2ORF1基因，阳性率为46．42％。证实，西宁市猪场和散养猪群中存在PCV2感染。     

云南省玉溪市猪捷申病的血清学调查分析

为了了解云南省玉溪市猪群感染猪捷申病的初步情况,试验采用商品化猪捷申病毒(PTV)抗原诊断试剂盒对玉溪市红塔区、通海县和元江县3个县区采集的455份猪血清样品(其中红塔区278份,通海县87份,元江县90份;散养户或规模化猪场317份,屠宰场138份,母猪205份,公猪250份)进行检测。结果表明:在455份血清样品中,375份为阳性,总阳性率为82.42%。其中红塔区猪捷申病阳性率为88.13%,通海县为65.52%,元江县为81.11%;散养户或规模化猪场阳性率为82.97%;屠宰场为81.16%;母猪阳性率为82.44%,公猪阳性率为77.20%。说明玉溪市猪群广泛存在PTV感染,该地区需要加强对猪捷申病的监测和防控。     

江苏省淮安市淮安区猪衣原体病的血清学调查

为了解江苏省淮安市淮安区猪衣原体病流行情况,采用ELISA试验对采自淮安区部分规模猪场及散养户的900份育肥猪血清,进行猪衣原体感染的血清流行病学调查。结果表明,阳性血清49份,阳性率为5.44%。其中,采自规模猪场的450份样品,阳性29份,阳性率为6.44%;散养户450份样品,阳性20份,阳性率为4.44%。各规模猪场之间的抗体阳性率有一定差异,最高为13.33%,个别猪场未检出阳性猪。散养户多数是阴性,散养户的平均阳性率低于规模场。     

山西省11个地市猪繁殖与呼吸综合征流行病学调研

猪繁殖与呼吸综合征(又称猪蓝耳病,PRRS)在我国已广泛流行.为查清山西省的流行状况,对全省11个地、市77个规模猪场和122个散养户进行猪蓝耳病的流行病学调研.共采集1 728份病料,用猪蓝耳病病毒RT-PCR诊断试剂盒进行病原检测.结果为规模猪场902头份,阳性243份,阳性率27%;散养户826头份,阳性188份,阳性率23%.证明山西省猪群感染比较严重,各地区感染程度不同,差异较大;猪群多以混合感染和继发感染为主.     

猪圆环病毒2型与猪TTV混合感染的流行病学调查

根据GenBank_h发表的猪圆环病毒2型（Porcinecircovirustype2,PCV2）基因组序列和TTV（Torquetenovirus）1、2型的UTR序列设计合成引物,建立了分别用于检测PCV2和TTV1、TTV2的PCR及巢式PCR方法。应用建立的PCR方法对送检的广东、福建和江西等7个省份258份血液和组织样品进行了PCV2、TTV1和TTV2的检测,确定猪群中PCV2与TTV1和／或TTV2混合感染情况。结果表明,94份样品表现为PCV2和TTV1的混合感染,占样品总数的36．4％;193份样品表现为PCV2和TTV2的混合感染,占74．8％;另外,还有一些样品为三重感染,占34．5％。由此可以看出,猪群中PCV2和／或TTV1和／或TTV2的混合感染很普遍。     

对青岛地区4个猪场的猪细环病毒II型的分子流行病学调查

为了解青岛地区各猪场中猪细环病毒II型（TTV2）的存在和感染情况,本实验对2012年3月至5月期间采自青岛地区4个猪场的59份猪血清样品利用病毒核酸提取试剂盒进行了猪细环病毒DNA提取,在此基础上利用TTv2的特异性引物进行PCR检测。结果显示只有莱西1个猪场的血清样品中检测到阳性,阳性率为13．8％,并且存在TTV1与TTV2混合感染的情况,混合感染率为6．9％。本实验结果证实某些猪场中存在猪细环病毒感染,由于TTV在猪的多系统衰竭综合征的病症发展中可能扮演一定角色,所以了解TTV在猪场中的存在状况具有重要意义。     

