流行性乙型脑炎的教育课件PPT-(1)

1、n History 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. Muscle hypertonia, knee hyperreflexia, Babinski

2、sign(+) Other history? Accessory examination?n Japanese encephalitis(JE), an acute infectious disease caused by the mosquito-borne Japanese encephalitis virus(JEV) and featured as inflammation in brain parenchyma.n Fever, confusion, coma, convulsion,pathological reflex and meningeal irritation . Res

3、piratory failure in severe cases,high mortality,and10% result in permanent neuropsychiatric sequelea.n A single stranded RNA, 40-50nm,11 kilobases genomes.RNA genome is packaged in the capsid protein forming the core of the virus.n The genomes also encodes several nonstructural proteins (NS1,NS2a,NS

4、3,NS4a,NS4b,and NS5)n JEV can be killed by disinfectant,100 2 minutes or 56 30 minutesn Antigenic stability, infection can produce complement-binding antibodies, neutralizing antibodies and hemagglutination inhibition antibodies, contribute to clinical diagnosis and epidemiological investigationn So

5、urces of infection: 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.n Other reservior includes cow, sheep, horse,duck

6、,goose and chicken.n Route 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.n Susceptible population: Generally

7、 susceptible, 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.n Epidemic feature: most cases in t

8、emperate and subtropical areas occur from June to September, while in tropical areas occur throughout the year.n Five 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.JEVMo

9、nonuclear macrophages multiplyviremiaInvade the CNSNot invade the CNSIncidenceLatent infectionJEVDirect invasionAntigen-antibody binding to the immune attackNerve cell lesionsVascular sheath formationThalamus, basal ganglia, brain stem, cerebellum,hippocampus, cerebral cortexGlialcell proliferationI

10、ncubation period of 5-15 days.the vast majority of infections 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. Anore

11、xia, nausea,or abdominal pain. Apathy and neck rigidity.n The proximity stage (fourth to tenth days) Hyperthermia Conscious disturbance Convulsion Respiratory failure Other nervous symptoms and signs Circulation failuren The proximity stage： Hyperthermia: acute onset; more than 40, lasts 7-10 days g

12、enerally and some grave cases can last for 3 weeks. The higher temperature, the longer course, the more serious of JE.n The proximity stage Conscious disturbance： Lethargy, delirium, coma, and disorientation are main presentations Appears mostly at the 3-8 days,lasting for almost 1 week A positive c

13、orralation between the serious and the lasting time of coma and the gravity of JE and prognosisn The proximity stage Convulsion： Causes: high fever, cerebral edema, brain parenchymal inflammation One or more focal/asymmetric signs appearing in the first few days Light : the face, lips, local convuls

14、ions, severe cases of the body About 30% of survivors have frank persistent motor language impairment.Respiratory failure: caused by inflammatory of brain parenchyma, hypoxia, cerebral edema, acute intracranial hypertension and cerebral hernia Cerebral henia： Spitting vomiting, convulsions Coma incr

15、eased Pupil changes. Anterior fontanel bulging, papilledeman The 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 accentuations first and th

16、e disappears and there are symptoms and meningeal irritation. hyperthermiaconvulsionRespiratory failureAre critical presentations of JE and respiratory failure is the leading cause of deathn The convalescence stage： Defervescence of fever and neurologic improvement It usually lasts for at least two

17、weeksn The sequelae stage： the existence of neuropsychiatric symptoms after 6 months 。 The incidence of about 5% to 20%. Clinical manifestationsn White blood cell: grows up to 1020109/L,neutrophil occupied more than 80%. Some patients have normal WBC counts.n Cerebrospinal fluid (CSF)：lumbar punctur

18、e to obtain CSF samples. n Cerebrospinal fluid (CSF)：The 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/dln Antiboby detection: Specific IgM antib

19、odies is the standard diagnostic test for 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 vaccinatio

20、ns n Nucleic acid detection: 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 begunn Inmaging studies: MRI and CTn Epidemiology data: rigorous seasonality :summer and aut

21、umn; less than 10 years old are more susceptible but more adult patients are seen now n Clinical features：acute onset headache, vomitting, hyperthermia, convulsion and positive pathologic reflex and meningeal irritation signn Laboratory examinations：peripheral blood picture , CSF, serum antibodies,E

22、EG,CT and MRI, brain biopsy n Virological investigation: JEV is difficult to be separated from blood and CSF. JEV antigen can be detected in such body fluid using PCR.Toxic bacillary dysenteryTuberculous meningitisPurulent meningitisEncephalitis bOnsetAcute，24 hour peakChronic,long course1-2 peak1-2

23、 peakSeasonSummer 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

24、 of pus cells, blood cultures of ShigellaCSF film smear TBCSF smear staining bacteriaCSF bacterial testing was negative. Specific IgM antibodiesn General treatmentn Symptomatic treatment hyperthermia, convulsion , respiratory failure n General treatment Coma patients should pay attention ： Oral clea

25、ning Prevent secondary bacterial infection Prevent bed sores occur Protect the cornea Anti-falling bed prevent the tongue bitten Note that water, electrolytes, acid-base balance, but not too much infusion volume to prevent brain edeman hyperthermia： Lower the room temperature Physical cooling:ice or

26、 alcohol cool saline With convulsions: hibernation therapy (chlorpromazine + promethazine)n convulsion： 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 o

27、f brain edema and dehydration agent rebound application Respiratory blockage: suction, oxygen, if necessary, tracheotomyn Respriatory failure： Brain edema : dehydrating agent Central respiratory failure: available respiratory stimulants Improve microcirculation, reduce cerebral edema: vasodilatorsn

28、Respriatory failure： 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

29、respiration ventilationn Recovery and sequelae of treatment: acupuncture, physical therapy, hyperbaric oxygen therapyn Control the source of infection : Vaccine the pigs before the epidemic seasonn Cut off the transmission: anti-mosquito, mosquito control.n Protection of susceptible populations, vac

30、cination injectionsn Vaccination 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.n Adverse reactions include local

31、 pain and redness, fever, gastrointestinal symptoms, headachen History 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. Musc