Tests For Toxoplasmosis In Humans

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Tests For Toxoplasmosis In Humans
Tests For Toxoplasmosis In Humans
Video: Tests For Toxoplasmosis In Humans
Video: Toxoplasmosis | Acquired vs Congenital | Signs, Symptoms, Diagnosis and Treatment 2023, February

Toxoplasmosis is one of the most common infectious diseases in the world. In some countries (for example, in the states of Latin America) more than 80-90% of the population is infected with it. In a normal state of immunity, a person does not even know that he was sick. However, in some cases, especially during pregnancy, the disease can negatively affect the functioning of the body. To avoid this, it is recommended to take a blood test for toxoplasmosis at the first appearance of symptoms of the disease.


  1. Toxoplasmosis: a quick reference
  2. Symptoms
  3. Infection routes
  4. Effects
  5. Delivery of analyzes
  6. Decoding of the obtained results
  7. Therapy for toxoplasmosis during pregnancy
  8. Conclusion

Toxoplasmosis: a quick reference

Toxoplasmosis develops as a result of ingestion of the simplest microorganisms "Toxoplasma gondi" into the human body.

After the formation of the cyst, the process of division begins, which leads to the destruction of the cell and the release of tachyzoites into the body. Due to the asexual reproduction of the latter, their number in the body begins to grow rapidly. Once in the lymph and blood, they spread the infection throughout the body.

Toxoplasma under a microscope
Toxoplasma under a microscope

After the appearance of tachyzoites, the immune system begins to respond to the invasion, destroying the pathogens. However, due to their rapid multiplication, new cysts form in the patient's cells. A vicious circle arises in which, despite the work of the immune system, new cysts are formed in the body. The latter can be in the host's body for life. It is possible to accurately determine their presence in the human body by decoding a blood test.


The clinical picture of the development of the disease depends on its form. With mild lymphatic toxoplasmosis, the patient may experience:

  1. Swollen lymph nodes.
  2. General malaise.
  3. Pain in the muscle area.
  4. Temperature increase.

In the chronic form of the disease, an inflammatory process that affects the internal structures of the eyes is added to these symptoms. The most dangerous is acute disseminated toxoplasmosis. It is also characterized by the appearance of a rash on the skin, as well as severe exhaustion.

Infection routes

The main source of infection is representatives of the feline family (including domestic cats). The initial stage of reproduction of the parasite occurs in the intestines of these animals. The feces of infected individuals contain eggs "Toxoplasma gondi", which cause infection after entering the human body.

The routes of infection with the disease are as follows:

  1. Contact with an infected animal, its excrement.
  2. Getting scratches and wounds from an infected individual.
  3. Blood transfusion (rare).
  4. Organ transplant (rare).

Due to intracellular development and the lack of a primary immune response, people are very susceptible to this infection. An infected person cannot act as a source of infection.


The disease is usually asymptomatic and goes unnoticed. However, in two cases, serious complications are possible:

  1. In citizens with AIDS, parasites spread throughout the body, which is fraught with the development of encephalitis, paralysis, seizures, and coma.
  2. Pregnant women can pass the infection on to their babies while they are in the womb. This situation poses a great danger to the fetus, and can be fatal.

In this case, the disease often leads to the development of blindness, mental retardation.

Delivery of analyzes

To detect infection, an enzyme immunoassay (hereinafter - ELISA) is performed. It is based on the search for specific antibodies (immunoglobulins IgG and IgM) in the patient's blood. As an additional measure, the polymerase reaction (PCR) method is used, which is based on the search for traces of parasite DNA in the patient's blood.

Material for analysis is taken from the cubital vein. Other venous vessels can also be used. Before carrying out the procedure, it is recommended to adhere to the following general rules:

  1. Do not take antibiotics within 14 days of blood collection.
  2. Give up alcohol completely 24 hours before taking the test.
  3. Avoid taking fatty and spicy foods 48 hours before the procedure.
  4. Do not take blood thinners the day before the test.

The factors listed above can negatively affect the analysis results and reduce their accuracy. Smokers should give up cigarettes at least 30 minutes before the procedure.

Decoding of the obtained results

With minimal knowledge, the patient can independently draw preliminary conclusions. The following variations in the analysis results are possible:

  1. IgG positive, IgM negative. The person who passed the test developed a strong immunity to toxoplasmosis, which indicates a past infection in the past.
  2. IgG negative, Ig negative Human has never been exposed. The causative agents of toxoplasmosis are absent in the body.
  3. IgG negative, IgM positive. There is "Toxoplasma gondi" in the body, there is an acute reaction from the body.
  4. Both indicators are positive. This result indicates a recent development of the disease.
Photo of decoding analysis for toxoplasmosis
Photo of decoding analysis for toxoplasmosis

Accordingly, if a positive IgG is indicated in the test results, it means that the person has developed a strong immunity to the parasite. This protein remains in the body forever.

The decoding of the analysis also contains an indicator of avidity (roughly speaking, it determines how successfully immunoglobulins can counteract the pathogen).

With an avidity index in the range from 41 to 59%, PCR analysis is performed. Based on manipulations with DNA enzymes, the presence of parasites in the body is determined. A positive result indicates the presence of a causative agent in the human body, a negative result indicates its absence.

Therapy for toxoplasmosis during pregnancy

IgG norm is more than 3 units per milliliter. This indicator indicates the presence of immunity to infection. At lower rates, therapy is carried out (but only with primary infection). For the treatment of toxoplasmosis in pregnant women, the following medications are used:

  1. Combination of pyrimethamine and sulfa drugs. Most effective method. Folic acid is also used to reduce negative side effects.
  2. Macrolides. They have a mild effect on the body of a pregnant woman, reducing the risk to the fetus. However, because of this, the effectiveness of the treatment decreases.

Usually the following drugs are used for therapy: "Rovamycin", "Pyrimethamine", "Folic acid", "Leucovorin", "Sulfadiazine".

The main goal of treatment is to reduce the activity of parasites. The most dangerous period of primary infection is the first trimester.

After the birth of a child, laboratory tests of his blood are carried out to determine the presence of pathogens.


Thus, for most people, toxoplasmosis is not dangerous. Moreover, many citizens are carriers of the pathogen without knowing it. However, the development of infection in pregnant women is fraught with negative consequences for the fetus, up to and including death.

To determine the presence of the pathogen in the body and the stage of development of the disease, an enzyme immunoassay is performed, the avidity of IgG and IgM proteins is determined, and the PCR method is used. Only pregnant women who first become infected with toxoplasmosis are subject to therapy.

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