《猪流感的免疫控制DBN02》由会员分享，可在线阅读，更多相关《猪流感的免疫控制DBN02（65页珍藏版）》请在金锄头文库上搜索。
1、猪流感的流行情况猪流感的流行情况和免疫控制和免疫控制张渊魁张渊魁 13332868393大北农集团动物保健事业部大北农集团动物保健事业部猪流感病毒感染世界上最常见的猪呼吸道疾病，特征为世界上最常见的猪呼吸道疾病，特征为uu发热（发热（发热（发热（39 39 C C C C -42 -42C C C C）持续持续持续持续 5-10 5-10 天，反应天，反应天，反应天，反应迟钝、迟钝、迟钝、迟钝、卷缩、扎堆、卷缩、扎堆、卷缩、扎堆、卷缩、扎堆、昏睡昏睡昏睡昏睡uu呼吸呼吸呼吸呼吸困难、困难、困难、困难、咳嗽、流咳嗽、流咳嗽、流咳嗽、流鼻液、鼻液、鼻液、鼻液、打喷嚏打喷嚏打喷嚏打喷嚏uu采食下降、
2、增重降低、采食下降、增重降低、采食下降、增重降低、采食下降、增重降低、推迟推迟推迟推迟2 2周上市周上市周上市周上市uu母猪繁殖障碍：流产母猪繁殖障碍：流产母猪繁殖障碍：流产母猪繁殖障碍：流产uuH1N1H1N1亚型病毒感染猪只很少发生死亡亚型病毒感染猪只很少发生死亡亚型病毒感染猪只很少发生死亡亚型病毒感染猪只很少发生死亡慢性慢性慢性慢性疾病疾病疾病疾病由由由由猪肺炎引起的高死亡率猪肺炎引起的高死亡率猪肺炎引起的高死亡率猪肺炎引起的高死亡率uu肺脏有实变区，有支气管肺炎病变肺脏有实变区，有支气管肺炎病变肺脏有实变区，有支气管肺炎病变肺脏有实变区，有支气管肺炎病变SIV造成的损失造成的损失Dr.
3、 Seehusen对育肥猪：与蓝耳病对育肥猪：与蓝耳病对育肥猪：与蓝耳病对育肥猪：与蓝耳病 PRRS PRRS 和链球菌混合感和链球菌混合感和链球菌混合感和链球菌混合感染，死亡率高个别达到染，死亡率高个别达到染，死亡率高个别达到染，死亡率高个别达到20%, 20%, 特别是农场主拒特别是农场主拒特别是农场主拒特别是农场主拒绝使用抗生素控制继发感染时。绝使用抗生素控制继发感染时。绝使用抗生素控制继发感染时。绝使用抗生素控制继发感染时。 9 9001 10000kgkg猪：感染猪：感染猪：感染猪：感染H1N1H1N1或或或或H3N2H3N2，到出栏时，到出栏时，到出栏时，到出栏时每头猪可导致每头猪
4、可导致每头猪可导致每头猪可导致$7.50 $20.00$7.50 $20.00的损失，包括淘的损失，包括淘的损失，包括淘的损失，包括淘汰猪，死亡，治疗，饲料转换等。汰猪，死亡，治疗，饲料转换等。汰猪，死亡，治疗，饲料转换等。汰猪，死亡，治疗，饲料转换等。2550kg2550kg猪：可导致猪：可导致猪：可导致猪：可导致$5.00 $6.00$5.00 $6.00的损失。的损失。的损失。的损失。 当猪流感在育肥猪场流行时，开始进行当猪流感在育肥猪场流行时，开始进行当猪流感在育肥猪场流行时，开始进行当猪流感在育肥猪场流行时，开始进行H3N2H3N2疫苗免疫时已经损失疫苗免疫时已经损失疫苗免疫时已经损
5、失疫苗免疫时已经损失$5.00 $10.00$5.00 $10.00。如果加上如果加上如果加上如果加上治疗费用损失治疗费用损失治疗费用损失治疗费用损失$15.00 $15.00 。SIV造成的损失造成的损失Dr. Mohr治疗费用：猪感染时应提供支持性疗法治疗费用：猪感染时应提供支持性疗法uu在保育舍需要额外增加治疗费在保育舍需要额外增加治疗费在保育舍需要额外增加治疗费在保育舍需要额外增加治疗费 $0.50/ $0.50/头头头头uu生长育肥阶段要生长育肥阶段要生长育肥阶段要生长育肥阶段要$0.25$0.40/$0.25$0.40/头。头。头。头。uuPRDCPRDC问题：问题：问题：问题：其
6、他疾病加重猪流感其他疾病加重猪流感其他疾病加重猪流感其他疾病加重猪流感有时猪流感加重其他疾病有时猪流感加重其他疾病有时猪流感加重其他疾病有时猪流感加重其他疾病SIV造成的损失造成的损失Dr. Mohr母猪流产死亡：母猪流产死亡：uu大多数情况下分娩率下降大多数情况下分娩率下降大多数情况下分娩率下降大多数情况下分娩率下降5%10%5%10%。uu产房母猪死亡率增加到产房母猪死亡率增加到产房母猪死亡率增加到产房母猪死亡率增加到4%5% 4%5% 。uu猪流感损失的最大组成部分猪流感损失的最大组成部分猪流感损失的最大组成部分猪流感损失的最大组成部分感染较大猪群感染较大猪群感染较大猪群感染较大猪群而又
7、不能控制，而又不能控制，而又不能控制，而又不能控制，且病毒仍将继续危害猪群且病毒仍将继续危害猪群且病毒仍将继续危害猪群且病毒仍将继续危害猪群猪流感病毒是PRDC最常见的分离物1. 蓝耳病病毒蓝耳病病毒PRRSV2. 霉形体霉形体M.hyopneumoniae3. 猪流感病毒猪流感病毒SIV对对生产导致巨大经济影响生产导致巨大经济影响猪流感病毒是PRDC最主要原发病原体破坏黏膜纤毛系统破坏黏膜纤毛系统uu为为休眠状态的病原体打开门户休眠状态的病原体打开门户uu为继发感染搭起舞台为继发感染搭起舞台霉形体，霉形体，霉形体，霉形体，放线杆菌放线杆菌放线杆菌放线杆菌, , 巴士杆菌巴士杆菌巴士杆菌巴士杆
8、菌副猪副猪副猪副猪嗜血杆菌，波氏杆菌嗜血杆菌，波氏杆菌嗜血杆菌，波氏杆菌嗜血杆菌，波氏杆菌与伪狂犬病病毒，霉形体并发感染与伪狂犬病病毒，霉形体并发感染与与PRRS有有协同作用协同作用猪流感病毒猪流感不是一种温和型疾病猪流感不是一种温和型疾病破坏黏膜纤毛系统破坏黏膜纤毛系统uu为为为为休眠状态的病原体打开门户休眠状态的病原体打开门户休眠状态的病原体打开门户休眠状态的病原体打开门户uu为继发感染搭起舞台为继发感染搭起舞台为继发感染搭起舞台为继发感染搭起舞台霉形体霉形体霉形体霉形体 放线杆菌放线杆菌放线杆菌放线杆菌, , 副猪副猪副猪副猪嗜血杆菌，波氏杆菌嗜血杆菌，波氏杆菌嗜血杆菌，波氏杆菌嗜血杆菌
9、，波氏杆菌, , 巴士杆菌巴士杆菌巴士杆菌巴士杆菌常与伪狂犬病病毒，霉形体并发感染常与伪狂犬病病毒，霉形体并发感染与与PRRS有有协同作用协同作用猪流感病毒流感病毒流感病毒uuA A型型型型Type A (Type A (主要感染人和动物主要感染人和动物主要感染人和动物主要感染人和动物) )uuB B型型型型Type B (Type B (主要感染人主要感染人主要感染人主要感染人) )uuC C型型型型Type C (Type C (主要感染人主要感染人主要感染人主要感染人) )病毒蛋白病毒蛋白uu血凝素血凝素血凝素血凝素( ( Hemagglutinin, HA or H) Hemagglu
10、tinin, HA or H)14 14 种亚型种亚型种亚型种亚型 uu神经氨酸酶神经氨酸酶神经氨酸酶神经氨酸酶( ( Neuraminidase, NA or N) Neuraminidase, NA or N)9 9 种亚型种亚型种亚型种亚型 猪流感病毒分离株的命名分离株的命名uu型型型型/ /动物种类动物种类动物种类动物种类/ /分离地点分离地点分离地点分离地点/ /分分分分离年代离年代离年代离年代uu例如例如例如例如. . A A型型型型/ /猪猪猪猪/ /Wisconsin/4Wisconsin/4754/94754/94猪流感病毒感染的历史至今猪流感已发现有至今猪流感已发现有60多
