Define Rubella & Congenital Rubella Syndrome. Describe its prevention and diagnosis.

Definition

• Rubella (German measles) is a mild viral illness caused by the rubella virus (a togavirus).
• Its major importance is that infection in early pregnancy causes the severe congenital rubella syndrome (CRS) in the fetus.

Postnatal Rubella (in the Child)

• Low-grade fever with a fine maculopapular rash (face → trunk, fades quickly).
• Tender posterior-auricular and sub-occipital lymphadenopathy (characteristic); Forchheimer spots on the palate.
• Usually mild and self-limiting.

Congenital Rubella Syndrome (CRS)

• Results from maternal infection in the first trimester.
• Classic triad — cataract, congenital heart disease (especially PDA) and sensorineural deafness.
• Also microcephaly, growth restriction, hepatosplenomegaly and a 'blueberry muffin' rash.

Prevention

• Rubella-containing vaccine (MR/MMR); ensuring immunity in women of child-bearing age is key to preventing CRS.
• Avoid the vaccine in pregnancy (live vaccine).

Diagnosis

• Postnatal rubella — clinical + rubella IgM if needed.
• CRS — maternal history, characteristic features, rubella IgM in the infant and virus detection.

Extended Features of CRS

• Ophthalmic — cataract, glaucoma, 'salt-and-pepper' retinopathy.
• Cardiac — PDA and pulmonary artery stenosis; CNS — microcephaly, intellectual disability.
• Others — hepatosplenomegaly, thrombocytopenia, 'blueberry muffin' rash, growth restriction.

WHY Vaccination Matters

Because there is no treatment for CRS, prevention through population immunity (MR/MMR) — especially in girls before child-bearing age — is the only effective strategy.

Risk is highest in the first 8–10 weeks of gestation.