流行性乙型脑炎的教育课件PPT1教学提纲.ppt

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1、流行性乙型脑炎的教育课件PPT1AbstractnJapanese encephalitis(JE),an acute infectious disease caused by the mosquito-borne Japanese encephalitis virus(JEV)and featured as inflammation in brain parenchyma.nFever,confusion,coma,convulsion,pathological reflex and meningeal irritation.Respiratory failure in severe cas

2、es,high mortality,and10%result in permanent neuropsychiatric sequelea.EtiologynA single stranded RNA,40-50nm,11 kilobases genomes.RNA genome is packaged in the capsid protein forming the core of the virus.nThe genomes also encodes several nonstructural proteins(NS1,NS2a,NS3,NS4a,NS4b,and NS5)nJEV ca

3、n be killed by disinfectant,100 2 minutes or 56 30 minutesEtiologynAntigenic stability,infection can produce complement-binding antibodies,neutralizing antibodies and hemagglutination inhibition antibodies,contribute to clinical diagnosis and epidemiological investigationEpidemiologynSources of infe

4、ction:JE is a zoonosis,mosquitoes become infected by feeding domestic pigs and wild birds infected with the JEV.JEV is amplified in the blood systems of the domestic pigs and wild birds.Pigs are the improtant amplified and reservoirs.nOther reservior includes cow,sheep,horse,duck,goose and chicken.E

5、pidemiologynRoute of transmission:the bite of an infected mosquito,primarily Culex species.Humans are a dead-end host in the JEV tramsmission cycle.JEV is not transmitted from person-to-person.Only domestic pigs and wild birds are carriers of the JEV.Epidemiology.nSusceptible population:Generally su

6、sceptible,especially residents of rural areas in endemic location,mostly asymptomatic.The ratio of patients and latent infection was 1:1000-2000.Pre-existing antibodies.Countries that still have periodic epidemics include India,Cambodia,Nepal and so on.Epidemiology.nEpidemic feature:most cases in te

7、mperate and subtropical areas occur from June to September,while in tropical areas occur throughout the year.nFive genotypes:genotypes I,II,III,IV,V.Genotypes I and III occur principally in temperate,epidemic areas,and genotype II and IV occur principally in tropical,endemic regions.Pathogenesis and

8、 PathologyJEVMononuclear macrophages multiplyviremiaInvade the CNSNot invade the CNSIncidenceLatent infectionThis section of brain was taken from a patient with Japanese This section of brain was taken from a patient with Japanese encephalitis,and shows the gross pathology found in all of the enceph

9、alitis,and shows the gross pathology found in all of the arbovirus encephalitides.The changes,which consist of perivascular arbovirus encephalitides.The changes,which consist of perivascular congestion and hemorrhage,may be diffuse or focal,but they are seen congestion and hemorrhage,may be diffuse

10、or focal,but they are seen predominantly in cortical gray and deep gray matterpredominantly in cortical gray and deep gray matterPathogenesis and PathologyJEVDirect invasionAntigen-antibody binding to the immune attackNerve cell lesionsVascular sheath formationThalamus,basal ganglia,brain stem,cereb

11、ellum,hippocampus,cerebral cortexGlialcell proliferationShow softening lesions,oval-shaped light pale Show softening lesions,oval-shaped light pale area,the structure was loose mesharea,the structure was loose meshClinical manifestationsIncubation period of 5-15 days.the vast majority of infections

12、are asymptomatic,only 1 in 250 infections develop into encephalitis.Typical manifestation:there are four stagesThe primary stage(1-3 days):onset was sudden with high fever,up to 39-41 in 1-2 days accompanied headache and malaise.Anorexia,nausea,or abdominal pain.Apathy and neck rigidity.Clinical man

13、ifestationsnThe proximity stage(fourth to tenth days)HyperthermiaConscious disturbanceConvulsionRespiratory failureOther nervous symptoms and signsCirculation failureClinical manifestationsnThe proximity stage：Hyperthermia:acute onset;more than 40,lasts 7-10 days generally and some grave cases can l

