Epidemic Encephalitis BDept. Of Infectious Disease[流行性乙型脑炎BDept传染病](PPT-41).ppt

Epidemic Encephalitis B,Dept.Of Infectious DiseaseShengjing HospitalCMU,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 parenchymaClinical feature:high fever altered consciousness convulsion meningeal irritation respiratory failure,Etiology,Causative agent:encephalitis B virus genus flavivirus of flaviviridaesingle strain of positive-sense RNA,virion is spheric,diameter:15 22nm,Resistance:unstable in environment,Sensitive to heat,disinfectants,ultraviolet rays,Etiology,antigenicity:stablehemagglutination inhibiting Abcomplement fixing Abneutralizing 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 susceptiblelifelong immunitysubclinical infection:overt infection 10002000:1,Epidemiology,Epidemiologic featuressporadic from July to Sep.children under 10yrs(26yrs)hypersporadic property,Pathogenesis,virus,mosquito biting,replication in mononuclear-phagocyte system(MPS),onset of illness,CNS,blood stream,blood-brain barrier,brief viremia,subclinical inf.,clearance,No.of virus of invasioncellular immunityblood brain barrier,Pathology,Place of lesion:all of CNScerebral cortex,midbrain and thalamus.Pathologic featuresgross examination:congestionhemorrhagecerebral edemasoften focuses,Pathology,microscopic examination:vascular lesion:endothelial cells swelling,necrosisneuron degeneration&necrosisneurogliocyte hyperplasia&inflammatory cells infiltration,perivascular cuffing,neuronophagia.,Clinical manifestation,incubation period:1014 days(421days)typical encephalitis B Initial period crisis period convalescent period sequela period,Clinical manifestation,Initial period:on the 1st to 3rd daysabrupt onsetfever with headache,nausea,vomiting lethargy,abdominal pain,diarrhea,Clinical manifestation,Crisis period-on the 4th 10th dayshigh fever:40,sustained for 710 days.altered consciousness:lethargy,confusion,delirium,stupor,semicoma,coma.convulsion or twitch:(4060%)respiratory failure:1540%,Clinical manifestation,central RF:reason of central RF:lesion of cerebral parenchyma(respiratory center injury in oblongata medulla)cerebral edemabrain herniaintracranial hypertensionhyponatremic encephalopathy,Clinical manifestation,manifestation of central RF:cacorhythmic breathing(cheyne-stokes breathing,apnea)brain herniaperipheral RF:dyspnea,regular breathing,Clinical manifestation,Other symptoms&signs of CNSmeningeal irritations(neck stiffness Kernigs&Brudzinskis signs positive)Deep tendon reflexes from hyperactive to disappearpathologic reflexes positivelimbs paralysis,Clinical manifestation,Convalescent periodT drop to normal in 25 daysneurologic function regain gradually(2W)remain some behavioral&psychologic abnormalities,aphasia,dementia,rigidity paralysis.6month-sequela,Clinical manifestation,Sequela periodaphasiadementiapersistent paralysis,Clinical manifestation,Clinical type:mild type common type severe type fulminant type,Clinical manifestation,Laboratory Findings,Blood picture:WBC 1020109/L neutrophil 80%Cerebrospinal fluid-aseptic meningitistransparent or slightly cloudy,pressure may be elevatedpleocytosis:50500106/Lprotein may be elevated mildlyglucose and chloride are normal,Laboratory Findings,Serological test:specific IgM Ab:blood or CSF,34d after onset,peak on 2 week ELISA or indirect immunofluorescencecomplement fixing Ab:2 week after onset,peak on 56 week,anamnestic diagnosisepidemiologic investigation,Laboratory Findings,hemagglutination inhibition Ab:5d after onset,peak on 2 weekdiagnosis:4 fold increase in titerepidemiologic investigationneutralized Ab epidemiologic investigation,Laboratory Findings,pathogenic test virus isolation:blood,CSF,brain tissue RT-PCR:RNA,Diagnosis,Epidemiological data:79 month10yrsClinical manifestation:fever,headache,vomiting,altered consciousness,convulsion,meningeal irritation,pathologic reflexes positive.Laboratory findings:WBC,CSF,IgM,Differential Diagnosis,toxic bacillary dysentery high fever,convulsion,coma.24h circulatory failure:earlystool examination:WBC,RBCCSF:normalmeningeal irritation:negative,Differential Diagnosis,tuberculous meningitis CSF,meningeal irritationpurulent meningitisother viral encephalitis,Treatment,General therapy:Isolation:preventing mosquito biting,T30nursing:mouth,skin,eye,turn over clapping back sputum aspiration,Treatment,fluid&electrolyte supplementation adult:15002000ml/d children:5080ml/kg/dSymptomatic therapyhigh fever:T38,Treatment,physical cooling(ice bag,alcohol bathing,cold saline enema)drug cooling antipyretic subhibernation:chlorpromazine 0.51mg/kg/time phenergan 0.51mg/kg/time 46h,35day,Treatment,convulsion:fever:cooling brain edema:20%mannitol 12g/kg/time 50%glucose dexamethason,Treatment,sedative:valium:adult:1020mg/time children:0.10.3mg/kg/time 10%chloral hydrate:adult:12g/time children:6080mg/kg/timesubhibernation:,Treatment,respiratory failure:keep airway clearsputum aspirationturn over,clapping back,postural drainageaerosolizationinhalation of oxygen,Treatment,reducing cerebral edema&hernia dehydrate:20%mannitol:12g/kg/time 50%glucose,vasodilator:654-2:adult:20mg/time children:0.51mg/kg/time 1030 min,Treatment,respiratory stimulant:lobeline:adult:39mg/time children:0.150.2mg/kg/time coramine:adult:0.3750.75g/time children:510mg/kg/time tracheal intubation or tracheotomy,biomotor,Treatment,Convalescent&sequela periodacupuncturemassage exercise etc.,Prevention,isolating patients and pig immunization,killing mosquito and preventing mosquito,vaccination:killed virus vaccine:6090%,病例分析,5岁患儿，8月15日开始发热头痛，呕吐一次，次日排稀便两次，精神不振，第三天晚间开始抽搐，神志不清。查体，T40，急病容，脉充实有力，呼吸略促，节律整，皮肤无瘀点、瘀斑，颈强(+)，克氏征(+)，肢体肌张力增强。辅助检查：,病例分析,血WBC 15109L，便常规WBC 05个Hp，CSF细胞数75106L，糖3.5mmol/L,氯化物115mmol/L，蛋白0.45g/L哪种诊断可能性大?提供诊断依据及主要鉴别诊断治疗要点,