Required to pass the test for toxoplasmosis is included in the set of tests on the so-called TORCH-infection, recommended every pregnant woman. In fact,, toxoplasmosis in humans can occur without showing any symptoms, So, that people are not even aware of his presence.
Why get tested
Developing in pregnant women, toxoplasmosis may cause severe pathologies embryo.
The causative agent of the disease - just, dwells within the cellular structures of the host organism. Mammals of the family cats act as definitive hosts of the parasite, which stands out from the stool of the external environment in the form of oocysts.
Oocysts fall to the intermediate hosts in the body. It is in their role may make people, birds, large and small cattle and animals from the rodent. Penetrating into the muscles and internal organs, oocysts are transformed into cysts and pseudocysts. Such contamination contribute to eating poorly washed vegetables and herbs and neglect hand washing after contact with the feces of infected cats (cleaning of the animal in the tray). By eating insufficiently roasted meat dishes - the body get the above forms of the microorganism.
Transmission of the pathogen from mother to child achieved by introducing into the organism of the embryo tachyzoites, who start parasite in his blood, namely in cells macrophages.
note! Although the degree of probability of infection of the fetus in humans does not exceed 15% during the initial trimester, for pregnant women is extremely important to promptly put into a laboratory blood test for toxoplasmosis.
If the cat lives in the house, it is very desirable to be tested for toxoplasmosis and your pet. In case of detection of the causative agent is recommended to temporarily transfer a cat on the content of their relatives or friends to cure fluffy patient and / or before the onset of labor in his mistress.
Diagnosis of toxoplasmosis is carried out in the laboratory with the help of blood tests.
Blood for toxoplasmosis is recommended to take, if a:
- the patient is planned pregnancy or she has already come;
- a pregnant revealed lymphadenopathy of unknown origin, while earlier blood test for toxoplasmosis, she did not hand over;
- the patient is HIV-positive;
- during the examination of the patient revealed enlargement of the liver and / or spleen of unclear origin;
- there is undiagnosed fever;
- pregnant patient during examination in the analysis results of questionable character about the availability of antibodies to Toxoplasma were obtained.
The main methods of diagnosing toxoplasmosis are considered:
- blood analysis by conducting ELISA (linked immunosorbent assay);
- immunohemilyuminestsentny analysis (Ihla);
- PCR diagnostics (polymerase chain reaction).
The first and second methods can detect immunoglobulins in the blood - antibodies to toxoplasmosis IgG and IgM.
Polymerase chain reaction (PCR) detects the presence in the material directly pathogen proteins, causing toxoplasmosis.
Toxoplasma do not differ from other microorganisms in the, which consist of antigens, are complex organic substances. With the penetration of the antigen in the blood of the human immune system responds to generation-immunoglobulin antibody, accumulating in the specified amounts, known titles.
- Development of IgM begins with the first days of infection, and the maximum titres observed on the second or third week of the disease. In this way, when blood IgM detection, we are talking about acute process.
- For three, and sometimes less than a month - this class of antibodies disappear, completely giving place immunoglobulins IgG, beginning production which occur in the second or third day after the "start" generation IgM. Maximum concentration they reach the end of the first month after the onset of disease.
Immunoglobulin G does not disappear, they remain in the blood for a long time, not infrequently, that life. For this reason, been ill patient holds a specific type of immune response, working against Toxoplasma cells so, more does not develop the disease during reinfection.
When deposited in pregnant patients analysis on antibodies to toxoplasmosis shows the presence of blood IgG antibody only, You do not need to worry for the future health of the child.
In various laboratories technique analyzes differ, according to this value and the results of "normal / high titer" will differ from each other in different institutions. Usually, The form is shown as the result itself, and the normal value.
- When the result is greater than the normal value, it is a positive result of the analysis.
- When the desired type in the analysis of antibodies are not detectable, or their titer is within the normal / low, This indicates a negative result it.
- Increased titer IgM detected in the analysis suggests, that the infection happened more than a few months. ago. In that case, when at the same IgG is not detected, then we can certainly talk about the active acute process.
- PCR diagnostics is characterized as the most sensitive method for the detection of pathogen. In carrying out this method toxoplasma DNA detected in a blood sample, less on research taking urine.
since PCR, undoubtedly, method is expensive, it is used, usually, to confirm or refute the results of the, which has already been obtained during the IFA. A positive PCR result indicates that, that the pathogen in the body is still really present, and there is an acute infectious process; negative - about, that he is no longer.
note! Competent transcript for toxoplasmosis research can make a doctor, considering not mere indicators analysis, but these additional diagnostic studies.
Often patients are interested, I like to be tested for toxoplasmosis correctly, whether it is necessary to comply with any restrictions before blood donation? In fact, no preparation for taking a blood test for toxoplasmosis is not required. It is recommended only on the eve of delivery limit intake of fatty foods, and the next day to hand over analyzes on an empty stomach.
Additional diagnostic techniques
For more information on the IgG antibody to toxoplasmosis, which will be useful as an attending physician in the diagnostic, and in terms of prognosis garden with suspected if the patient Toxoplasma infection, available, determining the avidity of antibodies in a patient. Especially such research will be relevant during pregnancy or planning her patient.
In vitro determination of IgG avidity plays a role of further confirming the diagnosis of test studies. They should be assigned to patients with these results:
IgG in excess of the boundary values, IgM - positive or, or questionable;
When forming the patient's immune response due to the introduction of the pathogen, stimulated by the lymphocyte clone forms the first specific proteins IgM, and then - specific IgG. For initial characterization of IgG properties have low avidity, they can weakly bind antigen. In the course of immune reactions of the body is gradually (in the weeks and months) synthesis observed increase in lymphocytic cells IgG, with high avidity, which are connected to their complementary antigens already much harder. their high degree of avidity for IgG specific proteins suggests, that the recent initial infection is possible in this case,. This fact is of great prognostic value in pregnant patients.
Let's see, why we make such a conclusion.
In some cases, trace amounts of Toxoplasma IgM proteins can be detected within a, two or even more years. I.e, we can say that, that if they were found in the blood, taken from a pregnant woman, you still can not accurately be sure, that there is a primary infection during pregnancy flowing. Also possible false positive results with a very high sensitivity systems. In these cases, the definition of blood IgG proteins with high avidity says, that the recent initial infection possible.
Low avidity IgG, average, found in three to five months. from the beginning of infection. Sometimes they can be shaped and longer. Detection of low avidity IgG in itself can not give occasion to affirm unequivocally that, that we are dealing with a fresh infection. but, as a further confirmation of it - is well suited. When we observe the reactivation of infection, Blood defined specific IgG vysokoavidnye.
- IgG avidity index Toxoplasma < 0,3 = Presence of low avidity IgG, that is, here we can not exclude a primary infection in the last 4 months.;
- index IgG avidity Toxoplasma ≥0,35 = presence of high avidity IgG, that is where we can eliminate the primary infection with toxoplasmosis during the last 4 months.;
- index avidity Toxoplasma IgG is 0,3-0,35 = Border is avidity IgG level in the material.
Timely diagnosis and complex treatment and preventive measures to prevent serious complications of the disease toxoplasmosis among potential risk groups.