RUBELLA

GERMAN MEASLES

Introduction

• Rubella, commonly known as German measles, is a disease caused by Rubella virus. The name is derived from the Latin, meaning little red.

• Rubella is also known as German measles because the disease was first described by German physicians, Friedrich Hoffmann, in the mid-eighteenth century.

• Rubella is a common childhood infection usually with minimal systemic upset although transient arthropathy may occur in adults. Serious complications are very rare.

• Rubella can affect anyone of any age and is generally a mild disease, rare in infants or those over the age of 40.

Cause and Transmission

• The disease is caused by Rubella virus, a togavirus that is enveloped and has a single-stranded RNA genome, 60-70nm diameter.

• The virus is transmitted by the respiratory route and replicates in the nasopharynx and lymph nodes.

• The virus is found in the blood 5 to 7 days after infection and spreads throughout the body.

• family Togaviridae genus Rubivirus• Virion is 60 nm, spherical, icosahedron• Enveloped with HA• ssRNA +ve sense. .

• Acquired rubella is transmitted via airborne droplet emission from the upper respiratory tract of active cases.

• The virus may also be present in the urine, feces and on the skin.

Signs and Symptoms• After an incubation period of 14-21 days, the

primary symptom of rubella virus infection is the appearance of a rash (exanthem) on the face which spreads to the trunk and limbs and usually fades after three days.

• The skin manifestations are called "blueberry muffin lesions."

• The rash disappears after a few days with no staining or peeling of the skin.

• Other symptoms include low grade fever, swollen glands (post cervical lymphadenopathy), joint pains, headache, conjunctivitis.

• The swollen glands or lymph nodes can persist for up to a week and the fever rarely rises above 38 oC (100.4 oF).

• Since the virus can cross the placenta, it can cause Congenital Rubella Syndrome in the newly born.

• Congenital infection may be mild and asymptomatic or severe, causing cataracts, glaucoma, deafness, heart abnormalities, mental retardation or death.

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CRS case definitions (1)

Suspected CRS: A child <1 year with A child <1 year with • maternal history of rubella in pregnancymaternal history of rubella in pregnancy

and/or• heart disease, or deafness, or eye signsheart disease, or deafness, or eye signs: :

white pupil (cataract); diminished vision; eye ball (congenital glaucoma)

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CRS case definitions (2) Clinically confirmed CRS:Clinically confirmed CRS: A child <1 year with A child <1 year with

two complications in group (a) or two complications in group (a) or one from (a) and one from (b)one from (a) and one from (b)

(a) cataract(s), congenital glaucoma, congenital (a) cataract(s), congenital glaucoma, congenital heart disease, loss of hearing, pigmentary heart disease, loss of hearing, pigmentary retinopathyretinopathy

(b) purpura, splenomegaly, microcephaly, mental (b) purpura, splenomegaly, microcephaly, mental retardation, meningoencephalitis, radiolucent retardation, meningoencephalitis, radiolucent bone disease, jaundice with onset within 24 bone disease, jaundice with onset within 24 hours after birth.hours after birth.

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CRS case definitions (3)

Laboratory-confirmed CRS:

An infant with a +ve blood test for rubella-specific IgM and clinically-confirmed CRS.

Congenital rubella infection (CRI): An infant with a positive blood test for rubella-specific IgM who

does not have clinically-confirmed CRS.

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Diagnosis

• Serodiagnosis is usually used for identification and hemagglutinin inhibition test can be used to identify and quantitate the antibody present.

• Rubella virus specific IgM antibodies are present in people recently infected by Rubella virus but these antibodies can persist for over a year and a positive test result needs to be interpreted with caution.

Laboratory DiagnosisPostnatal:Postnatal:

•Virus isolation (resp /urine)Virus isolation (resp /urine)•RT-PCRRT-PCR•Serology: Serology: Diagnosis of acute Diagnosis of acute infectioninfection1.1.Rising titres of antibody Rising titres of antibody (mainly IgG) - HAI, EIA(mainly IgG) - HAI, EIA2.2.Presence of rubella-specific Presence of rubella-specific IgM - EIAIgM - EIA• Antinatal screening can be Antinatal screening can be done for pregnant ladies.done for pregnant ladies.

Prenatal:Prenatal:

• amniotic fluid .amniotic fluid .

•Virus isolation.Virus isolation.

•RT-PCRRT-PCR

•Specific IgM can be Specific IgM can be detected in the 21detected in the 21stst w. in w. in the blood of child.the blood of child.

Prevention and Treatment

• Rubella vaccine is given to children at 15 months of age as a part of the MMR (measles-mumps-rubella) immunization.

• The vaccine is live and attenuated and confers lifelong immunity.

• There is no specific treatment for Rubella; management is a matter of responding to symptoms to diminish discomfort.

• Treatment of newly born babies is focused on management of the complications.

• Congenital heart defects and cataracts can be corrected by surgery.