兔病毒性出血症的诊治

兔病毒性出血症(Rabbit hemorrhagic disease,简称RHD)俗称兔瘟,或称兔出血症,是由兔病毒性出血症病毒(Rabbit hemorrhagic disease virus,简称RHDV)引起的兔的一种急性、高度接触性传染病,具有潜伏期短、发病率和死亡率极高的特点.临床上以呼吸系统出血、肝坏死、实质性器官水肿、淤血及出血性变化为特征.     

兔病毒性出血症诊断方法研究概况

兔病毒性出血症(RHD)是由兔病毒性出血症病毒(RHDV)引起的一种急性、高度致死性传染病,对易感兔致病率可达90%,致死率可达100%。本文对兔病毒性出血症的病原学、流行特点、检测方法等进行了综述,以期为其诊断和防治提供参考。     

兔瘟疫苗的研究应用现状

兔病毒性出血症(RHD)俗称"兔瘟",或称兔出血症,是由兔病毒性出血症病毒(RHDV)引起的兔的一种急性、高度接触性传染病,特征为呼吸系统出血、肝坏死、实质脏器水肿,瘀血及出血性变化.     

兔瘟基因工程疫苗临床应用效果浅析

兔病毒性出血症(Rabbit heamorrhagic disease,RHD)简称兔瘟,是由兔病毒性出血症病毒(Rabbitheamorrhagic disease,RHD)感染家兔并导致死亡的一种烈性病毒性传染病。本病一年四季均可发生,冬、春季节为发病高发期,以60日龄左右青年兔发病死亡率最高,未断奶仔兔几乎不发病。     

兔瘟2型诊断与防控

正兔病毒性出血症2型(RHD2)又称兔瘟2型,是由兔出血症病毒2型(RHDV2)引起的危害家兔和野兔的一种新型高度传染性、急性致死性疫病。该病是世界动物卫生组织(OIE)法定通报疫病,我国将其列为二类动物疫病。RHD2自2010年4月在法国首次报道后,主要在欧洲国家流行。     

兔病毒性出血症的预防与诊断

兔病毒性出血症又名兔出血性肺炎、兔出血症和兔瘟。由兔病毒性出血症病毒（RHDV）所致的兔的一种急性、败血性、高度接触传染性、致死性和以全身实质器官出血为主要特征的传染病。其临床特点是骤然发病，呼吸急促，急性猝死。病变特点是呼吸系统出血，肝坏死，其他实质脏器瘀血及出血。     

实验性兔病毒性出血症免疫器官超微结构的动态病理学观察

兔病毒性出血症(RHD)是由兔出血症病毒引起的一种急性、高度传染性、致死性的传染病，俗称兔瘟。目前，除西藏和台湾等地未见公开报道外，其他省区均有发生。其典型病变为全身各实质器官出血、水肿、瘀血，尤以肺、肝、脾、肾最为严重，这些在大体剖检和组织病理学方面已做的比较详细。徐福南、佘锐萍、贺宏斌、Cha Soo Lee、Valicek L等对宿主细胞结构做了深入细致的研究，     

兔病毒性出血症病理组织悬液灭活工艺的试验报告

兔病毒性出血症俗称兔瘟,是由兔病毒性出血症病毒引起家兔一种急性、烈性、高度致死性传染病。该病发病率、死亡率极高,一旦暴发,会给兔场带来毁灭性的打击。目前兔病毒性出血症仍以疫苗预防为主,而制备该灭活疫苗的兔病毒性出血症病理组织悬液的灭活工艺直接影响着疫苗的质量及企业的生产成本。为探索一种适合规模化生产     

