An overview of: Porcine circovirus type 2 猪 2 型圆环病毒概况 Darin Madson, DVM, PhD, DACVP 达林麦迪逊博士 Iowa State University 1

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1 An overview of: Porcine circovirus type 2 猪 2 型圆环病毒概况 Darin Madson, DVM, PhD, DACVP 达林麦迪逊博士 Iowa State University madson@iastate.edu 1

2 Presentation Outline 演讲大纲 Background 背景 Viral characteristics 病毒特征 Transmission 传播 Clinical signs and Diagnosis 临床症状与诊断 Prevention 预防 2

Background 背景 Porcine circoviruses are small, nonencapsulated, closed-circular, single-stranded DNA viruses 猪环状病毒是小型, 非包被, 封闭循环的单链 DNA 病毒 o Porcine circovirus type 1 (PCV1) 猪圆环病毒 1 型 Discovered as a

3 Background 背景 Porcine circoviruses are small, nonencapsulated, closed-circular, single-stranded DNA viruses 猪环状病毒是小型, 非包被, 封闭循环的单链 DNA 病毒 o Porcine circovirus type 1 (PCV1) 猪圆环病毒 1 型 Discovered as a contaminate - PK-15 cells (1974) 为污染物发现 - PK-15 细胞 (1974) Non-pathogenic in swine 不对猪致病 o Porcine circovirus type 2 (PCV2) 猪圆环病毒 2 型 Discovered in the 1990 s 1990 年代被发现 Associated with disease in swine 与猪病相关被作 PCV2 virions 3

4 Background 背景 Globally distributed and ubiquitous virus 分布并普及在全球各地 o Few negative herds 很少有阴性猪群 Economically important disease 经济上很重要的疾病 o Top 3 infectious agent in the swine industry 养猪业中排前 3 的传染病 $3-$20/pig (estimates) (Gillespie et al. 2009) 3-20 美元 / 猪 ( 估计 ) Infection generally occurs after waning of maternal antibodies 感染一般发生于母体抗体减弱后 o 7-15 weeks of age 7-15 周 Transmission 传染 o Horizontal pig to pig 水平传染猪与猪 o Vertical dam to offspring 垂直传染母畜与后代 4

Disease 疾病 1991 o clinically described (wasting) 临床上描述 1993 o PDNS lesions described 皮炎肾病综合征病变描述 1997 o PCV2 is isolated 分离猪 2 型圆环病毒 1999 o PCV2 associated reproductive

5 Disease 疾病 1991 o clinically described (wasting) 临床上描述 1993 o PDNS lesions described 皮炎肾病综合征病变描述 1997 o PCV2 is isolated 分离猪 2 型圆环病毒 1999 o PCV2 associated reproductive failure 与猪 2 型圆环病毒相关的繁殖问题 Historical antibodies 历史抗体 1967 (Germany) 德国 1969 (Belgium) 比利时 1970 (England) 英国 1973 (Ireland) 爱尔兰 1985 (North America) 北美 1989 (Japan) 日本 5

6 Multiple genotypes 多基因型 o PCV2b predominates worldwide (Rose et al. 2012) PCV2b 占世界主导 Global shift from PCV2a to PCV2b 全球正从 PCV2a 转变为 PCV2b Multiple clusters 多集群 o Location dependent 根据地区 Recombination 重组 o PCV2a/PCV2b virus PCV2a/PCV2b 病毒 o Location dependent clusters 依地区集群 Dual infection is possible 双重感染是可能的 PCV2 genotypes PCV2 基因型 1. PCV2a 2. PCV2b 3. PCV2c 6

7 Transmission 传播 Nasal-oral and fecal-oral 鼻 - 口腔和粪便 - 口腔 o Major route of transmission 主要传播途径 Virus secreted/excreted in: 病毒分泌 / 排泄进 : o Urine, ocular discharge, nasal discharge, salvia, feces 尿液, 眼分泌物, 鼻分泌物, 唾液, 粪便 Unknown transmission 未知传播 o Fomites (needles), insects, and rodents 污染源 ( 针头 ) 昆虫和啮齿动物 PCV2 can replicate in mice and transmit to other mice PCV2 能在老鼠中复制并传播 Aerosol 气雾 o Found in air/dust outside of barns 在猪舍外的空气 / 灰尘中发现 o Infectivity is unknown 传染性不明 7

8 Horizontal Transmission 水平传染 Viral shedding 病毒脱落 Shedding can be intermittent or continuous 脱落可以是间歇性或持续性的 Frequently associated with viremia 经常与病毒血症相关 Detected early post infection 1-5 days 感染后早发现 1-5 天 Peak shedding 2-4 wks. post infection 脱落高峰感染 2-4 周后 Shedding length variable 脱落时间变量 o Reported to 209 days in nasal secretions and feces of infected pigs 在感染猪的鼻腔分泌物和粪便中脱落可长达 209 天 o Persists longer in some pigs 在某些猪中持续更久 8

