Rubella, Congenital Syndrome (CRS)
1999 Case Definition
1999 Case Definition
Clinical Description
Presence of any defect(s) or laboratory data consistent with congenital rubella infection. Infants with congenital rubella syndrome usually present with more than one sign or symptom consistent with congenital rubella infection. However, infants may present with a single defect. Deafness is most common single defect.
Clinical Criteria
An illness, usually manifesting in infancy, resulting from rubella infection in utero and characterized by signs or symptoms from the following categories:
- Cataracts/congenital glaucoma, congenital heart disease (most commonly patent ductus arteriosus or peripheral pulmonary artery stenosis), hearing impairment, pigmentary retinopathy.
- Purpura, hepatosplenomegaly, jaundice, microcephaly, developmental delay, meningoencephalitis, radiolucent bone disease.
Laboratory Criteria For Diagnosis
- Isolation of rubella virus, OR
- Demonstration of rubella-specific immunoglobulin M (IgM) antibody, OR
- Infant rubella antibody level that persists at a higher level and for a longer period than expected from passive transfer of maternal antibody (i.e., rubella titer that does not drop at the expected rate of a twofold dilution per month).
- Polymerase chain reaction (PCR) positive rubella virus
Case Classification
Suspected
A case with some compatible clinical findings but not meeting the criteria for a probable case.
Probable
A case that is not laboratory confirmed and that has any two complications listed in item (1) of the clinical criteria or one complication from item (1) and one from item (2), and lacks evidence of any other etiology.
Confirmed
A clinically consistent case that is laboratory confirmed.
Other Criteria
Infection only: A case that demonstrates laboratory evidence of infection, but without any clinical symptoms or signs.
Comments
In probable cases, either or both of the eye-related findings (cataracts and congenital glaucoma) count as a single complication. In cases classified as infection only, if any compatible signs or symptoms (e.g., hearing loss) are identified later, the case is reclassified as confirmed.