Congenital rubella syndrome

Introduction to congenital rubella syndrome Congenital rubella syndrome is caused by rubella in the first trimester, and the rubella virus infects the fetus through the placenta, resulting in congenital malformations of the fetus. Newborns born can be immature, congenital heart disease, cataract, deafness, developmental disorders, etc., known as congenital rubella, or congenital rubella syndrome, damage caused by congenital rubella syndrome, except for a few temporary In addition, most of them are progressive or permanent lesions, and there is no specific treatment. Rubella virus is a kind of respiratory virus with weak resistance to the outside world, mainly transmitted by air droplets. Rubella can occur all year round, with a high incidence in spring. basic knowledge The proportion of illness: the incidence rate is about 0.005%-0.007% Susceptible population: newborn Mode of infection: vertical infection of mother and baby Complications: congenital cataract neurological deafness congenital heart disease myocarditis arrhythmia

Causes of congenital rubella syndrome

Virus infection (30%):

Rubella virus is a togavirus group in the arthropod virus, which is a pathogenic virus of rubella. It was isolated from the pharyngeal washings of patients with rubella by thweller and faneva (1962) and pdparkman et al. (1962). The virions are pleomorphic, 50-85 nm, coated. The particles contain rna (infectious nucleic acid) having a molecular weight of 2.6 to 4.0 x 106. Ether and 0.1% deoxycholate can be passivated and weakened in heat.

The rubella virus is an RNA virus, and the togavirus is a virus limited to humans. Under electron microscopy, the core is spherical, with a diameter of 50-70 nm. The antigenic structure of rubella virus is quite stable. It is known that there is only one antigenic type.

Contagion factor (25%):

The rubella virus is mainly spread by air droplets. The virus is present in the respiratory secretions of children and drug users. It produces droplets by coughing, sneezing, talking, etc., and is inhaled and infected by susceptible people. Susceptible persons may also be exposed to contact by contact with the feces of children with rubella, food utensils contaminated with urine, clothing and other supplies.

Genetic factors (10%):

Rubella virus can also be transmitted to the fetus through the placenta, which is an important way to cause CRS. RV can survive and proliferate in the placenta and fetus for a long time, resulting in multiple systems of chronic, progressive infection.

Pathogenesis:

After the rubella virus invades the upper respiratory tract, it first replicates in the local mucosa and cervical lymph nodes, and then invades the blood circulation to cause the first viremia. The virus reaches the monocyte system through the white blood cells, and then re-enters the blood circulation to cause the second viral blood. Symptoms, the rash is mainly caused by the rubella virus caused by capillary inflammation of the upper dermis, which is characterized by capillary congestion and mild inflammation.

The rubella virus can infect the fetus through the placenta. This is mainly because the placental barrier has not yet developed. The virus can produce persistent infection through the placental chorion. First, the placenta is initially formed in the early pregnancy, and its defense barrier function is not perfect. The virus can be transmitted to the placenta. Fetus; Secondly, pregnant women infected with rubella, within 3 months of pregnancy, is the three fetal germ layer differentiation, the important period of the formation of various organs, cell differentiation is inhibited, the formation of organs is affected, resulting in a variety of congenital malformations, pregnancy 3 months before the embryo, the fetus has no ability to resist the virus, and each organ is in the bud state, so it is vulnerable to the invasion and harm of the rubella virus. After the early pregnancy, the three germ layers are infected by the virus. The germ layer is particularly prominent. The asexual reproduction cell line of the affected tissue caused by rubella virus, which causes growth arrest, can be inherited to the progeny cells, and the cell differentiation is inhibited. The rubella virus is the most dangerous teratogenic factor, which can cause congenital cataract, retina. Inflammation, deafness, congenital heart disease, microcephaly and mental retardation, these diseases It is not obvious at birth, but it can be clearly manifested for several weeks, months or even years after birth. Gradually, deafness and retinopathy appear gradually; with age, there will be learning difficulties, abnormal behavior, and weak muscle strength. Symptoms such as imbalance of activity, and sensory disturbances may occur. The deformed children are born with a light weight even at full term, and 10% to 20% of them die within 1 year after birth. Relevant experts have shown that the incidence of fetal malformation is Pregnant women are infected with rubella virus in the morning and evening. Generally, the risk of initial infection in the early stage of pregnancy is large, and gradually decreases with the increase of gestational age.