11、年多年古典型猪流感病毒古典型猪流感病毒H1N1 亚型在世亚型在世界各地存在界各地存在H3N2 在欧洲发现已有在欧洲发现已有10年年1998年美国证实了年美国证实了H3N2水禽在猪流感病毒流行病学中的作用水禽在猪流感病毒水禽在猪流感病毒流行病学中的作用流行病学中的作用bb水禽在水禽在水禽在水禽在A A型禽流感病毒的流行病学中起到中心型禽流感病毒的流行病学中起到中心型禽流感病毒的流行病学中起到中心型禽流感病毒的流行病学中起到中心作用（从历史看来）。作用（从历史看来）。作用（从历史看来）。作用（从历史看来）。bb所有所有所有所有A A型禽流感病毒起源于禽类（遗传学研究型禽流感病毒起源于禽类（遗传学研
12、究型禽流感病毒起源于禽类（遗传学研究型禽流感病毒起源于禽类（遗传学研究表明）。表明）。表明）。表明）。bb在水禽可以见到所有在水禽可以见到所有在水禽可以见到所有在水禽可以见到所有1515种种种种HAHA和所有和所有和所有和所有9 9种种种种NANA各各各各种组合的亚型。水禽常呈广泛、亚临床感染，种组合的亚型。水禽常呈广泛、亚临床感染，种组合的亚型。水禽常呈广泛、亚临床感染，种组合的亚型。水禽常呈广泛、亚临床感染，是该病毒的自然贮存宿主。是该病毒的自然贮存宿主。是该病毒的自然贮存宿主。是该病毒的自然贮存宿主。bb自从自从自从自从19791979年以来，禽流感病毒在欧洲和北美年以来，禽流感病毒在欧
13、洲和北美年以来，禽流感病毒在欧洲和北美年以来，禽流感病毒在欧洲和北美洲猪流感病毒流行病学中的作用。洲猪流感病毒流行病学中的作用。洲猪流感病毒流行病学中的作用。洲猪流感病毒流行病学中的作用。水禽在猪流感病毒水禽在猪流感病毒流行病学中的作用流行病学中的作用bbA型禽流感病毒还是其他多种动物病原型禽流感病毒还是其他多种动物病原 对马和家禽（特别是鸡和火鸡）有极其重对马和家禽（特别是鸡和火鸡）有极其重对马和家禽（特别是鸡和火鸡）有极其重对马和家禽（特别是鸡和火鸡）有极其重要经济影响的疫病要经济影响的疫病要经济影响的疫病要经济影响的疫病 可引起人工饲养的水貂、自由生活的海洋可引起人工饲养的水貂、自由生活
14、的海洋可引起人工饲养的水貂、自由生活的海洋可引起人工饲养的水貂、自由生活的海洋哺乳动物严重的疾病哺乳动物严重的疾病哺乳动物严重的疾病哺乳动物严重的疾病 可引起奶牛奶产量下降、呼吸道疾病可引起奶牛奶产量下降、呼吸道疾病可引起奶牛奶产量下降、呼吸道疾病可引起奶牛奶产量下降、呼吸道疾病 也是人呼吸道疾病的重要病因也是人呼吸道疾病的重要病因也是人呼吸道疾病的重要病因也是人呼吸道疾病的重要病因历史上，猪流感历史上，猪流感历史上，猪流感历史上，猪流感与人的流感有密切联系与人的流感有密切联系与人的流感有密切联系与人的流感有密切联系1918年世界流感大流行又称作西班牙流感又称作西班牙流感uu这次流感并不是起源
15、于西班牙这次流感并不是起源于西班牙这次流感并不是起源于西班牙这次流感并不是起源于西班牙uu西班牙死了近西班牙死了近西班牙死了近西班牙死了近500500万人万人万人万人uu美国死了美国死了美国死了美国死了5050多万人，仅在多万人，仅在多万人，仅在多万人，仅在1010月份就死了月份就死了月份就死了月份就死了 19.6 19.6 万人万人万人万人uu全球死了全球死了全球死了全球死了2 2千多万人千多万人千多万人千多万人1918年夏天首次在临床上认识了猪流感年夏天首次在临床上认识了猪流感uu早期杂志专门探讨猪流感和人流感的相似性。早期杂志专门探讨猪流感和人流感的相似性。早期杂志专门探讨猪流感和人流感
16、的相似性。早期杂志专门探讨猪流感和人流感的相似性。uu现已知猪流感和人流感是由密切相关的病毒所引现已知猪流感和人流感是由密切相关的病毒所引现已知猪流感和人流感是由密切相关的病毒所引现已知猪流感和人流感是由密切相关的病毒所引起起起起人流感病毒和猪流感病毒bb从血清学实验证明，从血清学实验证明，从血清学实验证明，从血清学实验证明，19181918年人的流感大流行年人的流感大流行年人的流感大流行年人的流感大流行是由与是由与是由与是由与1930S1930S从猪体内所分离的从猪体内所分离的从猪体内所分离的从猪体内所分离的H1N1H1N1毒株相毒株相毒株相毒株相关的病毒所引起的。关的病毒所引起的。关的病毒
17、所引起的。关的病毒所引起的。bb从福尔马林固定的旧病理样品、以及从被北从福尔马林固定的旧病理样品、以及从被北从福尔马林固定的旧病理样品、以及从被北从福尔马林固定的旧病理样品、以及从被北极冻土所埋藏的人所采取的样品中，已经分极冻土所埋藏的人所采取的样品中，已经分极冻土所埋藏的人所采取的样品中，已经分极冻土所埋藏的人所采取的样品中，已经分离到离到离到离到19181918年人流感病毒的部分基因片段。研年人流感病毒的部分基因片段。研年人流感病毒的部分基因片段。研年人流感病毒的部分基因片段。研究步表明，这些人流感病毒和猪流感病毒有究步表明，这些人流感病毒和猪流感病毒有究步表明，这些人流感病毒和猪流感病毒
18、有究步表明，这些人流感病毒和猪流感病毒有密切联系。密切联系。密切联系。密切联系。bb是猪流感病毒先传染给人，还是人流感病毒是猪流感病毒先传染给人，还是人流感病毒是猪流感病毒先传染给人，还是人流感病毒是猪流感病毒先传染给人，还是人流感病毒先传染给猪？先传染给猪？先传染给猪？先传染给猪？人流感病毒和猪流感病毒bb从此流感病毒在人和猪之间相互传播从此流感病毒在人和猪之间相互传播bb猪流感病毒传播给人猪流感病毒传播给人 自自自自19741974年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发生过多次猪流感病毒传播给人事件，包括生过
19、多次猪流感病毒传播给人事件，包括生过多次猪流感病毒传播给人事件，包括生过多次猪流感病毒传播给人事件，包括6 6起人被感染致死事件。起人被感染致死事件。起人被感染致死事件。起人被感染致死事件。bb人流感病毒也可传染给猪人流感病毒也可传染给猪 这是这是1998年在美国出现的重组流感病毒年在美国出现的重组流感病毒H3N2的主要起因。的主要起因。流感病毒在人和猪之间传播流感病毒在人和猪之间传播猪流感病毒传播给人猪流感病毒传播给人uu自自自自19741974年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发年以来，在美国、欧洲、新西兰发生过多次猪流感病毒传播给人事
20、件，包括生过多次猪流感病毒传播给人事件，包括生过多次猪流感病毒传播给人事件，包括生过多次猪流感病毒传播给人事件，包括6 6起人被感染致死事件。起人被感染致死事件。起人被感染致死事件。起人被感染致死事件。人流感病毒也可传染给猪人流感病毒也可传染给猪uu这是这是这是这是19981998年在美国出现的重组流感病毒年在美国出现的重组流感病毒年在美国出现的重组流感病毒年在美国出现的重组流感病毒H3N2H3N2的主要起因。的主要起因。的主要起因。的主要起因。抗原变异&遗传进化抗原漂移：抗原漂移：uuHAHA亚型未变化，但抗原变异亚型未变化，但抗原变异亚型未变化，但抗原变异亚型未变化，但抗原变异uuHAHA
