What is Rubella?
Rubella is an acute viral disease that occurs with short-term fever, spotted or maculopapular rash, and an increase in cervical lymph nodes.
Causes of Rubella
Rubella virus belongs to the Togavirus (family Togaviridae, genus Rubivirus).
Virions are spherical particles with a diameter of 60-70 nm, rare fibers are located on the surface with a length of 8 nm and contain RNA. Unlike other Togaviruses, the rubella virus contains neuraminidase. The virus is pathogenic for some monkey species. It is able to multiply in many cell cultures, but it has a cytopathic effect on only a few, in particular on the culture of BHK-21 (hamster). The rubella virus agglutinates the erythrocytes of pigeons, geese, has hemolytic properties. In the external environment, the virus is unstable, dies quickly when dried, with changes in pH (below 6.8 and above 8.0), under the influence of ultraviolet rays, ether, formalin and other disinfectants.
Pathogenesis during Rubella
The contagious period begins 2 days before the rash, the peak of contagiousness decreases with the extinction of the rash. Neurological manifestations in these cases may occur on the 3-4th day of the rash, but sometimes precede them. Damage to the central nervous system in congenital rubella may be due to direct exposure to the virus, as evidenced by its release from the cerebrospinal fluid. Encephalitis with acquired rubella is rare, usually in young children, characterized by severe course and high mortality. In this case, the rubella virus cannot be isolated. The infectious-allergic nature of encephalitis is assumed. It is also established that the rubella virus can cause progressive panencephalitis.
Incidence: 396 per 100,000 population (2001).
The source of infection is a sick person or carrier. Contagious patient 2-3 days before the first signs and within 7 days of illness. The susceptibility to infection is high. Airborne propagation path. People of all ages are sick. Congenital rubella in the transplacental route of penetration from the sick mother to the fetus, such newborns are dangerous as a source of infection during the year.
When acquired rubella – contact with the patient for 11-21 days before the onset of the disease.
Symptoms of Rubella
On the first day of the disease, a roseolous or roseolous-papular rash appears on the unchanged background of the skin, mainly on the extensor surfaces of the limbs around the joints. After 2-3 days, this rash disappears without a trace. Moderate fever, mild catarrhal phenomena, spotted hyperemia of the soft palate, enlarged and moderately painful cervical, parotid and occipital lymph nodes. On the 4-7th day of the disease, a complication can develop in the form of serous meningitis or encephalitis with a relatively favorable course. Sometimes rubella panencephalitis progresses with an increase in neurological symptoms in the form of ataxia, convulsive seizures, depression of consciousness.
When a woman is infected with rubella in the first 8-10 weeks. pregnancy often occurs fetal death or severe violations of the embryogenesis process with the formation of gross developmental anomalies in the form of the Gregg triad: eye damage (cataract, retinopathy, glaucoma, chorioretinitis, microphthalmia), deafness and malformations of the cardiovascular system (open arterial duct, inter-atrial defects) and interventricular septum, pulmonary hypoplasia). Possible malformations of the central nervous system – micro-and macrocephaly. Therefore, with the development of rubella in the first trimester of pregnancy with typical seroconversion, abortion is recommended. When the fetus is infected after 16 weeks. pregnancy risk of congenital malformations less, develop a single developmental defects, sometimes meningoencephalitis joins.
Diagnosis of Rubella
Virus isolation is used by the classical virological method – sowing the mucus of the nose on embryonic tissues. Anti-avian antibodies are detected and their titer increase in CSC and neutralization is 4 times or more.
Rubella should be differentiated from measles, enterovirus infections, scarlet fever, secondary syphilis, allergic rashes on the skin.
Specific therapy does not exist. The main activities should be aimed at eliminating swelling and swelling of the brain (corticosteroids, lasix, cryoplasm), in the period of convalescence used nootropic drugs.
Patients acquired rubella isolate until full recovery, but not less than 5 days from the onset of the disease. It is recommended to isolate the first patient in an institution for up to 10 days from the onset of a rash. In some cases (if there is a family, a group of pregnant women), it is advisable to extend the period of separation to 3 weeks.
The impact on the rubella transmission mechanism consists in airing and damply cleaning the room, the ward where the patient is located.
Contact children under the age of 10 years who have not had rubella are not allowed to be sent to closed-type children’s institutions (sanatoria, children’s homes, etc.) within 21 days from the moment of separation with the patient.
Specific prevention. Use the live attenuated vaccine “Rudivaks”, as well as a combined vaccine against measles, epidemic mumps, rubella – “MMR”. In order to prevent congenital rubella, girls aged 12-16 should be vaccinated, followed by seronegative revaccination before the planned pregnancy.
It is impossible to vaccinate pregnant women: pregnancy is undesirable for 3 months. after immunization against rubella (does not exclude the possibility of post-vaccination damage to the fetus). The introduction of rubella vaccine is accompanied by the production of 95% of immunized specific antibodies.
In case of contact of a pregnant woman with a rubella patient, the question of preserving pregnancy should be resolved taking into account the results of a 2-fold serological examination (with mandatory determination of the quantitative content of specific immunoglobulins of classes M and G). If a pregnant woman has a stable titer of specific antibodies, the contact should be considered not dangerous.