Rubella is a contagious viral infectious disease that can be both asymptomatic and symptomatic. The rubella infection leads to very long-term immunity, most often for life (after healing).
It’s a benign infection in childhood. The risk is high in the pregnant woman because rubella can cause congenital malformations to the fetus.
Both the risk of fetal infection and the severity of embryo-fetal touch are inversely correlated with the age of pregnancy at the time of maternal infection.
In case of first maternal infection
- Before 11 weeks of pregnancy the frequency of transmission of maternal-foetal infection is about 90% and most commonly translates by severe impairment of the embryo.
- Between 11 and 18 weeks of pregnancy leads to congenital birth which often is limited to an isolated deafness.
- After 18 weeks of pregnancy the risk of congenital malformations to the fetus is very low (almost null).
In symptomatic patients, the disease has 2 stages: the invasion phase and the status phase.
Invasion phase
-Is short (1-5 days) and appears at only 25% of the patients, especially in adults. Is characterized by:
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- Discomfort
- Subfebrileness,
- Discreet pain at the pharynx level,
- Sometimes joint pain,
- Discreet enlargement of retro-auricular, posterior cervical and sub-occipitals ganglions. The enlargement of ganglions may persist for about 10-14 days after the eruption has disappeared.
Status phase
-Starts with the occurrence of the rash that is inconsistent.
-
- It is a maculopapular eruption (reddened skin lesions); it starts on the face and occupies trunk and upper limbs within 24 hours.
- On the second day it can get a rough skin appearance on the buttocks and lower limbs
- Disappears on the third day in the order in which it appeared.
The skin eruption occurs in a single wave (compared to the situation in other eruptive diseases).
The biggest inconveniences accused are joint pains. Especially in young people and women (with a frequency of 15-20% of cases). It affects both the large joints-knees, ankles, shoulders, punches and small ones at the hand. Sometimes they still appear in the invasion phase and can persist for a long time.
There can also be associated signs and symptoms, such as:
-
- Cough
- Headache
- Conjunctivitis
- Splenomegaly (increased spleen size),
- Fever. Rarely the fever lasts more than a day after the eruption occurs.
The diagnosis of certainty is based on laboratory analyses. Clinical diagnosis is not certain. There are other diseases that can lead to similar signs and symptoms. Therefore, the diagnosis is based on a blood sample collected within 28 days of the infection onset. In blood sample, the presence of Ig M antirubella antibodies is determined by an ELISA-type technique. There are also tests involving modern techniques of molecular biology (reserved for laboratories that have the necessary equipment; they are intended for virus detection).
Congenital rubella/Congenital rubella syndrome (CRS) – clinical manifestations in the newborn
The risk is:
-
- Fetal death
- Malformative congenital rubella
- Evolutionary congenital rubella.
Malformative congenital rubella
is detected:
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- Prior to birth (by ultrasound; the technique can allow detection the malformations of the central nervous system or of an intrauterine growth retardation),
- After birth,
- Or later (a complete balance of rubella sequelae can be done after several years of birth).
Birth generally affects:
-
- Auditory system,
- Visual system,
- Heart
- Central nervous system.
They are generally multiple and associated.
Ocular impairment includes:
-
- Cataract (the most common birth, generally bilateral),
- Microphthalmia,
- Glaucoma
- Corneal opacity.
Hearing impairment consists of deafness (frequently asymmetric and rarely complete). This is about a hearing loss that interests the high frequencies.
Cardiac malformations can be of many types but the most common are:
-
- Persistence of the arterial channel and
- Pulmonary stenosis.
Central nervous system lesions include:
-
- Microcephaly and
- Psychomotor retard.
Other rare malformations may be dental ones (hypoplasia, agenezia of certain teeth, micrognathia).
Congenital Rubella evolution
It refers to a generalized chronic viral infection. The virus is present both in viscera and pharynx, which makes the newborn very contagious. In this case, the newborn may be contagious for about 6 months, but infectiousness may persist even 24 months. Congenital Rubella evolution is generally associated with malformations present since birth.
The clinical picture associates at birth:
-
- Thrombocytopenic purpura,
- Hepatitis with Hepatoslenomegaly and jaundice,
- Lymphocytic meningitis with or without neurological signs,
- Myocarditis
- Interstitial pneumonia,
- Radiologically visible bone lesions.
Death occurs in 1 out of 5 cases.
Subsequently, neurological anomalies can also be found, a psychomotor retardation that can reveal an evolutionary rubella encephalitis.
The long-term prognosis is reserved.
The diagnosis to baby is based on:
-
- ELISA for the detection of antirubella IgM-type antibodies in the blood or
- Virus detection through genetic amplification techniques from pharyngeal exudate, blood, urine (e.g. PCR).
Children with congenital rubella may remain positive for antirubella IgM-type antibodies up to 6 months. In the pharyngeal or urinary samples of the childrens with congenital rubella the virus may persist until the age of 3 years.
The infectious agent
The rubella virus is an RNA virus in the Togaviridae family, genus Rubivirus.
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