重庆市部分地区牛传染性鼻气管炎和流行性牛白血病的血清学调查

为了解传染性鼻气管炎（IBR）和流行性牛白血病（BL）的流行情况，从重庆市辖区内11个区县（自治县）采集奶牛、黄牛、水牛血清共；369头份，用酶联免疫吸附试验（HLISA）检测IBR和BL抗体。结果从部分区县（自治县）检测出阳性样品，IBE阳性率介于2．70％～20．00％之间，总阳性率为4．61％；奶牛、黄牛、水牛总阳性率分别为5．34％、4．92％、0％。BL阳性率介于2．70％～52．50％之间，总阳性率为12．20％，奶牛、黄牛、水牛总阳性率分别为20．87％、1．64％、0％，提示该病在我市奶牛和黄牛牛群中存在，污染较广，应引起重视。     

共和县恰卜恰镇奶牛结核病感染情况调查

在被检的934头奶牛中,初检检出阳性结核病牛8头,可疑牛5头,对可疑牛复检后,检出阳性牛1头,共检出阳性牛9头,阳性率为0．96％（9／934）：阳性牛中黑白花奶牛7头,阳性率为1．17％（7／599）,当地黄牛2头,阳性率为0．60％（2／335）;从检测结果看,恰卜恰镇黑白花奶牛的阳性率;比当地黄牛的阳性率高,差异性极显著（P〈0．01）,说明黑白花奶牛对结核病的抵抗力比当地黄牛相对较差。     

动物类人乙型肝炎的调查

作者采用人的乙型肝炎ＥＬＩＳＡ诊断试剂盒检测动物的乙型肝炎。结果ＨＢｓＡｇ检测黄牛血清４３份，阳性率为２．３％（１／４３）；肝浸液４３份，阳性率为２７．９％（１２／４３）；肌浸液４３份，阳性率为９．３％（３／４３）；鸡血清７２份，阳性率为１２．５％（９／７２）；牛奶３７份，阳性率为１０．８％．ＨＢｅＡｇ检测黄牛血清４３份，阳性率为２．８％（２／７２）。其结果表明黄牛，鸡，奶牛均感染类人乙型肝炎病毒     

河南省肉牛病毒性腹泻的流行动态调查研究

从河南省15个县市的规模化肉牛场和散养户随机采取血清671份熏直肠粪拭子645份熏分别用微量细胞中和试验和双抗体夹心ELISA试剂盒检测牛病毒性腹泻/黏膜病(BVD/MD)的抗体和抗原。检测结果表明:十五个县市牛群的BVD/MD平均抗体阳性率为22.9%,其中肉牛抗体阳性率为21.0%鸦BVD/MD病毒抗原阳性检出率为7.22%～23.80%,从而证实中原地区肉牛群中已普遍存在有BVD/MD。     

云南省边境地区口蹄疫3ABC抗体调查

在云南与缅甸、老挝接壤或邻近的9个边境县(市)散养户、养殖场、交易市场采集牛血清3 129份、猪血清269份,应用口蹄疫病毒非结构蛋白3ABC抗体检测间接ELISA试剂盒进行检测并统计分析。统计分析结果显示,其中四个县(市)牛口蹄疫3ABC抗体阳性率分别为55%、54.44%、56.31%、44.38%,明显偏高;其中黄牛3ABC抗体阳性率为33.83%,水牛和奶牛分别为16.16%、0;放养牛3ABC抗体阳性率为27.65%,圈养牛3ABC抗体阳性率为15.05%;入境水牛和境内水牛口蹄疫3ABC抗体阳性率分别为14.66%和18.22%,差异不显著,入境黄牛和境内黄牛口蹄疫3ABC抗体阳性率分别为54.55%和33.74%,入境黄牛3ABC抗体水平显著偏高,存在口蹄疫传入风险。     

同德县尕巴松都镇奶牛结核病血清学检测

对同德县尕巴松都镇奶牛结核病进行了血清学检测.在被检的225头奶牛中,共检出阳性牛4头,阳性率为1.78％（4/225）;其中荷斯坦奶牛的阳性率为1.33％（3/225）,当地黄牛的阳性率为0.44％（1/225）.检测结果分析,该镇荷斯坦奶牛的阳性率比当地黄牛的阳性率高,差异性极显著（P＜0.01）.     

