Antibody seroprevalences against peste des petits ruminants (PPR) virus in camels, cattle, goats and sheep in Ethiopia

A questionnaire-survey data indicated that 26% of 276 farmers reported the presence of respiratory disease in their herds in 2001. The incidence was perceived as "high" in small ruminants and camels, but as "low" in cattle. Simultaneously, 2815 serum samples from camels (n=628), cattle (n=910), goats (n=442) and sheep (n=835) were tested. The peste des petits ruminants (PPR) antibody seroprevalence was 3% in camels, 9% in cattle, 9% in goats and 13% in sheep. The highest locality-specific seroprevalences were: camels 10%, cattle 16%, goats 22% and sheep 23%. The animals had not been vaccinated against rinderpest or PPR. Antibody seroprevalences detected in camels, cattle, goats and sheep confirmed natural transmission of PPR virus under field conditions.     

小反刍兽疫病毒在自然感染羊体内的病毒分布

为了解小反刍兽疫病毒在自然感染羊体内的分布情况,平行采集临床发病羊的脾脏、肺脏、心脏、肝脏、肾脏、大肠、淋巴结以及眼拭子、鼻拭子、肛门拭子、血清等样品,应用荧光RT-PCR方法对各样品进行平行检测,比较各样品检测Ct值,评估病毒分布和各样品中的病毒含量,结果显示,所有样品小反刍兽疫病毒核酸均为阳性,其中大肠、肺脏、脾脏和淋巴结的检测Ct值较小,表明小反刍兽疫病毒在自然感染羊体内呈全身分布,但在大肠、肺、脾和淋巴结等组织中的含量较高。     

A Review on Peste des Petits Ruminants (PPR) with Special Reference to PPR in Iran

In 1995, a peste des petits ruminants (PPR) outbreak was diagnosed in Ilam province in Iran near the border with Iraq both serologically and virologically. As then, despite all control measures, PPR has been identified in the whole country and has led to costs of at least US$1.5 million to the Iranian owners of sheep and goats.     

新疆小反刍兽疫疫情诊断

2013年12月新疆伊犁州霍城县发生不明山羊疫情,根据临床症状和剖检变化怀疑为小反刍兽疫感染。对3只病死山羊病料、8只患病山羊分泌物棉拭子样品和6只患病山羊血清样品分别进行病原学和血清学检测。利用竞争ELISA试剂盒对6份血清样本进行抗体检测,结果全部为阳性。利用抗原捕获ELISA试剂盒,在11只病羊样品中都检测到小反刍兽疫抗原。利用能特异性检测小反刍兽疫病毒的荧光定量RT-PCR方法,在11只病羊样品中检测到小反刍兽疫病毒核酸。利用特异引物进行PPRV N基因片段RT-PCR反应,从11只病羊样品中检测到PPRV核酸。针对2号样本病原核酸N基因和F基因片段进行序列同源性比较,结果该毒株与西藏流行株序列片段相似性分别为96.5%和97.5%。遗传进化分析,该病原属于谱系4,与巴基斯坦等国流行毒株遗传关系最近。     

Production and Characterization of Monoclonal Antibodies to Peste des Petits Ruminants (PPR) Virus

Peste des petits ruminants (PPR) is an acute, febrile viral disease of small ruminants, caused by a virus of the genus Morbillivirus. PPR and rinderpest viruses are antigenically related and need to be differentiated serologically. In the present study, 23 mouse monoclonal antibodies were produced by polyethyleneglycol (PEG)-mediated fusion of sensitized lymphocytes and myeloma cells. Among these, two belong to the IgM class and the remaining 21 to various subclasses of IgG. The MAbs from the IgG class designated 4B6 and 4B11 neutralized PPR virus in vitro. In radioimmunoprecipitation assay, 10 MAbs recognized nucleoprotein, 4 recognized the matrix protein and one each haemagglutinin and phosphoprotein. The remaining 7 MAbs failed to precipitate any defined viral protein. The reactivity pattern of the monoclonal antibodies in indirect ELISA indicated a close antigenic relationship within three Indian PPR (lineage 4) virus isolates and also within two rinderpest vaccine strains. All PPR virus isolates could be distinguished from rinderpest vaccine viruses on the basis of the reactivity pattern of all MAbs and anti-N protein MAbs. A set of six monoclonal antibodies specific to PPR virus could also be identified from the panel. From the panel of MAbs available, two MAbs were selected for diagnostic applications, one each for the detection of antigens and antibodies to PPR virus.     

