2010年猪群疫病流行动态分析报告及2011年猪群疫病流行动态预测

<正>12010年猪群疫病调查、检测结果1.12010年部分规模猪场发病猪群组织样品病原学检测结果(见表1)表1显示,各地区猪场发病猪群主要感染猪瘟病毒、猪蓝耳病病毒、圆环病毒2型。1.2规模猪场猪群疫病流行病学调查结果(见表2)由表2的调查结果中可以看出:在规模猪场中,以蓝耳病和圆环病毒2型为主。     

云南省部分地区种公猪精液携带繁殖障碍性病毒调查研究

为了解云南省部分地区规模化猪场种公猪精液繁殖障碍病毒性病原的感染状况,应用PCR对2014年—2016年间云南省部分地区规模化猪场212份种公猪精液进行了猪繁殖与呼吸综合征病毒(PRRSV)、猪瘟病毒(CSFV)、猪伪狂犬病病毒(PRV)、猪圆环病毒2型(PCV2)和猪细小病毒(PPV)5种与猪繁殖障碍有关的病原检测。结果表明,PPRSV阳性率为7.08%,CSFV阳性率为3.77%,PCV2阳性率为6.60%,PRV阳性率为3.30%,没有检测出PPV,PRRSV和PCV2的感染率呈上升趋势,其他疫病保持相对平稳态势。所有的混合感染样品中,均检测出了PRRSV,其中PRRSV和PCV2的混合感染最为常见。结果提示,控制猪场疫病发生的关键是控制PRRSV和PCV2的流行,有必要加强对种猪群的疫病病毒检测,推行种猪场主要疫病的控制与净化工作。     

湖南省长沙市某屠宰场猪群主要疫病检测

为了解湖南省临床健康猪群主要疫病流行情况,2017年从长沙市某屠宰场采集猪组织样品390份,应用实时荧光定量PCR方法,检测猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病病毒(PRV)、猪圆环病毒2型(PCV2)、高致病性猪繁殖与呼吸综合征病毒(HPPRRSV)和口蹄疫病毒(FMDV)。结果显示,这6种病毒的感染率分别为5.13%、23.85%、8.46%、77.95%、24.10%和0.51%。对猪群的混合感染情况进行分析发现:PCV2与其他病原的混合感染率最高;二重感染最高的是"PRV+PCV2",达到7.43%,其次是"PRRSV+PCV2",为2.31%;三重感染率最高的是"HPPRRSV+PRRSV+PCV2",达到11.54%,其次是"CSFV+HPPRRSV+PRRSV",为0.77%;四重感染最高的是"CSFV+HPPRRSV+PRRSV+PCV2",达到3.85%,其次是"HPPRRSV+PRRSV+PRV+PCV2",为0.77%。结果表明:临床健康猪群中的PCV2感染率最高,且常与PRRSV和PRV发生混合感染;加强养殖环节PCV2、PRRSV、HPPRRSV和PRV的监控,对于控制常见猪群疫病具有重要意义。     

一起猪瘟和沙门氏菌混合感染的诊治与防控

为了诊断延边朝鲜族自治州和龙市某养殖场猪群所发疾病,试验通过流行病学调查、临床症状观察、病理剖检、病死猪肝脾直接涂片观察、细菌学检测、利用酶联免疫吸附试验(ELISA)分别对猪瘟病毒(CSFV)、猪圆环病毒(PCV)、猪伪狂犬病毒(PRV)、猪蓝耳病毒(PRRSV)及猪流行性腹泻病毒(PEDV)进行检测,并根据诊断结果进行治疗与防控。结果表明:沙门氏菌和猪瘟病毒(CSFV)检测阳性,诊断该养殖场猪群所患疾病为猪瘟病毒和沙门氏菌的混合感染。用药治疗后,治愈55头(治愈率70.51%),死亡23头(病死率29.49%),疫病得到控制。     