重庆地区牛附红细胞体16S rRNA基因部分序列的测定和分析

目的对牛附红细胞体的16SrRNA基因序列进行测定和系统进化分析。方法无菌采取感染附红细胞体的黄牛、奶牛、水牛血液,提取附红细胞体的基因组DNA,根据GenBank公布的奶牛附红细胞体16SrRNA序列设计的特异性引物进行PCR扩增,并对PCR产物进行序列测定和系统进化分析。结果PCR扩增出的DNA片段均为415bp左右。序列测定和系统进化分析显示,三者间的相似度分别为（黄牛：水牛=99．52％;黄牛：奶牛：99．28％;奶牛：水牛=99．76％）。与GenBank上公布的Mycoplasma wenyonii（武汉株）序列比较存在有4个突变位点,相似度均〉98％。结论表明本次在重庆地区从牛体分离的附红细胞体为温氏附红细胞体。     

太原地区奶牛病毒性腹泻流行病学调查

为了解太原地区奶牛病毒性腹泻的流行情况,本研究采用牛病毒性腹泻病毒ELISA抗体检测试剂盒,对太原市不同地区的28个规模场、90个散养户及9个奶牛园区的460头奶牛的血清样品进行BVD抗体检测。结果显示:(1)各地区均有BVDV感染,阳性血清292份,平均阳性率为63.5%。其中养殖园区样品阳性率最高,为84.1%;其次为规模场,为76.7%;散养户阳性率最低,为36.0%。(2)同一养殖模式下,不同年龄段奶牛感染率相似。调查结果表明,在所调查区BVDV感染率较高,不同类牛场感染率差异较大,应采取相应措施进行防治。     

甘肃省武威市肉牛牛病毒性腹泻的流行病学调查

试验旨在掌握武威市肉牛群牛病毒性腹泻病毒（BVDV）的感染及流行现状,为防控肉牛牛病毒性腹泻病（BVD/MD）提供依据。应用酶联免疫吸附试验和RT-PCR方法,对采集自武威市各县区的512份肉牛血样和425份具有腹泻症状肉牛的粪便进行BVDV抗体和BVDV病原检测。结果显示,所检血样BVDV抗体总阳性率为60.16%;成年母牛、青年牛、犊牛样品BVDV抗体阳性率分别为74.45%、68.35%、26.47%;来自规模场和散养户样品BVDV抗体阳性率分别为57.06%、55.47%;粪便样品BVDV病原总阳性率为7.76%。研究表明,武威市各县区的肉牛群普遍存在BVDV感染,应采取有效措施加强BVD/MD防控和净化工作。     

2006年福建省牛病毒性腹泻病的血清学调查

对福建省9个地区的6个非免疫牛场和15个散养户采集的共计216份血清样品进行了牛病毒性腹泻病毒抗体的检测.结果规模场检出阳性血清147份,平均阳性率为92.5%,其中有3个规模场的血清阳性率高达100%;从散养户中检出阳性血清7份,平均阳性率为12.3%.另外,奶牛血清阳性率为88.8%,肉牛/黄牛血清阳性率为29.8%.调查表明,福建省规模牛场感染牛病毒性腹泻病毒较为严重.     

