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									RUBELLA [ GERMAN MEASLES ]

HISTORY OF RUBELLA
• 1941 – Opthalmologist Norman Gregg reported epidemic of congenital cataract among newborns. – linked to Rubella.

• 1962 - Virus was isolated.
• 1967 - Attenuated vaccine was developed.

RUBELLA
Acute childhood viral infection , mild, short duration.

 Characterised by low grade fever,
lymphadenopathy and maculopapular rash.

Affects adults also.
Virus associated with terratogenic effects. World wide distribution. Epidemics of Cyclic pattern every 6-8 years.

AGENT
RNA Toga virus • Only one antigenic type Source of infection: • Clinical /subclinical cases [ 50 - 65 %]. • No carriers in postnatally acquired rubella • Infants with congenital rubella: Shed virus for months . Communicability: Less communicable • 1 week – RASH -1 week.

HOST FACTORS
Age: 3-10 years, Developed countries > 15 years Immunity:
• 1 attack - life long immunity • Maternal antibodies protect infant during first 6 months • 40% of childbearing women susceptible

ENVIRONMENTAL FACTORS:
• Seasonal pattern– late winter & early spring • Poor housing, over crowding

Transmission:
• Directly from person-to-person by droplets from nose & throat, droplet nuclei • Portal of entry: Respiratory route • VERTICAL TRANSMISSION

Incubation period: 2-3 weeks (18 days) Duration – 3 days • 50-60% Asymptomatic • Mild and variable symptoms CLINICAL FEATURES:
1) PRODROMAL STAGE:

• Coryza, sore throat, low grade fever (mild) • Within 24 hours RASH starts.

2) LYMPHADENOPATHY Post-auricular and posterior cervical 7 days ------ RASH--------10 -14 days
3) RASH • Minute, discrete, pinkish, macular, not confluent like measles • Face----Trunk-----Extremities • Spreads and clears fast • Disappears 3 rd day

Complications
Congenital Rubella Arthralgia Encephalitis Thrombocytopenic purpura

DIAGNOSIS
• Virus isolation: Throat swab culture. • Serology— HAI (Hemagglutination inhibition test ) developed in 1966.
• Two blood samples collected – 1st within 5 days of onset, 2nd after 2 weeks. • Four fold rise in antibody titre in paired sera • Presence of IgM antibody- 2 weeks after RASH • Latest : ELISA & Radio-immune assay.

Congenital Rubella Syndrome
• Infants born with Defects secondary to intrauterine infection OR • Infant develops Symptoms/signs of intrauterine infection after birth • INHIBITION OF CELL DIVISION leads to Congenital Malformations and LBW • Gestational age at which maternal infection occurs determines extent of infection and effects on Fetus.

Congenital Rubella contd…
1 st Trimester: Abortion, still birth or multiple defects. Classical Triad of Deafness, Cataract & Patent Ductus Arteriosus Early 2nd Trimester: Only deafness 16th week onward: No major abnormalities

Other defects: Glaucoma, retinopathy, microcephaly, cerebral palsy, Mental Retardation, IUGR, Hepato-splenomegaly
Diagnosis of Congenital rubella: • Presence of IgM antibodies after birth • Persistence of IgG antibodies after 6 months

Active infection at birth
1. 2. 3. 4. 5. 6. Hemolytic anemia Thrombocytopenic purpura Petechial rash Pneumonia. Hepatitis Encephalitis

Newborn sheds virus up to 18 months

PREVENTION
GOAL: Prevent rubella infection during a future pregnancy Active immunisation : Live attenuated vaccine RA 27/ 3 vaccine – Produced in Human diploid fibroblast cells Dose: 0.5 ml subcutaneously Sero-conversion rate 95% Immunity persists life long / 14-16 years

Contraindication: Pregnancy. Avoid pregnancy for 3 months after vaccination. Adverse reactions: • Fever, • Mild Rash, • Arthralgia MEASLES –MUMPS- RUBELLA [ MMR ] Vaccine in children.

Vaccination strategy
1) Protect women of childbearing age (1539 years) to prevent terratogenic effects. 2) Immunize all children aged 1-14 years to interrupt transmission. 3) Routine universal immunization of all children at age 1 Adult women & children — Rubella Vaccine Children at age 1 - 5 year - MMR


								
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