Surveillance Case Definition

Rubella
(also known as German Measles)

CLINICAL DESCRIPTION

When contracted after birth, rubella is usually a mild disease characterized by a generalized maculopapular rash, swollen lymph nodes, and slight fever.  Transient inflammation of the joints rarely occurs in children, but is common in adolescents and adults, especially women.  Encephalitis (1 per 6,000 cases) and thrombocytopenia (1 per 3,000 cases) are rare complications.  Up to 50% of infections occur without recognized rash.

 

Rubella is of greatest danger to the unborn fetus.  Up to 90% of infants born to mothers infected in the first trimester will develop the physicial anomalies referred to as congenital rubella syndrome (CRS).  CRS, which can occur in the fetus of an infected pregnant woman, is characterized by any of a number of complications and findings, including blindness, heart defects, deafness, behavioral disorders, mental retardation, growth retardation, bone disease, enlarged liver and spleen, thrombocytopenia, and purple skin lesions.  Some effects may not be apparent at birth.

 

Reinfection has been demonstrated on rare occasions, but only very rarely has resulted in CRS.

CASE CLASSIFICATION (RUBELLA)

Clinical case definition

An illness that has all of the following characteristics:

·        Acute onset of generalized maculopapular rash

·        Temperature >99.0°F (>37.2°C), if measured

·        Arthralgia/arthritis, lymphadenopathy, or conjunctivitis

 

Laboratory criteria for diagnosis

·        Isolation of rubella virus, or

·        Significant rise between acute- and convalescent-phase titers in serum rubella immunoglobulin G antibody level by any standard serologic assay, or

·        Detection of rubella virus by polymerase chain reaction (PCR), or

·        Positive serologic test for rubella immunoglobulin M (IgM) antibody

 

1. CONFIRMED

A case that is laboratory confirmed or that meets the clinical case definition and is epidemiologically lined to a laboratory-confirmed case.

2. PROBABLE

A case that meets the clinical case definition, has no or noncontributory serologic or virologic testing, and is not epidemiologically linked to a laboratory-confirmed case.

3. POSSIBLE
   
   Not used

 

CASE CLASSIFICATION (CONGENITAL RUBELLA SYNDROME)

Clinical case definition

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), loss of hearing, 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 antibody , or

·        Detection of rubella virus by polymerase chain reaction (PCR), 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 two fold dilution per month).

 

1. CONFIRMED

A clinically compatible case that is laboratory confirmed.

2. PROBABLE

A case that is not laboratory confirmed and that has any two complications listed in the first bullet under clinical case definition and one from the second bullet and lacks evidence of any other etiology.

3. POSSIBLE
   
   Not used

Disease Index

Health & Senior Services

NJ InTouch

Last Updated: