共查询到20条相似文献，搜索用时 328 毫秒
1.
猪蓝耳病是一种高度接触性病毒性传染病，由PRRS病毒引起，呈地方性流行。 PRRS病毒只感染猪，不分品种和年龄均可被感染，但以妊娠母猪和1月龄以内的仔猪最易感。主要特征以妊娠母猪的繁殖障碍（流产、死胎、木乃伊胎）及各年龄猪特别是仔猪的呼吸道疾病为主。患病猪和带毒猪是本病的重要传染源。主要传播途径是接触感染、空气传播和精液传播，也可通过胎盘垂直传播。猪感染病毒后2～14周通过饮食、呼吸及直接接触或与污染有PRRSV的运输工具、器械接触均可感染。目前，蓝耳病已成为规模化猪场的主要疫病之一。 相似文献
2.
中西兽医综合防治猪繁殖与呼吸障碍综合征 总被引：1，自引：0，他引：1
猪繁殖与呼吸障碍综合征(PRRS)是由病毒引起的一种繁殖障碍和呼吸系统的传染病,该病临床上以母猪繁殖障碍和幼龄仔猪呼吸系统疾病为主要特征,母猪妊娠后期流产、产死胎、木乃伊胎、弱仔.该病可经呼吸道、空气、接触、精液和垂直传播方式进行传播.老鼠可能是猪繁殖与呼吸障碍综合征病毒的携带者和传播者. 相似文献
3.
2018年4月,新疆某规模化繁育猪场出现大量母猪流产,产死胎、木乃伊胎等繁育障碍症状。为确诊病因,采集胎儿组织和母猪流产分泌物,通过普通PCR、RT-PCR、real-timePCR技术,对猪繁殖与呼吸综合征病毒(PRRSV)、伪狂犬病病毒(PRV)、猪细小病毒(PPV)、弓形虫4种病原进行检测。结果显示,PRRSV检测呈阳性,PRV、PPV和弓形虫检测呈阴性。通过PRRSV特异性引物NSP2进行PRRSV毒株鉴定,确定该猪场存在PRRSV类NADC30毒株。结果表明,类NADC30毒株是导致该猪场出现母猪繁殖障碍的重要病原,说明该新型毒株已经蔓延到新疆地区,并开始对该地生猪养殖业造成危害。本试验为新疆地区猪场母猪繁殖障碍的病因调查提供了依据。 相似文献
4.
5.
猪繁殖与呼吸综合征（PRRS）是由猪繁殖与呼吸综合征病毒（PRRSV）引起的严重危害养猪业的传染病。以妊娠母猪流产、死产、弱胎、木乃伊胎等繁殖障碍及各年龄阶段猪的呼吸道症状为特征。 相似文献
6.
7.
<正>猪繁殖与呼吸综合征（PRRS）,又称猪蓝耳病,由猪繁殖与呼吸综合征病毒（PRRSV）引发的一种以猪只繁殖障碍和呼吸道症状为主要特征的具有高度传染性的病毒病。其传播途径分为垂直传播和水平传播。临床中,PRRS会引起妊娠母猪流产、早产、死产、产木乃伊胎和产弱仔及引发保育猪出现呼吸道症状,给我国养猪业带来严重的经济损失,成为危害中国养猪业的头号疾病。PRRS有着毒株多样性、 相似文献
8.
种猪繁殖障碍性疾病主要以妊娠母猪发生流产、死胎、木乃伊胎、产出无活力的弱仔、畸形仔、少仔和公、母猪的不育等为特征,给养猪业带来了巨大的经济损失.能够引起母猪繁殖障碍的病因比较复杂,既包括病原因素,又包括非病原因素.危害最严重的主要是病毒感染,如猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病病毒(PRV)、猪细小病毒(PPV)、猪日本乙型脑炎病毒(JEB)和猪瘟病毒(CSFV),另外猪圆环病毒(PCV)感染引起的母猪繁殖障碍也引起了人们的关注[1].对于发生母猪繁殖障碍性疾病的猪场,只有弄清发病主要原因,采取相应的措施才能有效地控制该病的流行. 相似文献
9.
10.
以流产、木乃伊和死产为主要特征的繁殖障碍给现代养猪业带来巨大的危害.母猪的繁殖障碍主要包括不育、空怀、屡配不孕、返情、死胎、流产、产弱仔和畸形胎等.引起母猪繁殖障碍的因素主要有两类:一类是引起生殖道原发性感染的病原(传染性因素),约占30%～40%;另一类是毒素、环境和营养等非传染性因素,约占60%～70%.但是,往往以传染性因子(尤其是病毒)的影响更加令人关注,其中影响较大的有PRV、猪细小病毒(PPV)、猪繁殖与呼吸综合征病毒(PRRSV)、日本乙型脑炎病毒(JEV)和猪瘟病毒(HCV).这些病毒所致疾病症状相似,都可以通过胎盘感染胎儿,进而影响胎儿的发育和存活. 相似文献
11.