21、基因的点突变基因的点突变基因的点突变基因的点突变抗原转变：抗原转变：uuHAHA亚型发生改变所致抗原变异亚型发生改变所致抗原变异亚型发生改变所致抗原变异亚型发生改变所致抗原变异uu基因重排基因重排基因重排基因重排种间传播而无基因重排种间传播而无基因重排uu也可导致抗原转变也可导致抗原转变也可导致抗原转变也可导致抗原转变抗原漂移bb抗原漂移发生于，早先感染所产生的抗抗原漂移发生于，早先感染所产生的抗体致使动物群中现在流行的病毒发生变体致使动物群中现在流行的病毒发生变异，以逃脱所感染免疫动物体内抗体的异，以逃脱所感染免疫动物体内抗体的中和作用。中和作用。bb尽管抗原漂移是动物群体免疫压力所致，尽管
22、抗原漂移是动物群体免疫压力所致，但是，抗原改变的基础是基因突变。但是，抗原改变的基础是基因突变。bb这种突变是逐渐进行的，并没有发生亚这种突变是逐渐进行的，并没有发生亚型的改变。型的改变。Swine influenza in the United States used to Swine influenza in the United States used to be a relatively predictable disease. It struck be a relatively predictable disease. It struck in the fall and winter
23、, when temperatures in the fall and winter, when temperatures dropped. The cause was a strain of swine dropped. The cause was a strain of swine influenza virus (SIV) known as H1N1. It influenza virus (SIV) known as H1N1. It spread through a barn like wildfire. Pigs ran spread through a barn like wil
24、dfire. Pigs ran a high fever and had a barking cough. But a high fever and had a barking cough. But unless secondary bacterial infections unless secondary bacterial infections developed, pigs recovered quickly and the developed, pigs recovered quickly and the swine producer had minimal production sw
25、ine producer had minimal production losses. losses. Today, swine flu is not as predictable. There is still a flu season and the traditional acute form of disease, but outbreaks can and often do occur at other times year. In most herds, SIV now manifests not as an acute outbreak, but as a chronic ill
26、ness that leads to production losses. SIV is more often seen in conjunction with SIV is more often seen in conjunction with other viral as well as bacterial infections. In other viral as well as bacterial infections. In fact, SIV, in addition to Mycoplasma fact, SIV, in addition to Mycoplasma hyopne
27、umoniae and PRRS (porcine hyopneumoniae and PRRS (porcine reproductive and respiratory syndrome) reproductive and respiratory syndrome) virus, is one of the three primary pathogens virus, is one of the three primary pathogens contributing to porcine respiratory disease contributing to porcine respir
28、atory disease complex, one of the most costly health complex, one of the most costly health problems affecting U.S. swine producers. problems affecting U.S. swine producers. And when infections such as SIV coexist And when infections such as SIV coexist with other viruses and bacteria, the severity
29、with other viruses and bacteria, the severity of illness is often worse, escalating losses of illness is often worse, escalating losses for the swine producer.for the swine producer. New Viral Strain最近出现了一种新的更复杂病原最近出现了一种新的更复杂病原H3N2H3N2，它是，它是首先于首先于19981998年秋天，在美国北卡州一个年秋天，在美国北卡州一个24002400头母猪的猪场中发现。该猪场