猪蓝耳病毒、猪圆环病毒2型与副猪嗜血杆菌混合感染的实验室诊断及血清抗体检测

为了确定山东省莱西市某猪场送检病猪的发病原因,并调查猪群主要疫病抗体水平以便为猪场疫病防控提供科学参考依据,试验采集送检病猪病料,综合运用临床观察、病理剖检、细菌分离鉴定和病毒核酸检测等技术进行确诊;并对分离菌进行药敏试验;使用ELISA检测试剂盒对猪群的猪圆环病毒2型(PCV-2)、猪蓝耳病毒(PRRSV)、猪瘟病毒(CSFV)和猪伪狂犬病病毒(PRV)4种主要病原进行检测,分析抗体水平。结果表明:送检病料经TSA培养基分离培养可见针尖状菌落,革兰氏染色镜检为阴性杆菌,生化试验鉴定为副猪嗜血杆菌;该分离细菌对大观霉素高度敏感,对头孢噻肟极度敏感;猪群中PRRSV和PCV-2为阳性,未检测出其他病毒;同场猪群的猪瘟抗体水平偏低需加强免疫,猪蓝耳病抗体水平不稳定,存在野毒感染风险。说明送检病例为PRRSV、PCV-2和副猪嗜血杆菌的混合感染,同场猪群需注意加强猪瘟免疫和猪蓝耳病抗体监测。     

当前我国猪传染病流行新特点与防控技术（上）

一、当前我国猪传染病流行新特点 (一)多病原混合感染并继发感染,使病原体多元化,症状复杂化 多病原混合感染并继发感染已成为当前猪群发生疫病流行的主要形式与特点,单一病原引发的疫病很少见,二种或二种以上病原,甚至多种病原共同引发已为常见.其病原有病毒、细菌,还有寄生虫等.     

2001-2008年湖南省猪群疫病流行情况分析

对近8年来接诊的1424个场次不完全诊断的临床猪病例进行统计,分析近年来猪群疫病的发生流行情况。结果显示,猪瘟、猪繁殖与呼吸综合征、猪圆环病毒2型感染、猪伪狂犬病是湖南省猪群的主要传染病;猪群疫病高发期可能是每年的6—9月;病例多集中在饲养量大和交通比较方便的区域;多重感染病例多,其中,猪圆环病毒2型的多重感染率最高。     

2019—2022年河池市屠宰猪群主要疫病监测分析

研究旨在了解河池市屠宰猪群主要疫病感染情况,于2019—2022年采集屠宰猪群组织混合样品,应用实时荧光定量RT-PCR检测猪繁殖与呼吸综合征病毒（PRRSV）、猪瘟病毒（CSFV）、口蹄疫病毒（FMDV）、猪塞内卡病毒（SVA）,应用荧光PCR检测圆环病毒2型（PCV2）、圆环病毒3型（PCV3）、伪狂犬病毒（PRV）。结果显示,检测的1 745份样品中,除FMDV和PRV没有检出外,其余5种病原均有检出,样品总体阳性率由高到低依次为42.87%(PCV2)、11.63%(PCV3)、8.48%(PRRSV)、0.80%(CSFV)、0.80%(SVA);县区检出率依次为100.00%(PCV2)、100.00%(PRRSV)、90.91%(PCV3)、54.55%(CSFV)、27.27%(SVA);5种病原存在不同程度的混合感染。研究表明,圆环病毒病、猪繁殖与呼吸综合征和猪瘟在河池市及其周边地区猪群中流行普遍,需进一步加强监测和做好防控措施。     

内蒙古地区猪群中HP-PRRS的流行病学调查

为掌握内蒙古地区猪群中高致病性猪蓝耳病(HP-PRRS)的流行规律,应用流行病学调查、病理剖检、血清学试验、分子生物学等方法对发病猪群进行了HP-PRRSV的研究.结果表明,临床上发病猪多为合并感染,病死率高.PCR检测16份送检样品中, HP-PRRS阳性率62.5%,猪蓝耳病(PRRS)阳性率18.8%,猪瘟(CSF)阳性率25%,伪狂犬病(PR)阳性率12.5%,猪细小病毒(PP)感染阳性率0%,猪圆环病毒2型(PCV-2)感染阳性率37.5%,而且以上这些猪病病毒抗体在猪群中普遍高于未发生HP-PRRS疫情之前.由此可见,目前猪病疫情是以HP-PRRSV为优势毒株,结合其他病原体混合感染而引发的.     

