Rubella is an acute viral infection, manifested by characteristic rashes on the background of moderate intoxication, accompanied by regional lymphadenopathy and hematological reaction. The rubella virus is introduced into the body through the mucous membrane of the respiratory tract, where it enters with inhaled air. The incubation period lasts from 10 to 25 days. Typical signs of rubella are the appearance of a rash on the face at first, its rapid spread throughout the body and the absence of palms and soles on the skin. The diagnosis of rubella is established clinically.
Rubella is caused by an RNA-containing virus of the genus Rubivirus. The virus is little resistant to environmental factors, it is easily inactivated under the influence of ultraviolet radiation, heating, chemical disinfectants. The virus can maintain its viability for several hours at room temperature, easily tolerates freezing.
The reservoir and source of the causative agent of rubella is a sick person. In this case, the disease can occur both with clinical symptoms and in a latent, erased form. Virus isolation begins a week before the manifestation of exanthema and lasts 5-7 days after. With congenital rubella in children, the pathogen is secreted with the secret of the nasopharyngeal mucosa, urine (sometimes with feces).
Rubella is spread by means of an aerosol transmission mechanism mainly by airborne droplets. Infection by contact and household means is possible with the general use of toys, dishes. Infection through hands and household items is not epidemiologically significant. When pregnant women are infected with rubella, transplacental transmission of infection to the fetus is carried out. Due to the weak resistance of the virus, infection with rubella requires closer communication than the transmission of pathogens of chickenpox, measles.
A person’s natural susceptibility is high. Especially in women of childbearing age, mainly 20-29 years old. The entrance gates of infection are the mucous membranes of the upper respiratory tract, sometimes damaged skin. Reproduction and accumulation of the virus occurs in the regional lymph nodes. The multiplied virus spreads with the blood flow, affecting other lymph nodes and settling in the skin, while provoking an immune response. The formed antibodies attack the virus and cleanse the body. Postinfectious immunity is persistent, lifelong.
The incubation period of rubella is 10-25 days. The disease in adults usually begins with prodromal signs: fever (sometimes it can reach quite high values), malaise, weakness, headache. Moderate runny nose, dry cough, sore throat, lacrimation, photophobia are often noted. Examination may reveal slight hyperemia of the pharynx and the posterior wall of the pharynx, irritation of the conjunctiva. These symptoms usually persist for one to three days. In children, catarrhal signs are most often absent.
In the initial period of the disease, both adults and children have lymphadenitis mainly of the occipital and mid-neck lymph nodes. Lymph nodes are enlarged in size, painful to the touch. Lymphadenitis can persist for up to 2-3 weeks. After the catarrhal period, rashes appear. The appearance of a rash is usually preceded by skin itching.
In 75-90% of cases, the rash appears on the first day of the disease, first on the face and neck, behind the ears, under the hair. In some cases, the rash may spread from a different localization. During the day, the rash covers various areas of the skin with the exception of the palms and soles. In particular, rashes on the buttocks, back, extensor surfaces of the extremities are characteristic, in rare cases, a small single enanthema of the oral mucosa (Forheim spots) is detected. The rash is small, spotty, not rising above the surface of the skin. The spots are red or pink, rounded, with smooth edges, the skin around the rash elements are not changed. In adults, the elements of the rash often merge, for children, a drain exanthema is not characteristic.
During the rash, the body temperature remains within the normal range, or rises to subfebrile figures, polylymphadenitis is noted. Sometimes myalgia and arthralgia occur, symptoms of dyspepsia, moderate hepatosplenomegaly may occur. Women often note the symptoms of polyarthritis. The rash usually persists for about 4 days, after which it quickly disappears, leaving no consequences. In general, rubella in adults proceeds almost the same as in children, but the severity and duration of the course is usually more significant, more vivid catarrhal symptoms, abundant discharge rash, signs of lymphadenopathy are less pronounced, may not be noted by patients at all.
Complications with rubella are not frequent, as a rule, arise as a result of the addition of a bacterial infection. Mainly among these there are secondary pneumonia, sore throats, otitis media. Sometimes rubella is complicated by arthritis, thrombocytopenic purpura. In adults, in rare cases, complications from the nervous system may develop: encephalitis, meningoencephalitis, encephalomyelitis.
Rubella is a great danger if it develops in pregnant women. The infection does not have a noticeable effect on the mother’s body, but has extremely adverse consequences for the fetus: ranging from congenital malformations to intrauterine death. The probability of the formation of malformations directly depends on the period of pregnancy at which rubella infection occurred. The same dependence can be traced in relation to the occurrence of congenital rubella: in mothers who become ill at 3-4 weeks of pregnancy, the risk of pathology of the baby is 60%, if a woman is affected after 13-14 weeks, it is reduced to 7%.
The methods of specific serological diagnosis of rubella have a retrospective diagnostic value, since paired sera are examined at intervals of 10 days. The increase in the titers of immunoglobulins M and G is determined using RSC, ELISA, RTGA or RIA.
In addition, serological analysis and staging of the lymphocyte blast transformation reaction is performed in pregnant women who have had contact with persons with rubella to identify infection and the likelihood of fetal damage. The analysis of the blood serum of a pregnant woman is performed as early as possible and no later than 12 days after contact with the patient. The detection of immunoglobulins G at these times usually indicates a previous infection and immunity to it, which allows you to safely maintain pregnancy. The appearance of antibodies only in the second serum (mainly immunoglobulins M) indicates an active infectious process that can negatively affect the development of the fetus.
Non-specific methods of laboratory diagnosis of rubella include a general blood test. The blood picture, as a rule, shows lymphocytosis with general leukopenia, an increase in ESR. In adults, plasmocytes can be detected in the blood. Additional diagnostic methods for rubella are needed mainly if complications are suspected. Diagnosis of pneumonia is carried out using lung radiography. In case of neurological disorders, brain EEG, rheoencephalography, Echo-EG are performed. The occurrence of otitis requires consultation with an otolaryngologist.
As a rule, rubella is treated on an outpatient basis, hospitalization is carried out only in case of dangerous complications. Etiotropic treatment of rubella has not been developed, in most cases recovery occurs independently due to the elimination of the virus as a result of the formed immune response.
Therapy in cases of severe course consists in the appointment of symptomatic and pathogenetic drugs (detoxification therapy, antipyretic sedatives, antihistamines). With the development of rubella arthritis, chloroquine is prescribed for 5-7 days. The development of neurological complications serves as an indication for the appointment of prednisone, dehydration therapy. Congenital rubella is currently not treatable.
Prognosis and prevention
In the vast majority of cases, the prognosis is favorable, the disease ends with a complete recovery without any consequences. The prognosis worsens in the case of the development of rubella encephalitis. Rubella is of particular importance in obstetric practice. The transfer of infection by the mother can have extremely adverse consequences for the fetus. The diversity of possible fetal malformations (congenital cataracts, deafness, heart defects, microcephaly, etc.) in pregnant rubella is the wider the earlier the infection took place.
Specific prevention of rubella in developed countries is carried out by routine vaccination with a live associated vaccine against measles, mumps and rubella. In addition, there are monovaccines. Vaccination against rubella is carried out twice, the first time at the age of 12-16 months, then revaccination at 6 years. In addition, in the future, adolescent girls and young women are often revaccinated.
Emergency prevention is carried out for contact children and pregnant women with the introduction of anti-redness immunoglobulin. Patients with rubella are isolated up to 5 days after the rash occurs. There are no special quarantine measures for patients and contact persons.