30、猪免疫了头母猪的猪场中发现。该猪场猪免疫了H1N1H1N1疫苗。不久疫苗。不久H3N2H3N2在依阿华、在依阿华、More recently, More recently, another complicating factor has emerged - a another complicating factor has emerged - a new viral strain called H3N2. It was first seen new viral strain called H3N2. It was first seen in the fall of 1998 in a 2,40
31、0-sow herd in in the fall of 1998 in a 2,400-sow herd in North Carolina that had been vaccinated for North Carolina that had been vaccinated for H1N1. Subsequently, cases of H3N2 flu H1N1. Subsequently, cases of H3N2 flu occurred in states including Iowa, Texas, occurred in states including Iowa, Te
32、xas, Minnesota and Illinois. Minnesota and Illinois. Compared with H1N1, H3N2 seems to cause more severe disease, possibly because herds have not yet developed any immunity to H3N2. A practitioner from Iowa who has treated A practitioner from Iowa who has treated several herds for H3N2 outbreaks say
33、s this several herds for H3N2 outbreaks says this new SIV strain does not seem to affect pigs new SIV strain does not seem to affect pigs as seriously as swine flu due to H1N1, but as seriously as swine flu due to H1N1, but the severity of illness in sows has been the severity of illness in sows has
34、 been particularly notable. Some animals have particularly notable. Some animals have temperatures up to 105 degrees F, a large temperatures up to 105 degrees F, a large percentage go off feed for four or five days percentage go off feed for four or five days and respiratory rates are increased. and
35、 respiratory rates are increased. Coughing has been significant, but it is not Coughing has been significant, but it is not the deep cough characteristic of H1N1. the deep cough characteristic of H1N1. H3N2 outbreaks also have resulted in H3N2 outbreaks also have resulted in abortions, sow deaths an
36、d production abortions, sow deaths and production losses. losses. bbExact figures on the economic losses that Exact figures on the economic losses that SIV outbreaks cause are not available, but SIV outbreaks cause are not available, but anecdotal experience indicates two sources. anecdotal experien
37、ce indicates two sources. One is for medication costs, particularly if One is for medication costs, particularly if SIV occurs in association with bacterial SIV occurs in association with bacterial infections and antibiotic treatment is infections and antibiotic treatment is required. The other and
38、probably larger required. The other and probably larger economic toll comes from the resulting economic toll comes from the resulting production losses. H3N2 outbreaks in some production losses. H3N2 outbreaks in some herds, for instance, have led to increased herds, for instance, have led to increa
39、sed mortality in the farrowing house and drops in mortality in the farrowing house and drops in farrowing rates from 5% to 10%. farrowing rates from 5% to 10%. bbLingering Questions bbNo one knows why the character of traditional H1N1 swine flu has changed, but it is probably related to the producti
