Refernce : Harrison textbook of medicine Davidson's textbook of meidine George Mathew

1. RUBELLA

2. Rubella
Rubella causes exanthem in the non-immunized
Causative Organism : Togavirus infection.
Mode of spread :
• droplet infection. Rubella is spread by respiratory droplet, with infectivity from up to 10
days before to 2 weeks after the onset of the rash
• transplacental infection takes place in the first trimester or later, persistence of the virus
is likely and severe congenital disease may result
Incubation period : 15–20 days

3. Clinical features
• In childhood, most cases are subclinicalal
• Prodromal Phase : fever, malaise, headache and lymphadenopathy.
• Examthematous phase : , maculopapular rash spreading from the face. The exanthematous stage
is characterised by pink macular rashes first appearing behind the ears and on the forehead, later
spreading downwards to the trunk and extremities. The rashes typically last 3 days. Although the
distribution of the rubella rash is similar to that of measles, the spread is much more rapid and the
rash does not darken or coalesce. An enanthem on the soft palate (Forchheimer spots) may be
seen. There may be associated polyarthritis and generalised lymphadenopathy that may persist for
2 weeks.
• Complications are rare but include thrombocytopenia and hepatitis. Encephalitis and
haemorrhage are occasionally reported.
• In adults, arthritis involving hands or knees is relatively common, especially in women.

4. Diagnosis
• Laboratory confirmation of rubella is required if there has been contact with a pregnant woman.
• This is achieved either by detection of rubella IgM in serum or by IgG seroconversion.
• In the exposed pregnant woman, absence of rubella-specific IgG confirms the potential for
congenital infection.
Prevention
• All children should be immunised with MMR vaccine.
• Congenital rubella syndrome may be controlled by testing women of childbearing age for
rubella antibodies and offering vaccination if seronegative.
• Antenatal rubella screening was offered to pregnant mothers
• pre-pregnancy MMR vaccination is considered to be a more effective method of protecting
pregnant women;
Complications : post-infectious encephalitis, thrombocytopenia, spontaneous abortion and
congenital rubella syndrome.

5. Congenital Rubella
Transmissible
• It is highest in the first trimester and so the rate of fetal disease
• 90% at <11 weeks
• The fetus is completely spared if infection occurs beyond 16 weeks.
Clinical Features
• The classical triad of congenital rubella syndrome consists of
1. deafness,
2. cataract
3. congenital heart disease.
• Delayed manifestations such as diabetes mellitus and renal disease have also been described.
• Congenital heart diseases, Ophthalmic diseases, Deafness, Mental retardation and
Microcephaly

6. Congenital Rubella
Diagnosis
• Diagnosis is by demonstration of positive rubella IgM in cord or neonatal blood.
Treatment
• No treatment exists.
• A unequivocal diagnosis of rubella in the first trimester of pregnancy is an indication for
maternal termination of pregnancy.
• Vaccinating all children particularly all adolescent girls against rubella is recommended
to reduce the burden of congenital rubella.

8. Expanded Rubella Syndrome
• Expanded rubella syndrome additionally includes the following manifestations:
• Hepatosplenomegaly
• Thrombocytopenic purpura
• Intrauterine growth retardation
• Myocarditis
• Interstitial pneumonia
• Humoral and cellular immunodeficiency.

9. Prevention
By active immunisation-This is a live attenuated vaccine.
Aim - to decrease the frequency of infection in the population and thus, decrease the chance
of susceptible pregnant females being exposed to the infection.
Regime
• all children at the age of 15 months along with mumps and measles vaccine (MMR
vaccine).
• A second dose is given to young females aged 11-13 years.
Contraindications
• Seronegative females of childbearing age should also be offered the vaccine.
• Rubella vaccine must never be given to pregnant females or to those who may
become pregnant within 3 months of immunisation, because of the high risk of
vaccine virus induced foetal damage.
• patients with immune deficiency diseases and those who are taking
immunosuppressive drugs.