四川兔病毒性出血症2型的分子生物学诊断

兔病毒性出血症2型(RHD2)是由兔出血症病毒2型(RHDV2)引起的家兔和野兔的高度传染性、急性致死性疫病。RHDV2目前主要在欧洲流行,引起的临床症状与经典兔病毒性出血症(RHD)相似,但毒株特性差异较大。2020年4月四川省两个兔场的家兔同时出现了疑似RHD症状,但用经典RHDV疫苗免疫后家兔发病及死亡情况均无好转。分别采集两个兔场的病死兔组织样品进行实验室诊断,使用OIE推荐的RHDV2特异性引物进行RT-PCR检测,两个发病兔场的兔组织混合样品均扩增出大小约800bp的片段。进一步的测序和Blast比对分析发现来自两个发病兔场的2条序列均与RHDV2参考毒株的VP60部分序列高度同源,其中同源性最高的是荷兰RHDV2分离株RHDV2-NL2016,分别为98.01%和97.95%。分析结果表明,报告发病的两兔场的病死兔均为RHDV2感染,这是我国首次官方确诊RHD2疫情。分别将两个兔场组织病料中的RHDV2毒株命名为SCADC-JT01和SCADC-JT02,有关这2株新毒株的毒株特性和基因组特征还有待进一步研究。     

一起兔瘟的诊断

兔瘟(Rabbit hemorrhagic disease,RHD)又称兔出血热,是由兔出血症病毒引起的以呼吸系统出血及实质器官水肿、淤血和出血变化为特征的一种急性、高度接触性、致死性传染疾病[1].2007年9月份大通县某兔场123只家兔发生急性死亡,送检至我院进行诊断,现将结果报告如下.     

No virus replication in domestic cats fed with RHDV-infected rabbit livers

Previous studies have shown that feral cats (Felis catus) from rabbit haemorrhagic disease (RHD) epidemic areas in New Zealand had antibodies against RHD Virus (RHDV) and RHDV RNA was identified by nested RT-PCR from one seropositive feral cat liver. To assess whether RHDV replicates and produces clinical consequences in cats following the consumption of RHDV-infected rabbit, a challenge trial was conducted by feeding cats RHDV-infected rabbit livers. Antibodies against RHDV were detected by immunoassay from sera of cats collected 10 days after the consumption of RHDV-infected livers. Animals fed four times with RHDV-infected livers, had higher antibody titres than animals fed only once. RHDV RNA was detected by nested RT-PCR from mesenteric lymph nodes, tonsil, spleen and liver of cats fed with RHDV-infected livers. RHDV anti-genomic RNA was also detected by nested RT-PCR from mesenteric lymph nodes collected from one animal 2 days after the fourth feed. RHDV was detected by antigen ELISA from cat faeces 1-2 days after the consumption of RHDV-infected livers. Even though a large amount of RHDV has been used, cats did not show any signs of disease. Although abortive RHDV replication could not be ruled out, active RHDV replication was not demonstrated.     

Codon optimization of the rabbit hemorrhagic disease virus (RHDV) capsid gene leads to increased gene expression in Spodoptera frugiperda 9 (Sf9) cells

Rabbit hemorrhagic disease (RHD) is contagious and highly lethal. Commercial vaccines against RHD are produced from the livers of experimentally infected rabbits. Although several groups have reported that recombinant subunit vaccines against rabbit hemorrhagic disease virus (RHDV) are promising, application of the vaccines has been restricted due to high production costs or low yield. In the present study, we performed codon optimization of the capsid gene to increase the number of preference codons and eliminate rare codons in Spodoptera frugiperda 9 (Sf9) cells. The capsid gene was then subcloned into the pFastBac plasmid, and the recombinant baculoviruses were identified with a plaque assay. As expected, expression of the optimized capsid protein was markedly increased in the Sf9 cells, and the recombinant capsid proteins self-assembled into virus-like particles (VLPs) that were released into the cell supernatant. Rabbits inoculated with the supernatant and the purified VLPs were protected against RHDV challenge. A rapid, specific antibody response against RHDV was detected by an ELISA in all of the experimental groups. In conclusion, this strategy of producing a recombinant subunit vaccine antigen can be used to develop a low-cost, insect cell-derived recombinant subunit vaccine against RHDV.     