9 209 days - recorded shedding 209 天记录的脱落 Slide courtesy of Dr. Abby Patterson 9

10 Vertical Transmission 垂直传染 Sow viremia 母猪病毒血症 o PCV2 crosses the placenta during dam viremia 在母体的血症中 PCV2 穿过胎盘 Most common route of fetal infection 胎儿感染的最常见的途径 Sow colostrum/milk 母猪初乳 / 奶 o PCV2 shed in for at least 27 days post-partum PCV2 在产后至少 27 天散播 o Colostrum contains more PCV2 than milk 初乳中含有比奶更多的 PCV2 o Infectious 传染病 Semen 精液 o Known to be infectious 被认为具传染性 o Shed for extended period 90 days 散播时间延长 90 天 o Evidence supports minor risk 有证据显示风险较小 10

断奶后多系统衰竭综合征 Pneumonia 肺炎 Diarrhea 腹泻 Porcine dermatitis and

11 PCVAD 圆环病毒相关疾病 Disease manifestations 疾病表现 Systemic disease 系统性疾病 o Post-weaning multisystemic wasting syndrome (PMWS) 断奶后多系统衰竭综合征 Pneumonia 肺炎 Diarrhea 腹泻 Porcine dermatitis and nephropathy syndrome 猪皮炎和肾病综合征 Reproductive failure 繁殖失败 11

12 Clinical disease 临床疾病 Subclinical infection 亚临床感染 Wasting 消瘦 Dyspnea 呼吸困难 Lymphadenopathy 淋巴结肿大 Pallor 苍白 Diarrhea 腹泻 Jaundice 黄疸 Fundamental clinical signs 主要临床表现 Stage of infection 阶段感染 Amount of viremia 病毒血症量 o 10 7 DNA copies/ml serum 每毫升血清中 10 7 DNA 拷贝 Growth performance 生长状况 Disease susceptibility 疾病易感性 PCV2 enhances disease of other infectious pathogens PCV2 增强其他传染病的病原体 12

13 Pictures courtesy of T. Opriessnig, M Turner, D Madson 13

14 Thickened small intestine 加厚的小肠 Pictures courtesy of T. Opriessnig, M. Yaeger 14

15 Type 3; hypersensitivity reaction Pictures courtesy of T. Opriessnig, M Turner, M Yaeger 15

16 PCVAD Diagnosis PCVAD 圆环病毒相关疾病诊断 Requirements 要求 1. Clinical signs of disease 疾病的临床症状 2. Lymphoid depletion +/- histiocytic replacement 淋巴耗竭 +/ - 组织细胞替代 3. PCV2 antigen or nucleic acid associated with lesions 与病变相关的 PCV2 抗原或核酸 16

17 PCV2 Reproductive Failure PCV2 繁殖失败 Dam 母畜 PCV2 naïve dams o Mainly gilts 主要是母猪 non-viable piglets 不可存活仔猪 o Mummified fetuses 木乃伊胎儿 o Stillborns 死产 o Weak-born piglets 弱仔猪 Abortion 流产 o Minority of cases 少数情况 Dam few clinical signs 母畜 - 很少有临床症状 Fetuses 胎儿 Infection 感染 o Following dam viremia 跟随母体血症 PCV2 tropism for fetal myocardiocytes 胎儿心肌细胞的向性 o Myocardial necrosis 心肌坏死 Gross lesions = rare 明显病变 = 罕见 o Heart failure 心脏衰竭 Enlarged heart 心脏扩大 Congested liver 肝挤塞 Pulmonary edema 肺水肿 Ascites 腹水 17

18 PCV2 Reproductive Failure PCV2 繁殖失败 18

Estimates 估计 o 10-20% of reproductive failure cases last decade are suspected to be associated with PCV2 infection 过去十年中, 生殖失败病例的 10-20% 被怀疑与 PCV2 感染相关 o Prior to vaccination

19 Estimates 估计 o 10-20% of reproductive failure cases last decade are suspected to be associated with PCV2 infection 过去十年中, 生殖失败病例的 10-20% 被怀疑与 PCV2 感染相关 o Prior to vaccination development and use 在疫苗的开发和利用之前 ISU diagnostics ISU 诊断 o 501 swine reproductive failure cases ( ) 501 例猪生殖失败例子 ( ) 12% were associated with PCV2 12% 与 PCV2 相关 o 58/501 19

PCV2 in utero infection PCV2 病毒在宫内感染 PCV2 associated reproductive failure PCV2 的相关繁殖失败 Clinical signs 临床症状 Weak born piglets 弱生仔猪 None: May appear normal 无 : 看上去正常 All parities 所有胎次 More common 更常见