安徽、江苏、广西部分地区水牛牛病毒性腹泻/粘膜病血清学监测

用微量细胞中和试验,对安徽、江苏和广西的１２个县部分水牛群血清样品（ｎ＝３４３）牛病毒性腹泻／粘膜病（ＢＶＤ／ＭＤ）中和抗体进行检测。结果从１０个县的血清中检出了ＢＶＤ／ＭＤ抗体,其中安徽水牛血清（ｎ＝１５０）ＢＶＤ／ＭＤ抗体平均阳性检出率为２４．２％（范围１０％～４６．７％）,江苏（ｎ＝１４３）ＢＶＤ／ＭＤ平均阳性检出率为８．４％（０％～１１．１％）,广西（ｎ＝５０）ＢＶＤ／ＭＤ平均阳性检出率为１０．０％（０％～１５．４％）。本调查说明我国水牛群中ＢＶＤ／ＭＤ流行在扩大。     

牦牛病毒性腹泻/粘膜病的防制研究

20世纪80年代以来，我国牦牛群中陆续发现牛病毒性腹泻／粘膜病(BVD／MD)，血清阳性率在30％～42．4％之间，病死率在30％左右，本研究先后从四川、西藏等地牦牛中分离出病毒，并对其进行各种生物学特征鉴定后，表明该病毒与标准毒属同一种，所不同的是四川牦牛病毒株属非致细胞病变型，即属NCP型。但回归本动物能复制出典型病例。目前尚无国产牛粘膜病疫苗用于生产。本研究依据猪瘟病毒与牛病毒性腹泻／粘膜病病毒具有交叉免疫性的原理，用猪瘟弱毒苗对牦牛病毒性腹泻／粘膜病进行预防，试验证明用猪瘟弱毒苗可以预防牛病毒性腹泻／粘膜病，且安全可靠，具有实用价值。     

北京地区规模化奶牛场牛病毒性腹泻病血清学调查

对北京郊区6个未进行牛病毒性腹泻病（BVD）免疫牛场的546份奶牛血清样品,使用牛病毒性腹泻抗体ELISA试剂盒进行检测,并对其中3个牛群进行牛病毒性腹泻病毒（BVDV）血清抗原筛查。共检出阳性血清514份,总阳性率94.1%,其中5个牛场的场内血清抗体阳性率在95%以上。牛病毒性腹泻持续性感染牛（PI牛）筛查的3个牛群均有阳性牛检出。结果表明,北京地区规模化奶牛场存在牛病毒性腹泻感染和接触史,应采取净化措施进行控制。     

Bovine respiratory syncytial virus seroprevalence and risk factors in endemic dairy cattle herds

The herd seroprevalence of bovine respiratory syncytial virus (BRSV) was studied in 59 dairy cattle herds using serology on random selected animals stratified by two age classes (heifers, cows). Risk factors for primary infections in heifers were investigated using a questionnaire on management conditions and data on bovine viral diarrhoea (BVD) status. At least one seropositive cow was present in all the herds. In 25% of the herds all individual were seropositive and 22% of herds had all heifers seronegative. Analysis of the influence of risk factors retained summer pasture and BVD status. In particular, absence of summer pasture and the BVD positive status of heifers were associated with an increased risk of BRSV infection in heifers group.     

Frequency of persistent bovine viral diarrhea virus infection in selected cattle herds

Sera and blood buffy coat samples were obtained from 3,157 cattle in 66 selected herds. Antibodies to bovine viral diarrhea (BVD) virus were detected in 89% of the serum samples by immunoprecipitation or virus-neutralization tests. Cytopathic or noncytopathic BVD viruses were isolated from blood buffy coat samples from 60 cattle in 6 herds. A second blood buffy coat sample was obtained from 54 of the 60 cattle 2 months after the initial sampling, and BVD virus was isolated again from each cow. The 54 cattle were considered persistently infected with BVD virus. The frequency of persistent infection was 1.7%.     

Practices and opinions of New Zealand beef cattle farmers towards bovine viral diarrhoea control in relation to real and perceived herd serological status

ABSTRACT

Aims: To investigate the seroprevalence of infection with bovine viral diarrhoea (BVD) virus among 75 beef herds and seroconversion in cattle during early pregnancy, and to determine the practices and opinions of farmers towards BVD control and their association with real and perceived herd serological status.