应用免疫组化PAP法检测兔出血症病毒抗原的动态分布

应用免疫组化PAP法检测了人工感染成年患兔、30～40日龄患兔以及自然感染患兔体内兔出血症病毒（RHDV）抗原的动态分布。结果表明,在成年患兔的肝、肾、脾、胃、十二指肠、睾丸以及幼兔的肝、肾、脾中检出了RHDV抗原;无论在成年或幼龄患兔,RHDV抗原主要位于受侵害细胞胞浆中,少部分位于核中;在成年患兔,RHDV抗原阳性细胞的数量随病程发展而增加,而在幼龄患兔,这种增加趋势不明显。本文还分析了RHDV抗原在患兔体内的动态分布与病变形成之间的关系。     

云南省楚雄州部分地区猪瘟血清学调查

为了解楚雄州部分地区的猪瘟免疫情况,利用酶联免疫法(ELISA)对楚雄市、南华县和禄丰县随机采取的393份血清进行猪瘟抗体检测,并对各县(市)的调查数据加以比较,了解猪瘟在楚雄州部分地区的免疫情况。结果显示,楚雄州部分地区均有较高的猪瘟抗体阳性率,各县(市)的猪瘟抗体阳性率都在80%以上,有的县(市)猪瘟抗体甚至达到了100%。说明楚雄州部分地区的猪瘟免疫效果较好,猪瘟免疫成功。     

Regulatory T cells are decreased in acute RHDV lethal infection of adult rabbits

Rabbit hemorrhagic disease virus (RHDV) is the etiologic agent of rabbit hemorrhagic disease (RHD), an acute lethal infection that kills 90% of adult rabbits due to severe acute liver inflammation. Interestingly, young rabbits are naturally resistant to RHDV infection. Here, we have compared naturally occurring CD4(+)Foxp3(+) regulatory T cells (Tregs) between young and adult rabbits after infection by RHDV. The number and frequency of Tregs was decreased in the spleen of adult rabbits 24h after the RHDV infection; this was in contrast with the unchanged number and frequency of splenic Tregs found in young rabbits after the same infection. Also, serum levels of IL-10 and TGF-β were enhanced in the infected adult rabbits whereas no alteration was observed in infected young rabbits. However, this increase is accompanied by a burst of pro-inflammatory cytokines, but seems not able to prevent the death of the animals with severe acute liver inflammation in few days after infection. Since Tregs downregulate inflammation, we conclude that their decrease may contribute to the natural susceptibility of adult rabbits to RHDV infection.     

Serological evidence for a non-protective RHDV-like virus

The data were recorded during a Rabbit haemorrhagic disease outbreak that occurred in France in 2001 in a wild population of rabbits that we have been monitoring since 2000. These data suggested the existence of non-protective antibodies due to a putative RHDV-like virus. Twenty-one blood and 22 liver samples were taken from the 26 corpses of recently dead rabbits that were found. RHDV was found in all liver samples. A first screening for RHD antibodies, carried out using an ELISA based on the detection of VP60-RHDV antigen, showed that 20 of the rabbits were seropositive. Moreover, we determined antibody titres for 13 of these 20 seropositive samples. All were > or = 1/400. Such titres normally indicate antibody levels sufficient to confer protection to all known RHDV or RHDV-like strains. For 16 samples, we determined whether these rabbits had died of a chronic or an acute form of the disease, by employing monoclonal antibody (Mabs)--based differential ELISA. All had died of an acute form of RHD. Because the antibodies detected by this VP60-ELISA test are known to appear 5-6 days after infection and since acute RHD generally kills the rabbits 2-3 days after infection, we assumed that the detected antibodies must have been present before the exposure to the virus that killed these rabbits. A second detection of antibodies was made with Mabs that are specific for RHDV. The results were negative, showing that the antibodies detected with the VP60 ELISA test were not specific for RHDV. We sequenced a portion of the VP60 gene of viruses isolated in 17 rabbits. All RHDV isolates were very similar to the RHDV strains commonly isolated in France during this period, suggesting that this viral strain was not a putative variant that is not neutralised by antibodies. Therefore we conclude that the detected antibodies were probably due to a RHDV-like virus that induces the production of detectable but non-protective antibodies.     

兔病毒性出血症病毒巢式RT-PCR检测方法的建立及应用

为建立一种快速的兔病毒性出血症病毒(rabbit hemorrhagic disease virus,RHDV)病原检测方法,本研究根据GenBank上登录的RHDV VP60基因序列,设计合成内外2对引物,优化PCR反应条件,建立了检测RHDV的巢式RT-PCR方法。该方法对兔轮状病毒、仙台病毒、健康兔肝脏组织的扩增结果均为阴性;该方法第1次扩增的敏感性是10 ng,第2次扩增的敏感性是0.1 ng,第2次比第1次扩增的敏感性高100倍。建立的巢式RT-PCR方法具有特异性强、敏感性高、重复性好等优点,可以准确快速检测出极低含量的RHDV,将为兔病毒性出血症的病原检测及分子流行病学调查等提供一种快速、简单、高效、特异、灵敏的检测方法。     

应用单克隆抗体夹心酶联免疫吸附试验检测兔出血症病毒

应用建立的单克隆抗体夹心酶联兔疫吸附试验（ＭｃＡｂ－ＥＬＩＳＡ）,检测了人工感染兔出血症病毒（ＲＨＤＶ）ＤＪＲＫ细胞毒、肝毒的兔以及自然感染ＲＨＤＶ的兔的组织样品。结果表明,感染死亡兔的肝、脾、肾、骨髓样品病毒抗原的检出率为１００％,淋巴结和肌肉的检出率分别为９７．５％和７９．５％。ＭｃＡｂ－ＥＬＩＳＡ能检出肌肉中血凝试验不能检出的ＲＨＤＶ抗原。此外,还用ＭｃＡｂ－ＥＬＩＳＡ检测了肝毒人工感染兔血中ＲＨＤＶ的动态,并对１０份兔出血症脏器灭活苗的效价作了滴定。     

An outbreak of rabbit hemorrhagic disease (RHD) caused by Lagovirus europaeus GI.2/rabbit hemorrhagic disease virus 2 (RHDV2) in Ehime, Japan

A total of ten 1–2-year-old rabbits died within 2 weeks at a facility in Ehime prefecture in May 2019. Necropsy revealed liver discoloration and fragility, hemorrhage of some organs and blood coagulation failure. On histopathologic examination, necrotizing hepatitis was a common finding, together with fibrin thrombi in the small vessels and hemorrhage in some organs. Rabbit hemorrhagic disease (RHD) virus gene was detected in liver samples, and viral particles of approximately 32 nm in diameter were found in the cytoplasm of degenerated hepatocytes by electron microscopy. Phylogenetic analysis based on the partial VP60 gene sequence classified it as Lagovirus europaeus GI.2/RHDV2. This is the first confirmed outbreak of RHD caused by globally emerging GI.2/RHDV2 in Japan.     

A simple and rapid method for isolation of caliciviruses from liver of infected rabbits

Rabbit Haemorrhagic Disease Virus (RHDV), a member of the Caliciviridae family, is the etiologic agent of Rabbit Haemorrhagic Disease (RHD); this viral disease is highly contagious and kills more than 90% of infected adult rabbits. Research on experimental calicivirus infection uses inocula obtained from livers of rabbits dying from calicivirus infection. This implies that caliciviruses have to be purified from liver homogenates. Current methods to isolate caliciviruses from rabbit livers are time consuming. We propose here a new procedure for fast purification of rabbit caliciviruses from liver homogenates that uses centrifugation through an iodixanol gradient. This method offers in approximately 2 h a sample with a high degree of calicivirus purity, as shown by its biochemical and immunocytochemistry analysis, which is also able to kill adult rabbits from RHD within 48 h of inoculation.