用裁截的E2重组蛋白作为抗原建立ELISA检测猪瘟病毒抗体

猪瘟 ( CSF)是猪的一种传染性致死性疫病 ,该病在家猪群和野猪群中流行传播 ,造成地方流行性感染。猪瘟病毒 ( CSFV)是黄病毒科瘟病毒属成员之一 ,本属中还有另 2种具有经济重要性的病毒 :边界病病毒 ( BDV)和牛病毒性腹泻病毒( BVDV)。瘟病毒属成员在结构上和抗原性上密切相关。 CSFV的基因组为长约 1 2 .3kb的正极性RNA,其编码为单一多蛋白 ,形成成熟的病毒蛋白。CSFV感染后 ,在猪体内产生抗结构蛋白 E2 、Erns及非结构蛋白 NS3抗体。囊膜糖蛋白 E2 是CSFV最具免疫原性的蛋白。为在无疫区进行CSF监测 ,或开展 CSF扑灭计划…     

Seroepidemiology of trichinellosis in Florida swine

Surveys for swine trichinellosis, conducted in Florida using a commercial enzyme-linked immunosorbent assay (ELISA) kit with a modified protocol for screening and Western blot as a definitive test, revealed significantly different seroprevalences of 0.3% (four of 1294 samples) and 2.8% (five of 179 samples) in domestic breeding swine and feral swine, respectively.

Seropositive swine were identified in four of 114 (3.5%) domestic swine herds and in three of six feral swine regions. The location of two domestic herds with seropositive swine within approximately 2 miles of one another, and adjacent to a region where a seropositive feral hog was identified, suggests that a focus of trichinellosis exists in this area. The occurrence of singleton reactors in domestic herds may be explained by the absence of the common modes of transmission and suggests that swine were infected incidentally by feeding on the infected carcasses of small wild mammals or rodents. Although the presence of Trichinella spiralis spiralis isolates cannot be excluded, it is more likely that a sylvatic Trichinella isolate occurs in Florida swine. This conclusion is supported by the low seroprevalence in domestic swine, the failure to detect larvae in domestic or feral swine and the high prevalence in Florida panthers.     

一种新的人兽共患病——猪戊型肝炎研究进展

猪戊型肝炎病毒(Hepatitis E virus,HEV)是导致猪戊型肝炎(HE)的病原体,现在很多国家和地区,如美国、日本、欧洲、中国、中国台湾、印度等都检测出了猪戊型肝炎病毒的抗体,少数国家和地区还有人感染猪戊型肝炎病毒的报道,越来越多的证据表明猪HE是一种人兽共患的传染病。     

非洲猪瘟的研究进展

非洲猪瘟是猪的一种急性、高度接触传染性疾病。其感染率高, 多种传播途径,死亡率可达100％,现还无有效的疫苗及治疗措施。非洲猪瘟在临床上与猪瘟相似，虽这2种疾病的病原体完全不同，但在诊断时极易误诊，为了进一步了解该病,作者综述了该病的病原、流行病学、临床症状、鉴别诊断及我国现状，从而为诊断该病提供了依据。     

猪戊型肝炎研究进展

我国为猪戊肝发病率比较高的地区之一,曾发生戊型肝炎的多次爆发或大面积的流行,并可传播给人类,与人的生活密切相关,回顾猪戊肝炎病毒结构特征研究,流行方式、临床症状及病理变化等,为猪戊型肝炎未来的诊断提供参照。文章收集国内外文献资料查询酶联免疫吸附试验(ELISA)、免疫电子显微镜(IEM)、免疫荧光实验(IFA)、荧光定量RT-PCR法对防治猪戊型肝炎进行研究,对其作了分析、比较和汇总。为猪戊型肝炎病毒提供了有效诊断方式以及防御措施。对猪戊型肝炎仍需养殖者认真护理,一旦确诊为动物戊型肝炎,应立即对其进行隔离治疗。     