Congenital rubella syndrome prevention

Treatment is extremely difficult, so it is mainly prevention.

Passive immunization

Try to avoid contact with rubella patients in the first 3 months of pregnancy. For example, pregnant women have not had rubella, have been exposed to rubella, and have not been vaccinated against rubella. If they have close contact with rubella patients, they can be passively immunized, that is, after contact. Intramuscular injection of high-efficiency immunoglobulin 20ml, or placental globulin 20ml within 3 days, this can prevent congenital rubella in the fetus, can have a certain protective effect.

2. Vaccination

Vaccination is an active immunization, which can reduce the susceptibility of the population and control the epidemic. To prevent congenital rubella, some girls in the country should be vaccinated against rubella. The best vaccination target is school-age girls and women who want to marry. Have never had rubella, nor have been vaccinated against rubella. The serum urticaria antibody should be measured first. If it is negative, it should be injected with rubella vaccine. The vaccine is a live attenuated rubella vaccine. It can also cause damage to the fetus. Pregnant women. More should not be vaccinated, there are currently measles-rubella-mumps, measles-rubella, rubella-mumps and other combined vaccines. China has applied rubella-mumps vaccine in 1989, 95% after vaccination There is no significant adverse reaction to the antibody.

3. Testing pregnant women

Pregnancy tests for pregnant women with rubella virus should be terminated in early pregnant women with confirmed rubella virus infection to prevent the birth of CRS infants.

Congenital rubella syndrome complications Complications congenital cataract neurological deafness congenital heart disease myocarditis arrhythmia

Pregnant women infected with rubella virus invade the fetus, can cause stillbirth, miscarriage or a variety of malformations, causing fetal complications, common congenital cataract, neurological deafness, encephalitis, congenital heart disease, mental retardation and even death.

1. Encephalitis encephalitis is the most common complication of rubella, which occurs 1 to 7 days after the rash. In severe cases, it can be coma for hours to days. Generally, it can be completely recovered. A few have sequelae or chronic progressive whole brain. inflammation.

2. Myocarditis can have tachycardia, arrhythmia, and abnormal electrocardiogram and myocardial zymogram, usually recovered within 4 to 8 weeks.

3. Hepatic transaminase abnormalities, more than 10 days to recover.

4. Arthritis can occur in the knees, elbows, ankles, wrists, fingers and other arthritis in the 2 to 3 days after the onset of the disease. It may have local redness, pain, and fever at the same time, and resolves spontaneously in 5 to 10 days.

5. bleeding tends to cause thrombocytopenia caused by rubella, relatively rare, often 3 to 4 days after the rash, skin mucous membrane spots, ecchymosis, gingival bleeding, hematemesis, blood in the stool, etc., 3 to 7 days after self-remission, individual patients can Death due to massive bleeding.

Symptoms of congenital rubella syndrome Common symptoms Post-ear lymph node enlargement Skin maculopapular hemolytic anemia Arteriolar ductal rash Liver splenomegaly Rheumatism

Pregnant women with rubella can be asymptomatic, or only symptoms of upper respiratory tract infections, such as fever, swollen lymph nodes (especially occipital lymph nodes and enlarged lymph nodes) and maculopapular rash, infection with rubella in early pregnancy Women, their fetal abortion, stillbirth more than normal pregnancy, congenital rubella infants after childbirth death, there are normal newborns at birth. There are also developmental disorders; there are obvious clinical manifestations also have occult infections, but Fetal infection In the early pregnancy, almost all organs may have temporary, or permanent, progressive damage, severe cases of liver, splenomegaly, jaundice, cyanosis, anterior sputum, or increased cerebrospinal fluid cells. It is found that congenital heart disease, cataract, deafness, microcephaly, etc., its prognosis is poor, such as rubella viral hepatitis, blood alkaline phosphatase and transaminase increased and combined with increased bilirubin; such as interstitial pneumonia Respiratory distress can occur.

1. Classification of congenital rubella syndrome by time, divided into 3 categories according to time:

(1) Neonatal congenital rubella syndrome: including obvious damage in the neonatal period.

(2) Delayed congenital rubella syndrome: including damage that is not obvious in the neonatal period and then significant.

(3) Late manifestations of congenital rubella: including new damage, there may be overlap between the above categories.

2. Clinical manifestations The clinical manifestations of congenital rubella syndrome are complex and involve the whole body system.

