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Early History of Measles
Reports of measles go back to at least 700
years, however, the first scientificdescription of the disease and its
distinction from smallpox attributed to the
Muslim physician Ibn Razi(Rhazes)860-932 who published a book
entitled "Smallpox and Measles" (inArabic: Kitab fi al-jadari wa-al-
hasbah).Dt.T.V.Rao MD 2
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Serious disease as Per WHO.
It remains a leadingcause of deathamong young childrenglobally, despite theavailability of a safeand effective vaccine.An estimated 197 000people died from
measles in 2007,mostly children underthe age of five
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Measles - Paramyxoviridae
Measles is an infectionof the respiratory systemcaused by a virus,specifically a
Paramyxovirus of thegenus MorbillivirusMorbilliviruses, like otherparamyxovirus, are
enveloped, single-stranded, negative-senseRNA viruses.
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Measles Virus
The measles virus is aspherical,nonsegmented, single-stranded RNA virus in
the Morbillivirusfamily,closely related to therinderpest and caninedistemper viruses. Itcontains six structural
proteins, three that arecomplexed to the RNAand three that areassociated with theviral membrane
envelope. Dt.T.V.Rao MD 5
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Fusion Protein
The F (fusion) protein isresponsible for fusion ofvirus and host cellmembranes, viral
penetration andhaemolysis. The H (hemagglutinin) protein isresponsible for adsorptionof the virus to cells.
There is only oneserotype of Measles virusand no subtypes have yetbeen recognized
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Measles
More than 20 millionpeople worldwide areaffected by measles eachyear. Measles outbreaks
are common in manyareas, including Europe.For many U.S. travellersand expatriates, the riskfor exposure to measles
can be high, but theillness can be preventedby a measles-containingvaccine
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Spread of Measles
Measles is spread through respiration
(contact with fluids from an infectedperson's nose and mouth, either directly or
through aerosol transmission), and ishighly. The infection has an averageincubation period of 14 days (range 6-19
days) and infectivity lasts from 2-4 daysprior to 2-5 days following the onset of therash.
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Measles threat to DevelopingWorld
In developing
countries, measlesaffects 30 million
children a year andcauses 1 milliondeaths. Measles
causes 15,000-60,000 cases ofblindness per year.
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Measles a Childhood Infection
Age-specific attackrates may be highestin susceptible infantsyounger than 12months, school-agedchildren, or youngadults, depending onlocal immunization
practices andincidence of thedisease.
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Prominent features andcomplications in Measles
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Patients on Physicalexamination
Patients tend to appear moderately ill anduncomfortable because of their viral prodromalsymptoms.
The Koplik spots are 1-2 mm, blue-gray maculeson an erythematous base.
The measles rash is a Maculopapulareythematous rash that involves the palms and
soles. Lesion density is greatest above the shoulders,
where macular lesions may coalesce
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Early Symptoms in Measles
The incubation period from exposure to
onset of symptoms ranges from 8-12 days.The prodromal phase is marked by
malaise, fever, anorexia,and conjunctivitis, cough, and coryza(the "3 Cs"). The entire course of
uncomplicated measles, from lateprodrome to resolution of fever and rash,is 7-10 days. Cough may be the final
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Beginning of Illness inMeasles
Approximately 10 days after the initial exposureto the virus, the classic viral prodrome occurs.
Fever
Non-productive cough
Coryza
Conjunctivitis
Additional prodromal symptoms may includemalaise, myalgia's, photophobia, and periorbitaloedema.
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A rash is leadingmanifestations
Typically begins at the
hairline and spreadscaudally over the next 3days as the prodromalsymptoms resolve.
The rash lasts 4-6 daysand then fades from thehead downward.
Desquamation may be
present but is generallynot severe.
Complete recovery fromthe illness generallyoccurs within 7-10 daysfrom the onset of the rashDt.T.V.Rao MD 15
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Koplik Spots leading clue toMeasles
With in 2-3 days,
the pathognomonicKoplik spots
typically arise onthe buccal,gingival, and labial
mucosa
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Rash is a Prominent Feature
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Risk factors for infection
Children withimmunodeficiencydue to HIV oracquiredimmunodeficiencysyndrome (AIDS),leukaemia, alkylatingagents, or
corticosteroid therapy,regardless ofimmunization status
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Spread of Virus
The highly
contagious virus isspread by
coughing andsneezing, closepersonal contact or
direct contact withinfected nasal orthroat secretion
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Risk factors for severemeasles
Malnutrition
Underlying
immunodeficiency
Pregnancy
Vitamin Adeficiency
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Mortality Rate in Measles
The mortality rateassociated withuncomplicated measles inimmunocompetent, well
nourished children is lowbut raises rapidly withmalnourishment(marked in African
children ), inimmunocompromised,and to lesser extent withage.
