The worms that hit a person can not always be detected by scraping or stool analysis, as they parasitize not only the organs of the digestive tract. That's why specialists often insist that patients with suspicious symptoms donate blood for antibodies to helminths. To what extent is this research effective, what is the preparation for it and the technique of carrying out, and what types of parasites are identified with it? This is only a small list of issues that concern many people suffering from this scourge. Let's try to sort them out in order. First of all, it is necessary to find out what indications are necessary for carrying out this blood test, since the detection in it of an antibody( AT) against antigens of certain helminths is a direct indicator of human infection with parasites. Specialists identify the following factors that make this type of diagnosis necessary:
- Planned screening of people living in areas with a high risk of infection;
- Suspected possible presence of helminths in the body;
- Conducting general epidemiological studies in the region;
- A history of high leukocytosis;
- A medical examination for people who have the possibility of contracting worms by the nature of their activities - workers of meat-packing plants and cattle-breeding farms.
A high content of antigen to helminth antigens in the blood is possible in the case of a recent infection or ongoing. The results of the analysis are interpreted as follows:
- A positive result of the antibody and helminth antibodies assay indicates that there are parasites in the body. But it can also be false if there is a history of the patient of such diseases as cirrhosis of the liver, tuberculosis or oncology, accompanied by lesions of internal organs;
- The negative result of the blood test, which detects antibodies to the antigens of the worms, suggests that they have not been detected. But he does not exclude the infection that has just occurred, since ATs are developed to him 2 weeks after infection.
When donating blood on AT to helminths?
There are such helminthic invasions, in which it is practically impossible to detect eggs of parasites in feces. With them, the only way to diagnose is to identify specific antibodies to parasite antigens. With the help of this study, it is possible to determine the presence of 4 invasions: trichinosis, toxocariasis, echinococcosis and opisthorchiasis.
Toxocara is a parasite of the digestive organs of domestic animals. In humans, it never ripens to an adult. This parasite is dangerous because its larvae migrate from the infected person from the organ to the organ, causing severe allergic reactions, lesions of the eyes, lungs or liver of the patient. The study of the blood composition for antibodies to helmint toxoxare is the most sensitive analysis and rapidly reveals toxocariasis.
Round trichinella worm causes such a multi-stage disease, which has serious complications, like trichinosis. The infection of a person with these parasites occurs through the meat of carnivorous mammals that has undergone insufficient heat treatment. Antibodies to the antigens of these helminths are produced in the patient's blood 14 days after the invasion.
Fluke, belonging to the trematode class, causes a dangerous disease of opisthorchiasis, accompanied by lesions of the pancreas, gall bladder and liver. This parasite is transferred by freshwater fish from the family of carp and mollusks. Infection with helminths occurs when a person consumes fish that has undergone a culinary treatment. Early detection of opisthorchiasis is facilitated by the presence in the patient's blood of specific IgG antibodies. They start to be developed 2 weeks after infection.
The blood test reveals not only antibodies to the 4 helminths. With the help of it you can find the simplest parasites of lamblia. But it is not the main method of diagnosis for giardiasis, since AT will remain positive after the course of treatment for a long time. This study does not give an accurate answer to the question of whether a person is suffering from giardiasis at the present time.
Preparation for the analysis of blood for antibodies to helminth antigens
In order for the result to be as reliable as possible, it should be properly prepared:
- It is not recommended to eat before the test, as it should be performed on an empty stomach. The only thing you can do is drink plain water;
- Physical stresses before blood testing for antibodies to helminths should also be excluded;
- One day before the diagnosis it is forbidden to drink alcoholic beverages and eat fatty, smoked or salty foods.
If possible, a week before the analysis, you should cancel any medications. In the event that there is no such possibility, it is necessary to inform the doctor - the diagnostician about the medicines used. If this is not done, the blood for antibodies to helminth antigens will show unreliable results.