rubella
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RubellaTRANSCRIPT
RUBELLADr.T.V.Rao MD
History - Rubella
The Teratogenic property of the infection was documented by an Australian ophthalmologist Norman McAlister Gregg, in 1941
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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.
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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 lives. Because of routine vaccination against rubella since 1970 , rubella is now rarely reported.
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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 Enveloped Spherical Virus carry hem
agglutinin Virus multiply in the
cytoplasm of infected cell.
Prevailing Genotypes
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Cause and Transmission• The disease is caused by Rubella virus, a toga
virus 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.
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Acquired Rubella • 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. Dr.T.V.Rao MD 9
Signs and Symptoms• After an incubation period of 14-21 days,
the primary symptom of rubella virus infection is the appearance of a rash (exanthema) on the face which spreads to the trunk and limbs and usually fades after three days.
• The skin manifestations are called "blueberry muffin lesions."
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Main Clinical Events
The clinical events occurring in the neonatal age is more important and divided into two major groups
1 Post Natal Rubella 2 Congenital Rubella
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Features of Rubella Infection
• 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).
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How Adults acquire InfectionAcquired, (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, feces and on the skin. There is no carrier state: the reservoir exists entirely in active human cases. The disease has an incubation period of 2 to 3 weeks.
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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.
Systemic events of Rubella Infection
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Rubella during Pregnancy• "Rubella infection in
pregnant women during the first three months of pregnancy may result in the baby being born with birth defects or congenital rubella syndrome
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Post natal Rubella Occurs in Neonates and
Childhood Adult infection occurs through
mucosa of the upper respiratory tract spread to cervical lymph nodes
Viremia develops 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
Congenital Manifestations
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An Infant Presenting with Congenital Cataract
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Rubella RashesWhen epidemics
occur with similar features it is more suggestive of Rubella epidemics
Other Enterovirus infections can produce similar manifestations.
Other manifestations and complications
May produce transient Arthritis, in women in particular.
Serious complications are
Thrombocytopenia Purpura Encephalitis
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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
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.
Culturing the Virus
The virus can be cultured and adopted to continuous cell lines Rabbit kidney
cells (RK 13 ) and
Vero cells
Diagnosis of Rubella in Adults
Clinical Diagnosis is unreliableMany viral infections mimic
RubellaSpecific diagnosis of infection
with 1 Isolation of virus 2 Evidence of seroconversion
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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 Immunofluresecentet methods
Serology In Rubella Hemagglutination inhibition
test for Rubella is of Diagnostic significance
ELISA tests are greater importance
A raise in Antibody titers must be demonstrated 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 in USA and several developed countries
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Treatment and PreventionRubella 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 fatal infections.Dr.T.V.Rao MD 30
Congenital Rubella
• 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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Congenital Rubella Syndrome Maternal Viremia with Rubella infection
during pregnancy may result in infection of placenta and fetes.
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
abnormalitiesDr.T.V.Rao MD 32
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 new-born upto 12-18 months.
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Clinical Findings( Congenital Rubella Syndrome )
May be transient effects in infants.
Permanent manifestations may be apparent at birth, become recognized during the first year.
Developmental abnormalities appear during childhood and adolescents. Dr.T.V.Rao MD 34
Rubella Epidemic• The largest rubella epidemic in the United
States occurred in 1964-1965, and resulted in the birth of an estimated 30,000 infants with congenital rubella syndrome. As many as 85% of pregnant women with clinical rubella delivered babies with congenital rubella. The highest percentage of congenital rubella occurred when the pregnant mothers had rubella during the first trimester
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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
Other Neurological manifestations Problems in balance Motor skills in
preschool children altered.
A rare complication of Pan 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,
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. Dr.T.V.Rao MD 39
Treatment, Prevention, Control
No specific treatment is available
CRS 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
MMR Vaccine The MMR vaccine is a mixture of three live
attenuated viruses, administered via injection for immunization against measles, mumps and rubella. It is generally administered to children around the age of one year, with a second dose before starting school (i.e. age 4/5). The second dose is not a booster; it is a dose to produce immunity in the small number of persons (2-5%) who fail to develop measles immunity after the first dose In the United States, the vaccine was licensed in 1963 and the second dose was introduced in the mid 1990s. It is widely used in all National, Universal Immunization programmes Dr.T.V.Rao MD 41
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