临沧部分地区猪细小病毒感染的血清学调查

为了解临沧地区猪细小病毒(PPV)的感染情况,采用酶联免疫吸附试验(ELISA),对临沧部分地区规模化猪场和散养户饲养猪的190份血清样品进行了猪细小病毒抗体检测。结果表明,临沧地区规模化猪场和散养户的猪细小病毒抗体总阳性率为66.32%,其中规模化猪场为71.52%,散养户猪群为32.00%,不同年龄段的种公猪、种母猪、育肥猪、仔猪抗体阳性率分别为50.00%、82.52%、43.59%、50.00%。从检测结果说明临沧地区存在猪细小病毒的感染。     

山东省猪群TTV感染情况及分子流行病学分析

为了确定Torque teno virus(TTV)在山东省猪群中是否存在及其感染情况,本研究利用套式PCR方法检测了来自山东省不同地区10个猪场的230份血液样品和组织样品。结果表明猪群中TTV1和TTV2感染总阳性率分别为45.2%和85.7%。两者的混合感染率为39.3%。用套式PCR引物扩增出TTV1和TTV2的部分片段,并将扩增出的部分基因与已报道的TTV1和TTV2病毒序列进行比较分析。分析结果显示TTV可分为TTV1和TTV2两大分支,其TTV1和TTV2与参考株相比同源性分别为88.0%～92.8%和91.9%～94.1%。本研究证实在山东省猪群中存在TTV感染,由于TTV可以感染人,其在公共卫生学方面的意义应当引起我们的重视。     

云南省临沧地区猪伪狂犬病血清流行病学调查

为了解云南省临沧地区猪伪狂犬病病毒(PRV)的感染情况,采用酶联免疫吸附试验(ELISA),对临沧部分地区规模化猪场和散养户饲养猪的190份血清样品进行了猪伪狂犬病病毒gB抗体检测。结果显示,临沧地区规模化猪场和散养户的猪伪狂犬病毒gB抗体阳性率为73.16%,其中规模化猪场为81.82%,散养户猪群为16%。从检测结果来看,临沧地区存在猪伪狂犬病毒感染,应加大免疫力度。     

2010年国内部分省份猪场常见病毒性疾病的病原学调查

随着规模化养猪业的发展,传染性疾病越来越多,混合感染或多重感染十分普遍,给疾病的诊断和预防带来很大困难。本文将我们实验室2010年分别采自福建、广西、河南、上海、内蒙、浙江、江苏和山西等地发病猪场的185份病料,通过RT-PCR和PCR方法对其进行猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus,PRRSV）、猪繁殖障碍的猪瘟病毒（Classical swine fever virus,CSFV）、猪圆环病毒2（Porcine circovirus type 2,PCV2）、猪细小病毒（Porcine parvovirus,PPV）、猪伪狂犬病毒（Pseudorabies virus,PRV）、细环病毒2（Torque teno virus 2,TTV2）等病毒检测。结果表明在所检的病料中PRRSV、PCV2和TTV2的阳性率比较高,分别为49.2%、62.2%和95.1%。有些地方TTV2的阳性率高达100%;同时,还存在很普遍的PRRSV与PCV2、PRRSV与TTV2、PCV2与TTV2等混合感染,混合感染率分别为27.6%、45.4%、58.4%;以及PRRSV、PCV2与TTV2的三重感染率为24.9%。同时对部分PRRSV阳性病料的PRRSV GP5和nsp2基因分别进行测序,分析测序结果表明病料中的PRRSV的GP5和nsp2序列与PRRSV HuN4株的相应序列的亲缘关系分别在98.2%和96.2%以上,且在nsp2区域都存在30个不连续氨基酸的缺失,说明现在临床中所流行的PRRSV可能仍是与高致病性PRRSV基因型相似的病毒。通过本文可以及时了解当前养猪场的病毒性疾病的流行情况,为猪场病毒性疾病的防控提供依据。     