20 PCV2 in utero infection PCV2 病毒在宫内感染 PCV2 associated reproductive failure PCV2 的相关繁殖失败 Clinical signs 临床症状 Weak born piglets 弱生仔猪 None: May appear normal 无 : 看上去正常 All parities 所有胎次 More common 更常见 Clinical signs 临床症状 Mummies 木乃伊 Stillborns 死产 Primarily gilts 主要是母猪 Diagnosis 诊断 Pre-suckle serum 哺乳前血清 PCR for viremia PCR 测血症 ELISA for antibodies ELISA 测抗体 Diagnosis 诊断 PCV2 IHC PCV2 免疫组化 Myocarditis 心肌炎 Lymphoid depletion 淋巴耗竭 20

21 Vaccine 疫苗 21

22 Commercial vaccine production 商业疫苗生产 Beach and Meng

and morbidity 降低发病率和死亡率 Increases growth parameters 增加生长参数 o Average daily gain 平均日增重 o Feed

23 Significantly reduces 显著减少 o PCV2 viremiapcv2 病毒血症 o Shedding after challenge 接种后病毒脱落 Stimulates neutralizing antibodies 刺激中和抗体 Reduces associated microscopic lesions 减少相关的微观病变 Reduces mortality and morbidity 降低发病率和死亡率 Increases growth parameters 增加生长参数 o Average daily gain 平均日增重 o Feed efficiency 饲料效率 General information 一般信息 PCV2a and PCV2b Clinical and subclinical infections 临床和亚临床的感染 23

24 Conclusions a meta-analysis 分析后的结论 1. Vaccination significantly increased ADG 疫苗显著提高日平均重量 Kristensen et al 2011 o Nursery and grow-finish phases 保育和生长到成猪阶段 2. Vaccination significantly decreased mortality 疫苗显著减少了死亡率 o Nursery and grow-finish phases 保育和生长到成猪阶段 3. No difference between commercial vaccines 商业疫苗间无区别 4. PCV2 vaccination is economically beneficial PCV2 疫苗能带来经济效益 24

Dam Vaccination 母畜疫苗 Primary effects 主要影响 dam antibody level 母畜抗体水平 signs of fetal infection 胎儿感染的迹象 Reduced dam viremia 母畜血症减少 Frequently not detectable 经常不可检测 Decreased PCV2 in utero infection 宫内感染

25 Dam Vaccination 母畜疫苗 Primary effects 主要影响 dam antibody level 母畜抗体水平 signs of fetal infection 胎儿感染的迹象 Reduced dam viremia 母畜血症减少 Frequently not detectable 经常不可检测 Decreased PCV2 in utero infection 宫内感染 PCV2 下降 PCV2 colostral shedding PCV2 的初乳分泌 Secondary effects 次要影响 service interval 服务间隔 sow mortality 母猪死亡率 pre-wean mortality 断奶前死亡率 weaned pigs/sow 断奶仔猪 / 母猪 weaning weights 断奶时重量 farrowing rate 产仔率 birth weights 出生体重 25

General information 总体信息 Protects against clinical disease development 防止临床疾病的发展 o Not infection 无感染 Dam antibody levels vary 母畜抗体水平有所不同 o Within and between herds 群内和群之间 Piglet uptake can vary from

26 General information 总体信息 Protects against clinical disease development 防止临床疾病的发展 o Not infection 无感染 Dam antibody levels vary 母畜抗体水平有所不同 o Within and between herds 群内和群之间 Piglet uptake can vary from the same dam 仔猪可从同一母畜摄取不同量 PCV2 antibody half-life is around 3 weeks PCV2 抗体的半衰期约 3 个星期 Antibodies can last up to 18 weeks 抗体可以持续到 18 周 Interference 干扰 Scientific data = +/- 科学数据 =+/ - No interference 无干扰 o In 4 wks old pigs and then challenged at 8 wks of age 在 4 周大的猪中, 之后 8 周接种 US 美国 Interference 有干扰 o Piglets with high maternal antibody have interference 高母源抗体的仔猪有干扰 Europe 欧洲 26

27 Thanks for listening! 谢谢听讲! 27

Mycoplasma hyopneumoniae and its role in the Porcine Respiratory Disease Complex 猪肺炎支原体及其在猪呼吸系统综合疾病中的作用 Dr. Maria Pieters 玛丽亚皮特斯博士

Mycoplasma hyopneumoniae and its role in the Porcine Respiratory Disease Complex 猪肺炎支原体及其在猪呼吸系统综合疾病中的作用 Dr. Maria Pieters 玛丽亚皮特斯博士 Outline 纲要 Porcine Respiratory Disease Complex (PRDC) 猪呼吸道疾病综合征 (PRDC)

An overview of: Porcine circovirus type 2 猪 2 型圆环病毒概况 Darin Madson, DVM, PhD, DACVP 达林 麦迪逊博士 Iowa State University 1

An overview of: Porcine circovirus type 2 猪 2 型圆环病毒概况 Darin Madson, DVM, PhD, DACVP 达林麦迪逊博士 Iowa State University 1