Rubella, also known as German measles, is a viral infection caused by the togavirus. Following the introduction of the MMR vaccine it is now rare. If contracted during pregnancy there is a risk of congenital rubella syndrome.

• Incubation period: 14-21 days
• individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash.

Risk

• in first 8-10 weeks risk of damage to fetus is as high as 90%
• damage is rare after 16 weeks

Features of congenital rubella syndrome

• Rubella presents with nonspecific symptoms and signs such as fever, coryza, arthralgia, a rash, which classically starts on the face and moves down to the trunk, sparing the arms and legs), and lymphadenopathy (classically post-auricular). Classically, the rash spares the limbs, as opposed to the rash of measles which involves the limbs.

Diagnosis

• suspected cases should be discussed immediately with the local Health Protection Unit (HPU) as type/timing of investigations may vary
• Diagnosis is confirmed by serology: IgM antibodies are raised in women recently exposed to the virus
• it should be noted that it is very difficult to distinguish rubella from parvovirus B19 clinically. It is therefore important to also check parvovirus B19 serology as there is a 30% risk of transplacental infection, with a 5-10% risk of fetal loss

Management

• suspected cases of rubella in pregnancy should be discussed with the local Health Protection Unit
• since 2016, rubella immunity is no longer routinely checked at the booking visit
• if a woman is however tested at any point and no immunity is demonstrated they should be advised to keep away from people who might have rubella