Selection and identification of single-domain antibody against Peste des Petits Ruminants virus

BackgroundPeste des petits ruminants (PPR) is an infectious disease caused by the peste des petits ruminants virus (PPRV) that mainly produces respiratory symptoms in affected animals, resulting in great losses in the world''s agriculture industry every year. Single-domain variable heavy chain (VHH) antibody fragments, also referred to as nanobodies, have high expression yields and other advantages including ease of purification and high solubility.ObjectivesThe purpose of this study is to obtain a single-domain antibody with good reactivity and high specificity against PPRV.MethodsA VHH cDNA library was established by immunizing camels with PPRV vaccine, and the capacity and diversity of the library were examined. Four PPRV VHHs were selected, and the biological activity and antigen-binding capacity of the four VHHs were identified by western blot, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) analyses. ELISA was used to identify whether the four VHHs were specific for PPRV, and VHH neutralization tests were carried out. ELISA and western blot analyses were used to identify which PPRV protein was targeted by VHH2.ResultsThe PPRV cDNA library was constructed successfully. The library capacity was greater than 2.0 × 10⁶ cfu/mL, and the inserted fragment size was approximately 400 bp to 2000 bp. The average length of the cDNA library fragment was about 1000 bp, and the recombination rate was approximately 100%. Four single-domain antibody sequences were selected, and proteins expressed in the supernatant were obtained. The four VHHs were shown to have biological activity, close affinity to PPRV, and no cross-reaction with common sheep diseases. All four VHHs had neutralization activity, and VHH2 was specific to the PPRV M protein.ConclusionsThe results of this preliminary research of PPRV VHHs showed that four screened VHH antibodies could be useful in future applications. This study provided new materials for inclusion in PPRV research.     

Utilization of protein-A in immuno-histochemical techniques for detection of Peste des Petits Ruminants (PPR) virus antigens in tissues of experimentally infected goats

This paper constitutes the first record of utilizing the S. aureus protein-A (PA), conjugated to peroxidase enzyme, for the detection of the Peste des Petits Ruminants (PPR) virus antigens in tissues of experimentally infected goats. The goats were experimentally infected with a virulent PPR virus, which was previously isolated from a severe natural disease outbreak in gazelles, during 2002 in Saudi Arabia. The technique is rapid, and has the superiority over the peroxidase –anti-peroxidase (PAP) test in that, inactivation of the indigenous peroxidase in the tissues is not required and that it can be used against a wide range of animal species. An advantage over the other immunolabelled conjugates is that PA attaches specifically to the crystalizable fraction (Fc) of the IgG molecule, thus allowing the antigen binding fraction (Fab) of the molecule, free to interact specifically with the antigen. So, it doesn't actually compete with the antigen for the Fab portion of the IgG molecule. In the present study, PA conjugate detected the PPR virus antigens in various tissues of the experimentally infected goats.     

Post-vaccination antibodies profile against Peste des petits ruminants (PPR) virus in sheep and goats of Punjab,Pakistan

A total of 70 sheep and 330 goats were selected randomly. All the animals were kept under same housing and management conditions. Serum samples were collected from all the animals and tested for the presence of antibodies against Peste des petits ruminants (PPR) virus using competitive ELISA (cELISA). All the animals were found negative showing percentage inhibition (PI) values <50. The animals were vaccinated against PPR with Nig/75/1 strain vaccine of PPR Serum samples were collected from randomly selected 12 sheep and 30 goats at 10, 30 and 45 days post-vaccination. The samples were subjected to cELISA to determine the presence of antibodies against PPRV. The samples with PI >50 were considered as sero-positive. The sheep found positive at 10, 30 and 45 days post-vaccination were 1(8.3%), 7(58.3%) and 12(100%) respectively. In case of goats 3(10.0%), 29(96.6%) and 27(90.0%) animals gave positive results at 10, 30 and 45 days post-vaccination respectively. Mean PI values in sheep at 10, 30 and 45 days post-vaccination were recorded as 37, 65 and 91 respectively, whereas in goats these values were 43, 78 and 86 respectively.     

