猪群健康管理技术实录(ppt).pptVIP

Swine Health Management Factsheet 猪群健康管理技术实录PRRS猪繁殖呼吸综合症 Dr. Jim Fairles 范如杰博士 Herd Health Specialist动物健康专家 China Canada Animal Health Initiative中加动物健康启动项目 Introduction引言 is caused by a virus 是一种病毒病 classified as an arterivirus as recently as 1991 直到1991年才确定病源为动脉炎病毒科的一种病毒 been first recognized in the USA in the mid 1980‘s and was called Mystery swine disease or blue ear disease. 80年代中期在美国首次发现，被称为神秘猪病或蓝耳病 Introduction引言 Attacks macrophages (immune defense cell) and destroys them 攻击并破坏巨噬细胞（免疫防御细胞） Up to 40% of the macrophages are destroyed 破坏巨噬细胞比例可达40％之多 removes a major part of the bodies defense mechanism and allows bacteria and other viruses to proliferate and do damage 机体防御机制的重要功能丧失，使得细菌以及其它病毒得以增殖并导致破坏。 Introduction引言 E.g. - noticeable increase in severity of enzootic pneumonia in grower/finisher units when they become infected with PRRS virus 例如，生长肥育阶段感染PRRS病毒后可明显增加地方性肺炎发病的严重程度 increase can occur in clinical cases of meningitis in herds in which virulent Streptococcus suis type 2 is enzootic 在地方性二型猪链球菌病存在的情况下，PRRS可增加脑膜炎的临床病例 Epidemiology 流行病学 The virus is spread by nasal secretions, saliva, feces and urine 病毒 通过鼻腔分泌物、唾液、粪和尿传播 field studies suggest it can be airborne for up to 3km (2 miles) 野外研究证明在3公里（2英里）范围内这种病可经由空气转播 A carrier state exists in the pig that can last for 2-3 months 猪体带毒状态可持续2-3月 Artificial insemination can be a potential method of spread if semen is used when the virus is present in the blood (viremia) 如果血液中存在病毒（毒血症），那么通过人工受精也可能传播病毒 Epidemiology流行病学 Adult animals excrete virus for much shorter periods of time (14 days) 成年家畜排泄病毒的时间短得多（14天） PRRSV may infect fetuses from mid pregnancy onwards and is excreted in salvia, colostrum and milk. PRRS病毒可感染妊娠中期以后的胎儿童乐园，并且能够通过唾液、乳以及初乳扩散。 Maternal antibody – short duration (5-10 days) 母原抗体 – 持续时间短暂（5至10天） Methods of Spread 传播方式 Movement of carrier pigs. 带毒猪只的转移 Airborne transmission up to 3km (2 miles). 最远3公里的空气传播 Mechanical means via feces, dust, droplets and contamin