Rubella and Rubella Vaccine

Rubella and Rubella Vaccine

• Rubella and Rubella Vaccine

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 described by Gregg in 1941

Rubella Virus

• Togavirus

• RNA virus

• One antigenic type

• Rapidly inactivated by chemical agents, low pH, heat and ultraviolet light

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

• Lymphadenopathy in second week

• Maculopapular rash 14-17 days after exposure

Rubella Complications

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

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

Rubella Laboratory Diagnosis

• Isolation of rubella virus from clinical specimen (e.g., nasopharynx, urine)

• Significant rise in rubella IgG by any standard serologic assay (e.g., enzyme immunoassay)

• Positive serologic test for rubella IgM antibody

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, 1966-2001*

• Rubella - United States, 1966-2001*

Rubella - United States, 1980-2001*

• Rubella - United States, 1980-2001*

Rubella - United States, 1980-2000 Age Distribution of Reported Cases

Rubella and CRS in the United States, 1990s

• Most reported rubella in the U.S. since the mid-1990s has occurred among foreign-born Hispanic adults

• Rubella outbreaks have occurred in workplaces where most employees are foreign-born

• 83% of CRS since 1997 occurred in children of unvaccinated women born to Hispanic women, most born in Latin America

Rubella Case Definition

• Acute onset of generalized maculopapular rash, and

• Temperature of >37.2 C (>99 F), if measured, and

• Arthritis/arthralgia or lymphadenopathy or conjunctivitis

Rubella Outbreak Control Guidelines

• Laboratory diagnosis of rubella and CRS

• Step-by-step guidelines on evaluation and management of outbreak

• Rubella prevention and control among women of childbearing age

• Rubella and CRS surveillance

Rubella Vaccine

Rubella Vaccine

• Composition Live virus (RA 27/3 strain)

• Efficacy 95% (Range, 90%-97%)

• Duration of Immunity Lifelong

• Schedule 1 Dose

• Should be administered with measles and mumps as MMR

Rubella Vaccine (MMR) Indications

• All infants >12 months of age

• Susceptible adolescents and adults without documented evidence of rubella immunity

• Emphasis on non-pregnant women of childbearing age, particularly those born outside the U.S.

Rubella Immunity

• Documentation of one dose of rubella-containing vaccine on or after the first birthday

• Serologic evidence of immunity

• Birth before 1957 (except women of childbearing age)

Rubella Immunity

• Birth before 1957 is not acceptable evidence of rubella immunity for women who might become pregnant

• Only serology or documented vaccination should be accepted

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

Rubella Vaccine Arthropathy

• Acute joint symptoms in about 25% of susceptable adult women

• Frank arthritis occurs in about 10%

• Rare reports of chronic or persistent symptoms

• Population-based studies have not confirmed association

MMR Vaccine Contraindications and Precautions

• Severe allergic reaction to prior dose or vaccine component

• Pregnancy

• Immunosuppression

• Moderate or severe acute illness

• Recent blood product

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%

Rubella Vaccine Recommendations for Increasing Coverage

• Continued routine vaccination of children at age >12 months with vaccination required for school entry

• Screen and vaccinate susceptible persons

• health care workers
• college entry
• prenatal with postpartum vaccination
• other health care visits
• workplace

National Immunization Program

• Hotline [phone]

• Email [e-mail]

• Website www.cdc.gov/nip