Rubella is a viral infection, that has the acquired form (with the air-droplet mechanism of transmission, mild clinical signs and benign completion) and innate (with the transplacental mechanism of transmission and development of severe fetal defects).
Etiology: an agent is a RNA-containing Rubivirus from the Togaviruses.
Rubivirus
Epidemiology:
– the source of infection is a patient or carrier;
– the mechanism of transmission is air-droplet, transplacental;
– receptivity is common, especially high in children 2-9 years.
Pathogenesis
Acquired Rubella:
1. An entrance gate is the mucus membranes of nasopharynx, where virus is replicating.
1. Hematogenous distribution (viremia).
2. Damage of organs and systems.
3. Immunological answer, recovery.
Innate Rubella:
1. Transplacental infection of the fetus.
4. Destruction of the cells by the virus, violation of the correct organs’ development.
5. Forming of the development defects.
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) (photo 11);
- toxic syndrome (mild);
- increase of cervical, occipital lymph nodes (rarely – polyadenopathy).
Rubella, throat and skin changes
The rashes in acquired Rubella
Diagnostic criteria of the innate Rubella:
Classical Triad:
1. Cataract.
2. Congenital heart disease (open aortic channel, aortic valves defect, aortic stenosis, coarctation of the aorta, ventricular septal defect and pulmonary atery stenosis, atrial septal defect, large arteries transposition).
3. Deafness.
Exept enumerated:
• Microcephalus
• Microphthalmia
• Rhetinopathy
• Cornea clouding
• Glaucoma
• Clift palate
• Intersticial pneumonia
• Hepatitis
• Myocarditis
• Meningoencephalitis
• Damage of the vestibular organ
• Urinary tract and sexual organs defect
• Dermatitis
• Thrombocytopenia
• Hemolytic anemia
• Hypogammaglobulinemia
• Secondary immune deficit
• Low birth weight
The congenital Rubella rashes, cataract
Classification of the acquired Rubella:
By the type:
- typical forms;
- atypical forms (effaced, asymptomatic).
By the severity:
- mild;
- moderate;
- severe;
By the course:
- smooth (uncomplicated);
- uneven (complicated).
Specific complications: meningitis, encephalitis, synovitis.
Diagnosis example
Rubella, typical form, exanthema period, moderate severity, uncomplicated duration
Confirmation of the diagnosis:
1. Complete blood test: leucopenia, lymphocytosis, plasmatic cells, normal ESR.
12. PCR – selection of virus from the nasopharyngeal smears, excrements, urine, blood, saliva and CSF.
13. Serologic – NR, PHAR (stable positive result in case of the innate rubella), CBR with 4 times or more increasing of the antibody tytre in dynamics.
14. 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).
15. Express methods – phase-contrasting microscopy, micro agglutination reaction.
Differential diagnosis with measles, scarlet fever, allergic exanthema, infectious mononucleosis.
Treatment:
Base 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:
Base therapy:
• Bed regimen till body temperature normalization, disappearance of general cerebral and considerable improvement of focal neurological signs, not less than 14-16 days;
• A diet (before stable vital functions is due to adequate parenteral infusion therapy);
• Brest
1/2-1/3 of average volume with a next increase to the complete volume during 2-3nd days;
• A milk vegetable diet (№5) is appointed for preschoolers or school children, 5-6 times per day with the next passing to the diet №2 whether №15 (depending the age) in the recovery period;
• Oral fluids intake corresponds to age norms (with including the IV fluids);
• Antibacterial therapy: for infants at presence of concomitant bacterial infection, chronic infection, inflammatory changes in the CBC (by the broadspectrum antibiotic in average therapeutic doses, a short course).
Etiologic therapy: specific therapy is absent.
Pathogenetic therapy:
• Glucocrticoids 3-5 mg/kg (by prednisolon), course not more than 10 days;
• Vascular medicine (penthoxyphyllin, nicergolin and others like that);
• In posthypoxia period – nootrops, vitamins group B;
• In case of CSF hypertension – dehydration by 25 % MgSO4 IM, lasix 1-3 mg/kg IV or IM, acethazolamid orally;
• In case of seizures – Anticonvulsant therapy: benzodiasepins (seduxenum, sibasonum) 0.3-0.5 mg/kg IV, if they are ineffective – 1 % hexenalum or thiopenthalum sodii in 3-5 mg/kg IV. Dehydration therapy: lasix 2-3 mg/kg IM or IV.
Prognosis:
• Recovery;
• Invalaidization (in case of the innate Rubella).
Prophylaxis:
• Isolation of patients on 4 days from the disease beginning, new-born with innate Rubella – 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), (in Ukraine vaccination in 12 month, revaccination in 6 years, if not done before – in 15 years by monovaccine in girls).
n Passive prophylaxis to seronegative pregnant, (to children does not performed).
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