5th Annual Advocacy Project:

ImmuneWiseSection on Medical Students,

Residents, and Fellowship Trainees2009-2010

Morning Report

Case Presentation

• A 24 year old G1P0 woman and her husband arrive for a prenatal visit

• The woman is a day care provider, and lets you know that there was a case of rubella reported at the day care center where she works– She was in her first trimester

Case Presentation

• In order to work at the day care center, her immunization record was reviewed– She was up-to-date (had two MMRs)

• She also had blood work done following her exposure (because she told her OB about it)– She was tested for rubella antibody– Her rubella IgG was positive

Case presentation

• The positive rubella IgG indicates immunity!

• The woman still has a lot of questions about rubella, especially about what it could have meant for the baby and what to watch for in the children at the day care center…

Rubella - Epidemiology• Droplet or Direct

Transmission• Humans are the only

source• Pre-vaccine

– Epidemic disease in 6-9 year cycles

• Post-vaccine (1969)– < 25 cases/year in the

U.S. since 2001– Vaccine is immunogenic

in 98% of recipients– Lifeline immunity in 90%

Rubella - epidemiology

• In the last decade, the rate of congenital rubella is down to less than 10 cases each year

• Occurrence of congenital defects is 85% if the maternal infection is during the 1st trimester --- this drops to 25% by end of 2nd trimester– One-half of maternal infections are subclinical

Rubella – ClinicalCongenital

• The ‘R’ of TORCH infections• Clinical findings may include:

– Ophthalmologic: Cataracts, pigmented retinopathy, microphthalmos, congenital glaucoma

– Dermatologic: Dermal erythropoiesis (“blueberry muffin rash”)– Cardiac: PDA, pulmonary artery stenosis– Auditory: Sensorineural hearing impairment

• This is the most common manifestation

– Neurologic: Mental retardation

• A majority of infants with proven congenital rubella are asymptomatic in the neonatal period

Congenital Rubella

Rubella – ClinicalChildren/Adolescents

• Incubation period 14-23 days– 25% of patients are asymptomatic but still transmit

disease

• Prodrome: Malaise, low-grade fever, eye pain, sore throat, lymphadenopathy (occipital, post-auricular, cervical)

• Exanthum– Discrete, pinkish red, fine, maculopapular; rarely puritic– Begins on face – spread is cephalocaudal – Generalized by 24 hours, usually resolved within 72

hours

Fine, maculopapular rashon face and chest

Rash (close-up)

Rubella – ClinicalChildren/Adolescents

• Arthralgias/Arthritis– Especially Fingers, wrists, and knees – More common in adolescents– Develops day 2-3 and lasts for up to 10 days

• Encephalitis – rare!

• Thrombocytopenia and purpura – rare!

Rubella Diagnosis

• Rubella-specific IgM antibody usually indicates a recent infection– False positives from rheumatoid factor, parvovirus

IgM, heterophile antibody

• Virus is best isolated by cell culture of throat or nasal specimens (special test)

• Blood, urine, CSF can be particularly helpful in congenital infections

Rubella - Treatment

• Supportive care

• Isolation with droplet precautions for 7 days after the onset of rash

• Infants with congenital rubella are considered contagious until 1 year of age!

From Prep 2005A 3100 gram term male infant is being evaluated in the nursery

shortly after birth. Findings on physical examination include a cataract in the left eye and a heart murmur. There is no evidence of intrauterine growth retardation, microcephaly, or hepatosplenomegaly. Of the following, the MOST likely cause of these findings in this infant is

A. Cytomegalovirus

B. Herpes simplex virus

C. Rubella

D. Syphilis

E. Toxoplasmosis

From Prep 2005A 3100 gram term male infant is being evaluated in the nursery

shortly after birth. Findings on physical examination include a cataract in the left eye and a heart murmur. There is no evidence of intrauterine growth retardation, microcephaly, or hepatosplenomegaly. Of the following, the MOST likely cause of these findings in this infant is

A. Cytomegalovirus

B. Herpes simplex virus

C. Rubella

D. Syphilis

E. Toxoplasmosis

References

• Centers for Disease Control

• Red Book 2009 – paper and online

• www.sciencemuseum.org.uk/broughttolife