RUBELLADr.RAHUL.K.R DEPT: OF SWASTHAVRITTA

What is Rubella

Rubella (German measles) is a disease caused by the rubella virus. Rubella is usually a mild illness. Most people who have had rubella or the vaccine are protected against the virus for the rest of their life. Because of routine vaccination against rubella since 1970 , rubella is now rarely reported.

History - Rubella

Infection in early pregnancy leads to fetal death or abnormalities.

The Teratogenic property of the infection was documented by an Australian ophthalmologist Norman Gregg in 1941.

Rubella( German Measles ) Rubella is also called as 3

day Measles or German Measles.

Family – Togaviridae Genus - Rubivirus In general belong to

Togavirus group

Rubella Virus

Rubella virus are ss – RNA virus Diameter 50 – 70 nm Spherical Virus carry hemagglutinin Virus multiply in the cytoplasm

of infected cell. Virus can be recovered from

nasopharynx, throat, CSF, urine.

Rashes First indicator of the disease. Minute pinkish, macular rash. First appear in face and spread rapidly to the

extremities and trunk. Disappear altogether by 3rd day. 25% of rubella cases are with out rash (subclinical) Other Enterovirus infections can produce similar

manifestations.

Main Clinical Events

The clinical events occuring in the neonatal age is more important and divided into two major groups

1 Post Natal Rubella 2 Congenital Rubella

Source of infection

There is no carrier state: the reservoir exists entirely in active human cases. The disease has an incubation period of 2 to 3 weeks.

Acquired, (i.e. not congenital), rubella is transmitted via airborne droplet emission from the upper respiratory tract of active cases. The virus may also be present in the urine, faeces and on the skin.

Systemic events of Rubella Infection

Clinical findings

Malaise Low grade fever Morbilliform rash Rash starts on Face

Extremities Rarely lasts more than 5

days No features of the rash

give clues to definitive diagnosis of Rubella.

Other manifestations and complications

May produce transient Arthritis, in women in particular.

Serious complications are Thrombocytopenia

Purpura Encephalitis

Immunity - Rubella Antibodies appear in serum as

rash fades and antibody titers raise

Rapid raise in 1 – 3 weeks Rash in association with

detection of IgM indicates recent infection.

IgG antibodies persist for life. 2nd attack is very rare.

Immunity - Protects

One attack of Rubella infection, protects for life

Immune mothers transfer antibodies to off springs who are in turn are protected for 4 – 6 months.

Post natal Rubella Occurs in Neonates and Childhood Adult infection occurs through

mucosa of the upper respiratory tract spread to cervical lymphnodes

Viremia devlops after 7 – 9 day Lasts for 13 – 15 days Leads to development of antibodies The appearance of antibodies

coincides the appearance of suggestive immulogic basis for the rash

In 20 – 50 % cases of primary infections are subclinical

Diagnosis of Rubella in Adults

Clinical Diagnosis is unreliable Many viral infections mimic Rubella Specific diagnosis of infection with 1 Isolation of virus 2 Evidence of seroconversion

Isolation and Identification of virus

Nasopharyngeal or throat swabs taken 6 days prior or after appearance of rash is a good source of Rubella virus

Using cell cultured in shell vial antigens can be detected by Immunofluorescence method.

Serology In Rubella Hemagglutination inhibition

test for Rubella is of Diagnostic significance

ELISA tests are greater importance

A raise in Antibody titers must be demonostrated between two serum samples taken at least 10 days apart.

Or Detection of Rubella specific IgM must be detected in a single specimen.

Epidemiology

Rubella is world wide in distribution Occurs round the year, Epidemics occur every 20 – 25 years Infection is transmitted by respiratory route The use of Rubella vaccine has now eliminated

both epidemic and endemic Rubella.

Treatment and Prevention

Rubella is a mild self limited illness. No specific treatment or Antiviral treatment is

indicated. However Laboratory proved and clinically missed

Rubella in the Ist 3-4 months of pregnancy is associated with fetal infections.

Congenital Rubella Syndrome(CRS)

Maternal viremia with Rubella infection during pregnancy may result in infection of placenta and fetus (vertical transmission).

The growth rate of fetal cells are reduced. Results in fewer number of cells after the birth. Lead to deranged and hypo plastic organ

development. Results in structural damage and abnormalities

Rubella infection – At various trimesters

Ist trimester infections lead to abnormalities in 85 % of cases. and greater damage to organs

2nd trimester infections lead to defects in 16 % > 20 weeks of pregnancy fetal defects are uncommon However Rubella infection can also lead to fetal

deaths, and spontaneous abortion. The intrauterine infections lead to viral excretion in

various secretion in newborn upto 12-18 months.

Classical Triad of Rubella Classical Triad Cataract Cardiac abnormalities Deafness

Other manifestations Growth retardation

Rash Hepatosplenomegaly

Jaundice Meningoencephalitis

CNS defects lead to moderate to profound mental retardation.

Congenital Rubella syndrome(CRS)

Other Neurological manifestions

Problems in balance Motor skills in

preschool children altered.

A rare complication of encephalitis can occur in second decade with Congenital rubella syndrome may progress to death.

Diagnosis ofCongenital Rubella Syndrome

Demonstration of Rubella antibodies of IgM in a new born is diagnostic value. As IgM group do not cross the placenta and they are produce in the infected fetus,

Treatment, Prevention, Control No specific treatment is availableCRS can be prevented by

effective immunization of the young children and teenage girls, remain the best option to prevent Congenital Rubella Syndrome.

The component of Rubella in MMR vaccine protects the vaccinated.

Dose 0.5ml subcutaneous.

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