Hepatitis E virus in Cuba: A cross-sectional serological and virological study in pigs and people occupationally exposed to pigs

Surveillance of hepatitis E virus (HEV) in risk groups is an important strategy to monitor its circulation pattern and to timely detect changes thereof. The aims of this cross-sectional study were to estimate the prevalence of HEV infections in pigs and humans from different regions of the country, to identify risk factors for increasing anti-HEV IgG prevalence and to characterize HEV strains. The presence of anti-HEV antibodies was assessed by commercial ELISA in serum samples from the general population, farm and slaughterhouse employees, as well as pigs sampled in the three regions of Cuba from February to September 2016. Overall, individuals with occupational exposure to swine or swine products (70/248, 28.2%) were 4 times more likely to be seropositive compared to the general population (25/285, 8.7%; OR: 4.18; p < .001). Within the risk group, risk factors included age, number of years working in a professional activity with direct exposure to swine, geographic region and distance between residence and closest professional swine setting, while wearing gloves had a protective effect. Prevalence of total anti-HEV antibodies in swine was 88.2% (165/187) and HEV RNA was detected by real-time RT-PCR in 9.2% (16/173) swine stools. All HEV strains sequenced clustered within genotype 3. Some strains clearly belonged to subtype 3a, while another group of strains was related with subtypes 3b and 3 k but partial HEV sequences did not allow unequivocal subtype assignment. These findings suggest that the high HEV exposure in Cuban individuals with swine-related occupations could be due to enzootic HEV in certain regions, direct contact with infectious animals or their products as well as environmental contamination.     

Use of heteroduplex mobility assays (HMA) for pre-sequencing screening and identification of variant strains of swine and avian hepatitis E viruses

Hepatitis E virus (HEV), the causative agent of human hepatitis E, is an important public health problem in many developing countries and is also endemic in many industrialized countries including the US. The discoveries of avian and swine HEVs by our group from chickens and pigs, respectively, suggest that hepatitis E may be a zoonosis. Current methods for molecular epidemiological studies of HEV require PCR amplification of field strains of HEV followed by DNA sequencing and sequence analyses, which are laborious and expensive. As novel or variant strains of HEV continue to evolve rapidly both in humans and other animals, it is important to develop a rapid pre-sequencing screening method to select field isolates for further molecular characterization. In this study, we developed two heteroduplex mobility assays (HMA) (one for swine HEV based on the ORF2 region, and the other for avian HEV based on the ORF1 region) to genetically differentiate field strains of avian and swine HEVs from known reference strains. The ORF2 regions of 22 swine HEV isolates and the ORF1 regions of 13 avian HEV isolates were amplified by PCR, sequenced and analyzed by HMA against reference prototype swine HEV strain and reference prototype avian HEV strain, respectively. We showed that, in general, the HMA profiles correlate well with nucleotide sequence identities and with phylogenetic clustering between field strains and the reference swine HEV or avian HEV strains. Field isolates with similar HMA patterns generally showed similar sequence identities with the reference strains and clustered together in the phylogenetic trees. Therefore, by using different HEV isolates as references, the HMA developed in this study can be used as a pre-sequencing screening tool to identify variant HEV isolates for further molecular epidemiological studies.     