免疫区小反刍兽疫免疫抗体监测与分析

本文报告应用C-ELISA方法监测小反刍兽疫免疫区山羊、绵羊和牦牛PPR免疫抗体的结果。结果显示:检测免疫山羊血清298份,阳性163份,阳性率54.70%;检测免疫绵羊血清588份,阳性140份,阳性率23.81%;累计检测免疫羊(山羊和绵羊)血清886份,阳性303份,阳性率34.20%;检测免疫区非免疫牦牛血清353份,阳性51份,阳性率14.45%。并对试验结果显示的免疫区羊免疫抗体阳性率偏低、山羊和绵羊免疫抗体阳性率差异大及免疫区接触牦牛PPR抗体呈阳性的检测结果进行了分析。     

小反刍兽疫研究进展

小反刍兽疫(PPR)是由小反刍兽疫病毒(PPRV)引起的急性或亚急性传染病,为世界动物卫生组织(OIE)法定报告的动物疫病,易感动物以山羊、绵羊等小反刍动物为主。目前,小反刍兽疫主要流行于西非、中非、中东、阿拉伯半岛及南亚等地区。敏感特异的检测方法和高效的预防性疫苗将为该病的防控奠定良好的基础。论文对小反刍兽疫全球流行现状、诊断技术及疫苗研究进展进行了综述。     

小反刍兽疫研究进展

小反刍兽疫病毒(PPRV)是副黏病毒科(Paramyxoviridae)麻疹病毒属(Morbolivirus)的成员,主要感染山羊、绵羊等小反刍动物,引起一种高度接触性病毒性传染病。小反刍兽疫为一种重大的外来性疾病,2007年在中国西藏自治区日土县首次发生。自2013年末以来中国新疆、青海、甘肃、宁夏、内蒙、湖南、辽宁等地频繁暴发小反兽疫疫情,给中国的畜牧业带来了巨大的损失,引起极大的重视。为更好的分析小反刍兽疫的病原特性及采取有效的防控措施,文章对小反刍兽疫的病原学及疫苗研究进展进行论述。     

Seroprevalence and sero-conversion after vaccination against Peste des Petits Ruminants in sheep and goats from Awash Fentale District, Afar, Ethiopia

A cross-sectional epidemiological study followed by vaccination and postvaccinal serum antibody assessment against Peste des Petits Ruminants (PPR) in small ruminant population of Awash Fentale District, Afar, Ethiopia, was conducted from September 2006 to June 2007 with the aim of investigating seroprevalence and post-vaccination sero-conversion rate. A total of 1239 sera collected from sheep and goats which were not vaccinated, were screened by using nucleoprotein-based competitive enzyme-linked immunosorbent assay (c-ELISA). Only 21 (1.70%) animals were found to be positive. Following the base-line seroprevalence study, small ruminants in the area were vaccinated using the attenuated homologous PPR virus (Nigeria 75/1) strain vaccine, produced at National Veterinary Institute (NVI) in Debre-Zeit, Ethiopia. A total of 1096 small ruminants were resampled from the vaccinated population fourteen days after vaccination. The postvaccination sero-conversion rate in the population was found to be 61.13%, indicating a relatively weak herd immunity. The main reason for the low sero-conversion could be the thermolabile nature of the vaccine, since no statistically significant difference was observed between small ruminants vaccinated by Veterinary Professionals and Community Animal Health Workers (CAHWs), using Chi-squared test at 95% CI (P>0.05). This signifies the need for thermostable vaccine that could potentially increase the herd immunity in addition to that being administered by CAHWs independently. The current finding indicated that CAHWs could participate in vaccination campaigns in such areas as Afar, where there are few veterinarians despite of the huge livestock populations, as means of pastoralists' livelihood.     

