A helminthic invasion caused by flatworms from the genus of opisthorchia is dangerous not so much in itself as the complications caused by it, which in some cases can lead to death. Therefore, it is so important to identify infection in the early stages, in order to start treatment in time and avoid negative consequences. The difficulty lies in the fact that opisthorchias have no characteristic symptoms, and are distinguished by polymorphism and similarity with many other diseases. If there is a suspicion of infection with worms, instrumental and laboratory diagnostics are performed:
- detailed and biochemical blood test;
- urine and feces analysis;
- fibrogastroduodenal diagnostics;
- enzyme-linked immunosorbent assay;
- ultrasound of the abdominal cavity;
- endoscopy and X-ray.
In the presence of reasonable suspicions, the doctor prescribes a survey. At the same time, the blood test is the main one for the acute course of the disease, and when going to the chronic stage it is used as an additional one in combination with other methods of diagnosing helminthic invasion.
What tests should I take with opisthorchiasis?
Diagnosis of the disease is carried out directly when parasite eggs are detected in stool samples or indirectly, noting changes that indicate the presence of opisthorchias in the blood. The analysis of blood in adults can be:
- general;
- biochemical;
- is an enzyme immunoassay.
The elevated white blood cell count and the rate of erythrocyte sedimentation( ESR) in general blood analysis serve as indirect indicators indicating the onset of the disease. With worms, eosinophils are contained in the blood in increased amounts. This is due to a high level of indicators of allergic reactions. In biochemical analysis, the blood will show the disease at an elevated level of thymol and sulemic samples, as well as the content of the pancreatic enzyme. The method allows you to find out the stage of the disease and adjust the treatment, based on the characteristics of the functional state of the organs based on the content of enzymes. For example, elevated levels of ACT indicate pancreatitis, liver cancer, hepatitis, or cirrhosis.
Elevated levels of alpha-amylase in the blood indicate pancreatitis, cholecystitis, tumors in the pancreatic duct. The elevated content of the liver enzyme ALT indicates liver damage by parasites. Stagnation of bile in the ducts with an increase in bilirubin is also revealed during this analysis. At the same time, the protein and its individual fractions, the content of cholesterol and amylase are simultaneously detected. More complex, and at the same time with greater probability of confirmation of the disease are serological blood tests.
ELISA for opisthorchiasis
As is known, in the normal state, there are no antibodies to helminthic agents in the serum. At the very beginning of the lesion by parasites, the body reacts to their intrusion with an acute allergic reaction with a sharp increase in the content of eosinophils in the blood. When a foreign body enters the human body, antibodies to helminthiasis are immediately produced. To destroy the foreign protein-antigen, which is opisthorchia, several varieties of AT are produced in the body to the opisthorchiasis, but in view of the specific nature of their action, even at high concentrations, the coefficient of positivity in the disease is usually not high. This is due to the short period of the action of antibodies and it is impossible for an immunity to cope with this problem independently.
In case of a prolonged course of the disease, the opistorchia antigens bind to antibodies, forming the CEC of the opisthorchiasis. ELISA for opisthorchiasis in the acute stage is 100% sensitive, and this figure is reduced to 70% when the disease is transferred to the chronic stage. With a positive blood test for helminthiasis, the presence of IgM immunoglobulins indicates an acute form of the early stage of infection, antibodies of class G( IgG) can diagnose a chronic or acute late stage of the disease, but require additional diagnosis. If both types of antibodies are present, this indicates an exacerbation of late helminthiasis.
Antibodies to IgG opisthorhams are produced two months after the invasion and stay at this level for quite some time. Helminthiasis of IgG positive does not always mean infection with helminthic invasion. The fact that the substance IgG is present in the body in diseases of the liver, lungs, as well as in the case of cancer. Therefore, in order to clarify the diagnosis of IgG, repeated studies are carried out in two weeks.
The IgG test is used for diagnosis in the early stage of helminthiosis. At what titer it is possible to establish the diagnosis, depends on many circumstances, but basically if the titer is at the level of 1/100 or more, then opisthorchiasis is present with a high probability. At a titre increased in the period when the parasites have just settled in the body, but did not have time to start laying eggs, it is possible to start active treatment at the earliest stages. Specificity of IgG screen of opistorchs is low, so to clarify positive opisthorchiasis the test is repeated after 10-14 days.
The level of false positive results depends on the presence of concomitant diseases and ranges from 1.5% for parasitic diseases, to almost thirty percent for fascioliasis. It should be taken into account that the serological reactions of the indigenous people practically do not give a positive result and this is due to the fact that:
- Genetic changes occurred with the development of immunity to helminthiasis.
- Infection occurs in early childhood, and the acute phase passes unnoticed.
In addition, the negative indicators of opisthorchiasis in the blood may be false due to the use of certain medications or diseases that worsen the immunodeficiency of a person.
The definition of opisthorchiasis in humans can be as follows. A sample of serum is added to the well of the polystyrene plate, in which the antigen of the agent of the opisthorchiasis is fixed in the desired concentration. If there is a helminthic invasion, antibodies in the serum bind to the antigen. Antibody detection is performed by adding an enzyme labeled reagent that binds to it. Adding a colorless substance that stains the enzyme, the intensity of this color reveals the number of detected antibodies.
If the disease is started, then the leveling of antibodies occurs and the immunological responses lose their sharpness. In these cases, when determining which tests to pass to opisthorchiasis, they turn to the method for determining circulating immunocomplexes-the CEC.This method is the most difficult and for a choice where to pass analyzes, the special laboratory with the expensive equipment is required. CEC positive in serum allows you to assign the necessary treatment in the chronic stage of the disease. To detect the worms of the CEC, a special set of reagents is used.
The choice of institutions where it is possible to take tests is quite wide( medical institutions, immunological laboratories of diagnostic centers), and a doctor of any specialty, starting with a general practitioner and finishing with an infectious disease specialist, can prescribe a referral. The obtained analysis, even if it is negative, but there is a risk of infection with opisthores, must be supplemented by additional examinations.
How to take an analysis for opisthorchiasis?
No special measures are required when preparing for the delivery of tests. Specifically, which ones you need to pass, the attending physician points out, but necessarily they include coproskopy, duodenal sounding and a blood test.
To give blood for helminthiasis it is necessary on an empty stomach and take it from the vein. It is desirable for several days before the procedure to change the diet, exclude products with increased gas production. The last meal is made no later than seven in the evening preceding the procedure.
Decoding of blood test for opisthorchiasis
The results of laboratory diagnostics( negative, doubtful or positive) require further interpretation. The reliability of helminthiosis in the blood is established in the early stages with the presence of AT to opisthorch. The presence of IgM in the body manifests itself immediately after the first contact with parasites, without waiting for their transformation into mature individuals.
When decoding the blood test, special attention is paid to the titles, the result of which is:
- Negative with titles less than 1: 100.
- Positive, greater than 1: 100.
- Not installed - valid at 1: 100.
Recently, the use of polymerase chain reaction has become increasingly popular, which is used to identify the genetic apparatus of opisthorchiasis KP.
Even if the results of ELISA, biochemical and general blood test indicators are normal, it is recommended to clarify the diagnosis by parasitological methods. However, with the first positive results and symptoms that allow to suspect a helminthic invasion, it is better to apply immediately with the Pirantel opisthorchiasis, which is one of the most effective medicines.