Measles

• Highly contagious viral illness

• First described in 7th century

• Near universal infection of childhoodin prevaccination era

• Common and often fatal in developingareas

• Paramyxovirus (RNA)

• Rapidly inactivated by heat and light

Measles Pathogenesis

• Respiratory transmission of virus

• Replication in nasopharynx andregional lymph nodes

• Primary viremia 2-3 days afterexposure

• Secondary viremia 5-7 days afterexposure with spread to tissues

Measles Clinical Features

• Incubation period 10-12 days

• Stepwise increase in fever to103°F or higher

• Cough, coryza, conjunctivitis

• Koplik spots

Prodrome

Measles Clinical Features

• 2-4 days after prodrome, 14 daysafter exposure

•Maculopapular, becomesconfluent

• Begins on face and head

• Persists 5-6 days

• Fades in order of appearance

Rash

Condition

Diarrhea

Otitis media

Pneumonia

Encephalitis

Hospitalization

Death

Percent reported

8

7

6

0.1

18

0.2

Measles Complications

Based on 1985-1992 surveillance data

Measles Epidemiology

• Reservoir Human

• Transmission Respiratory Airborne

• Temporal pattern Peak in late winter–spring

• Communicability 4 days before to 4 days after rash onset

0

100

200

300

400

500

600

700

800

900

1950 1960 1970 1980 1990 2000

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Measles—United States, 1950-2005

Measles Vaccine

• Composition Live virus

• Efficacy 95% (range, 90%-98%)

• Duration ofImmunity Lifelong

• Schedule 2 doses

• Should be administered with mumps andrubella as MMR, or with mumps, rubellaand varicella as MMRV

MMR Vaccine Failure

• Measles, mumps, or rubelladisease (or lack of immunity) in apreviously vaccinated person

• 2%-5% of recipients do notrespond to the first dose

• Caused by antibody, damagedvaccine, record errors

• Most persons with vaccine failurewill respond to second dose

Measles Mumps Rubella Vaccine

• 12 -15 months is therecommended and minimum age(more effective at 15 months)

•MMR given before 12 monthsshould not be counted as a validdose

• 2nd dose at 4-6 years

Second Dose of Measles Vaccine

• Intended to produce measlesimmunity in persons who failed torespond to the first dose (primaryvaccine failure)

•May boost antibody titers in somepersons

Measles VaccineIndications for Revaccination

• Vaccinated before the first birthday

• Vaccinated with killed measlesvaccine

• Vaccinated prior to 1968 with anunknown type of vaccine

• Vaccinated with IG in addition to afurther attenuated strain or vaccineof unknown type

MMR Adverse Reactions

• Fever 5%-15%

• Rash 5%

• Joint symptoms 25%

• Thrombocytopenia <1/30,000 doses

• Parotitis rare

• Deafness rare

• Encephalopathy <1/1,000,000 doses

MMR Vaccine and Autism

•Measles vaccine connection firstsuggested by Britishgastroenterologist

• Diagnosis of autism often made insecond year of life

•Multiple studies have shown NOassociation

MMR VaccineContraindications and Precautions

• Severe allergic reaction to vaccinecomponent or following prior dose

• Pregnancy

• Immunosuppression

•Moderate or severe acute illness

• Recent blood product

Measles and MumpsVaccines and Egg Allergy

•Measles and mumps virusesgrown in chick embryo fibroblastculture

• Studies have demonstrated safetyof MMR in egg allergic children

• Vaccinate without testing

Measles Vaccine and HIV Infection

• MMR recommended for persons withasymptomatic and mildlysymptomatic HIV infection

• NOT recommended for those withevidence of severe immuno-suppression

Vaccine Storage and HandlingMMR Vaccine

• Store 35o - 46oF (2o - 8oC) (may bestored in the freezer)

• Store diluent at room temperatureor refrigerate

• Protect vaccine from light

• Discard if not used within 8 hoursreconstitution

Mumps

• Acute viral illness

• Parotitis and orchitis described byHippocrates in 5th century BC

• Viral etiology described byJohnson and Goodpasture in 1934

• Frequent cause of outbreaksamong military personnel inprevaccine era

Mumps Virus

• Paramyxovirus

• RNA virus

• One antigenic type

• Rapidly inactivated by chemicalagents, heat, and ultraviolet light

Mumps Pathogenesis

• Respiratory transmission of virus

• Replication in nasopharynx andregional lymph nodes

• Viremia 12-25 days after exposurewith spread to tissues

•Multiple tissues infected duringviremia

Mumps Clinical Features

• Incubation period 14-18 days

• Nonspecific prodrome of myalgia,malaise, headache, low-grade fever

• Parotitis in 30%-40%

• Up to 20% of infectionsasymptomatic

CNS involvement

Orchitis

Pancreatitis

Deafness

Death

15% of clinical cases

20%-50% in post-

pubertal males

2%-5%

1/20,000

Average 1 per year

(1980 – 1999)