Methods: Blood samples were collected before mating in 75 beef herds across New Zealand from 15 unvaccinated heifers that had delivered their first calf that season. Serum samples were tested for BVD antibodies using ELISA individually, and after pooling samples for each farm. Animals that were antibody-negative were retested at either pregnancy diagnosis or weaning. Farmers were asked to complete a detailed survey about herd demographics, BVD testing and vaccination practices, and opinions towards national BVD control.

Results: Based on the pooled serum antibody ELISA results, there were 28/75 (37%) negative herds, 15/75 (20%) suspect herds, and 32/75 (43%) positive herds. Of 1,117 animals sampled 729 (65.3%) tested negative for BVD virus antibodies; when retested, 47/589 (8.0%) animals from 13/55 (24%) herds had seroconverted. Among 71 famers providing survey responses 11 (15%) believed their herd was infected with BVD, 24 (34%) were unsure and 36 (51%) did not think their herd was infected. Only 19/71 (18%) farmers had performed any BVD testing within the past 5 years and 50/70 (71%) had not vaccinated any cattle for BVD. Support for national BVD eradication programme was strong in 51/71 (56%) respondents, but the biggest challenge to BVD control was considered to be famer compliance. Compared to farmers who did not think their herd was infected, more farmers who thought BVD was present in their herds had previously tested for BVD, would consider testing all replacement calves, and would support establishing a national BVD database; fewer would consider purchasing BVD tested or vaccinated cattle only.

Conclusions and clinical relevance: Only 15% of the beef farmers in this study believed their herds were infected with BVD virus and few of them had undertaken BVD screening. Nevertheless many were supportive of implementing a national BVD control programme. It is likely that the lack of farmer awareness around BVD and the failure of farmers to recognise the potential impacts in their herds are hindering progress in controlling the disease in New Zealand. There are opportunities for New Zealand veterinarians to be more proactive in helping beef farmers explore BVD management options.     

蚌埠市某奶牛场IBRV和BVDV的血清学调查

本试验对蚌埠市一家未进行牛传染性鼻气管炎及病毒性腹泻免疫的规模化奶牛场的94份奶牛血清样品,分别使用牛传染性鼻气管炎及病毒性腹泻抗体ELISA试剂盒进行检测,共检出牛传染性鼻气管炎阳性血清65份,阳性检出率为69．15％;病毒性腹泻阳性血清83份,阳性检出率为88．30％。结果表明,该规模化奶牛场存在牛传染性鼻气管炎及病毒性腹泻的感染和接触史,应采取净化措施进行控制。     

云南省牛病毒性腹泻-黏膜病血清流行病学调查

[目的]牛病毒性腹泻—黏膜病(bovine viral diarrhea-mucosal disease, BVD)引起牛腹泻、呼吸系统疾病、生殖功能障碍、免疫抑制、母畜流产、死胎等,对牛产业发展危害严重。牛病毒性腹泻—黏膜病病毒(bovine viral diarrhea-mucosal disease virus, BVDV)在我国大部分牛群中普遍存在,各地流行情况严重程度不同,本调查旨在调查云南省BVDV的流行情况。[方法]调查通过采用商品化的酶联免疫吸附试验(ELISA)试剂盒对BVDV感染和流行情况进行调查,采集了云南省4个州10个县(市)的部分规模牛场及散养户的牛血清样品456份。[结果]结果发现,云南省不同地区所检的牛血清样品总抗体阳性率为16.45%(75/456),抗原阳性率为0.53%(2/378),其中抗体阳性率以大理州洱源县60.0%(9/15)最高,而丽江市华坪县的血清样品中未检测到抗体阳性,大理州宾川县和丽江市宁蒗县的抗原阳性率较低,分别为7.69%(1/13)和4.00%(1/25)。云南省规模场牛的血清样品抗体总阳性率为27.27%(45/165),抗原阳性率为1.15%(1/87),散养户牛的分别为10.31%(30/291)和0.34%(1/291)。[结论]云南省的牛群中存在着BVDV感染的情况,其抗体抗原的阳性率水平跟地区有着紧密的联系,不同的养殖方式抗原抗体水平存在着一定差异,必须要加强云南省BVDV监测与防控,减少其造成的经济损失。