Analysis for TORCH infection - Causes, symptoms and treatment. MF.
Perinatal infections account for approximately 2-3% of all congenital abnormalities of the fetus. Most infections are dangerous for primary infection during pregnancy. Recurrences of herpes can be dangerous during labor and in the postpartum period.
What is ToRCH infection?
Abbreviation T. o. R. C. H. appeared from the first letters of the most dangerous infections for the fetus - Toxoplasma( toxoplasma infection) - Rubella( rubella) - Cytomegalovirus( cytomegalovirus) - Herpes( herpes).This is a classic infection. In addition, they are also referred to infections such as parvovirus( infection caused by parvovirus B19), listeriosis, hepatitis B and C, and several others. All of them can affect people of any gender and age, but the term itself is used in relation to women who are preparing for pregnancy, pregnant women, as well as the fetus and the newborn. Rubella, toxoplasmosis, cytomegalovirus and herpetic infection are among the most common infections. In most cases, the first meeting with them occurs in childhood and adolescence - this is called primary infection, after which there is immune protection. If the body meets the infection repeatedly, it is called a secondary infection or reinfection.
Than ToRCH infections are dangerous?
In pregnancy, a primary infection of any of the group with TORCH infection is dangerous. That is, a meeting with the infection to which immunity has not been developed. Such infection is accompanied by a pronounced circulation in the blood of microbes that can enter the child's body.
An important feature of the infections of this group is that there may not be symptoms or they may be less pronounced. At this time, the infection will adversely affect the condition of the fetus and the course of pregnancy.
Why is the examination performed?
It is up to pregnancy( or in early terms) we need to find out whether there was an infection or not. If there was - you do not have to worry, this infection is not dangerous for a pregnant woman. If not, the doctor will tell you about a package of preventive measures( for example, if it's rubella - you can get vaccinated if it's about toxoplasm - you can follow certain rules to reduce the risk of infection, etc.).In addition, for those infections to which there are no protective antibodies, it is important to conduct regular monitoring so as not to miss infection during pregnancy.
How is the diagnosis made and how is the examination carried out?
The diagnosis only on clinical manifestations( rash, lymph node enlargement, temperature, etc.) often causes difficulties, since in most cases the symptoms are not very pronounced or nonspecific. More accurate is the laboratory diagnosis - the determination of antibodies in the blood.
A blood test for antibodies can show:
- was there a meeting with the
- infection if there was when.
Interestingly, in all mammalian species, the five classes of immunoglobulins are homologous, that is, these classes developed before the mammalian species was divided into species. This indicates the optimality of their properties and the need for survival. Antibodies( immunoglobulins) are special proteins of the immune system that are produced when they meet with an agent. Antibodies are specific, that is, they act on a specific agent. To clarify the specificity for the designation of antibodies, the name of the pathogen against which the antibodies are directed is added. In this case, for example, we are talking about antibodies to rubella, parvovirus B19, toxoplasm and so on. International designation of immunoglobulins - Ig. The capital Latin letter after Ig denotes the class of immunoglobulins. There are 5 classes of such classes: M, G, A, E, D. Five classes of antibodies are distinguished, of which the most important are G, M, A( IgG, IgM, IgA).
For the diagnosis of TORCH infections, IgM and IgG are significant. Different immunoglobulins appear at different stages of the immune response and are in the blood at different times, so their definition allows the doctor to determine the time of infection, and therefore, to predict the risks, correctly assign diagnostic and therapeutic procedures.
IgM increase soon after the onset of the disease, peaking at 1-4 weeks( this is the average figure, there may be differences for different infections), then decrease within a few months. For some infections, the duration of the presence of a significant amount of specific IgM antibodies can be quite large. In these situations, the IgG antibodies assay is helpful( see below).The rapid appearance of antibodies of IgM class allows to diagnose the acute form of the disease at the very beginning.
IgG is determined a little later( no earlier than 2 weeks after the onset of the disease), their levels increase more slowly than IgM, but they remain substantially longer( for some infections throughout life).An increase in IgG levels indicates that the body has already met this infection.