40、on systems used in the modern swine industry and the large number of animals moving in and out of swine farms. How the H3N2 strain got into U.S. herds is How the H3N2 strain got into U.S. herds is also a mystery. An H3N2 strain has been also a mystery. An H3N2 strain has been present in European swi
41、ne herds for over 10 present in European swine herds for over 10 years, but research to date indicates it is not years, but research to date indicates it is not exactly the same H3N2 strain now affecting exactly the same H3N2 strain now affecting U.S. herds. What is known with certainty is U.S. herd
42、s. What is known with certainty is that outbreaks of SIV due to H3N2 has that outbreaks of SIV due to H3N2 has increased faster than anyone imagined increased faster than anyone imagined possible. Today, the new H3N2 strain is possible. Today, the new H3N2 strain is reported to be nearly as prevalen
43、t as H1N1.reported to be nearly as prevalent as H1N1. At one North Carolina diagnostic lab, the distribution of H1N1 and H3N2 in isolates sent for testing is running about 50/50. At the National Veterinary Services Laboratories in Ames, Iowa, 54% of isolates have been H1N1 and 46% H3N2 since the fal
44、l of 1998. Just a few years ago, the prevalence of the H3N2 based on blood testing of samples was less then 3%. bbDiagnosing SIVDiagnosing SIVbbIf a herd vaccinated against H1N1 has a flu If a herd vaccinated against H1N1 has a flu outbreak, H3N2 should be suspected, outbreak, H3N2 should be suspect
45、ed, particularly if sows develop high fevers. particularly if sows develop high fevers. Otherwise, H2N2 and H1N1 cannot be Otherwise, H2N2 and H1N1 cannot be differentiated based on clinical signs alone. differentiated based on clinical signs alone. Diagnosis at a lab is required so that Diagnosis a
46、t a lab is required so that producers can implement appropriate control producers can implement appropriate control measures. measures. The most widely available method of diagnosing SIV is with a blood test, or serology, known as hemagglutination inhibition (HI). It takes a few days to perform thes
47、e types of tests, which can differentiate between H1N1 and H3N2 antibodies. A positive HI test indicates exposure to swine influenza through natural exposure and, in young pigs, it may reflect maternal antibody to SIV. A positive result can also result from vaccination. Other types of tests detect a
48、ntigens to SIV in tissues or secretions. One is the fluorescent antibody assay (FA); another is the immunohistochemistry test (IHC). Both FA and IHC can yield results within 24-48 hours. Producers and veterinarians need to ask the lab for additional testing to distinguish H1N1 from H3N2. Sample coll
49、ection and handling is important Sample collection and handling is important to assure accurate results. It is best to ask to assure accurate results. It is best to ask the lab how it wants samples collected and the lab how it wants samples collected and sent. Generally, however, samples should sent
