Rubella

Rubella (Rubeola), also known in English-speaking countries as German measles, is an acute viral disease characterized by lymphadenopathy, skin rash, headache and runny nose.

ICD-10 codes

• Q06. Rubella (German measles).
• B06.0. Rubella with neurological complications.
• B06.8. Rubella with other complications.
• B06.9. Rubella without complications.

Epidemiology of rubella

Rubella in England is very rare. In 2010, only 12 episodes of the disease were recorded. But in countries where routine immunization of the population against rubella is not carried out, respectively, this disease is a much larger problem.

Most often rubella are affected by children aged 5-15 years. Often rubella is also found in adults, but after 40 years such cases are rare.

Source of the causative agent of infection - patients, including with the erased and atypical course of the disease, persons with asymptomatic infection and virus carriers. The virus is released from the mucus of the upper respiratory tract for 1-2 weeks before the onset of the rash and within 3 weeks after the rash. In children with congenital rubella, the pathogen can be excreted from the body with urine, sputum, feces up to 2 years after birth.

The main route of transmission of the pathogen is airborne. Viralemia, which develops with rubella, determines the intrauterine way of transmission from mother to fetus, as well as the probability of parenteral transmission of the pathogen. The spread of the pathogen through the care items is of no practical significance.

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What causes rubella?

Rubella is caused by an RNA-containing virus that belongs to the family of tobawirus, due to which a person is covered with a small red rash. Infection occurs by airborne droplets or through direct contact with the carrier. When a pregnant woman is infected, the virus enters the fetus through the placenta.

The rubella virion has a spherical shape, 60-70 nm in diameter, consists of an outer shell and a nucleocapsid. The genome is formed by an unsegmented molecule + RNA. The virion is antigenically homogeneous.

The rubella virus is sensitive to the action of chemical agents. It is inactivated by the action of ether, chloroform, formalin. At a temperature of 56 ° C perished in 30 minutes, at 100 ° C - after 2 minutes, when exposed to ultraviolet radiation - after 30 seconds. If there is a protein in the protein medium, the resistance of the virus increases. At low temperatures, the virus retains its biological activity well. The optimal pH for the virus is 6.8-8.1.

What pathogenesis is rubella?

The site of primary replication of the virus is unknown, but already in the incubation period, viremia develops, and the virus is released into the environment with exhaled aerosol, urine and feces. The virus penetrates the body through the mucous membranes of the upper respiratory tract. Later, the virus multiplies in the lymph nodes (this process is accompanied by polyadenopathy), as well as in the skin epithelium, leading to the appearance of a rash. The virus penetrates the GEB and the placenta. As a result of activation of interferon production, formation of cellular and humoral immunity, the circulation of the virus stops and recovery comes, However, in pregnant women and children with congenital rubella virus can exist in the body for a long time.

Rubella during pregnancy

Despite the fact that this disease is called "light", for pregnant women it can be a serious danger if a woman "picks up" the infection within the first 16 weeks. The rubella virus penetrates the fetus through the placenta and disrupts the normal intrauterine development of the baby. The degree of damage to the fetus depends on the gestational age. Most often, the virus affects the vision of the child, which can lead to cataracts. It is also dangerous for the baby's hearing, because the virus can provoke its complete loss. Usually, rubella does not require treatment, after 7-10 days all the symptoms are completely gone. Physicians recommend that patients adhere to bed rest and take pain for ibuprofen or paracetamol.

What are the symptoms of rubella?

The incubation period of rubella lasts 14-21 days, then the prodromal period lasts 1-5 days, which is usually characterized by fever, malaise, lymphadenopathy, in adults it usually flows easily, and in adolescents may be absent. Characterized by swelling and soreness of the occipital, pozaushnyh and dorsal lymph nodes. Pharyngeal symptoms of rubella appear.

The first symptom is usually a rash. Typical symptoms of rubella are a rise in temperature (very rarely above 38 degrees), a runny nose, a headache, swollen lymph nodes and a rash. 

