Basic information of rubella

Rubella is caused by rubella virus, a common acute infectious disease, characterized by low fever, systemic rash, often accompanied by ear, occipital lymph nodes. As the systemic symptoms of light, short course, often that the disease does not matter, but in recent years in the outbreak of rubella, severe cases have been reported frequently. If the women in early pregnancy rubella infection, will seriously damage the fetus, causing congenital rubella syndrome (CRS). Chinese medicine called the disease as rubella, wind fever, rash. That the Department of wind-heat when the feelings of evil, caused by the skin surface.

The pathogenesis of rubella

Patients with rubella, rubella virus first in the upper respiratory tract mucosa and cervical lymph node replication, and then into the blood circulation caused by viremia, disseminated to lymph nodes caused by systemic lymphadenopathy, the virus directly damage the vascular endothelial cell rash. At present, many believe that the rash is due to rubella virus antigen-antibody complex caused by the upper dermal capillaries caused by inflammation. The disease is mild, the pathological findings are not many, skin and lymph nodes were acute, chronic non-specific inflammation. Rubella virus can cause encephalitis, brain edema, non-specific perivascular infiltration, nerve cell degeneration and mild meningeal reaction, but also in infection after ten years due to chronic persistent lesions caused by chronic total encephalitis. The pathogenesis of congenital rubella is not clear, pregnant women infected with rubella, the rubella virus can be in the viremia stage with the bloodstream infection of the placenta last infection of the fetus. Placental chorion is infected after a more persistent small blood vessels and capillary wall widespread involvement of the phenomenon. The more the mother was infected in the early gestational age rubella, the more chance of fetal infection, the first month of gestation, 10% to 50% of the infection, the first 2 months of 10% to 30%, the first 3 months 5% to 20%, 4 months of 1% to 5%, after a few fetuses may still be infected. As the fetus, especially the rubella virus infection in the fetus after lack of cellular immune function and does not produce interferon and other facts, rubella virus in the body is widespread, and with fetal cell division, hyperplasia invades the next generation of cells, continue to multiply passages, the formation of sustained , Multiple organ systemic infection, and thus produce a variety of congenital defects symptoms, it is called congenital rubella syndrome. The most common are cataract, neurogenic deafness, congenital heart disease, meningoencephalitis, myocardial necrosis, interstitial pneumonia, giant cell hepatitis, nephritis, hypospadias. Such newborns continue to detox after birth for several months or even years. There are a lot of birth did not appear obvious symptoms, but by the serological examination confirmed when the tires have been rubella virus infection. Recent studies have repeatedly revealed that children with congenital rubella are often abnormal immune response.

Pathological causes of rubella

The rubella virus is an RNA virus and belongs to the family Togaviridae, a virus that is restricted to human infection. Electron microscope, mostly spherical, diameter 50 ~ 70nm, 30nm within the core. Envelope thickness 8nm, the surface has a lot of 5 ~ 6nm outward protruding structure, containing hemagglutinin. The virus particle consists of RNA and a shell (capsid) protein (C) and three envelope proteins (E1, E2a and E2b). E1 and E2 have good immunogenicity, can cause the body to produce neutralizing antibodies and hemagglutination inhibition antibodies. Rubella virus is only one serotype, with Togaviridae more than 60 kinds of viruses without antigen cross. Rubella virus can survive in the placenta or fetal body (and several months or even years after birth), causing chronic, multi-system chronic progressive infection. The virus can be in rabbit kidney, millet rat kidney, green monkey kidney, rabbit cornea and other cell culture growth, can agglutinate chicken, pigeon, goose and human "O" type red blood cells. Virus in vitro viability is weak, on the ultraviolet, ether, chloroform, formaldehyde, cesium chloride, sodium deoxycholate and so sensitive. PH <6.8 and> 8.1 are not easy to grow, pH <3.0 can be inactivated. The virus is not heat-resistant, 56 ℃ 30min, 37 ℃ 1.5h can kill it, 4 ℃ storage instability in the -60 ~ -70 ℃ can maintain the vitality of 3 months, dry and frozen can be stored for 9 months.

The diagnosis of rubella disease

Rubella patients rash form between measles and scarlet fever, and should focus on these three common fever rash disease for differential diagnosis (Table 2). In addition, the rubella still need to contact with children with acute rash, drug rash, infectious mononucleosis syndrome, enterovirus infection, such as Coxsackie virus A group 2,4,9,16 type and B group 1,3, 5 type, ECHO virus type 4, 9, 16 infection phase identification. Congenital rubella syndrome and intrauterine infection with toxoplasmosis, cytomegalovirus infection, herpes simplex virus infection phase identification. These three intrauterine infection and congenital rubella have similar symptoms.

Prevention and treatment of rubella

Because the symptoms of rubella light, the general prognosis is good, it does not seem particularly necessary to prevent, but congenital rubella damage, can cause stillbirth, premature birth or a variety of congenital malformations, so prevention should focus on congenital rubella.

1. Quarantine quarantine patients should be isolated to 5 days after the rash. However, mild symptoms of the disease, latent infection and more, it is easy to be ignored, not easy to do all the isolation. General contact may not quarantine, but pregnancy, especially in early pregnancy pregnant women during the rubella epidemic should avoid contact with rubella patients.

2. Automatic immunization Internationally after more than 10 years of widespread use of live attenuated rubella vaccine, have proved safe and effective, antibody positive conversion rate after inoculation of more than 95%, only very few short-term inoculation fever, rash, lymphadenopathy and Joint swelling and pain and other reactions, most of the immune antibody persistence can be maintained at 7 years. For example, the United States advocates adolescents aged from 1 to adolescence, especially children in kindergartens and primary schools, because the incidence of rubella in children is the highest, and can be passed to pregnant women and other adults. Adolescent and adult women, should also be vaccinated, inoculated with congenital rubella has been significantly reduced. Despite the current on the rubella vaccine strain on the human body, fetal understanding of the impact is not enough, but the live vaccine of the weak virus does through the placenta infection of fetal malformations, so pregnant women should not accept such live vaccine. Rubella vaccine has long been combined with measles, mumps vaccine used. Some places such as Shanghai, Wuhan, Shandong has long been able to prepare rubella live attenuated vaccine, can produce a higher positive rate of antibodies. Shanghai has begun to use live attenuated rubella vaccine and will be gradually included in the implementation of immunization program, the focus of immunization in addition to children in addition to children, including prenatal women of childbearing age, including high, junior high school graduating class girls. The protection of rubella vaccine, maintenance time and other studies are still in-depth.