虫媒病毒和出血热病毒课件_3.ppt

Chapter 23  Arbovirus of prevalence in China ---classified as Flavivirus ? JEV-infection ? Asymptomatic infection ? Abortive infection ? Cause epidemic encephalitis B (0.1%) 3.Laboratory Diagnosis ? Isolation of virus (cell culture) ? Serological diagnosis 1.Biological properties ?Dengue virus -infection ? route of transmisson ? primary infection→dengue fever ? reinfection→dengue hemorrhagic fever(DHF) or dengue shock syndrome (DSS) ? pathogenesis of DHF/DSS:ADE(antibody-dependent enhancement) 3.Laboratory diagnosis  and prophylaxis ? Laboratory diagnosis ---isolation of virus, detection of viral Ag and specific IgM or of viral RNA ? Prophylaxis 2.Pathogenicity * * ?Small spherical particle(40-70nm), +ssRNA, icosahedral nucleocapsid, envelope and spike ?Feature of diseases caused by Arbovirus 主要有流行性乙型脑炎病毒、登革病毒和森林脑炎病毒 一群节肢动物媒介病毒 p302表 ?arthropod----both vector and reservoir hosts of virus ?transmitted by bite of arthropod ?obvious season and district ?clinical manifestations (发热、脑炎、出血热) 节肢动物既是传播 媒介又是储存宿主 Common characteristics ? also called Japanese encephalitis virus(JEV) ? the most common cause of epidemic encephalitis 1. Biological Properties ? Cultivation ? Antigenicity ? Typical flavivirus both in structure and in shape ? Structural protein:C,M and E protein(hemagglutinin) 能凝集雏鸡、鸽和鹅的红细胞（PH6.0) +ss-RNA ?suckling mice ? embryo-eggs ? cell culture(C6/36 cell) (single and stable) (球形、单正链RNA 、 20面体对称的包膜病毒) ? Natural cycles of JEV mosquito domestic animal or birds domestic animal mosquito or birds (viremia) 病毒血症 bite human (culex) (young pigs) o