Pre-pregnancy test
| IgG | IgM | |
| detected No | meeting found with this pathogen has already taken place, and this agent does not represent a serious danger for the unborn child | |
| No | detected. No | encountered with this infection during pregnancy.future child. During pregnancy, it is recommended to monitor the level of antibodies( once a month) * Antibodies may be absent and in the earliest period after infection. |
| detected. | detected. A recent encounter with this infectious agent is not excluded, but by the time of pregnancy the immunity is already formed and there will be no danger. | |
| No | detected |
detected during pregnancy
| IgG | IgM | |
| detected No | detected If the analysis was performed at the earliest stages of pregnancy, the body's encounter with this pathogen has already taken place, and this agent does not pose a serious danger for the unborn child. If the analysis is not submitted at the earliest possible date, the presence of IgG may be due to a recent infection, already during pregnancy. In this case, additional testing methods are recommended( see below IgG avidity). | |
| Not detected | Not detected | Meeting this infection during pregnancy can be a threat to the future of the child. The analysis should be repeated once a month. |
| detected | detected The presence of IgG and IgM may be due to a recent infection, already during pregnancy. But it also does not exclude infection before pregnancy. In this case, additional testing methods are recommended( see below avidity, immunoblot ). | |
| Not detected | detected. The presence of IgM may be due to a recent infection, already during pregnancy. But also does not exclude and reactivation of the infection, not dangerous in pregnancy. In this case, additional testing methods are recommended( see below immunoblot ). |
Additional and confirmatory studies: avidity of IgG antibodies
When it is necessary to understand how long the IgG antibodies in the body have been present( that is, how long the infection has occurred), a special test for IgG antibody avidity( from Latin Avidity - greedy) is conducted. IgG antibodies in the development of the immune response gradually increase the binding strength of the infectious agent. This bond strength is called avidity. At the very beginning IgG binds the pathogen, but the connection is rather weak. Such IgG is called low-viscous. After a few weeks, the antibody is able to bind its target much more strongly. Such antibodies are called high-avidity.
Thus, the appearance of low-antibodies shows that a dangerous encounter with the virus or toxoplasm has taken place recently. In case of detection of low-grade antibodies during pregnancy, confirmatory methods of investigation are appointed for decision-making( see below immunoblot).The result of the analysis is represented by the avidity index, expressed in percent.
Additional and confirmatory studies: immunoblot
Conventional analyzes for antibodies to infections by ELISA are screened, that is, they allow one to suspect the presence of an acute infection or a recent infection requiring certain actions. In the case of suspected acute infection during pregnancy before the start of treatment requires more specific( confirmatory) tests.
Immunoblot - a highly specific and highly sensitive method:
Sensitivity 97%
Specificity 99%
High resolution between negative and positive results!
More precise detection of the duration of infection
The essence of the method of immunoblotting( blotting - from angl, blot, spot) is as follows. In the process of immune response, the body produces antibodies to different proteins of the infectious agent at different times. For example, when encountering toxoplasm, first the appearance of IgG antibodies to ROP1, then to the MAG1 protein, and later to the SAG1 protein. If we determine antibodies to each of these proteins in the serum, we will be able to know when antibody production began, to within 2-3 weeks if the infection was recently.
Immunoblot studies are more expensive and time-consuming than screening tests for antibodies. Therefore, usually the examination is carried out in two stages: first a risk group is identified( serological test for the presence of antibodies IgG and IgM).Further, if a suspected infection is suspected, an immunoblot assay is performed.
Important: Once you have obtained the screening results for the antibody test, you should consult your physician.
Read more about 6 dangerous infections
Rubella .When infected in the first trimester, almost 90% of the fetus is affected. Rubella is a problem specific to Russia. Many women were sick in childhood - they no longer fear infection. But often occurs in mild form and the disease remains unnoticed. Infection can be prevented by vaccinating - you just have to pass the test! If antibodies IgG and IgM are not present - go for vaccination.
Toxoplasmosis - infection occurs less often, the disease has suffered about 15% of women of reproductive age, that is, 75% of women can get infected with toxoplasm during pregnancy! Very effective prevention and treatment during pregnancy. It is important to know exactly the status of the infection before pregnancy or at the earliest. If antibodies IgG and IgM are not present - learn from your doctor how not to become infected with toxoplasmosis during pregnancy and how to control the level of antibodies( 1 time per month).
Herpes 1 and 2 type - is especially dangerous in childbirth and after childbirth. In the absence of antibodies to herpes, in addition to preventing infection during pregnancy, close attention should be paid to the baby after childbirth.
Cytomegalovirus - transmitted by airborne droplets, most women of reproductive age have already met with the virus( up to 90%).At 10% of women there are no antibodies, therefore, there is a risk of CMV infection, and the probability of infection of the fetus is 30%!If there are no antibodies, be sure to ask your doctor how to not get infected and how to monitor the level of antibodies. Especially dangerous in the autumn-winter period!
Parvovirus B19 - increased risk of infection in the fall and winter. There may be an asymptomatic or asymptomatic course, so it is important to carry out tests for antibodies to parvovirus B19 before pregnancy. If there are no antibodies - monthly observation of antibodies during pregnancy.
How to take tests for a TORCH infection?
Analyzes are given on an empty stomach( at least 6 hours after the last meal).Take the tests at any convenient day for you - all our offices are open 7 days a week!
Blood is taken from the vein for analysis. If you want to bring the material with you, you need to take the blood in a test tube with a clot activator or an empty tube( without anticoagulant) and prepare the serum. Serum can be stored and transported at a temperature of + 4 ° C for 1 day, then at -20 ° C.