Rubella rarely has complications. Symptoms of rubella such as good-quality polyarthritis with lesions of small and medium joints, thrombocytopenic purpura are possible .

The rash is similar to measles, but less common and disappears faster. It appears on the face and neck and quickly moves to the trunk and limbs. Redness of the face can be observed. On the 2nd day it becomes scarlet-like (spotted) with a reddish blush. Petechial elements on the soft palate (Forshehmer spots) turn into red spots. The rash persists for 3-5 days.

Common symptoms of rubella in children may be absent or be mild and include malaise and sometimes arthralgia. In adults, as a rule, the general symptoms are almost not expressed, although fever, weakness, headache, joint stiffness, transient arthritis, minor rhinitis can occur. Fever is usually resolved on the 2nd day of the rash.

Encephalitis is rare, during large outbreaks among the military. This complication is typical, but can lead to death. Thrombocytopenic purpura and otitis media are rare.
 

How is rubella diagnosed?

The diagnosis of "rubella" is established on the basis of clinical and epidemiological data and a picture of blood.

Rubella may be suspected in the patient in the presence of characteristic adenopathy and rash. Laboratory diagnosis of rubella is necessary only in pregnant women, patients with encephalitis and newborns. Increasing the antibody titer 4 or more times between the acute phase and the reconvalescence phase confirms the diagnosis.

The specific diagnosis of rubella is based on the use of RSK, RTGA, ELISA and RIF in paired sera. The determination of specific antibodies belonging to the IgM class is carried out no later than the 12th day after exposure to the source of the infection.

When differential diagnosis should take into account measles, scarlet fever, secondary syphilis, reaction to drugs, infectious erythema, infectious mononucleosis, ECHO-, coxsackinfection. Infections caused by enterovirus and parvovirus B19 (infectious erythema) may not be clinically distinct. Rubella differs from measles with an easier flow, faster disappearance of the rash, easier and short-term general symptoms, lack of Koplic stains, photophobia and coughing. Even observation for one day shows that scarlet fever is accompanied by more severe symptoms and pharyngitis than rubella. In secondary syphilis, lymph nodes are painless and the rash is usually expressed on the palms and soles. Laboratory diagnosis of syphilis is usually done easily. In infectious mononucleosis, more severe angina is observed, a longer and more severe malaise and the presence of atypical mononuclear cells in the blood smear, the presence of antibodies to the Epstein-Barr virus.

How is rubella treated?

Rubella is treated without any drugs. Specific therapy of encephalitis does not exist.

How is rubella prevented?

Having had a rubella once, a person acquires lifelong immunity. However, because of the high risk that rubella pose for pregnant women, WHO recommends doing a preventive vaccination.

Patients are isolated at home for 5 days from the moment of rash. Disinfection and separation of contact children are not carried out. Rubella is prevented by vaccination, vaccination against measles, mumps and rubella has been carried out in Russia since 1997.

Vaccination against rubella live vaccine is routine. As a result of vaccination of persons over 15 years of age, immunity develops in more than 95% of vaccinated people and no cases of viral transmission have been proven. Vaccination against rubella is recommended to children and everyone else at post-puerperate age, especially to people from organized collectives - students, the military, health workers, emigrants and those working with young children. Vaccination should not be carried out to persons with immune system disorders. Routine vaccination is recommended for all susceptible women immediately after delivery. Screened among women of childbearing age for the presence of antibodies to rubella and all seronegative are immunized. However, this vaccination can not be carried out unless there is certainty that for at least 28 days after it there will not be a pregnancy: a vaccine virus can infect a fetus during an early pregnancy. The syndrome of congenital rubella is not described, the risk of fetal damage is estimated to be up to 3%. The use of rubella vaccine is contraindicated during pregnancy. After vaccination against rubella in children, there is rarely a rise in temperature, the appearance of rash, lymphadenopathy, polyneuropathy, arthralgia and arthritis; tenderness of the joints, swelling of the joints can sometimes be in adults, especially in women.