50、. Generally, however, samples should be taken from acutely ill pigs with an be taken from acutely ill pigs with an elevated temperature. If too much time elevated temperature. If too much time elapses between the time the flu erupts and elapses between the time the flu erupts and samples are taken,
51、the virus might not be samples are taken, the virus might not be present and the results could be erroneously present and the results could be erroneously negative. negative. bbManaging SIVbbWhen an SIV outbreak occurs, the only treatment available is control of fever with aspirin or antipyretic dru
52、gs. If secondary bacterial infections develop, antibiotic treatment may be necessary. It also helps to reduce stress by keeping sick animals as comfortable as possible. bbBecause treatment options are limited and because SIV is more likely than before to occur in association with other diseases, lea
53、ding to more severe illness and economic losses, the best approach to SIV management is prevention through biosecurity and vaccination.Good biosecurity requires that new stock be negative for SIV exposure. New stock also should be quarantined. Traffic onto swine farms should be limited and any equip
54、ment used around stock disinfected. Vaccines for SIV are effective, but it is Vaccines for SIV are effective, but it is imperative that accurate diagnosis be made imperative that accurate diagnosis be made of the SIV strain affecting a given herd. In of the SIV strain affecting a given herd. In othe
55、r words, if H3N2 is causing a problem, other words, if H3N2 is causing a problem, vaccination with the H1N1 vaccine will not vaccination with the H1N1 vaccine will not help. In some herds, H1N1 may be the help. In some herds, H1N1 may be the cause of flu outbreaks, and the H1N1 cause of flu outbreak
56、s, and the H1N1 vaccine is appropriate. In other cases, herds vaccine is appropriate. In other cases, herds may need vaccinated against both SIV may need vaccinated against both SIV strains. strains. bbVaccines for H1N1 have long been available. Vaccines for H1N1 have long been available. A conditio
57、nally licensed vaccine for H3N2 A conditionally licensed vaccine for H3N2 was developed and produced by Schering-was developed and produced by Schering-Plough Animal Health Corp. within months of Plough Animal Health Corp. within months of the first H3N2 outbreak in North Carolina. the first H3N2 ou
58、tbreak in North Carolina. The vaccine, which has since been updated The vaccine, which has since been updated to include a U.S. H3N2 isolate found in U.S. to include a U.S. H3N2 isolate found in U.S. herds., has already been administered to herds., has already been administered to thousands of anima
59、ls and is proving to be thousands of animals and is proving to be both safe and effective. A combination both safe and effective. A combination vaccine offering protection against both vaccine offering protection against both H3N2 and the older H1N1 strain is in H3N2 and the older H1N1 strain is in
