Rubella

Rubella is a contagious viral infection that occurs most often in children and young adults and usually causes mild respiratory infections. Sometimes it can lead to severe complications and death. Epidemics of rubella occur in communities with low immunization coverage. Rubella infection in pregnant women may cause foetal death or congenital defects known as congenital rubella syndrome (CRS). It is the leading vaccine-preventable cause of birth defects.

The following are standard case definitions to allow national health authorities to interpret data in an international context. However, during an outbreak case definitions may be adapted to the local context and the Red Cross Red Crescent should use those agreed/established by national health authorities. NB: Consider that during community-based surveillance, volunteers should use broad (simplified) case definitions (referred to as community case definitions) to recognize most or all possible cases, provide relevant risk communication and appropriate actions and encourage them to seek care. Other actors such as healthcare workers or investigators studying the cause of a disease, on the other hand, can use more specific case definitions that may require laboratory confirmation.

Rubella

Suspected rubella case: Any patient of any age in whom a health worker suspects rubella. A health worker should suspect rubella when a patient presents with: fever, maculopapular rash; and cervical, suboccipital or postauricular swollen lymph nodes (adenopathy) or joint pain (arthralgia/arthritis).

Clinical confirmation: Rubella cannot be confirmed clinically: laboratory confirmation is required.

Laboratory-confirmed rubella case: Because of the difficulty of clinical diagnosis of rubella, laboratory confirmation is required. A laboratory-confirmed case is a suspected case with a positive blood test for rubella-specific IgM antibodies. The blood specimen should be obtained within 28 days after the onset of rash.

Epidemiologically confirmed rubella case: A patient with a febrile rash illness that is linked epidemiologically to a laboratory-confirmed rubella case.

WHO case definition source of information: https://www3.paho.org/hq/index.php?option=com_content&view=article&id=757:2009-rubella-case-definition&Itemid=843&showall=1&lang=fr

Congenital rubella syndrome (CRS)

Suspected CRS case: Any infant less than one year of age in whom a health worker suspects CRS. A health worker should suspect CRS when an infant 0—11 months of age presents with heart disease and/or suspicion of hearing impairment/deafness and/or one or more of the following eye signs: white pupil (cataract), diminished vision, pendular movement of the eyes (nystagmus), squint, smaller eyeball (microphthalmia), or larger eyeball (congenital glaucoma). A health worker should also suspect CRS when an infant’s mother has a history of suspected or confirmed rubella during pregnancy, even when the infant shows no signs of CRS.

Clinically confirmed CRS case: An infant in whom a qualified physician detects at least two of the complications listed in (a) below or one in (a) and one in (b):

(a) cataract(s), congenital glaucoma, congenital heart disease, loss of hearing, pigmentary retinopathy.

(b) purple spots on the skin (purpura), enlarged spleen (splenomegaly), small head (microcephaly), mental retardation, meningoencephalitis, forearm bone disease, jaundice that begins within 24 hours after birth.

Laboratory confirmed CRS case: An infant with clinically confirmed CRS who has a positive blood test for rubella-specific IgM antibodies (100 per cent of such infants are positive at the age of 0—5 months of age; 60 per cent are positive at 6—11 months of age). Where special laboratory resources are available the detection of rubella virus in specimens from the throat or urine of an infant with suspected CRS provides laboratory confirmation of CRS (60 per cent of such infants shed rubella virus at the age of 1—4 months of age; 30 per cent at 5—8 months of age: 10 per cent at 9—11 months of age).

Congenital rubella infection (CRI): If a mother has suspected or confirmed rubella in pregnancy the infant should have a rubella-specific IgM antibodies blood test. An infant who does not have clinical signs of CRS but who has a positive rubella-specific IgM antibodies test is classified as having congenital rubella infection (CRI).

WHO case definition source of information: https://www.who.int

• Being unvaccinated is the main risk factor for contracting the disease.
• Rubella infection in pregnant women, especially during the first trimester, may cause miscarriage, foetal death, stillbirth or live-born infants with congenital rubella syndrome (CRS).
• Crowded settings in outbreak areas increase the risk of transmission.
• Lack of proper sanitation and hygiene measures.
• Vaccine-preventable disease outbreaks can be particularly deadly in countries experiencing or recovering from a natural disaster or conflict. Damage to health infrastructure and health services interrupts routine immunization and overcrowding in residential camps greatly increases the risk of infection.

Attack rates will vary from one outbreak to another. In case of an outbreak, consult the latest information provided by health authorities.

It depends on the vaccination rate in an outbreak area. Secondary attack rates among non-immune household contacts are high.

• Babies born to women who were pregnant during the infection are at high risk of permanent birth defects and lifelong disability.  
• Immunosuppressed persons such as those receiving chemotherapy,  transplant recipients or HIV carriers.
• People with chronic diseases such as renal disease, cancer, chronic lung or liver disease, and diabetes.

Rubella virus.

Humans.

• Droplet spread: sneezing, coughing, and talking produce droplets that transmit the virus. Sharing eating and drinking utensils can increase droplet spread.
• Vertical transmission: rubella virus can be transmitted from the pregnant woman to the foetus, especially in the first trimester.

14 days (range 12—23 days).

The most infectious period for rubella is usually one to five days after the appearance of the rash. Infants with CRS may excrete the virus for a year or more.

• In children and adults, rubella is usually mild, with symptoms including a rash, low fever (under 39 °C), headache, cough, runny nose, nausea and mild pink eye (conjunctivitis). The rash, which occurs in 50–80 per cent of cases, usually starts on the face and neck before progressing down the body and lasts one to three days. Swollen lymph glands behind the ears and in the neck are the most characteristic clinical feature.
• Up to 70 per cent of women who get rubella may develop arthritis and painful joints that usually last from three to ten days. This is rare in children and men.
• When a woman is infected with the rubella virus early in pregnancy, there is a 90 per cent chance of passing the virus on to the foetus. This can cause miscarriage, stillbirth or severe birth defects known as Congenital Rubella Syndrome (CRS). Children with CRS commonly experience deafness, cataracts, heart defects, intellectual disabilities, and liver and spleen damage. Less common birth defects from CRS include glaucoma, brain damage, thyroid and other problems, and inflammation of the lungs.
• 25—50 per cent of people infected with rubella will not experience any symptoms.

Measles; scarlet fever; monkeypox; hand, foot and mouth disease (HFMD). In humanitarian settings where populations live in crowded conditions it is important to be alert to the similar clinical presentations of measles and rubella and ensure that relevant response actions follow laboratory confirmation of suspect cases.

The presence of rubella IgM antibodies or demonstration of a significant rise in rubella IgG antibodies from paired acute and convalescent serum samples provides evidence of ongoing or recent rubella infection. It can also be confirmed by detection of rubella virus by polymerase chain reaction (PCR).

Please refer to the appropriate local or international guidelines for clinical management. All clinical management including the administration of any treatment or vaccine should be conducted by health professionals.

• Patient isolation is necessary.
• There is no specific treatment for rubella. The disease is, however, preventable by vaccination.
• Rubella vaccines are commonly available in combination with other vaccines such as with vaccines against measles, mumps or varicella.

• Immunity after rubella infection appears to persist throughout life. However, on rare occasions, serologically documented re-infections have occurred, and re-infection during pregnancy resulting in CRS has been reported.
• Two doses of rubella vaccine provide long-lasting high efficiency.