兒科學(xué)英文課件：16 measles

1、MEASLES Acute respiratory infectious disease caused by measles virus Clinical feature: Fever, Cough, Coryza, Conjunctivitis, Exanthem Specific sign: Kopliks Spots IntroductionClassification: ssRNAvirus Family: paramyxoviridaePathogenSerotype: Only oneLocation: Patients respiratory secretions Blood,

2、Urine of patientsCharacterization: 1. Sensitive to heat , ultraviolet light and disinfectant 2. Low temperature resistancePathogenEpidemiology infective stage:The infective stage is from the late of incubation stage to the 5th day after rash eruption. If complication occurs, the infective stage prol

3、ongs to the 10th day after rash eruption. Infectious sources- PatientsRoutes of transmissionEpidemiologyDroplet sprayPopulation susceptibilityEpidemiology It is susceptible to all the people without infection or inoculation. The age of peak incidence is from 6 months to 5 years old. Prior to the use

4、 of vaccineAfter the use of vaccineMorbidity (1/100000)Major epidemics: 500-1000Mild epidemics: 4009.5 in 1990Peak seasonIn winter and springIn any time of a yearEpidemic cycleMajor epidemics appear by 2-4 yr intervalsLonger cycle Sporadic cases increasedAge6m-5y (98%10y)Below 6m and teenageClinical

5、 manifestationsTypical casessevere manifestationsmore complicationshigh mortality Atypical cases increasedmild manifestationsless complicationsrarely deathEpidemiological FeaturesIncubation periodApparent manifestationsPathogenesisRespiratory epitheliumregional lymph nodesPrimary viremiamononuclear

6、phagocytic system Respiratory tract, conjunctiva, skin, etcVirus eliminationsecondary viremiaReported mechanisms of measles immune suppression.1. Functional Impairment1)Suppression of lymphocyte proliferation2)Altered cytokine profiles3)Lymphoproliferation defect due to MV-infected DC4)Immune modula

7、tion mediated by viral proteins5)Modulation of cell membrane components6)Inhibition of hematopoiesis2.Depletion1)Lymphocyte infection & depletion2)Bystander lymphocyte apoptosis3)DC infection & depletion4)T-cell apoptosis after interaction with MV-infected DC-Multinucleated giant cell(MGC)Pathology

8、= 15-100m MGC is the basic pathological change, with early diagnosis value.2、Maculopapular rash Branny desquamation Brownish discoloration3、Kopliks Spots1. Respiratory tract involvement widelyPathology13Typical measlesAtypical measleskey pointIncubation period Prodromal periodExanthemperiodConvalesc

9、ent period10-14 daysExposureTypical measlesKopliks SpotsA kind of rash present on mucous membranesGrayish spots as small as grain of sand on bright red background of mucosaMucous membrane opposite the 2nd lower molar, but may spread over the rest of the buccal mucosa. Appear and disappear rapidly (1

10、 - 2 days before the rash to 2- 3 days after the rash) Prodromal stage: 3-4days Fever Catarrh Kopliks Spots Other symptoms: anorexia, malaise ,diarrhea, and generalized lymphadenopathy. Fever: temperature rises Catarrh is more seriousExanthem stage: 3-5daysMaculopapular rashFeverCatarrhMaculopapular

11、 rash Other manifestations: light hepatomegaly and splenomegaly, enlarged lymph nodes gastrointestinal symptoms Exanthem stage: 3-5daysConvalescent stage: 3-5 days All symptoms relieve gradually. The rash fades in the same order it erupts 1.Branny desquamation 2.Brownish discoloration (hyperpigmenta

12、tion) Significant for the restrospective diagnosis for measlesConvalescent stage: 3-5 days Temp Kopliks spots皮疹色素沉著及脫屑 414039383736臨床分期前驅(qū)期出疹期恢復(fù)期Days 1-141234567891011121314眼結(jié)合膜炎咳嗽Summary of typical clinical featuresAtypical clinical manifestations of measles1. Mild measles2. Severe measles Complicat

13、ionsPneumonia is the most frequent complication of measles and it is the leading cause of death in measles. The younger the children, the more frequent of pneumonia. Two causes may involved: (1) Primary pneumonia (2) Secondary pneumonia- PneumoniaComplications The second most frequent complication C

14、auses: measles virus, other viruses or bacteria Laryngitis is more common and more severe in younger children. - LaryngitisHeadache, nausea, vomiting, meningeal irritation, convulsion, conscious disturbance Clinical feature: 2-5 days after the rash eruption similar to encephalitis caused by other vi

15、rusComplications- EncephalitisComplications SSPE is a quite rare complication with a low incidence of 1/1,000,000 It is a chronic encephalitis caused by persistent infection of mutational measles virus in central nervous system Long interval between the onset of measles and SSPEThe high risk of age

16、is 5-15 years old.- Subacute sclerosing panencephalitis (SSPE)Complications-Exacerbation of tuberculosis infectionUnderlying tuberculosis change to active TB disseminated TB tuberculous meningitisA temporary loss of hypersensitivity reaction to tuberculin skin testing-Malnutrition and Vitamin A defi

17、ciencyComplications Persistence of high fever Malfunction of gastrointestinal tract Old bad tradition Clinical features: night blindness, corneal ulceration, blindness, etc Routine administration of vitamin A with measles Lab studies The white blood cell count and differential WBC tends to be low an

18、d LC is relatively high Multinucleated giant cells can be demon strated in smears of the buccal mucosa during the prodromal stage. Testing of specific IgM in serum Measles virus isolationDiagnosis Epidemiologic data Clinical data Laboratory dataDiagnosis -Epidemiologic dataAgeSeasonHistory of contac

19、t with patientHistory of inoculationDiagnosis-Clinical dataProdromal periodConvalescent periodKopliks spotsTypical rash Correlation of rash and feverCatarrhBranny desquamation Brownish discolorationExanthem periodDiagnosis -Laboratory data Multinucleated giant cells Testing of specific IgM in serum

20、The diagnosis is usually made from the characteristic clinical picture, laboratory confirmation is rarely needed.Differential diagnosis Rubella Roseola infantum Differential diagnosisDifferential diagnosisPrevention Control of sources of infections The susceptible contacts will be isolated for clini

21、cal observation for 3 weeks after exposure. Quarantine period Abrupt the ways of transmission Sterilize wardPrevention Control of sources of infections Abrupt the ways of transmission Protect the susceptible passive immunization active immunizationPrevention Post-exposure prophylaxis by immune globu

22、lin can prevent or modify measles in susceptible contacts To be effective, it must be given within 5 days after exposure -Passive immunizationImmune globulin can be given intramuscularly at a dose of 0.25ml/kgFor immunocompromised individuals the dose is 0.5ml/kgMeasles VaccineComposition : attenuat

23、ed live virusEfficacy : 95% (range, 90%-98%)Schedule: 2 doses， decided by the susceptible groups in different regionsPrevention- Active immunization 2 doses starting at age 8 months, then at age 7 years Pregnant women Children with immunodeficiency Children with untreated tuberculosis Cancer patients Organ transplantation receptor Children with long term immunosuppressive therapyPrevention-Contraindication:Treatment Antipyretics for fever Be