饲料安全和品质在非洲猪瘟防控中的作用及对策

自2018年8月非洲猪瘟在我国发生以来,生猪产业遭受了前所未有的打击,目前非洲猪瘟仍然没有有效疫苗,生猪复产任务任重道远。在非洲猪瘟防控常态化新形势下,饲料的安全和品质是非洲猪瘟防控中的重要一环。文章综述了饲料安全和品质在非洲猪瘟防控中的作用以及应对策略,为当前非洲猪瘟疫情下饲料安全和生猪健康养殖提供参考。     

Molecular Characterization of a H9N2 Subtype Swine Influenza Virus

The objective of this study was to explore the epidemic situation and pathogenic characteristics of swine influenza virus (SIV) in Shandong Province. In the spring of 2019, 130 swine nasal swab samples were collected from a slaughterhouse in Tai'an city, Shandong Province for virus isolation and identification. The whole genome of isolated virus was sequenced and analyzed. Meanwhile, 1 527 swine serum samples were collected from swine farms in 8 regions of Shandong province and their anti-SIV antibody were detected by HI assay using standard avian H9N2 antigen. The results showed that a H9N2 subtype influenza virus strain was isolated and named as A/swine/Shandong/TA009/2019(H9N2). The homology analysis showed that the isolated virus had close genetic relationship with A/environment-air/Kunshan/NIOSH-BL20/2018(H9N2) and A/environment-air/Kunshan/NIOSH-BL25/2018(H9N2), and the nucleotide homology of the gene fragments were above 99.5%. Phylogenetic analysis results demonstrated that HA and NA genes of the isolated virus belong to the Y280-like lineage, PB2 and M genes belong to the G1-like lineage, and PB1, PA, NP and NS genes belong to the SH/F98-like lineage. The cleavage site in HA protein is “PSRSSR/GL”, which was in accordance with the molecular biological characteristics of low pathogenic avian influenza virus.The position 216 of HA protein is L, and it has the ability to bind human-derived sialic acid α 2,6-Gal. The results of HI showed that 9 among 1 527 serum samples were positive with a positive rate of 0.59%. The isolated virus was swine-derived H9N2 virus, and serological investigations revealed that H9N2 subtype virus infection was present in swine herds in Shandong Province. The results of this study suggest that continuous surveillance of the SIV epidemiological situation and its pathogenic characteristics should be strengthened.     

1株猪源H9N2亚型流感病毒的分子特征

旨在进一步了解山东省猪流感的流行情况及其病原特征,笔者于2019年春季,在山东省泰安某屠宰场采集130份猪鼻拭子,进行病毒分离鉴定;并对分离病毒进行全基因组测序和分子特征分析;用禽H9N2亚型标准抗原联合血凝抑制方法检测2018—2019年从山东省8个地区猪场采集的1 527份猪血清样品中的猪流感病毒抗体。结果显示：分离到1株H9N2亚型流感病毒,命名为A/swine/Shandong/TA009/2019（H9N2）。分离病毒与A/environment-air/Kunshan/NIOSH-BL20/2018（H9N2）和A/environment-air/Kunshan/NIOSH-BL25/2018（H9N2）遗传关系最近,其基因片段的核苷酸相似性均在99.5%以上。分离病毒的HA和NA基因属于Y280-like分支,PB2和M基因属于G1-like分支,PB1、PA、NP和NS基因属于SH/F98-like分支。分离病毒HA蛋白裂解位点处的氨基酸序列为“PSRSSR/GL”,符合低致病性禽流感病毒的分子生物学特性。HA蛋白的216位为L,具有结合人源唾液酸α 2,6-Gal的能力。血清学分析结果显示,9份血清中H9N2抗体呈阳性,其总阳性率为0.59%。综上：本研究分离到1株猪源H9N2亚型流感病毒,并在猪血清中检测到H9N2抗体,提示应加强对猪流感的流行情况及其病原特征的持续监测。     

牛病毒性腹泻病毒在猪瘟疫苗中的污染情况及其检测方法的研究进展

牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)和猪瘟病毒(classical swine fever virus,CSFV)同属黄病毒科瘟病毒属,猪瘟疫苗中污染BVDV可引起免疫失败。但由于两者在病毒粒子结构、基因组结构和抗原特性等方面均很接近,在血清学上存在交叉反应,因此难以检测猪瘟疫苗中污染的BVDV。文章对BVDV在猪瘟疫苗中的污染情况和检测方法进行了论述,旨在为猪瘟疫苗污染BVDV的检测提供理论基础。