Rubella and congenital rubella syndrome

Rubella and congenital rubella syndrome

 In the fourth of our series on systemic disorders and the eye,
Dr Iain Phillips looks at the ocular effects of rubella and its complications in new-born children

Rubella, or German measles, was first described in the 18th century and was known as a 'mild illness', which only caused occasional complications. This was until 1941, when Sir Norman Gregg described the ocular complications in the new-born baby following maternal rubella infection during the pregnancy.1
The importance of rubella and the effects of its complications were seen in the pandemic of 1962-5. During this period, 11,000 foetal deaths and 20,000 cases of congenital rubella syndrome (CRS) were seen.
The rubella virus is an enveloped single-stranded RNA virus, belonging to the Togavirus family. Little genetic variation is seen in different strains of the virus. Humans are the only known host of the disease and it is most common in spring and early summer. The infection is spread through airborne droplets and the initial infection is established in the upper respiratory tract. The virus incubates for 12-21 days.2 Towards the end of this period the virus spreads into the bloodstream, forming a viraemia, and then on to the target organs including the skin and joints. Sufferers are infectious for up to a week before and a week after the development of the rash.