猪繁殖与呼吸综合征血清学调查

猪繁殖与呼吸综合征（ＰＲＲＳ）是１９８７年首发于北美和欧洲的一种猪的新传染病〔１〕,其病原为猪繁殖与呼吸综合征病毒〔２,３〕。该病毒在国际病毒分类委员会第六次报告中（１９９６）,归属于冠状病毒科动脉炎病毒属,系正股单股ＲＮＡ病毒〔４〕。该病主要症状为...     

德州市猪繁殖呼吸综合征（PRRS）血清学调查

德州市猪繁殖呼吸综合征（ＰＲＲＳ）血清学调查李春生杨绍曾范伟兴①陈静②李学海刘万成①缪典祥王景波（山东省德州市畜牧局２５３０００①②山东省畜牧兽医总站山东农业大学ＰＲＲＳ是近几年来新发现的一种猪的病毒性传染病,病原是ＰＲＲＳＶ,该病主要造成母猪的繁殖...     

猪繁殖与呼吸综合征的血清学调查

猪繁殖与呼吸综合征（PRRS）是由PRRSV引起的一种接触性传染病。为了了解PRRS在我省几个较大种猪场中的流行情况，我们于2004年6月份利用ELISA诊断试剂盒进行了PRRS调查。报告如下。     

广西猪繁殖与呼吸综合征血清学调查

猪繁殖与呼吸综合征(PRRS)俗称蓝耳病,是80年代末期发现的以妊娠母猪流产、早产、死胎、木乃伊胎和弱仔及仔猪呼吸道症状高死亡率为主要特征的一种新的病毒性传染病.1987年首先在美国发现本病,而后世界各地陆续有报道本病的流行暴发.我国大陆在1996年初首次报道首例PRRS.目前,PRRS已在我国某些地区流行,并已造成严重的经济损失.为摸清PRRS在我区的感染情况,1999-2000年两年间我们应用ELISA方法对来自全区各地的猪血清进行PRRS监测.现将结果报道如下:     

猪繁殖与呼吸综合征血清学调查

猪繁殖与呼吸综合征（PRRS）是以引起母猪发热、厌食和流产、死产、木乃伊胎、弱仔等繁殖障碍以及仔猪的呼吸道症状和高死亡率为特征的一种接触性传染病，各种日龄的猪均可感染。其主要危害是造成流产数和不育发生率增加，生长率下降，猪的死亡率增加，饲料转化率下降等。     

猪繁殖与呼吸综合征的血清学调查

利用ＰＲＲＳＶ ＥＬＩＳＡ诊断试剂盒对西宁、大通的部分种猪场的２２０份血清进行ＰＲＳＶ的血清学调查,共检出阳性７６份,阳性率为３４．５５％,表明该病已在我省几个主要猪场中广泛流行。     

甘肃省集约化猪场猪繁殖与呼吸综合症的血清学调查

猪繁殖与呼吸综合症（ＰＲＲＳ）是一种新近发现的猪病毒性疾病,其特征为各种年龄猪均可感染发病。主要临床症状以发病猪不食、嗜睡、体温升高;繁殖母猪受精率低下;妊娠母猪发生早产、晚期流产、死胎、弱胎及木乃伊胎;哺乳母猪泌乳不足,严重影响新生仔猪的生长发育,甚至死亡;种公猪性功能下降,影响精液质量和精子活力;仔猪和育肥猪表现呼吸系统症状,呼吸困难和急促,呈间质性肺炎,耳部及肢体皮肤发绀。该病自１９９５年１１月在我国发生以来,已在全国大部分省市出现,危害十分严重。为了查清该病在甘肃省的感染和流行情况,我ｗ…     

山西省猪繁殖与呼吸综合征血清学调查

猪繁殖与呼吸综合征(PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)所致的猪的一种病毒性传染病,以引起母猪发热、厌食和流产、产死胎、木乃伊胎、弱仔等繁殖障碍以及仔猪的呼吸道症状和高死亡率为特征。各种日龄的猪均可感染,其主要危害是造成流产数和不育发生率增加,生长率下降,猪的死亡率增加,饲料转化率下降等。     