60、development and should become available development and should become available later this year. later this year. Schering-Plough Animal Health has and will Schering-Plough Animal Health has and will continue to keep in close touch with swine continue to keep in close touch with swine veterinarians
61、and diagnostic labs and plans veterinarians and diagnostic labs and plans to further update the vaccine as needed. to further update the vaccine as needed. Likewise, swine producers need to work Likewise, swine producers need to work closely with their veterinarians to plan their closely with their
62、veterinarians to plan their vaccine program. In some herds affected by vaccine program. In some herds affected by H3N2, producers started by vaccinating just H3N2, producers started by vaccinating just gilts, but found they also needed to gilts, but found they also needed to vaccinate sows prefarrow
63、ing to prevent vaccinate sows prefarrowing to prevent H3N2 outbreaks. H3N2 outbreaks. When it is necessary to vaccinate pigs in sow-vaccinated herds, waiting until maternal antibodies to SIV have dropped helps assure vaccine efficacy. If the vaccine is administered before then, maternal antibody may
64、 prevent the vaccine from working. In the United States, SIV is clearly a changing disease and management has become more complicated. But with good biosecurity, accurate diagnosis of the SIV strain and administration of the appropriate vaccine, good control can be achieved and associated losses min
65、imized. 猪是流感病毒重组的基地SIV1997-1998的抗原转变美国美国19761977年、年、19881999年的血清年的血清学检测结果表明，学检测结果表明，H1N1是猪流感的最是猪流感的最常见病原常见病原uu在这段时间，约在这段时间，约在这段时间，约在这段时间，约50%50%的猪的猪的猪的猪H1H1亚型抗体阳性，亚型抗体阳性，亚型抗体阳性，亚型抗体阳性，而只有而只有而只有而只有1%1%的猪的猪的猪的猪H3H3亚型抗体阳性亚型抗体阳性亚型抗体阳性亚型抗体阳性19971998年的一项研究结果表明年的一项研究结果表明uuH3H3亚型抗体阳性率上升为以前的亚型抗体阳性率上升为以前的亚型抗体
66、阳性率上升为以前的亚型抗体阳性率上升为以前的8 8倍倍倍倍1998年在美国猪体内分离到年在美国猪体内分离到H3N2毒株毒株就证实发生了抗原转变。就证实发生了抗原转变。猪流感病毒H3N2的出现19981998年年年年8 8月在美国的北卡罗来那州的一个月在美国的北卡罗来那州的一个月在美国的北卡罗来那州的一个月在美国的北卡罗来那州的一个 24002400头母猪头母猪头母猪头母猪猪场中分离到猪场中分离到猪场中分离到猪场中分离到H3N2H3N2毒株。毒株。毒株。毒株。该猪场猪免疫了该猪场猪免疫了该猪场猪免疫了该猪场猪免疫了H1N1H1N1疫苗。疫苗。疫苗。疫苗。感染猪发生了流感样呼吸道疾病，种母猪流感染
67、猪发生了流感样呼吸道疾病，种母猪流感染猪发生了流感样呼吸道疾病，种母猪流感染猪发生了流感样呼吸道疾病，种母猪流产，成年母猪死亡产，成年母猪死亡产，成年母猪死亡产，成年母猪死亡2%2%（典型猪流感猪只死亡（典型猪流感猪只死亡（典型猪流感猪只死亡（典型猪流感猪只死亡很少）。很少）。很少）。很少）。之后又从美国德克萨斯州、明尼苏达州之后又从美国德克萨斯州、明尼苏达州之后又从美国德克萨斯州、明尼苏达州之后又从美国德克萨斯州、明尼苏达州 、衣、衣、衣、衣阿华州和依利诺斯州的猪只中分离到阿华州和依利诺斯州的猪只中分离到阿华州和依利诺斯州的猪只中分离到阿华州和依利诺斯州的猪只中分离到H3N2H3N2毒毒毒毒
68、株。株。株。株。猪流感病毒H3N2的出现各病毒分离株分析结果表明各病毒分离株分析结果表明uu19981998年年年年3 3月在美国的衣阿华、明尼苏达、内月在美国的衣阿华、明尼苏达、内月在美国的衣阿华、明尼苏达、内月在美国的衣阿华、明尼苏达、内布拉斯加州的猪已感染了布拉斯加州的猪已感染了布拉斯加州的猪已感染了布拉斯加州的猪已感染了 H3N2H3N2，uu1997 1997 年年年年1 1月在加拿大安大略的猪已感染了月在加拿大安大略的猪已感染了月在加拿大安大略的猪已感染了月在加拿大安大略的猪已感染了 H3N2 H3N2 。此次流行前，北美分离到此次流行前，北美分离到H3N2仅有仅有2次次uu197
69、71977年在科罗拉多年在科罗拉多年在科罗拉多年在科罗拉多uu19911991年在加拿大年在加拿大年在加拿大年在加拿大北卡罗来纳1998年H3N2猪流感病毒H3HA=人人N2NA=人人PB1多聚酶多聚酶=人人基质蛋白（基质蛋白（M1，M2）=猪猪核衣壳蛋白核衣壳蛋白=猪猪非结构蛋白非结构蛋白=猪猪H3N2猪流感病毒19982000H3HA=人人N2NA=人人PB1多聚酶多聚酶=人人基质蛋白（基质蛋白（M1，M2）=猪猪核蛋白核蛋白=猪猪非结构蛋白非结构蛋白=猪猪PA，PB2多聚酶多聚酶=禽禽安大略1997年H3N2猪流感病毒H3HA=人人N2NA=人人PB1多聚酶多聚酶=人人基质蛋白（基质蛋白