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Modified Measles
Modified measles occurs in children
who have received serum
immunoglobulin after their exposureto measles. The measles symptom
complex may still occur, but the
incubation period is as long as 21days, with the same symptoms as
measles but milder.
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Atypical Measles
Atypical measlesoccurs inindividuals whowere previouslyimmunized withthe killed measlesvaccine between1963 and 1967and who haveincompleteimmunity.
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Sub acute sclerosing panencephalitisSSPE
SSPE is a neurodegenerative diseasecaused by persistent infection of the brainby an altered form of the measles virus.
Neither the biology underlying the viralpersistence nor the triggering mechanismfor viral reactivation is well understood. In
most cases, infected children remainsymptom-free for 6-15 years after acutemeasles infection[
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Sub acute sclerosingpanencephalitis
Subacute sclerosingpanencephalitis(SSPE) 1 in 100,000people infected withmeasles developSSPE. SSPE is'incurable' but thecondition can be
managed bymedication iftreatment is started atan early stage.
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Clinical Presentation of SSPE
Characterized by a history of primary
measles infection usually before the age of2 years, followed by several asymptomatic
years (615 on average), and thengradual, progressive psycho neurologicaldeterioration, consisting of personality
change, seizures, myoclonus, ataxia,photosensitivity, ocular abnormalities,spasticity, and coma.
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Diagnosis of Measles
Most cases ofMeasles arediagnosed clinically,usually in patients
home or in Generalpractice
Direct Virologicalconfirmation is difficultin most of theDeveloping countries
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Diagnosis withImmunofluorescence
Direct andindirectimmunofluores
cence havebeen usedextensively to
demonstrateMV antigens incells from NPS
specimens.Dt.T.V.Rao MD 28
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Diagnosis by Viral Isolation
Measles virus can beisolated form a varietyof sources, e.g. throator conjunctivalwashings, sputum,
urinary sediment cellsand lymphocytes.Primary human kidney(HEK) cells are the best,although primarymonkey kidney can beused as well.Continuous cell linessuch as Vero cells canalso be used
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Diagnosis bySerology
Diagnosis of measlesinfection can be made ifthe antibody titres rise by4 fold between the acute
and the convalescentphase or if measles-specific IgM is found. Themethods that can be used
include HAI, CF,neutralization and ELISAtests.
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Diagnosis of SSPE
The presence ofmeasles specificantibodies in the CSFis the most reliable
means of laboratorydiagnosis of SSPE.Demonstration of MV-specific antibodies in
the CSF may besufficient with,
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Epidemiological Trends
Measles epidemicsoccur every 2 year indeveloped countries
in the absence ofwidespread use ofvaccine
Poverty and
overcrowdingincreases epidemics
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Treatment
Severe complications frommeasles can be avoided though
supportive care that ensures goodnutrition, adequate fluid intakeand treatment Antibiotics should
be prescribed to treat eye and earinfections, and pneumonia.
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VACCINATION
The Vaccines areLive attenuatedcontainingEdmonston B orSchwartz strainswhich will giveseroconversionrate of 90%.
The immunityproduce may belife long.
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Measles vaccine is given asMMR Vaccine
The measles vaccine isoften incorporated withrubella and/or mumpsvaccines in countries
where these illnesses areproblems. It is equallyeffective in the single orcombined form.
The combinationproved to beeffective and safe
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Two doses of MeaslesVaccine
Continued progressdepends on ensuringthat all children
receive two doses ofmeasles vaccineincluding one dose bytheir first birthday,
strengthening diseasesurveillance systems,and providingeffective treatment for
measles. Dt.T.V.Rao MD 36
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Changing trends for a BoosterDose
About 15% ofvaccinated
children fail todevelopimmunity
from the firstdose.
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