2009年我国部分猪群输血传播病毒感染情况调查

为调查输血传播病毒(TTV)在我国猪群中的感染状况,本研究对2009年采自29个省市的1990份猪血清样品进行了TTV1、TTV2的双重PCR方法检测,并对结果进行了统计分析.结果表明,我国猪群中TTV总的感染率为63.37％(1261/1990),其中TTV1感染率为55.88％(1112/1990),TTV2为32.91％ (655/1990),TTV1和TTV2双重感染率为25.43％(506/1990).进而对样品的地区性分布特征、样品来源等影响因素进行分析,表明我国猪群中TTV感染率以东北地区最高,西北地区最低.样品来源不是影响感染率的关键因素.     

我国部分地区猪圆环病毒2型和猪细环病毒混合感染的调查

为了解猪圆环病毒2型(PCV-2)和猪细环病毒(TTV)混合感染情况,用PCR方法对来自湖南、江西、广东、福建和广西五省区的193份猪组织样品进行PCV-2、TTV-1和TTV-2进行检测。结果显示,PCV-2感染率为61.1%(118/193),PCV-2和TTV-1混合感染率为32.1%(62/193),PCV-2和TTV-2混合感染率为16.9%(32/193),3种病原混合感染率为9.8%(19/193),2006年PCV-2和TTV的混合感染率最高。由此可见,目前猪群中存在PCV-2和猪TTV的混合感染,PCV-2和TTV-1型混合感染率高于和TTV-2型的混合感染率,且存在一定比例的三重感染情况。     

猪瘟耐热保护剂活疫苗（兔源）免疫效果监测

为了解掌握猪瘟耐热保护剂活疫苗在自然状态下的强制免疫效果,在春秋二季集中免疫之后,跟踪监测了50个规模猪场和380个散养户仔猪血样2140份。监测结果发现：春防猪瘟样品抗体监测阳性率为67.3%,其中规模场79.8%,散户56.3%;秋防猪瘟样品抗体监测阳性率为69.1%,其中,免疫B苗的抗体阳性率为70.1%（规模场81.6%,散户61.3%）,C苗的抗体阳性率为65.8%（规模场78.5%,散户51.2%）。春防抗体离散度平均37.5%,其中规模场25.5%,散户48.2%;秋防B苗接种的抗体离散度31.4%,其中规模场28.4%,散户35.6%;秋防C苗接种的抗体离散度41.5%,其中规模场42.1%,散户41.2%。     

Prevalence of swine Torque teno virus genogroups 1 and 2 in Japanese swine with suspected post-weaning multisystemic wasting syndrome and porcine respiratory disease complex

Torque teno virus (TTV) was first isolated from a human hepatitis patient in 1997. TTV was also identified in several animals, including pigs, cattle, sheep, cats and dogs. In this study, we analysed the prevalence of swine TTV genogroups 1 (TTV1) and 2 (TTV2) in Japanese swine populations with suspected post-weaning multisystemic wasting syndrome and porcine respiratory disease by using a nested polymerase chain reaction method. Of 153 serum samples from 16 different herds in Japan, TTV1 was detected in 46 samples (30%), TTV2 in 47 samples (31%) and both in 15 samples (10%). There was no significant difference in the detection rate among geographical regions. The overall prevalence rate of TTV genogroups was significantly lower in ≤30-day-old pigs (11%) compared to that in older age groups (54–82%). These results suggest that swine TTV may be widespread in post-weaning pigs and could play aetiological roles in pig diseases in Japan. This is the first report on the prevalence of swine TTV in Japan.     

