Rubella

Rubella or German measles is a viral disease with a characteristic red rash. The name “Rubella” is derived from the Latin word which means “little red.” Vaccination against Rubella has resulted in a decline in the number of cases of both rubella infection and congenital rubella syndrome worldwide.

It is caused by the Rubella virus that belongs to a family of viruses called Togaviridae. The natural host for this virus is humans. The virus is transmitted through the nasal lining or epithelium. It is transmitted from the nasal secretions of infected individuals. From the nasal lining, it enters the bloodstream from where the virus travels to various sites in the body, including the brain, eyes, joints, lymph nodes in multiple parts of the body.
For congenital rubella syndrome, transmission is through the placenta from the infected mother to the fetus. Infection during the early phases of pregnancy (first trimester) causes severe organ damage in the developing fetus.

Although the worldwide incidence of rubella and congenital rubella syndrome has decreased, it is still prevalent in countries where vaccination against rubella is not available. Morbidity and mortality associated with congenital rubella are higher.
There is no association of infection rates with race, ethnicity, and gender as such. Males and females from all parts of the world are equally susceptible.
Before the rubella vaccine was introduced, the disease was primarily seen in children between ages 5 to 14 years, but its incidence in adults older than 20 years, typically in the United States, has increased.

Most cases of rubella are asymptomatic. The incubation period is around 14 to 21 days. Before the onset of rash, the following symptoms can be observed:

• Eye pain
• Conjunctivitis
• Sore throat
• Headache
• General body aches
• Low-grade fever
• Chills
• Nausea
• Tender areas behind ears and back of the head due to lymph nodes enlargement
• Some patients also develop small spots on the soft palate
  The characteristic rash of rubella consists of rose-pink spots that start from the face and neck and spread to the extremities. It typically lasts for three days and disappears at the end of the third day. The rash is accompanied by fever, swollen lymph nodes, and itching.
  The classic triad of Congenital rubella is:
• Hearing loss that may be one-sided or in both years and can manifest as late as the second year of life
• Abnormalities in the eye include glaucoma, cataract, retinopathy, etc. These can progress to permanent blindness as well.
• Abnormalities of the heart, the most common finding, is patent ductus arteriosus (PDA).

Other findings of congenital rubella vary, depending upon the time of infection during pregnancy. Infections in the earlier part of pregnancy have more detrimental effects. These include:

• Intrauterine death (IUD)
• CNS abnormalities
• Lung disorders causing interstitial pneumonia
• Liver defects
• Bone lesions
• Skin defects
• Blood disorders such as anemia

Many cases of rubella may be asymptomatic, and the rash resembles a lot of viral infections. Therefore laboratory investigations for the diagnosis of rubella are of prime importance. These include:

• Serology testing is done by measuring IgM or IgG antibody levels. The presence of IgM and a four-fold increase in the levels of IgG antibodies against rubella is confirmatory for diagnosis.
• Viral culture from urine or nasal samples can also be done, but it is an expensive and time-consuming method.
• Congenital rubella can be detected by serologic testing of placental blood for antibodies.
• Other methods for diagnosis of congenital rubella are placental biopsy and then PCR for detection of the virus.
• In some babies with congenital rubella, the virus can persist after birth for up to one year and be detected through serologic testing.
• Complete blood count may indicate leukopenia and thrombocytopenia.
• Liver function tests such as bilirubin, ALT, ALP, etc., are also raised.

Differential diagnoses for rubella are:

• Herpes simplex infection
• Measles
• Contact dermatitis
• Syphilis
• Mononucleosis caused by Epstein-Barr virus (EBV)
• Cytomegalovirus infection
• Toxoplasmosis

No specific anti-viral against rubella is available. Symptomatic treatment is provided to cope with troublesome manifestations.

• Rehydration through oral liquids is advised to avoid dehydration and electrolyte imbalance.
• Starch baths and antihistamines manage itching due to rash.
• Complicated cases of arthritis are given NSAIDS for pain management.
• Patients with a severe decrease in blood cells due to infection can receive intravenous transfusions to replace those.
  Treatment for congenital rubella syndrome is also supportive. It consists of:
• Hearing and vision screening for otherwise asymptomatic newborns.
• Ocular consultation for symptomatic babies with eye defects.
• Care in ICU for babies who develop respiratory distress.
• Babies with elevated levels of bilirubin are treated with phototherapy to avoid permanent brain damage.
• Congenital heart abnormalities require surgical care.

• The most effective prevention against the disease is vaccination. The Rubella vaccine was introduced in 1979 as a combination vaccine called MMR (measles, mumps, and rubella). It is given in two doses. The first dose is given at 12-15 months of age and the second dose between 4 to 6 years. The vaccine is highly effective, and a single dose confers almost lifelong immunity against the disease.
• Females of childbearing age should be assessed for rubella vaccination status and receive a vaccination if they have not received it already. It is contraindicated in pregnant females.
• At-risk individuals or individuals who have encountered an infected person should be checked for their vaccination status against rubella.
• Positive cases should be isolated from otherwise healthy individuals for at least seven days.
• Children with congenital rubella can spread infection through contact, so they should be isolated until one year of age, or at least two viral culture samples taken at one-month intervals have tested negative.