14、ast for 3 weeks.The higher temperature,the longer course,the more serious of JE.Clinical manifestationsnThe proximity stageConscious disturbance：Lethargy,delirium,coma,and disorientation are main presentationsAppears mostly at the 3-8 days,lasting for almost 1 weekA positive corralation between the

15、serious and the lasting time of coma and the gravity of JE and prognosisClinical manifestationsnThe proximity stage Convulsion：Causes:high fever,cerebral edema,brain parenchymal inflammationOne or more focal/asymmetric signs appearing in the first few daysLight:the face,lips,local convulsions,severe

16、 cases of the bodyAbout 30%of survivors have frank persistent motor language impairment.Clinical manifestationsRespiratory failure:caused by inflammatory of brain parenchyma,hypoxia,cerebral edema,acute intracranial hypertension and cerebral hernia Cerebral henia：Spitting vomiting,convulsionsComa in

17、creasedPupil changes.Anterior fontanel bulging,papilledemaClinical manifestationsnThe proximity stage：Circulation failure:rarely,tachycardia,hyper or hypotension and rarely ECG evidence of pericarditis.Other nervous symptoms and signs:superficial reflex disappears or weakens;deep reflex accentuation

18、s first and the disappears and there are symptoms and meningeal irritation.Clinical manifestations hyperthermiaconvulsionRespiratory failureAre critical presentations of JE and respiratory failure is the leading cause of deathClinical manifestationsnThe convalescence stage：Defervescence of fever and

19、 neurologic improvementIt usually lasts for at least two weeksClinical manifestationsnThe sequelae stage：the existence of neuropsychiatric symptoms after 6 months。The incidence of about 5%to 20%.Axial T2 weighted(TR/TE=2500/90)image.(A)Hyperintense Axial T2 weighted(TR/TE=2500/90)image.(A)Hyperinten

20、se lesions at bilateral thalami(arrows)were shown on the 14th days lesions at bilateral thalami(arrows)were shown on the 14th days after onset.(B)Small hyperintense lesions at bilateral thalami after onset.(B)Small hyperintense lesions at bilateral thalami(arrows)on the 60th day after onset(arrows)o

21、n the 60th day after onsetClinical manifestationsLaboratory examinationsnWhite blood cell:grows up to 1020109/L,neutrophil occupied more than 80%.Some patients have normal WBC counts.nCerebrospinal fluid(CSF)：lumbar puncture to obtain CSF samples.Laboratory examinationsnCerebrospinal fluid(CSF)：The

22、opening pressure is usually normal but may be raised.Mononuclear white blood cells may be 50500106/L;Glucose levels are normal;Protein levels are mildly elevated in most cases,often less than 900mg/dlLaboratory examinationsnAntiboby detection:Specific IgM antibodies is the standard diagnostic test f

23、or JE,nearly 100%sensitivity;IgM antibody levels may be found even within 7 days of symptoms.False-negative results may occur if the samples are testd too early.Some cross-reactivity may arise from other flaviviruses and from JE and yellow fever vaccinations Laboratory examinationsnNucleic acid dete

24、ction:detection of viral genome by RT-PCR is easier to perform and highly reliable with 100%sensitivity,JEV has been isolated up to even almost 4 months after clinical symptoms have begunnInmaging studies:MRI and CTDiagnosisnEpidemiology data:rigorous seasonality:summer and autumn;less than 10 years

25、 old are more susceptible but more adult patients are seen now nClinical features：acute onset headache,vomitting,hyperthermia,convulsion and positive pathologic reflex and meningeal irritation signDiagnosisnLaboratory examinations：peripheral blood picture,CSF,serum antibodies,EEG,CT and MRI,brain bi

26、opsy nVirological investigation:JEV is difficult to be separated from blood and CSF.JEV antigen can be detected in such body fluid using PCR.Differential diagnosisToxic bacillary dysenteryTuberculous meningitisPurulent meningitisEncephalitis bOnsetAcute，24 hour peakChronic,long course1-2 peak1-2 pea

