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Measles, Mumps and Rubella Ch 10, 11 & 12 Measles Highly contagious viral illness
First described in 7th century
Near universal infection of childhood in prevaccination era
Remains the leading cause of vaccine-preventable death in children
Paramyxovirus (RNA)
Rapidly inactivated by heat and light Measles Pathogenesis and Clinical Features Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Primary viremia 2-3 days after exposure
Secondary viremia 5-7 days after exposure with spread to tissues
Incubation period 10-12 days
Stepwise increase in fever to 103°F or higher
Cough, coryza, conjunctivitis
Koplik spots
2-4 days after prodrome, 14 days after exposure
Maculopapular, becomes confluent
Begins on face and head
Persists 5-6 days
Fades in order of appearance
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 Measles Vaccine Composition Live virus
Efficacy 95% (range, 90%-98%)
Duration of Immunity Lifelong
Schedule 2 doses
Should be administered with mumps and rubella as MMR, or with mumps, rubella and varicella as MMRV
1941 - 894,134 U.S. cases
1995 - 288 U.S. cases
Infants vaccinated at <12m who were born to naturally-infected mothers may not develop sustained antibody levels when later revaccinated
Primary failure
No seroconversion
Secondary failure
Loss of protection after seroconversion Vaccine Failure Measles Vaccine Indications for Revaccination Vaccinated before the first birthday
Vaccinated with killed measles vaccine
Vaccinated prior to 1968 with an unknown type of vaccine
Vaccinated with IG in addition to a further attenuated strain or vaccine of unknown type Mumps Acute viral illness
Parotitis and orchitis described by Hippocrates in 5th century BC
Viral etiology described by Johnson and Goodpasture in 1934
Frequent cause of outbreaks among military personnel in prevaccine era Mumps Virus Paramyxovirus
RNA virus
One antigenic type
Rapidly inactivated by chemical agents, heat, and ultraviolet light Mumps Pathogenesis Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Viremia 12-25 days after exposure with spread to tissues
Multiple tissues infected during viremia 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 infections asymptomatic 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 Mumps Outbreak, 2006 Source of the initial cases unknown
Outbreak peaked in mid-April
Median age of persons reported with mumps was 22 years
Highest incidence was among young adults 18-24 years of age, many of whom were college students
Transmission of mumps virus occurred in many settings, including college dormitories and healthcare facilities MMWR 2006;55(42):1152-3 Factors Contributing To Mumps Outbreak, 2006 College campus environment
Lack of a 2-dose MMR college entry requirement or lack of enforcement of a requirement
Delayed recognition and diagnosis of mumps
Mumps vaccine failure
Vaccine might be less effective in preventing asymptomatic infection or atypical mumps than in preventing parotitis
Waning immunity Passive immunization against mumps Immune globulin ineffective for postexposure prophylaxis
does not prevent disease or reduce complications
Transplacental maternal antibody appears to protect infants for first year of life Mumps Vaccine Composition Live virus (Jeryl Lynn strain)
Efficacy 95% (Range, 90%-97%)
Duration of Immunity Lifelong
Schedule >1 Dose
Should be administered with measles and rubella (MMR) or with measles, rubella and varicella (MMRV) Rubella From Latin meaning "little red"
Discovered in 18th century - thought to be variant of measles
First described as distinct clinical entity in German literature
Congenital rubella syndrome (CRS) described by Gregg in 1941 Rubella Virus Togavirus
RNA virus
One antigenic type
Rapidly inactivated by chemical agents, ultraviolet light, low pH, and heat Rubella Pathogenesis Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Viremia 5-7 days after exposure with spread to tissues
Placenta and fetus infected during viremia Rubella Clinical Features Incubation period 14 days
(range 12-23 days)
Prodrome of low-grade fever
Maculopapular rash 14-17 days after 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 Rubella Syndrome Infection may affect all organs
May lead to fetal death or premature delivery
Severity of damage to fetus depends on gestational age
Up to 85% of infants affected if infected during first trimester Congenital Rubella Syndrome Deafness
Cataracts
Heart defects
Microcephaly
Mental retardation
Bone alterations
Liver and spleen damage Rubella Epidemiology Reservoir Human
Transmission Respiratory Subclinical cases may transmit
Temporal pattern Peak in late winter and spring
Communicability 7 days before to 5-7 days
after rash onset Infants with CRS may shed virus for a year or more Rubella - United States, 1966-2005 Year Rubella Vaccine Composition Live virus (RA 27/3 strain)
Efficacy 95% (Range, 90%-97%)
Duration of Immunity Lifelong
Schedule At least 1 dose
Should be administered with measles and mumps as MMR or with measles, mumps and varicella as MMRV Rubella Vaccine Arthropathy Acute arthralgia in about 25% of vaccinated, susceptible adult women
Acute arthritis-like signs and symptoms occurs in about 10% of recipients
Rare reports of chronic or persistent symptoms
Population-based studies have not confirmed an association with rubella vaccine Vaccination of Women of Childbearing Age Ask if pregnant or likely to become so in next 4 weeks
Exclude those who say "yes"
For others
explain theoretical risks
vaccinate Vaccination in Pregnancy Study 1971-1989 321 women vaccinated
324 live births
No observed CRS
95% confidence limits 0%-1.2% Measles Mumps Rubella Vaccine 12 -15 months is the recommended and minimum age (more effective at 15 months)
MMR given before 12 months should not be counted as a valid dose
2nd dose at 4-6 years 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
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