小反刍兽疫研究进展

小反刍兽疫是由小反刍兽疫病毒引起的一种重大烈性传染病,主要发生于山羊和绵羊等小反刍兽,在国际上已经得到广泛的重视。本文对小反刍兽疫的病毒病原学、流行病学、临床特征、病理变化以及诊断和疫苗研制等国际上的最新进展进行了全面综述。     

小反刍兽疫研究现状

小反刍兽疫(Peste des petits ruminants,PPR)是由小反刍兽疫病毒(Peste des petits ruminants virus,PPRV)引起的一种主要感染小反刍动物的急性、接触性传染病,发病率、死亡率高.近年来,小反刍兽疫(PPR)呈扩散的趋势,成为重要的跨国动物传染病之一,我国周边国家频繁器发该病.2007年7月25日暴发于西藏自治区日土县的我国首例小反刍尊疫疫情,更是对我国如何做好该病的防控工作提出了新的要求和挑战.为了增强广大兽医工作者和相关人士对本病的认识,文中就小反刍兽疫的病原学、流行病学、临床症状、病理特征以及诊断方法等方面的研究现状进行了综述.     

Economics of Prophylaxis against Peste des Petits Ruminants and Gastrointestinal Helminthosis in Small Ruminants in North Cameroon

Data on reproduction and mortality were collected over one year from 5100 sheep and 13 300 goats in treated and control flocks. The treated animals received vaccination against peste des petits ruminants (PPR) and anthelmintics twice a year. Productivity parameters (fecundity and mortality rates) obtained with and without prophylaxis were fitted into a benefit–cost economic analysis model and run for project lifespans varying from one to five years. At a 7% discount rate, the overall benefits for a project lifespan of five years were estimated as over 15 million FCFA and 11 million FCFA for sheep and goats, respectively. The benefit–cost ratio ranged from 2.26 to 3.27 in goats and 3.01 to 4.23 in sheep, depending on the project lifespan. It was concluded that PPR and gastrointestinal helminthosis are important causes of economic losses in small ruminants in Cameroon. A national or even a regional vaccination campaign against PPR and strategic anthelmintic treatment of small ruminants are recommended.     

OIE小反刍兽疫标准简介

世界动物卫生组织(OIE)小反刍兽疫(PPR)标准是各国PPR防控和绵羊、山羊等小反刍动物及其产品流通贸易应遵守的规定.通过梳理OIE-PPR标准修订历史沿革,从小反刍动物及其产品进出口贸易要求以及PPR状态、监测、病原灭活等方面介绍了2002、2013和2021年版标准的修订情况、具体条款,以及由此带来的新要求.继而...     

小反刍兽疫病毒间接ELISA抗体检测方法的建立与初步应用

本研究利用原核表达的小反刍兽疫病毒核衣壳（N）蛋白作为标准抗原蛋白,建立PPRV抗体检测方法,同时对建立的检测方法的相关条件进行了优化。通过优化确定抗原的最佳包被浓度为10 mg/L,血清最佳稀释度为1∶40,二抗的使用浓度为1∶200,血清及二抗的最佳反应条件为37 ℃孵育60 min,底物的最佳反应时间为37 ℃ 15 min。通过批内及批间重复性的评价,变异系数均小于0.1,表明本检测方法具有较高的可重复性。经过临床样品检测证明,建立的检测方法可用于临床PPRV抗体的检测。     

Current situation of Peste des petits ruminants (PPR) in the Sudan

The current situation of PPR in Sudan was investigated. A total of 61 tissue samples were collected from various PPR suspected outbreaks in sheep in Sudan during 2008. Collected tissue samples were tested for PPR antigen using IcELISA, PPR antigen was detected in 26 out of 61 samples (42.6%). Highest antigen detection rate was in specimens collected from western Sudan. A total of 1198 serum samples were collected from sheep (n = 500), camels (n = 392), and goats (n = 306) from different areas in Sudan (Khartoum, Gezira, Tambool, River Nile, Kordofan, White Nile, Blue Nile, Gedarif, Kassala, Halfa ElGadida, Port Sudan). Collected sera were examined for PPR antibodies using cELISA, a total of 336 (67.2%) sheep, 170 (55.6%) goat and 1 (0.3%) camel samples were found to be positive.