Encephalitis BDept Of Infectious Disease流行性乙型脑炎BDept传染病（PPT41）课件.ppt

Epidemic Encephalitis B Dept. Of Infectious Disease Shengjing Hospital CMU Definition Epidemic encephalitis B is acute infectious disease caused by encephalitis B virus,usually occurs in summer fall.The virus is transmitted by mosquito. Pathologic lesions: cerebral parenchyma Clinical feature: high fever altered consciousness convulsion meningeal irritation respiratory failure Etiology Causative agent: encephalitis B virus genus flavivirus of flaviviridae single strain of positive-sense RNA, virion is spheric, diameter: 15 ~ 22nm, Resistance: unstable in environment, Sensitive to heat, disinfectants, ultraviolet rays Etiology antigenicity: stable hemagglutination inhibiting Ab complement fixing Ab neutralizing Ab Epidemiology Source of infection domestic animals: pig, horse, dog poultry: chicken, duck, goose. patients: Epidemiology Route of transmission insect borne: mosquito biting , vector: mosquito, culex tritaeniorhynchus. Survived winter mosquitoes pigs mosquitoes mosquitoes person pigs Epidemiology Susceptibility of population: universal susceptible lifelong immunity subclinical infection : overt infection 1000~2000:1 Epidemiology Epidemiologic features sporadic from July to Sep. children under 10yrs (2~6yrs) hypersporadic property Pathogenesis Pathology Place of lesion: all of CNS cerebral cortex, midbrain and thalamus . Pathologic features gross examination: congestion hemorrhage cerebral edema soften focuses Pathology microscopic examination: