1、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
2、 feveraltered 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, disinfecta
3、nts,ultraviolet rays,Etiology,antigenicity: stable hemagglutination inhibiting Ab complement fixing Ab neutralizing Ab,Epidemiology,Source of infectiondomestic animals: pig, horse, dogpoultry: chicken, duck, goose.patients:,Epidemiology,Route of transmissioninsect borne: mosquito biting , vector: mo
4、squito, culex tritaeniorhynchus.Survived winter mosquitoespigsmosquitoes mosquitoes personpigs,Epidemiology,Susceptibility of population: universal susceptible lifelong immunity subclinical infection : overt infection 10002000:1,Epidemiology,Epidemiologic features sporadic from July to Sep. children
5、 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 invasion cellular immunity blood brain barrier,Pathology,Pla
6、ce of lesion: all of CNS cerebral cortex, midbrain and thalamus . Pathologic features gross examination: congestion hemorrhage cerebral edema soften focuses,Pathology,microscopic examination: vascular lesion: endothelial cells swelling, necrosis neuron degeneration & necrosis neurogliocyte hyperplas
7、ia & inflammatory cells infiltration,perivascular cuffing , neuronophagia.,Clinical manifestation,incubation period:1014 days (421days )typical encephalitis BInitial periodcrisis periodconvalescent period sequela period,Clinical manifestation,Initial period : on the 1st to 3rd days abrupt onset feve
8、r 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
9、%,Clinical manifestation,central RF: reason of central RF: lesion of cerebral parenchyma (respiratory center injury in oblongata medulla) cerebral edema brain hernia intracranial hypertension hyponatremic encephalopathy,Clinical manifestation,manifestation of central RF: cacorhythmic breathing(cheyn
10、e-stokes breathing, apnea) brain hernia peripheral RF: dyspnea, regular breathing,Clinical manifestation,Other symptoms & signs of CNS meningeal irritations (neck stiffnessKernigs & Brudzinskis signs positive) Deep tendon reflexes from hyperactive to disappear pathologic reflexes positive limbs para
11、lysis,Clinical manifestation,Convalescent period T drop to normal in 25 days neurologic function regain gradually(2W) remain some behavioral & psychologic abnormalities,aphasia, dementia, rigidity paralysis. 6month - sequela,Clinical manifestation,Sequela period aphasia dementia persistent paralysis
12、,Clinical manifestation,Clinical type:mild typecommon typesevere typefulminant type,Clinical manifestation,Laboratory Findings,Blood picture: WBC 1020109 /L neutrophil 80%Cerebrospinal fluid - aseptic meningitis transparent or slightly cloudy, pressure may be elevated pleocytosis: 50500106/L protein
13、 may be elevated mildly glucose and chloride are normal,Laboratory Findings,Serological test: specific IgM Ab: blood or CSF,34d after onset, peak on 2 weekELISA or indirect immunofluorescence complement fixing Ab:2 week after onset, peak on 56 week, anamnestic diagnosis epidemiologic investigation,L
14、aboratory Findings,hemagglutination inhibition Ab:5d after onset, peak on 2 week diagnosis: 4 fold increase in titer epidemiologic investigation neutralized Abepidemiologic investigation,Laboratory Findings,pathogenic test virus isolation: blood, CSF, brain tissue RT-PCR : RNA,Diagnosis,Epidemiologi
15、cal data: 79 month 10yrs Clinical manifestation:fever, headache, vomiting, altered consciousness, convulsion, meningeal irritation, pathologic reflexes positive. Laboratory findings:WBC, CSF, IgM,Differential Diagnosis,toxic bacillary dysenteryhigh fever,convulsion,coma. 24h circulatory failure: ear
16、ly stool examination: WBC, RBC CSF: normal meningeal irritation: negative,Differential Diagnosis,tuberculous meningitisCSF, meningeal irritation purulent meningitis other viral encephalitis,Treatment,General therapy: Isolation:preventing mosquito biting, T30 nursing: mouth, skin, eye,turn overclappi
17、ng back sputum aspiration,Treatment,fluid & electrolyte supplementationadult: 15002000ml/dchildren: 5080ml/kg/dSymptomatic therapy high fever: T38,Treatment,physical cooling (ice bag, alcohol bathing, cold saline enema) drug cooling antipyreticsubhibernation:chlorpromazine 0.51mg/kg/timephenergan 0.
18、51mg/kg/time 46h, 35day,Treatment,convulsion: fever: coolingbrain edema: 20% mannitol 12g/kg/time50% glucosedexamethason,Treatment,sedative: valium: adult:1020mg/timechildren: 0.10.3mg/ kg/ time10% chloral hydrate:adult:12g/timechildren: 6080mg/kg/time subhibernation:,Treatment,respiratory failure:
19、keep airway clear sputum aspiration turn over , clapping back, postural drainage aerosolization inhalation of oxygen,Treatment,reducing cerebral edema & hernia dehydrate : 20% mannitol :12g/kg/time50% glucose , vasodilator: 654-2: adult: 20mg/timechildren: 0.51mg/kg/time1030 min,Treatment,respirator
20、y stimulant:lobeline: adult: 39mg/timechildren: 0.150.2mg/kg/timecoramine: adult: 0.3750.75g/timechildren: 510mg/kg/time tracheal intubation or tracheotomy, biomotor,Treatment,Convalescent & sequela period acupuncture massage 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,