Productive disorder induced by porcine reproductive and respiratory syndrome virus (PRRSV) is characterized by low conception rate, irregular return to estrus and abortion during early gestation sow; Later-term abortion, early farrowing, stillborn, mummies and weak-born piglets are generally happened at second half of gestation.Piglets with congenital infection become more sensitive to secondary infection, and there exists excreted virus which infects the negative animals on every side.PRRSV passes through the placenta mediated by macrophages/monocytes, which cause pathological damage in the maternal-fetal interface, and virus replication in the fetal implantation sites plays a role in the fetal death and sow abortion.PRRSV infection prevention and viremia shortening for sow are conductive to reduce PRRSV vertical transmission.In addition, biosafety measures, reasonable pig flow and strict disinfection are carried out to control horizontal transmission, and vaccine immunization and medicine administration are done to protect susceptible animals.The main purpose of this review is to summarize PRRSV vertical transmission during each stage of gestation and subsequent reproductive failure. 相似文献
12.
A randomised, double-blinded, placebo-controlled study into the effectiveness and safety of a vaccine against porcine reproductive and respiratory syndrome virus (PRRSV) was carried out on three farms with a history compatible with chronic PRRSV infection; representative groups of sows and gilts were injected with a live vaccine against PRRSV, and during the next six weeks no side effects were observed. The remaining sows and gilts on the three farms were then vaccinated with the same vaccine. Again, no side effects were observed. There were significant reductions in abortion, reproductive disease, returns to oestrus and the numbers of stillborn pigs per sow, and significant increases in the numbers of liveborn pigs per sow and weaned pigs per sow among the vaccinated animals. 相似文献
13.
Pathogenesis of in utero infection in porcine fetuses with porcine reproductive and respiratory syndrome virus. 
下载免费PDF全文
下载免费PDF全文 Porcine fetuses were exposed in utero to porcine reproductive and respiratory syndrome virus (PRRSV) at stages of gestation ranging from 34 to 85 days and examined 17 to 31 days later to determine the effect of gestational age on fetal susceptibility. For each of the 8 litters tested during the study, all of the fetuses of 1 horn of the uterus were exposed to virus by intraamniotic injection; those of the other horn were exposed similarly to a sham inoculum that consisted of sterile cell culture medium. Viral infectivity titers associated with fetal tissues collected at necropsy indicated that, regardless of gestational age, the virus had replicated in fetuses exposed intraamniotically. In addition, virus had also spread and replicated in sham-inoculated littermates in 3 litters. On the basis of these findings it appears that there may be little or no temporal difference in fetal susceptibility to infection with PRRSV. If so, the lack of early fetal death as a commonly recognized feature of naturally occurring cases of PRRS may be due to a greater resistance of early gestational fetuses to the lethal effects of PRRSV, as suggested by this study, and/or a greater likelihood of transplacental infection during late gestation. 相似文献
14.
Porcine reproductive and respiratory syndrome virus (PRRSV)-induced reproductive problems are characterized by embryonic death, late-term abortions, early farrowing and increase in number of dead and mummified fetuses, and weak-born piglets. The virus recovery from fetal tissues illustrates transplacental infection, but despite many studies on the subject, the means by which PRRSV spreads from mother to fetus and the exact pathophysiological basis of the virus-induced reproductive failure remain unexplained. Recent findings from our group indicate that the endometrium and placenta are involved in the PRRSV passage from mother to fetus and that virus replication in the endometrial/placental tissues can be the actual reason for fetal death. The main purpose of this review is to clarify the role that PRRSV replication and PRRSV-induced changes in the endometrium/placenta play in the pathogenesis of PRRSV-induced reproductive failure in pregnant sows. In addition, strategies to control placental and transplacental PRRSV infection are discussed. 相似文献
15.
Risk factors for infection of sow herds with porcine reproductive and respiratory syndrome (PRRS) virus 总被引：10，自引：0，他引：10
Mortensen S Stryhn H Søgaard R Boklund A Stärk KD Christensen J Willeberg P 《Preventive veterinary medicine》2002,53(1-2):83-101
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. 相似文献
16.
Bierk MD Dee SA Rossow KD Collins JE Guedes MI Pijoan C Molitor TW 《The Veterinary record》2001,148(22):687-690
Forty-five sows and 15 boars were selected at random from a breeding herd known to be chronically infected with porcine reproductive and respiratory syndrome virus (PRRSV) and lymphoid, immune-privileged, and non-lymphoid/non-immune-privileged tissues were tested for the presence of the virus by PCR, virus isolation, and immunohistochemistry. The virus was isolated from the lateral retropharyngeal lymph node of one sow; the isolate was nucleic acid sequenced and determined to be of field origin, and it was inoculated into two PRRSV-naive pregnant sows (A and B) at 95 days of gestation. They were necropsied 14 days later and samples of maternal and fetal tissue and blood samples were collected. Sow A had 10 fresh, six partially autolysed, and two mummified fetuses, and sow B had six fresh and viable fetuses. Viral nucleic acid was detected by PCR in tissue pools from each sow and also from pooled fetal tissues, and the virus was isolated from fetal pools from sow A. 相似文献
17.
Maldonado J Segalés J Martínez-Puig D Calsamiglia M Riera P Domingo M Artigas C 《Veterinary journal (London, England : 1997)》2005,169(3):23-456
The objective of the present study was to determine the presence of recognised abortifacient viruses such as porcine reproductive and respiratory virus (PRRSV), Aujeszky's disease virus (ADV), porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2), in tissues from aborted fetuses and stillborn neonates in cases of late reproductive failure in swine. A total of 293 specimens (fetuses aborted in the last third of gestation and stillborn piglets) from 100 different cases of late-term abortions and premature farrowing from 15 different Spanish provinces were studied. PRRSV was detected in 9/100 cases by RT-PCR. Only 1/100 cases analysed (corresponding to a late-term aborted fetus with a negative PRRSV RT-PCR result) was positive for PCV2 by PCR. Neither ADV (monitored by viral isolation plus antigen detection) nor PPV (monitored by ELISA antigen capture test) infection was identified. The results suggest that PRRSV is one of the most important infectious agents, if not the most relevant one, associated with fetal infection leading to abortion or premature farrowing in Spain. Moreover, other viral pathogens such as ADV, PPV and PCV2 seem to have a minor impact on reproductive disease. 相似文献
18.
Infection dynamics and clinical manifestations following experimental inoculation of gilts at 90 days of gestation with a low dose of porcine reproductive and respiratory syndrome virus 下载免费PDF全文
下载免费PDF全文 Jean Paul Cano Scott A. Dee Michael P. Murtaugh Albert Rovira Robert B. Morrison 《Canadian journal of veterinary research》2009,73(4):303-307
Understanding the dynamics of porcine reproductive and respiratory syndrome virus (PRRSV) vertical transmission is important to enhance the accuracy of monitoring protocols for endemically infected breeding herds. The objectives of this study were to determine the prevalence of PRRSV within infected litters, to quantify viremia, and to identify specific attributes of infected individuals. Eight gilts were intramuscularly inoculated with 101 TCID50 of a mildly virulent PRRSV strain (MN-30100) at 90 d of gestation. All inoculated gilts transmitted the virus in utero. The proportion of PRRSV PCR-positive piglets and the level of viremia in the piglets were higher at 4 d of age than at birth or at weaning. No specific attributes were associated with PRRSV infection in the piglets. This is the first report, that we are aware of, documenting the efficient in utero transmission of an extremely low dose of a mildly virulent strain of PRRSV. The results support the sampling of piglets late during lactation as a tool to monitor PRRSV shedding from sow-herds. 相似文献
19.
J. Dewulf H. Laevens F. Koenen K. Mintiens A. De Kruif 《Zoonoses and public health》2001,48(8):583-591
An experimental infection with classical swine fever (CSF) virus in 12 conventional gilts, housed in a sow‐box housing system, was conducted in order to evaluate horizontal transmission, clinical, virological and serological response, and the effect on gestation. Two of the 12 gilts, of which 10 were pregnant, were experimentally inoculated. They became viraemic for the first time 6 days post‐inoculation (dpi). The contact gilts became viraemic between 18 and 21 days post‐inoculation. On the basis of virological findings and the martingale estimate of R0 (13.0) it was concluded that the two experimentally inoculated gilts infected all contact gilts, although random contacts between gilts were not possible. The presence of CSF infection could be diagnosed earlier and during a longer period when the leucocyte count or polymerase chain reaction were used in comparison with virus isolation in whole blood (P < 0.05). The observed clinical symptoms were atypical and highly variable between the gilts, which hampered clinical diagnosis. The pregnant gilts became infected between day 43 and 67 of gestation. In all cases vertical virus transmission occurred and this resulted partially in abortion and/or mummification. 相似文献