(1) Performance at birth: Infants born to live birth may present some acute lesions, such as neonatal thrombocytopenic purpura, which are scattered at the time of birth, and often have other temporary lesions and Long bones have poor calcification of the ankle, hepatosplenomegaly, hepatitis, hemolytic anemia and fullness of the anterior sputum, or increased cells of the cerebrospinal fluid. These conditions are severe manifestations of congenital infection, low birth weight at birth, congenital rubella often Causes intrauterine growth retardation, often less than gestational age at birth, it is reported that 60% of birth weight of congenital infection is less than the 10th percentile, 90% is less than the 15th percentile, and about half of the birth weight is less than 2500g. Other manifestations include congenital heart disease, cataract, deafness, and microcephaly. The prognosis is poor. According to the results of a follow-up of 58 infants with purpura for 1 year, the mortality rate is as high as 35%. Rubella virus hepatitis can also occur in neonatal period. And interstitial pneumonia.

(2) Deafness: 66%, mostly bilateral sensorineural deafness or conduction disorder, the degree of damage on both sides is basically the same, the incidence of deafness of congenital rubella increases with the detection age. The degree of deafness can be light or heavy, which in turn leads to language development disorders. Deafness is caused by degeneration of the cochlea and Corti device. Hearing can be progressively deteriorated after the first year of birth, and suddenly develops into hearing loss.

(3) Eye damage: 78%, mostly bilateral, with the highest incidence of cataract, cataract may be small or undetectable at birth, must be carefully examined with an ophthalmoscope, followed by congenital glaucoma, manifested as corneal enlargement , opacity, anterior chamber deepening, high intraocular pressure, glaucoma of congenital rubella must be operated, normal newborns may have a transient corneal opacity, but can disappear on their own, regardless of rubella, small eyeballs often coexist with cataract, retinal melanin Spot is common in congenital rubella, and may be the only manifestation of eye damage. Retinal melanin plaque is more common on one side, and its spot size and shape are different. This change does not interfere with vision and contributes to the diagnosis of congenital rubella. .

(4) Cardiovascular malformation: About 58% of children with congenital rubella syndrome with rubella virus in the first 2 months of pregnancy have heart damage, the most common is patent ductus arteriosus, and some people are positive for rubella virus from the wall of the duct. In addition, pulmonary artery and its branch stenosis, atrial septal defect, pulmonary stenosis, tetralogy of Fallot, etc., generally do not have serious cardiac damage at birth, but there are also heart failure within 1 month after birth.

(5) central nervous system lesions: 62%, mainly manifested as mental retardation, microcephaly, severe motor impairment and typical spasmodic bilateral hernias, soft meningitis appeared several weeks after birth, encephalitis Pre-existing plump, irritability, lethargy, dystonia, episodes of paralysis, increased number of cells in cerebrospinal fluid and increased protein, have been reported in light, chronic encephalitis, 50% of cerebrospinal fluid or other parts can be isolated from rubella virus, The positive rate of severe virus isolation is as high as 70% or more, and a few can be manifested as chronic progressive whole encephalitis. The mental, behavioral, and motor disorders of the sick child are the result of congenital rubella encephalitis and may become permanent damage.

(6) Others: such as thrombocytopenia, neonatal thrombocytopenic purpura, the incidence rate of 15% to 58%. Most disappeared 1 month after birth, hemolytic anemia, systemic lymph node tumor, hepatosplenomegaly, hepatitis, Astragalus, bone damage, cartilage capillaries do not grow, X-ray see the distal femur and the proximal end of the cavity bone density reduction, similar to congenital syphilis changes, the same as the costal cartilage end, skin rash, abnormal skin lines, groin Hey, rubella pneumonia and other serious deformities.

Examination of congenital rubella syndrome

1. Blood: The total number of white blood cells is reduced, and the number of lymphocytes in the classification is relatively increased, and atypical lymphocytes may appear.

2. Serum antibody detection: including hemagglutination inhibition test, immunofluorescence test, radioimmunoassay and enzyme-linked immunosorbent assay to detect specific IgM and IgG antibodies in the serum of children.