猪戊型肝炎病毒的流行病学调查

利用双抗原夹心ELISA对2009-2011年间采自广东省各地区的若干猪场的484份血清样品,进行血清流行病学调查;对69份病猪胆汁样品进行分子流行病学调查,分离得到猪源戊型肝炎病毒(swine hepatitis E virus, swHEV),并基于ORF2部分基因序列进行核苷酸序列比对、相似性分析和遗传进化树分析,以期初步了解广东各地猪群戊型肝炎(hepatitis E, HE)的感染情况和流行特点。试验结果显示,全部被检查猪的swHEV抗体平均阳性率为71.9%(348/484),分离的猪源HEV毒株均属于基因Ⅳ型,阳性率为71.0%(49/69)。调查结果表明基因Ⅳ型swHEV在广东地区普遍流行。     

猪圆环病毒2型、猪巨细胞病毒和TTV-2混合感染的流行病学调查

本研究根据猪圆环病毒2型（PCV2）ORF2、猪巨细胞病毒（PCMV）gB基因和TTV2非编码区序列合成引物,利用PCR方法对2009年来自江苏、浙江、上海、广东和广西等5个省市76个患病猪群的仔猪病料进行了病原学检测。结果显示,PCV2阳性率64.5%（49/76）,TTV2阳性率47.4%（36/76）,PCMV阳...     

Detection of swine torque teno virus in Italian pig herds

Anellovirus is a recently created, floating genus of viruses. Torque teno virus (TTV), the type species in the genus, was first discovered in a human patient with a post-transfusion hepatitis of unknown aetiology. Recently, TTV genetically related to but distinct from those discovered in humans have also been found in animals, including pigs. The aims of this study were to estimate the prevalence of swine TTV in Italian pig herds and some risk factors possibly associated with this infection. Serum samples from 179 healthy pigs from 10 farms located in north-central Italy were tested by polymerase chain reaction for the presence of swine TTV DNA. Viral DNA was found in the sera of 43 pigs (24.0%), coming from eight of the 10 farms examined. Prevalence was significantly higher in finishing herds (40.1%) than in farrow-to-finish herds (11.0%) and did not depend on the size of the herd. Within the finishing herds the prevalence was significantly higher in weaners (57.4%) than in fatteners (22.9%), but this difference was not observed in farrow-to-finish herds. No relationship was observed between the prevalence of swine TTV and the implementation of some general hygiene practices and biosecurity procedures within the herds.     

Efficient surveillance of pig populations using oral fluids

Currently virus surveillance in swine herds is constrained by the cost-effectiveness and efficiency of sampling methods. The objective of this study was to assess the value of using oral fluids collected by barn personnel as a method of surveillance based on PCR testing. Approximately 12,150 pigs in 10 wean-to-finish barns on 10 farms were monitored for the presence of porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and Torque teno virus genogroups 1 (TTV1) and 2 (TTV2) by sampling oral fluid specimens. Oral fluid samples were collected from 6 pens at each site starting at the time of pig placement (～3 weeks of age) and continuing thereafter at 2-week intervals for a period of 18 weeks. Data were analyzed both on a pen basis and barn basis. Overall, 508 (85%) samples were positive for PCV2, 73 (12%) for PRRSV, 46 (8%) for IAV, 483 (81%) for TTV2, and 155 (26%) for TTV1 during the study period. The estimated arithmetic means of the quantitative PCR-positive oral fluids for PCV2, PRRSV, and IAV were 1×10(4.62), 1×10(4.97), and 1×10(5.49)per ml. With a single exception, all barns were positive for PCV2 and TTV2 at every sampling point in the study. Virus detection varied among barns, particularly for IAV and PRRSV. The pen level, cumulative distribution of agent combinations between all 10 barns were statistically different. The most commonly observed patterns were PCV2+TTV2 (239 pen samples, 40%), PCV2+TTV1+TTV2 (88 pen samples, 15%), and PCV2 alone (66 pen samples, 11%). This "proof-of-concept" project showed that a variety of viruses could be detected either intermittently or continuously in pig populations and demonstrated that barn herd virus status is highly variable, even among barns in the same production system. Oral fluid sampling is a promising approach for increasing the efficiency and cost effectiveness of virus surveillance in swine herds.