Rubella, also known as German measles or 3-day measles, is a viral infection caused by rubella virus which is a togavirus. Rubella itself is a self-limiting mild illness, but it poses a big risk during pregnancy as it can lead to congenital rubella syndrome.
🏘️ Epidemiology
Before the introduction of the MMR vaccine, rubella was most common between the ages of 5-10 years old.
The WHO has made a plan to eliminate rubella through the Global Vaccine Action Plan.
Since 2013 there have been about only 10 confirmed cases of rubella in England.
Pathophysiology
The rubella virus is an RNA virus with a glycolipid envelope. It is readily inactivated by chemical agents, low pH, heat and cold. It is transmitted by direct contact or droplet contact with bodily fluids (such a nasopharyngeal secretions). The incubation period ranges from 2-23 days. The virus replicates in the nasopharyngeal and local lymph nodes and then spreads via the blood throughout the body. This is how it may pass through the placenta to the foetus.
The symptoms that arise are mainly due to the infection, but the immune response can cause some of its symptoms.
⚠️ Risk factors
- Incomplete vaccinations
- Contact with infected
- International travel
😷 Presentation
Rubella has no specific features to the disease itself. They are very similar to other viral infections. Infection arises 2-3 weeks after exposure. Symptoms include:
- Rash - in 50-80% of cases. It generally starts on the face or behind the ears → then spreads down. It is usually present for 3-5 days (3 day measles).
- Lymphadenopathy
- Arthritis
- Arthralgia
- Malaise
🔍 Investigations
The diagnosis of rubella should be confirmed through serological testing such as ELISA to confirm the presence of IgM or IgG antibodies.
One should have a low threshold of suspicion for rubella in pregnant women (especially <20 weeks gestation) and it should always be excluded in pregnant women with a rash and presentation that may resemble rubella.
Parvovirus B19 is similar to rubella and should also be checked.
🧰 Management
Contact local Health Protection Team as it is a notifiable disease.
Supportive management is all that is required.
Pregnancies that are <20 weeks gestation arre at greatest risk of congenital rubella syndrome (CRS). In fact, there have been no published case reports of CRS beyond 20 week gestation. At 11-16 weeks there is a 10-20% risk and before 8-10 weeks there is a 90% risk with a likelihood of having multiple defects.
There is no treatment to prevent CRS but we need to refer to obstetrics urgently.
They may give intramuscular immunoglobulin and may do further diagnostic tests such as amniocentesis or fetal blood sampling.
⚠️ Immunisation should not be given during pregnancy, but may be given postpartum. They should also not be given to a women attempting to become pregnant. If a women has been given the MMR vaccine, they should avoid becoming pregnant for 28 days.
🚨 Complications
Risk of CRS is greatest in the first 8-10 weeks of gestation.
😷 Presentation
- Sensorineural deafness
- Congenital cataracts
- Retinopathy - termed salt and pepper retinopathy due to its appearance on fundus exam.
- Congenital heart disease - such as patent ductus arteriosus.
- Growth retardation
- Microcephaly
- Micrognathia - this is an undersized jaw.
- Purpuric skin lesions - described as a blueberry muffin rash.
- Learning disabilities