Mumps Complications

Mumps Epidemiology

• Reservoir Human Asymptomatic infections

may transmit

• Transmission Respiratory drop nuclei

• Temporal pattern Peak in late winter and spring

• Communicability Three days before to four days after onset of active

disease

0

20

40

60

80

100

120

140

160

1970 1975 1980 1985 1990 1995 2000 2005

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Mumps—United States, 1968-2005

Year

Mumps Outbreak, 2006

• Source of the initial cases unknown

• Outbreak peaked in mid-April

• Median age of persons reported withmumps was 22 years

• Highest incidence was among youngadults 18-24 years of age, many of whomwere college students

• Transmission of mumps virus occurred inmany settings, including collegedormitories and healthcare facilities

MMWR 2006;55(42):1152-3

Factors Contributing To MumpsOutbreak, 2006

• College campus environment

• Lack of a 2-dose MMR college entryrequirement or lack of enforcement of arequirement

• Delayed recognition and diagnosis ofmumps

• Mumps vaccine failure

• Vaccine might be less effective inpreventing asymptomatic infection oratypical mumps than in preventing parotitis

• Waning immunity

Mumps Vaccine

• Composition Live virus (Jeryl Lynn strain)

• Efficacy 95% (Range, 90%-97%)

• Duration ofImmunity Lifelong

• Schedule >1 Dose

• Should be administered with measles andrubella (MMR) or with measles, rubella andvaricella (MMRV)

Rubella• From Latin meaning "little red"

• Discovered in 18th century - thoughtto be variant of measles

• First described as distinct clinicalentity in German literature

• Congenital rubella syndrome (CRS)described by Gregg in 1941

Rubella Virus

• Togavirus

• RNA virus

• One antigenic type

• Rapidly inactivated by chemicalagents, ultraviolet light, low pH,and heat

Rubella Pathogenesis

• Respiratory transmission of virus

• Replication in nasopharynx andregional lymph nodes

• Viremia 5-7 days after exposurewith spread to tissues

• Placenta and fetus infected duringviremia

Rubella Clinical Features

• Incubation period 14 days

(range 12-23 days)

• Prodrome of low-grade fever

•Maculopapular rash 14-17 daysafter exposure

• Usually quite mild

Epidemic Rubella – United States,1964-1965

• 12.5 million rubella cases

• 2,000 encephalitis cases

• 11,250 abortions(surgical/spontaneous)

• 2,100 neonatal deaths

• 20,000 CRS cases

–deaf - 11,600

–blind - 3,580

–mentally retarded - 1,800

Congenital RubellaSyndrome

• Infection may affect all organs

• May lead to fetal death or prematuredelivery

• Severity of damage to fetus dependson gestational age

• Up to 85% of infants affected ifinfected during first trimester

Congenital RubellaSyndrome

• Deafness

• Cataracts

• Heart defects

•Microcephaly

•Mental retardation

• Bone alterations

• Liver and spleen damage

Rubella Epidemiology

• Reservoir Human

• Transmission RespiratorySubclinical cases maytransmit

• Temporal pattern Peak in late winter and spring

• Communicability 7 days before to 5-7 days

after rash onsetInfants with CRS may shed virus for a year or more

0

10000

20000

30000

40000

50000

60000

70000

1966 1970 1975 1980 1985 1990 1995 2000 2005

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30

40

50

60

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CR

S C

ases

Rubella CRS

Rubella - United States, 1966-2005

Year

Rubella Vaccine

• Composition Live virus (RA 27/3 strain)

• Efficacy 95% (Range, 90%-97%)

• Duration ofImmunity Lifelong

• Schedule At least 1 dose

• Should be administered with measles and mumpsas MMR or with measles, mumps and varicella asMMRV

Rubella VaccineArthropathy

• Acute arthralgia in about 25% ofvaccinated, susceptible adult women

• Acute arthritis-like signs and symptomsoccurs in about 10% of recipients

• Rare reports of chronic or persistentsymptoms

• Population-based studies have notconfirmed an association with rubellavaccine

Vaccination of Womenof Childbearing Age

• Ask if pregnant or likely tobecome so in next 4 weeks

• Exclude those who say "yes"

• For others

– explain theoretical risks

– vaccinate

Vaccination inPregnancy Study 1971-

1989• 321 women vaccinated

• 324 live births

• No observed CRS

• 95% confidence limits 0%-1.2%