医学精品课件：8麻疹.ppt

1、Yinghu Chen,M.DChildrens Hospital of Zhejiang UniversityOutlinenEtiologynEpidemiologynPathogenesisnClinical manifestationsnLab findingsnTreatmentnComplicationsnPreventionsIntroductionnHistorically widespread but now very rarenCharacterized by fever,coryza,cough,Kopliks spots,and maculopapular rash E

2、tiologynMeasles virus,a single-stranded RNA paramyxovirus with one antigenic type.Humans are the only natural host nFound in nasopharyngeal secretions,blood and urine,during the prodromal period and for a short time after the rash appearsnRemain active for 1-2 days at room temperatureEpidemiologynSp

3、read throughout the world,vaccine-preventable diseasenFor susceptible persons,90%of the exposed acquire disease nInfection sources:patients and person with latent infectionnContagious period:5 days before and after the rash appearance,accompanied with pneumonia,prolonging to 10th daynTransmission:ai

4、rborne and contact nSeason:spring,Age:5-10yrnNew trends:measles appears in 8m infants and elders,due to inadequate vaccination as well as vaccine failurePathogenesisnProcess of virus in the body (two times of viremia)Invade airway endothelial cells,portal lymph node,and multiply(warthin-Finkeldey gi

5、ant cell)Some invade to blood Captured by Monocyte-macrophage system,and replicates greatly,Invade blood second time,cause disseminated lesions,some target T cellsnThe host immunity decrease,induce secondary bacterial infection and TB reactivationEndothelial cellsDendritic cellT cellsPathogenesisnKo

6、plik spots Consist of serous exudate and proliferation of endothelial cells nInterstitial pneumonia due to measles virusnBronchopneumonia may due to secondary bacterial infectionnPerivascular demyelinization in brain and spinal cordnSubacute sclerosing panencephalitis(SSPE)Degeneration of the cortex

7、 and white matter with inclusion bodies,occur 7-11yr after measles,measles antibodies are detected in CSFClinical manifestaionsnPersons with typical symptomsimmunocompetent children who didnt receive measles vaccine,or vaccine failure,and didnt receive immunoglobulin nFour stagesIncubation stage:6-1

8、2d,may transmit virus by 9-10th dayProdromal stage:3-5d,fever,cough,coryza,Koplik spotsRash stage:rash erupts for 2-3d,and fadesRecovery stageProdromal stagenLast 3-5d,low-grade to moderate fever,dry cough,coryza,and conjunctivitis,photophobia,Koplik spots.Koplik spots and Stimson linenKoplik spots:

9、1-2d before rash,grayish white dots,as small as grains,opposite the lower molars,may spread over the buccal mucosa,last 12-24hrnStimson line:transverse line of inflammation along the eyelid marginRash stagenTemperature rises abruptly as the rash appears and often reaches 40 or highernThe rash appear

10、s and fade downward sequence:stars(faint macules)on the upper lateral part of neck,behind the ears,along the hairline,cheek,spreads to entire face(maculopapular),neck,upper arms,chest back,abdomen,entire arm,thighs,and finally reach feet on the 2nd-3rd daynIn uncomplicated cases,as the rash appears

11、on the legs and feet,the patients may appear desperately ill,but the symptoms subside within 2dnBranny desquamation within 7-10dBlack measlesnHemorrhagic type of measlesBleeding may occur from mouth,nose,or bowel,thrombocytopeniaOccurs in immunocompromised or secondly infection patientsnRash is conf

12、luent,petechiaenOften accompanied with pneumonia,heart failure,disseminated intravascular coagulation(DIC),high mortalityModified measlesnMild casesnOccurs in person with partial protection against measles,such as vaccine,immuoglobulinLaboratory findings nCytopathic changeWarthin-Finkeldey cells:con

13、sist of multinucleated giant cells with intranuclear inclusionsnAntigen:in nasal mucosanPCR nVirus isolationnAntibodiesIgM and IgG become detectable when the rash appears nLeucocytopenia with a relative lymphocytosis Chest radiographnMay show interstitial or perihilar infiltrates,but do not distingu

14、ish measles pneumonia and bacterial superinfection.DiagnosisnContact historynCharacteristic clinical picturenLaboratory confirmation is rarely neededDifferential diagnosisnAll kind of fever with red rashesnSuch as:Rubella,roseola,scarlet fever,meningococcemia,drug fever,Kawasaki disease,serum sickne

15、ss,infectious mononucleosis,toxoplasmosis,etcDifferential diagnosisnEnteroviral and adenoviral infections,rubella:The rashes are less striking without desquamationnRoseola infantum:the rash appears as fever disappearsnSerum illness and drug fever:The absence of administration of a drug historyRed ra

16、sh in bacterium infectionnAcute meningococcemiaThe rash is petechial,and purpuric without cough and conjunctivitisnStreptococcal scarlet feverThe diffuse,finely papular rash has a“goose flesh”texture,“sandpaper”texture,strawberry tongue,red pharynx.Perioral and periorbital area,palm,and soles have n

17、o rash.Rash desquamates after 7-14dnStaphylococcal scarlet feverResembles streptococcal scarlet fever Except strawberry tongue,pharynx,and focal infection usually presents TreatmentnNo specific antiviral therapynSupportive treatment:antipyratic,bed rest,fluid intake,avoiding exposure to strong light

18、snVitamin A:7-12m infant:100,000IU,1y:200,000IU,reduce the morbidity and mortalitynComplications such as encephalitis,giant cell pneumonia,DIC must be assessed individuallynSecondary infection requires antimicrobial therapynImmune globulin and corticosteroids has limited valueComplicationnPneumoniaI

19、nterstitial pneumonia:may be caused by measles virus(giant cell pneumonia),measles pneumonia in HIV-infected patients is often fatal.However,bacterial superinfection and bronchopneumonia is more frequentnReactivation of TB infection,and anergy to PPDnMyocarditisAn infrequent serious complication,var

20、ies from transient electrocardiographic changes to heart failure,and cardiogenic shockComplication in nervous system nEary encephalitis1-2/1000 cases,occur from prodromal period to final stagenLate encephalitisDemyelinization,probably an immunopathologic phenomenon.nSubacute sclerosing panencephalit

21、is(SSPE)A chronic encephalitis caused by persistant measles virus infection of the central nervous system,occur 8-10yr after measlesInsidiously onset,subtle changes in behavior,and deterioration of schoolwork,and finally dementia.1/1,000,000 measlePrognosisnDeaths:bronchopneumonia or encephalitis(15

22、%),with malignancy or HIV infectionnSSPEPreventnAttenuate live measle vaccineTwo times(8m,4-6yr),not booster,but intensive immunization nContraindications:Immunocompromised states,pregnancy or recent administration of IVIg Postexposure prophylaxisnVaccine within 72 hr(produce antibody within 7-12d)nImmune globulin within 6dTypical temperature curve of measles and the effectiveness of passive immunizationTake home pointsnKoplik spotsnFeature of measles maculopapular rashnDifferential diagnosis of red rashnComplicationsnPost exposure prophylaxis