Toxoplasmosis is, at first glance, a harmless disease. Most people are not even aware of infection. However, its danger increases if the pathogenic microorganism enters the body of a pregnant woman, thereby posing a serious threat to the normal process of pregnancy and the development of the baby. From our article you will learn in detail about the methods for diagnosing this disease. In addition, we will help you understand the results of the analysis for toxoplasmosis, their interpretation is also indicated in the article.
What is toxoplasmosis?
Toxoplasmosis is a parasitic infectious disease. They can be ill only once, after which the body produces persistent, often lifetime, antibodies to the pathogenic microorganism. The disease is widespread. So, in some countries, for example, Latin America and Africa, 90% of the population is infected, in Russia the incidence rate is 30%. Despite such high rates of global spread of toxoplasmosis, not enough attention is paid to the prevention and diagnosis of infection. This is due to the fact that in most cases the disease is asymptomatic and does not have a noticeable negative effect on the health of an infected person. However, there are complex forms of toxoplasmosis that affect the nervous system, organs of vision and the respiratory tract of the patient.
Methods of infection with toxoplasmosis
Infection from person to person is impossible. The root cause of infection is pets - cats. It is the intestinal environment of this animal that is a favorable environment for the reproduction of a microorganism. During bowel movements, infected cats secrete a form of toxoplasmosis spores such as oocysts. Other animals can swallow them, becoming temporary carriers. Infection can spread to plants, including vegetables. Therefore, you can get infected by close contact with cats, failure to comply with personal hygiene standards, eating improperly processed meat, unwashed vegetables and fruits.
What is the danger of toxoplasmosis during pregnancy?
Infection of a woman with toxoplasmosis directly during pregnancy is an extremely dangerous phenomenon for an unborn baby. Due to the high risk of possible complications, doctors at the stage of pregnancy planning recommend testing for toxoplasmosis. The norm, transcript of the analysis are described in detail below. The longer the gestation period, the higher the likelihood of infection entering the fetus. But at the same time, the "adult" the unborn baby, the more likely it is that the disease will not bring significant harm to his health. When an expectant mother is infected, the following complications are possible:
in the early stages, infection often leads to an undeveloped pregnancy or miscarriage;
the disease can cause premature birth;
the fetus may experience disorders of the nervous system, organs of vision, liver and brain.
With a negative result, a woman is recommended to follow all methods of prevention. If a positive analysis for toxoplasmosis is received, then pregnancy can be planned after 3 months. During this short period, the body will develop antibodies to infection, and re-infection will become impossible.
Types of tests for toxoplasmosis
What toxoplasmosis tests offer modern diagnostic methods? There are only two of them: enzyme immunoassay and polymerase chain reaction method . The first is based on the production of special antibodies by the body to combat the disease. PCR diagnostics detect the DNA of the pathogen.
Enzyme-linked immunosorbent assay (ELISA)
For the diagnosis of toxoplasmosis using biochemical blood reactions, the presence of immunoglobulin M (IgM) and G (IgG) proteins is isolated. Group M antibodies are produced in the body from the moment of infection to three weeks of infection, after which they gradually disappear. Accordingly, if IgM immunoglobulins were found during the examination, this is a positive analysis for toxoplasmosis. In addition, the disease is acute.
Group G antibodies (IgG) begin to be produced on the third day of infection. During the course of the disease, their number increases, trying to protect the body from parasitic invasion. Unlike group M immunoglobulins, IgG antibodies do not disappear from the body. They are detected during the analysis for a long period, and in most cases they protect a person for life from reinfection. If antibodies of group G display the results of an analysis for toxoplasmosis, decryption can have several options:
The infection was a long time ago. In this case, the detected IgG is not an obstacle to pregnancy.
Primary infection is possible. This condition is extremely dangerous for the development of the fetus. Additional examinations are required.
How to determine whether toxoplasmosis is dangerous or not in this case? Indicators of analyzes of the so-called avidity (the ability of group G immunoglobulins to bind to toxoplasma to neutralize it) will help the doctor correctly decipher the results. At the discretion of the specialist, PCR diagnosis of toxoplasmosis is also prescribed .
Deciphering the results of the analysis for toxoplasmosis by ELISA
How to decipher the ELISA test for toxoplasmosis ? To interpret the results, consult your healthcare provider or use the table below. But do not forget that only a specialist can make a final diagnosis. Some results require additional examinations to confirm or deny the alleged infection.
Toxoplasmosis: normal. Decryption of the analysis carried out by ELISA| IgM indicators | IgG indicators | Decryption |
| - | - | The body has never been infected with toxoplasmosis. Pregnant women are at risk of infection with this disease. A woman needs regular tests throughout the pregnancy. |
| - | + | The analysis of avidity of antibodies and PCR diagnostics are recommended. High avidity and a negative PCR result indicate an old infection and a developed immunity to toxoplasmosis developed by the body. |
| + | - | Positive toxoplasmosis test. To confirm the result, an avidity test and PCR diagnostics are prescribed. |
| + | + | Primary infection is possible. Additional examinations are needed. |
What is avidity?
As mentioned above, some results of the analysis for toxoplasmosis, deciphering them sometimes is not possible without additional diagnostic procedures, requires analysis for the avidity of antibodies. The binding activity of immunoglobulins with toxoplasma increases every day after infection. Accordingly, after conducting such an analysis, we can reliably talk about the acute infectious process or its absence.
Deciphering the results of avidity of antibodies
How to decipher avidity screening for toxoplasmosis? The analysis standards and deviations are indicated below:
Indicators less than 40 units indicate a low ability of antibodies to toxoplasma to attach. This means that the infection occurred within 2-3 days ago, and the disease is in the acute phase. This is the most unfavorable option for pregnancy toxoplasmosis test result. Analysis indicators require immediate medical attention and a treatment plan.
If the results indicate 41-59 units, then they are considered transient and require re-examination after 2 weeks.
The presence of more than 60 units as a result of the analysis of the avidity of antibodies to toxoplasma indicates persistent immunity to the disease. In this case, there is no likelihood of reinfection. This is the most favorable option for avidity results.
It is worth considering the fact that the results of examination for toxoplasmosis can significantly differ. The rate of analysis depends on the laboratory and the equipment used in it. Therefore, check the diagnostic results with those indicated on the form.
Diagnosis of Toxoplasmosis by PCR
The method of polymerase chain reaction is prescribed to determine toxoplasmosis only according to indications or to confirm the results of ELISA. Its essence is to detect the DNA of a pathogenic organism. The advantage of this diagnostic method is its high accuracy and the ability to detect the pathogen even with a small amount in the body.
How to decipher the analysis for toxoplasmosis carried out by PCR? To interpret the result is quite simple:
A positive analysis indicates the presence of toxoplasmosis DNA in biological material. This means a primary infection and an acute form of the disease.
A negative result means no pathogen.
How to get tested for toxoplasmosis?
You are assigned to be tested for toxoplasmosis: how to take it, do you need preliminary preparation? There are no specific guidelines for collecting material for analysis. It is only necessary to adhere to well-known recommendations before donating venous blood:
2 weeks before the proposed analysis, you need to stop taking antibacterial drugs.
Limit the use of fried, heavy foods, alcohol, and caffeine within 2 days before the procedure.
12 hours before the analysis, do not use aromatic gels and soap, perfumes.
It can be concluded that the results of the analysis for toxoplasmosis are not always clear. Decryption can only be done by a doctor. A misinterpretation threatens an error in the diagnosis and incorrect or untimely treatment. This can negatively affect the development of the future baby. Therefore, you should not independently decipher the results of tests for toxoplasmosis; consult a specialist for this.