(1) Determination of rubella virus IgG: It can be determined by various methods. After the mother is infected with rubella, the acute phase of rubella-specific antibody IgG is 4 times or higher than the recovery period, and the rubella-specific antibody IgG is 6-12 months after birth. Sustained positive, suggesting a congenital infection. Because IgG antibodies can pass through the placenta, but the fetal antibodies passed through the placenta disappear for 2 to 3 months, so even if the IgG antibody is positive for 3 months, it is impossible to determine the infection of the baby. If the baby is IgG positive for 5-6 months after birth, , prompted for congenital rubella infection.

(2) Determination of rubella virus IgM antibody: elevated rubella-specific antibody IgM also indicates rubella infection in pregnant mothers or infants, pregnant women suspected of rubella infection, such as specific rubella virus IgM antibody positive, indicating that pregnant women have primary rubella infection, For example, in the early pregnancy, artificial abortion may be considered, such as measuring the specific antibody IgM of the rubella virus in the fetal blood, and the IgM antibody of the rubella virus detected by the newborn or the cord blood may be diagnosed as a congenital rubella virus infection.

(3) Rapid diagnosis: The direct fluorescence test method can be used to detect rubella virus antigen in pharyngeal secretions.

3. Isolation of the virus: 7 days before and after the rash and 5 days after the rash, the rubella virus is isolated from the nasopharyngeal secretions, blood, cerebrospinal fluid, feces and urine or other pathological tissues of the child, and the pregnant woman can be from the villus tissue or the amniotic fluid. Detection of rubella virus, by separating rubella virus from amniotic fluid, or using molecular biology techniques to perform perinatal diagnosis of chorionic biopsy specimens. In addition, monoclonal antibodies and PCR techniques can be used to detect viruses, congenital rubella. The long-term detoxification of children after childbirth can last for several weeks to several months. Generally, the positive rate of virus isolation is higher, and the positive rate of virus isolation decreases with the increase of the age of birth, except for a few children, usually 1 year old. The virus can no longer be separated in the future.

1. X-ray examination: understanding the heart and lung lesions, can be found in interstitial pneumonia changes and congenital heart disease, long bone X-ray visible femur distal and femur proximal end of the bone density decreased.

2. Electrocardiogram: It varies with heart damage.

3. B-ultrasound: Identify various congenital heart malformations, hepatosplenomegaly and so on.

4. Brain CT scan: The ventricle enlargement is seen, especially the enlargement of the fourth ventricle caused by cerebellar atrophy.

Diagnosis and diagnosis of congenital rubella syndrome

Diagnostic criteria

1. Epidemiological data: Pregnant women have a history of rubella exposure or history in the early stages of pregnancy, and have been confirmed in the laboratory that the mother has been infected with rubella.

2. Abnormal performance after birth: Children have one or several manifestations of birth defects.

3. Detection of specific IgM antibodies: In the early stage of infants, specific rubella IgM antibodies are present in serum or cerebrospinal fluid samples, which can be diagnosed as congenital rubella.

4. Continued IgG antibody: When the passive parental antibody is absent from 8 to 12 months after birth, a considerable level of rubella IgG antibody continues to appear in the continuous serum samples, which is helpful for the diagnosis of congenital rubella.

The diagnosis of congenital rubella relies on virological and serological tests to confirm the diagnosis of rubella virus in children with congenital rubella, pharyngeal secretions, urine, cerebrospinal fluid or other pathological tissues.

Differential diagnosis

1. Encephalitis meningitis: 62% of children with congenital rubella, central nervous system lesions, meningitis, encephalitis, progressive rubella encephalitis is a progressive neuropathy in children with congenital rubella The identification of encephalitis caused by other causes is mainly: congenital rubella is often accompanied by congenital defects (such as deafness, cataract, microcephaly and congenital heart disease), manifested as progressive paralysis, ataxia , intelligent damage and horror.

If a child with congenital rubella develops progressive neurological symptoms, accompanied by cerebrospinal fluid cell counts, increased total protein content and gamma globulin content, elevated serum antibody titer in cerebrospinal fluid and serum, and rubella virus found in brain tissue, Can be diagnosed.

2. Other intrauterine virus infections: Common features of other intrauterine infections such as cytomegalovirus infection, herpes simplex virus, toxoplasmosis infection, etc. are: fetuses often have microcephaly, small eye deformities and retinopathy, mostly at birth Low-weight children, due to a wide range of lesions, often have hepatosplenomegaly and jaundice in the neonatal period, late sequelae with deafness, mental retardation, organic changes in the central nervous system, etc., the identification mainly depends on laboratory tests.

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