河北省猪繁殖与呼吸综合征血清学调查

应用ELISA试剂盒对2008年9月至2009年3月河北省不同地区规模化猪场猪繁殖与呼吸综合征(PRRS)的流行情况进行了血清学调查。共检测血清1 663份,检出阳性血清882份,阳性率53.04%。其中非免疫猪场861份血清,阳性血清289份,阳性率33.57%;免疫PRRSV疫苗的猪场血清802份,阳性血清593份,阳性率73.94%。非免疫猪场母猪阳性率为45.81%,仔猪为33.86%。提示河北省存在猪繁殖与呼吸综合征,应采取多种措施积极防制。     

猪繁殖和呼吸综合征油乳剂灭活苗的研制

使用猪场自行分离的PRRSV,进行细胞转瓶培养,收获病毒液后灭活,乳化制成油乳苗,各项指标检测均合格,并且免疫试验效果较好.     

Molecular characterization of recent Korean porcine reproductive and respiratory syndrome (PRRS) viruses and comparison to other Asian PRRS viruses

Twenty-eight PRRS viruses (PRRSVs) isolated from various pig farms in Korea between 2002 and 2003 were sequenced for open-reading frame (ORF) 5 and/or full-length genome and compared with numerous PRRSVs reported from North America, Europe and Asia. All Korean isolates examined were genetically of the North American genotype. The ORF5 sequence of one isolate was identical to Ingelvac PRRS MLV vaccine virus. ORF5 nucleotide sequence divergence of the remaining 27 Korean PRRSVs from VR-2332, the prototype of the North American PRRSV and parental strain of the MLV vaccine virus, ranged from 1.3% to 12.9%, which corresponded to 2.0% to 14.9% divergence at the amino acid level, raising a concern on the efficacy of the MLV vaccine. Phylogenetic analyses of ORF5 and/or full-length sequences revealed that the Korean PRRSVs formed a clade distinct from PRRSVs reported from other Asian countries (China, Taiwan, Japan, and Thailand). Our study demonstrated that PRRSVs of the North American genotype were introduced to the Korean swine population some time ago and have evolved independently from PRRSV in other Asian countries, suggesting that geographic separation might influence the molecular evolution of PRRSV. This should be taken into consideration when a national PRRS prevention and control policy for international trade is established.     

Risk factors for infection of sow herds with porcine reproductive and respiratory syndrome (PRRS) virus

In 1992, the porcine reproductive and respiratory syndrome virus (PRRSV) of European type (PRRSV-EU) was introduced in Denmark. By 1996, the virus had spread to approximately 25% of the Danish herds. In January 1996, a modified-live vaccine based on the American type of the virus (PRRSV-US) was used in replacement boars for Danish artificial insemination (AI) centres and from July 1996, the vaccine was used in PRRSV-EU infected herds for prevention of disease. Soon after vaccine introduction, PRRSV non-infected herds experienced outbreaks of disease due to infection with PRRSV-US. In this study, we investigated the risk factors (biosecurity level, animals, exposure from PRRSV-US-infected neighbour herds, semen, herd size, pig density and herd density) for infection with PRRSV-US in a cohort of 1071 sow herds; we used a nested case-control study. The retrospective observation period lasted from June 1996 (when they all were non-infected) to October 1997. Seventy-three non-vaccinated, closed sow herds became infected with the vaccine strain during this period. Each case herd was matched with two control herds from the cohort (controls had not been infected at the time of infection in the case herds). The data were analysed using a Cox-regression model. The hazard of infection increased significantly with exposure from PRRSV-US-infected neighbouring herds, purchase of animals from herds incubating PRRSV-US infection, increasing herd size and purchase of semen from boars at PRRSV-US-infected AI centres. The results are consistent with the modified-live vaccine strain spread to other herds by trade with animals and semen and by neighbour (area) transmission. We suggest that virus spread by aerosols was a frequent mode of transmission.     