70、（M1，M2）=人人核衣壳蛋白核衣壳蛋白=人人非结构蛋白非结构蛋白=人人PB2，PA多聚酶多聚酶=人人美国当今猪流感流行情况美国当今猪流感流行情况美国美国只有只有11%左右左右猪群可能无猪流感猪群可能无猪流感Dr. Gene Erickson（Rollins Animal Disease Lab, North Carolina Department of Agriculture, Raleigh）uuH3N2H3N2和和和和H1N1H1N1各占各占各占各占50%50%Dr. Sabrina Swenson（National Veterinary Service Laboratories, Am
71、es, Iowa）uu从从从从1998.8 1999.9.301998.8 1999.9.30日，约日，约日，约日，约H1 H1 占占占占50% H350% H3占占占占50%50%uu 从从从从1999.10.1 2000.2.211999.10.1 2000.2.21，H1H1占占占占 62% H3 62% H3 占占占占38% 38% uu从从从从H3H3发现以来，发现以来，发现以来，发现以来，54%54%为为为为 H1H1， 46%46%为为为为 H3.H3.美国猪流感现状美国猪流感现状H1N1：uuH1HA=H1HA=猪猪猪猪uuN1NA=N1NA=猪猪猪猪uuPB1PB1多聚酶多聚
72、酶多聚酶多聚酶= =猪猪猪猪uu基质蛋白（基质蛋白（基质蛋白（基质蛋白（M1M1，M2M2）= =猪猪猪猪uu核衣壳蛋白核衣壳蛋白核衣壳蛋白核衣壳蛋白= =猪猪猪猪uu非结构蛋白非结构蛋白非结构蛋白非结构蛋白= =猪猪猪猪uuPB2PB2，PAPA多聚酶多聚酶多聚酶多聚酶= =猪猪猪猪美国猪流感现状H3N2：uuH3HA=H3HA=人人人人uuN2NA=N2NA=人人人人uuPB1PB1多聚酶多聚酶多聚酶多聚酶= =人人人人uu基质蛋白（基质蛋白（基质蛋白（基质蛋白（M1M1，M2M2）= =猪猪猪猪uu核衣壳蛋白核衣壳蛋白核衣壳蛋白核衣壳蛋白= =猪猪猪猪uu非结构蛋白非结构蛋白非结构蛋白非
73、结构蛋白= =猪猪猪猪uuPB2PB2，PAPA多聚酶多聚酶多聚酶多聚酶= =禽禽禽禽A/猪猪/安大略安大略/019111,2/99（H4N6）1999年年10月，月，3周的病程：周的病程：uu咳嗽、呼吸困难、体重下降咳嗽、呼吸困难、体重下降咳嗽、呼吸困难、体重下降咳嗽、呼吸困难、体重下降uu26002600头生长肥育猪、青年公猪有头生长肥育猪、青年公猪有头生长肥育猪、青年公猪有头生长肥育猪、青年公猪有5%5%被感染被感染被感染被感染uu1212头死亡（可分离到链球菌、多杀性巴氏头死亡（可分离到链球菌、多杀性巴氏头死亡（可分离到链球菌、多杀性巴氏头死亡（可分离到链球菌、多杀性巴氏杆菌、化脓放线
74、杆菌）杆菌、化脓放线杆菌）杆菌、化脓放线杆菌）杆菌、化脓放线杆菌）PRRSVPRRSV、PRCVPRCV、胸膜肺炎阴性、胸膜肺炎阴性、胸膜肺炎阴性、胸膜肺炎阴性免疫过霉形体和嗜血杆菌菌苗免疫过霉形体和嗜血杆菌菌苗免疫过霉形体和嗜血杆菌菌苗免疫过霉形体和嗜血杆菌菌苗以前没发生过流感，也没有进行免疫以前没发生过流感，也没有进行免疫以前没发生过流感，也没有进行免疫以前没发生过流感，也没有进行免疫uu附近湖泊水禽可分离到流感病毒附近湖泊水禽可分离到流感病毒附近湖泊水禽可分离到流感病毒附近湖泊水禽可分离到流感病毒猪流感的流行病学猪流感的流行病学传播传播:uu通过通过鼻腔分泌物鼻腔分泌物uu通过通过空气空
75、气无无季节性季节性uu 春、春、夏、秋、冬夏、秋、冬u 大雾，低温，高湿加速疾病的传播大雾，低温，高湿加速疾病的传播H3N2 猪流感猪流感临床症状临床症状uu许多情况下与许多情况下与H1N1猪流感相似猪流感相似 发烧发烧发烧发烧(39(39C)High fevers C)High fevers 精神沉郁精神沉郁精神沉郁精神沉郁流产与死亡流产与死亡流产与死亡流产与死亡咳嗽咳嗽咳嗽咳嗽H3N2 猪流感猪流感严重病例特征严重病例特征uu一些猪场感染发病严重一些猪场感染发病严重发病率接近发病率接近发病率接近发病率接近100%100%成年猪死亡率超过成年猪死亡率超过成年猪死亡率超过成年猪死亡率超过4%4
76、%。与与与与PRRSPRRS和链球菌和链球菌和链球菌和链球菌StrepStrep. .混合感染，育肥混合感染，育肥混合感染，育肥混合感染，育肥猪死亡率高个别达到猪死亡率高个别达到猪死亡率高个别达到猪死亡率高个别达到20%20%（Dr. Dr. SeehusenSeehusen）流产率超过流产率超过流产率超过流产率超过1 10%0%诊断建议临床症状流行病学临床症状流行病学病理解剖病理解剖血清学检测血清学检测uu选择发烧病猪选择发烧病猪选择发烧病猪选择发烧病猪 uu至少从至少从至少从至少从5 5头猪采集头猪采集头猪采集头猪采集1010个鼻咽拭子，并将其放入合适个鼻咽拭子，并将其放入合适个鼻咽拭子，
77、并将其放入合适个鼻咽拭子，并将其放入合适病毒运输媒介，送往诊断室作病毒鉴定病毒运输媒介，送往诊断室作病毒鉴定病毒运输媒介，送往诊断室作病毒鉴定病毒运输媒介，送往诊断室作病毒鉴定uu提供肺组织作为鼻咽拭子的后选样品提供肺组织作为鼻咽拭子的后选样品提供肺组织作为鼻咽拭子的后选样品提供肺组织作为鼻咽拭子的后选样品uu需要在病前和病后样品，需要在病前和病后样品，需要在病前和病后样品，需要在病前和病后样品，2 2次采样间隔次采样间隔次采样间隔次采样间隔2-3 2-3 周周周周uu血清学转变明显血清学转变明显血清学转变明显血清学转变明显猪流感的控制方法猪流感的控制方法作好生物安全工作，严格控制猪群的转移作
78、好生物安全工作，严格控制猪群的转移作好生物安全工作，严格控制猪群的转移作好生物安全工作，严格控制猪群的转移加强通风加强通风加强通风加强通风爆发时爆发时爆发时爆发时的支持疗法的支持疗法的支持疗法的支持疗法uu解热：阿司匹林解热：阿司匹林解热：阿司匹林解热：阿司匹林uu镇痛：安乃近镇痛：安乃近镇痛：安乃近镇痛：安乃近uu减少应激减少应激减少应激减少应激uu抗继发感染：氟甲砜霉素抗继发感染：氟甲砜霉素抗继发感染：氟甲砜霉素抗继发感染：氟甲砜霉素战略战略战略战略性使用猪流感疫苗性使用猪流感疫苗性使用猪流感疫苗性使用猪流感疫苗疫苗的使用疫苗的使用流行期免疫接种流行期免疫接种uu可缩短发病病程可缩短发病病程uu可控制疾病的扩散可控制疾病的扩散非流行时免疫接种非流行时免疫接种uu使猪群的免疫水平趋于一致使猪群的免疫水平趋于一致uu提高机体的免疫力（猪群的健康状况）提高机体的免疫力（猪群的健康状况）uu预防疾病的发生预防疾病的发生uu减少减少猪群中病毒的排放猪群中病毒的排放免疫计划简单小猪小猪uu每头份每头份2ml，两次免疫间隔，两次免疫间隔3周周种猪种猪免疫免疫uu配种配种前，或前，或配种时，或分娩前配种时，或分娩前uu首次免疫每头份首次免疫每头份2ml，两次间隔，两次间隔3周周uu以后每年以后每年2次次SIV Significant Reduction in Viral Shedding
