Rubella

Aetiology and epidemiology

Rubella is a self-limiting benign illness occurring in adults and children worldwide. It is caused by the rubella virus and spread by airborne transmission or droplet.

The incubation period for rubella is around 2 weeks after which a prodrome of headaches, fever and lymphadenopathy occur. The infectivity period is typically from 7 days before to around 7 days after the onset of the characteristic rash.

Clinical assessment

Rubella is most commonly associated with a characteristic macular rash starting on the face then passing down over the body to the feet. In addition, it is also associated with:

• Fever
• Tender occipital and posterior auricular lymphadenopathy
• Arthralgia
• Respiratory involvement

Another characteristic is the appearance of Forschheimer spots. These are pin-point red macules and petechiae, which may be seen on the soft palate and uvula during the rash phase.

Investigations

The clinical signs of rubella can be difficult to distinguish from other viral illnesses such as parvovirus B19, measles, dengue and human herpesvirus 6.

Clinical diagnosis of rubella is therefore unreliable and laboratory confirmation of the disease is required, particularly during pregnancy due to the potential consequences to the foetus.

Immunoglobulin G and Immunoglobulin M assays should be used.

Management

Rubella is a notifiable disease and notification is required based on clinical suspicion. Children diagnosed with rubella should remain off school for at least 5 days following the onset of the rash.

Women should avoid pregnancy until 3 months after immunisation.

Complications

Complications of rubella are rare, although conditions which can arise are listed in Table 1.

The risks of congenital defects (congenital rubella syndrome) are highest (90%) if infection occurs within the first 12 weeks of pregnancy. Under these circumstances, follow-up should be arranged.