RUBELLA

German measles or three days measles

Rubella is a viral infection caused by the rubella virus and can be both acquired or innate { at birth through transplacental mechanism of transmission and development of severe fetal defects}. 

I is caused by the rubella virus an agent is a RNA-containing Rubivirus from the Togaviruses {single-stranded RNA genome}. The virus is transmitted by the respiratory route and replicates in the nasopharynx and lymph nodes. It is known that the virus also has teratogenic properties and is capable of crossing the placenta and infecting the fetus where it stops cells from developing or destroys them which results in birth defects.

It is usually spread through air-droplets by coughing,sneezing from persons infected or carries of the virus,or transplacental mechanism,receptivity is common, especially high in children 2-9 years.

Pathogenesis

Acquired Rubella:

  1. The virus gains entrance through the mucus membranes of the nasopharynx here it begins to replicate.
  2. later begins to spread hematogenically {viremia}.
  3. Damage of organs and systems occur
  4. Immune system responds and recovery begins.

Innate Rubella:  

  1. Transplacental infection of the fetus.
  2. destruction of the cells by the virus, violation of the correct organs’ development.
  3. Forming of the development defects.

Symptoms

Rubella usualy presents with symptoms similar to the flu, however, the primary symptom of rubella virus infection is the appearance of a rash (exanthem) on the face which spreads to the trunk and limbs and usually fades after three days {that is why it is often referred to as three-day measles}.

 The facial rash usually clears as it spreads to other parts of the body. Other symptoms include low grade fever, swollen glands {sub-occipital and posterior cervical lymphadenopathy}, joint pains, headache, and conjunctivitis.

Typically the rubella rash is pink/light red and causes itching and often lasts for about three days. The rash disappears after a few days with no staining or peeling of the skin.

In children rubella normally causes symptoms which last two days and include

  • Rash beginning on the face which spreads to the rest of the body.
  • Low fever of less than 38.3 °C (101 °F).
  • Posterior cervical lymphadenopathy.

In older children and adults additional symptoms may be present including:

  • Swollen glands
  • Coryza (cold-like symptoms)
  • Aching joints (especially in young women)

Severe complications of rubella include:

  • Brain inflammation (encephalitis)
  • Low platelet count
  • Ear infection.

Diagnostic criteria of the acquired Rubella:

  • Latent period – 18-23 days
  • prodromal period – 1-2 days

– mild toxic syndrome

– mild catarrhal syndrome (rhinitis, pharyngitis, catarrhal tonsillitis)

– increase of posterior cervical, occipital lymph nodes

  • Period of exanthema (rashes, erruption) – 3-4 days

– rashes (maculous, pinky, on face, trunk, extensor surfaces of extremities, on the unchanged background, arises during one day)

– toxic syndrome (mild)

– increase of  cervical, occipital lymph nodes (rarer – polyadenopathy)

Diagnostic criteria of the innate Rubella:

Classical Triad:        

  1. Cataract
  2. Inborn heart disease {open aortic channel, aortic valves defect, aortic stenosis, coarctation of aorta, intraventricular septal defect and pulmonary atery stenosis, intraatrial septal defect, large arteries transposition} {patent ductus arteriosus being the most common}
  3. Deafness

Confirmation of the diagnosis:

  1. Complete blood test: leucopenia, lymphocytosis, plasmatic cells, normal ESR
  2. PLR  – selection of virus from the nasopharyngeal smears, excrements, urine, blood, saliva and CSF.
  3. Serologic – NR, SHAR (stable positive result in case of the innate rubella), CBR with 4 times or more increasing of the antibody tytre in dynamics.
  4. Immune-enzyme analysis (ELISA test) with measuring of specific antibodies Ig M in the acute phase (and in the innate rubella) and Ig G after the recovery (in the blood or, if necessary, in CSF)
  5. Express methods – phase-contrasting microscopy, micro agglutination reaction

Differential diagnosis with measles, Scarlet fever, allergic exanthema, infectious mononucleosis (see Measles)

Treatment

There is no specific treatment for rubella; however, management is a matter of responding to symptoms to diminish discomfort.

Basic therapy:

  • Bed regime in an acute period, then half-bed regime (3-7 days)
  •  Hygienic regime, often room ventilation
  •  Control of fever and myalgia (when the temperature is more than 38.5-39˚C); in chilren before 2 mo and in case of perinatal CNS damage, seizures in the history, severe heart deseases – when the temperature is up to 38˚C with acetaminophen (paracetamol 10-15 mg/kg not often than every 4 hours (not more than 5 times per day) or ibuprophen 10 mg/kg per dose, not often than every 6 hours.

In case of encephalitis, meningitis:

  •  Glicocorticoids 2-5 mg/kg/day (equivalent to prednisone)
  • IV detoxication 50 ml/kg/day (5% glucose, 0.9% NaCl not more than 20 ml/kg on 1 infusion)
  •  lasix 1-3 mg/kg
  • seduxen 0.3 mg/kg (if indicated)
  • trental, curantil, cavinton (0.2-0.5 ml/kg)
  • noothropil (50 ml/kg/day)

Etiologic therapy:

  • Preparations of recombinant interferon (in case of acquired Rubella with the CNS defeat, innate Rubella)

Prophylaxis:

  • Isolation of patients on 4 days from the disease beginning, new-born with innate German measles – up to 1 year.
  • An active immunization (vaccination) is done in 12-18 months by MMR vaccine (together with vaccination against measles, and mumps). Revaccination at 4 to 6 years or at 10 to 11 years, if not done before – vaccination by monovaccine in 12-14 years (girls).
  • Passive prophylaxis to seronegative pregnant, (to children does not performed).