Rubella

Synonym: German Measles

• A viral infection once seen mainly in spring and early summer. Epidemics occur every 6 to 9 years in populations with no vaccination programme.¹ In addition:
  • Before introduction of vaccination it was endemic in virtually all countries.
  • In the absence of mass vaccination approximately 10–20% of women reaching child-bearing age are susceptible to rubella.
  • It is now quite rare in developed nations since the introduction of immunisation (initially in young girls and now covering most children via the MMR vaccination). The vaccine is safe and vaccination is a very successful health intervention.²
  • Adverse publicity about the MMR and lower uptake of vaccination have increased susceptibility to rubella.³
  • It is a Notifiable Disease.^4,4,5
• An RNA virus (Genus Rubivirus family Togaviridae) with man as the only known host:
  • There is only one major antigenic type.
  • It is transmitted as airborne droplets between close contacts (unlike most togaviruses which are arthropod borne).
  • The incubation period is 14–21 days with patients being infectious for up to 7 days before and 5 days after symptoms appear.
  • Infectivity is greatest just before and on the day of symptoms appearing.
• Its major complication is the congenital rubella syndrome:
  • This causes a wide variety of malformations affecting the cardiac, ocular, central nervous and skeletal systems when a pregnant mother is infected.
  • This is still a problem in many developing countries.⁶
  • It could become more of a problem again in developed countries in certain vulnerable groups (such as unvaccinated immigrants with no immunity).^7,8

• The incidence of rubella was 0.1 per 100,000 in 1999.
• In 1996 there were 2770 confirmed cases in all age groups in England and Wales, decreasing to 16 in 2004 and 30 in 2006.
• In 1990–2000 there was an average of average <5 congenitally infected infants reported each year and there were <10 terminations.
• Between 1996 and 2000 a total of 16 congenital rubella births were registered with the National Congenital Rubella Surveillance Programme.⁴

• Symptoms:
  • Prodromal phase of lassitude, fever, headache, conjunctivitis and anorexia with rhinorrhoea very similar to a cold. The prodrome may be absent in children and tends to be more noticeable in adults.
  • Rash then develops (may be absent, especially in young children) – initially, pink discrete macules that coalesce, starting behind ears and on face, spreading to trunk then extremities.
  • Cervical, suboccipital, and postauricular lymphadenopathy is characteristic and may precede the rash.
  • Constitutional symptoms are usually mild (can be more prominent in adults).
  • In older patients arthralgia is common.
• Signs:
  • There may be petechiae on the soft palate (Forschheimer sign), but this is not diagnostic for rubella.
  • The rash is shown in close up, but it should be remembered that clinical diagnosis is unreliable.

• Contact dermatitis
• Erythema multiforme/drug eruptions
• Measles
• Cutaneous manifestations of syphilis
• Scarlet fever
• Kawasaki disease
• Arthropod-borne infections (for example rocky mountain spotted fever)

Clinical diagnosis is unreliable since symptoms are often fleeting and mimicked by other viruses. In particular the rash is not diagnostic.

• Investigations are not usually necessary (although it is important to confirm infection in pregnant women - see below).
• Confirmation of diagnosis can be made early by PCR test of samples from oropharynx, urine and conjunctiva in infants.⁹
• Presence of rubella IgM is diagnostic (may persist for up to a year) and persistence of IgG after 6 months is strongly suggestive.
• FBC may show low WBC count with increased proportion of lymphocytes and thrombocytopenia (usually resolves in a month).
• Rubella virus may be identified via throat swab, blood or urine examination, and CSF.

• There is no specific treatment.
• Keep child away from school for 7 days after rash appears.
• Use antipyretics for fever – avoid aspirin in children due to danger of Reye's syndrome.
• Ask about any contact with pregnant women.
• Where suspected infection occurs in a pregnant woman it should be confirmed by investigation, in liaison with a virologist, and counselling given about the dangers to fetus. Management requires referral and expert support.

• Complications occur rarely
• Rubella encephalopathy may occur about 6 days after rash (usually full recovery in a few days without sequelae)
• Orchitis
• Guillain Barré/neuritis
• Panencephalitis

• The advice is that children should be excluded from school for 5-7 days after onset of the rash.¹⁰ This is not an effective preventive measure as the infection is most contagious before appearance of the rash.
• Vaccination via MMR in second year of life plus pre-school booster with antenatal screening for rubella susceptibility.
• Where non-immunity to rubella is discovered during pregnancy, immunisation after delivery offers protection for future pregnancies.

See Congenital Rubella Syndrome.

• Initially considered a variant of measles ("first disease") or scarlet fever ("second disease"), and called "third disease" ("fourth disease" was Duke's disease - may have been a staphylococcal or enteroviral infection, "fifth disease" being parvovirus infection or erythema infectiosum, and "sixth disease" being roseola infantum from herpes virus 6).
• Described first in the German medical literature as "Rötheln", in the mid-18th century, and as a separate entity in 1814 by George Maton, hence "German measles".
• Given the name Rubella in 1866 by Royal Artillery surgeon Henry Veale.
• The American physician Alfred Hess (1975-1933) postulated a viral aetiology in 1914. He also wrote books on scurvy and rickets, showing that the missing factor for scurvy was abundant in citrus fruits and tomatoes, and introduced sunlight treatment for rickets.
• The enveloped RNA Rubella virus itself was isolated in 1962 by Parkman and Weller. It is a togavirus, genus Rubivirus, and is most closely related to group A arboviruses (for example Eastern and Western Equine Encephalitis viruses).