Sow performance in an endemically porcine reproductive and respiratory syndrome (PRRS)-infected farm after sow vaccination with an attenuated PRRS vaccine

The objective of this field study was to evaluate in an endemically porcine reproductive and respiratory syndrome (PRRS) virus-infected farm the reproductive performance of sows after their vaccination with a PRRS attenuated vaccine. In a farrow-to-finish pig farm with history of endemic PRRS virus infection, a total of 200 gilts and sows were used. They were divided in 2 groups of 100 animals. The first group was used as untreated controls, while the animals of the second group were vaccinated against PRRS virus using the attenuated Porcilis PRRS vaccine (Intervet International, The Netherlands) based on European strain. All health and reproductive parameters were recorded from the time of vaccination up to next weaning. No adverse systemic or local reactions or side effects relative to vaccination were noted. Compared to controls, vaccinated sows showed significantly improved farrowing rate (89% versus 78%) and a tendency for fewer returns to oestrus, particularly those at irregular intervals. Fewer sows farrowed prematurely and showed post-partum dysgalactia syndrome, but more live pigs were born and weaned in each litter after vaccination. It was concluded that vaccination of sows with Porcilis PRRS attenuated vaccine in farms with endemic PRRSV infection has beneficial effects on their health and fertility.     

Clinical signs and their association with herd demographics and porcine reproductive and respiratory syndrome (PRRS) control strategies in PRRS PCR-positive swine herds in Ontario

The purposes of this study were to describe the clinical signs observed in PRRS positive herds during a porcine reproductive and respiratory syndrome (PRRS) outbreak in Ontario and to determine associations between these clinical signs and herd demographics and PRRS control strategies. All PRRS polymerase chain reaction-(PCR)-positive submissions to a diagnostic laboratory between September 1, 2004 and August 31, 2007 were identified (n = 1864). After meeting eligibility requirements and agreeing to voluntary study participation, producers from 455 of these submissions were surveyed for information on clinical signs observed in their herds, herd demographics, and PRRS control strategies used in their herds at the time that the PCR-positive samples were taken. Larger herd size was associated with an increased risk of reporting abortion, weakborn piglets, off-feed sows, and sow mortality in sow herds, and with an increased risk of reporting mortality in finishing herds. When disease control strategies were examined, use of a commercial PRRS vaccine in sows and gilts was associated with a decreased risk of reporting weakborn pigs and high pre-weaning mortality, while the use of serum inoculation in breeding animals was associated with an increased risk of reporting off-feed sows and sow mortality. Providing biofeedback of stillborn/mummified piglets, placenta or feces to gilts was associated with an increased risk of reporting respiratory disease and mortality in finishing pigs while all-in/all-out flow in farrowing rooms was associated with an increased risk of reporting sow mortality and weakborn piglets.     

4种猪生殖和呼吸综合征灭活疫苗免疫效果比较

猪生殖和呼吸障碍综合征 ( PRRS)是由猪PRRS病毒引起的猪的一种急性高度接触性传染病 ,我国最初于 1 995年报道 ,到目前为止 ,很多地方有此病报道 ,PRRS一旦感染 ,即会在猪场内循环往复、无休止的传播。给养猪生产造成严重的经济损失。目前 ,对该病尚无有效的治疗方法 ,疫苗免疫虽然能在一定程度上减轻疫情的严重情况 ,仍在疫苗的选用上存在不少问题。对于 PRRS弱毒苗疫苗 ,由于其疫苗毒能持续存在数周乃至数月 ,可引起免疫猪长期排毒、散毒 ,或通过胎盘引起先天感染 ;同时 ,疫苗毒株也可出现毒力返强、毒株变异及不同疫苗毒株、疫苗…     

猪繁殖与呼吸综合征的诊断

20 0 2年 10月胶东某规模化猪场发生以妊娠母猪流产、产死胎 ,仔猪出现以呼吸道症状为主的疾病 ,经流行病学分析、症状观察、病理剖检、病毒分离及ELISA、 PCR检测确诊为猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome,PRRS)。现将该场 PRRS的诊治情况报告如下。1　发病情况及临床症状该场为自繁自养猪场 ,来诊时共存栏大小猪 90 0余头。母猪 12 4头 ,处于妊娠期的有 5 2头 ,其中初产母猪 15头。中大肉猪 4 0 0多头。据畜主介绍 ,该场2 0 0 2年 9月初即有 6头母猪分别于预产期前 3～ 7天左右开始流产 ,在这之前 …