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Detailed information of CONGENITAL RUBELLA
CONGENITAL RUBELLA
DEFINITION:
A contagious infectious disease caused by an RNA Togavirus with
ocular, central nervous system (CNS), and systemic manifestations.
EPIDEMIOLOGY:
- incidence: 1/10,000 live births (in immunized populations)
- age of onset:
- risk factors:
PATHOGENESIS:
- the rate of transmission is inversely related to the
gestational age:
- 1st trimester - 75-90%
- 2nd trimester - 35-40%
- 3rd trimester - 25-50%
- the risk of congenital malformations also varies
inversely with the gestational age:
- 9-12 weeks - 30% (increased risk of congenital heart
disease & deafness)
- 13-20 weeks - 10% (")
- 20 weeks - little risk of malformations but may
produce chronic infection of the eyes, ears, & CNS
- inadvertent immunization of a pregnant seronegative
women rarely produces fetal infection (1-2%) and does not
cause congenital or teratogenic abnormalities
2. Maternal Reinfection
- rare but can cause congenital rubella infection and
teratogenesis
2. Background
- maternal viremia -> infection of the placenta -> transmitted
to the fetus -> fetal viremia with dissemination to multiple
organs and tissues + vasculitis -> chronic infection in utero
and persisting for months to years after birth -> vascular
insufficiency and tissue necrosis -> limited fetal growth and
teratogenicity
- production of maternal IgG and fetal IgM to rubella does not
appear to be protective in many cases
- late-onset manifestations may be due to eventual
immune-mediated injury
- maternal rubella may produce no fetal infection, infection
only, infection + congenital abnormalities, or fetal death
- up to 70% of patients with symptomatic congenital rubella
may be asymptomatic in the neonatal period
- viral excretion most active 1-3 months after birth with
2-20% excreting virus at 1 year of age
CLINICAL FEATURES:
- IUGR
- low birth weight
- prematurity
- stillbirth
- spontaneous abortion
2. Early Manifestations
- cloudy corneas
- cataracts
- chorioretinitis
- retinitis pigmentosa
- microphthalmia
2. CNS
- hydrocephaly
- microcephaly
- meningoencephalitis
- large anterior fontanelle
- seizures
- lethargy/irritability
3. Systemic
- hepatomegaly
- splenomegaly
- jaundice
2. Cardiovascular
- peripheral pulmonary stenosis
- pulmonary valve stenosis
- patent ductus arteriosus
2. Minor
- ASD, VSD
- myocarditis
- aortic arch abnormalities
3. Cutaneous
- adenopathy
- "blueberry muffin" rash
- thrombocytopenia purpura
4. Others
- failure to thrive
- interstitial pneumonitis
- thymic hypoplasia
- renal artery stenosis +/- hypertension
3. Late Manifestations (2 months -> 2 years after birth)
- autism
- behavioural disorders
- hypotonia
- mental retardation
- progressive rubella panencephalitis
- psychomotor retardation
- sensorineuronal hearing loss
- +/- deafness
2. Endocrine
- Growth Hormone Deficiency
- Thyroid - hyper- or hypothryoidism, thyroiditis
- Diabetes Mellitus
- Precocious Puberty
INVESTIGATIONS:
- gold standard
- from urine, naspharynx, CSF
2. Serology
- fetal rubella-specific IgM
- persistence of rubella-specific IgG after 8-12 months of
age
3. Others
2. Serum
- conjugated hyperbilirubinemia, unconjugated
hyperbilirubinemia
- elevated transaminases (hepatitis)
- anemia, thrombocytopenia, leukopenia
- hypogammaglobulinemia
3. CSF
- elevated protein with slight pleocytosis (WBC's)
4. Imaging Studies
- intracranial calcifications
2. Skeletal X-Rays
- bony radiolucencies with "celery stalk" lesions at the
ends of the femur and humerus
MANAGEMENT:
- multidisciplinary approach
- Paediatrics, Neurology, Endocrinology, Ophthalmology,
Cardiology, ENT, Audilogy, PT, etc.
- surgical repair of cataracts and/or congenital heart
defects
- seizure control
2. Prognosis
- 10-20% mortality rate in 1st year
- significant morbidity
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Pediatric Database - CONGENITAL RUBELLA
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