27、kSeasonSummer to autumnNon-seasonalwinter and springSummer to autumnCSFNormalChloride and glucose are low,high protein,cell count 50*106/LChloride and glucose are low,high protein,cell count 1000*106/LChloride and glucose are normal,high protein,cell count 50500*106/LPathogenAnus dry smear of pus ce

28、lls,blood cultures of ShigellaCSF film smear TBCSF smear staining bacteriaCSF bacterial testing was negative.Specific IgM antibodiesTreatmentnGeneral treatmentnSymptomatic treatment hyperthermia,convulsion,respiratory failure TreatmentnGeneral treatmentComa patients should pay attention：Oral cleanin

29、gPrevent secondary bacterial infectionPrevent bed sores occurProtect the corneaAnti-falling bedprevent the tongue bittenNote that water,electrolytes,acid-base balance,but not too much infusion volume to prevent brain edemaTreatmentnhyperthermia：Lower the room temperaturePhysical cooling:ice or alcoh

30、ol cool salineWith convulsions:hibernation therapy(chlorpromazine+promethazine)Treatmentnconvulsion：Cerebral edema:dehydration,20%mannitol 1-2g/Kg,intravenous infusion,4-6h time,while combined with adrenal cortex hormones,furosemide,50%GS,to reduce vascular permeability,Prevention of brain edema and

31、 dehydration agent rebound applicationRespiratory blockage:suction,oxygen,if necessary,tracheotomyTreatmentnRespriatory failure：Brain edema:dehydrating agentCentral respiratory failure:available respiratory stimulantsImprove microcirculation,reduce cerebral edema:vasodilatorsTreatmentnRespriatory fa

32、ilure：Respiratory secretions Infarct:suction,atomization inhalation of-chymotrypsin;with bronchospasm may be 0.25%-0.5%isoproterenol inhalation.And appropriate treatment with antibiotics such as bacterial infection.If necessary,endotracheal intubation or incision,artificial respiration ventilationTr

33、eatmentnRecovery and sequelae of treatment:acupuncture,physical therapy,hyperbaric oxygen therapyprognosisnControl the source of infection:Vaccine the pigs before the epidemic seasonnCut off the transmission:anti-mosquito,mosquito control.nProtection of susceptible populations,vaccination injections

34、prognosisnVaccination injections:the current dosing schedule for patients aged 3 years or older is 1ml subcutaneously on days 0,7,and 30(0.5ml in patients aged 1-2y).Administer the last dose of vaccine at least 10days prior to travel in an endemic area.nAdverse reactions include local pain and redne

35、ss,fever,gastrointestinal symptoms,headacheCase reportnHistory taking：A boy,4 years old，born in the countryside.Fever last for 4 days，convulsion and confusion last about 6 hours.Physical examination：T 40.5，R 30bpm，P 120bpm，BP100/60mmHg.Unconsciousness,conjunctival edema,lungs can be heard wheezes.Mu

36、scle hypertonia,knee hyperreflexia,Babinski sign(+)Other history?Accessory examination?Case reportnOther historyBefore the disease with or without diarrhea,cough,wound infectionWith or without history of chronic fever and coughHistory of vaccinationThe living environmentWith or without similar patie

37、ntsCase reportnTake into account the supplementary examinationsWBC analysisConventional stool CSFBlood culture Case reportnFurther historyHeadache,projectile vomiting at early onsetHealth,history of vaccination is unknownSlaughter pig local free-range,mosquito is more.The recent local similar patien

38、ts.Auxiliary examination：WBC15109/L，N82。Conventional stool is normal。CSF：WBC 62106/LnDignosis?Treatment？Case reportnDignosis:JEVnTreatment：General treatment:oxygen.Infusion supplement water,electrolytes,vitamins.Choose antimicrobials to prevent respiratory tract infection Control temperatureKeep respiratory tract unobstructed:Timing sputum suction,roll over,take backRelieve cerebral edema:mannitol+50%glucose alternating intravenousThank you！此课件下载可自行编辑修改，仅供参考！此课件下载可自行编辑修改，仅供参考！感谢您的支持，我们努力做得更好！谢谢感谢您的支持，我们努力做得更好！谢谢