The diagnosis of Giardiasis in adults and children consists of several stages. First, the infectious disease doctor or pediatrician carefully analyzes the complaints of his patient, makes a clinical picture of the disease, and then confirms the diagnosis with an instrumental examination( ultrasound of the abdominal cavity organs) and the results of laboratory tests. Each method allows to form a degree of intensity of manifestations of pathologies provoked by giardiasis. Experts today can find out what complications could cause intestinal infection, at what stage of development the disease is, what methods of struggle are best used at this stage.
It is extremely rare to diagnose giardiasis in the early stages. The acute phase lasts only a week, the symptoms of infection are similar to those of any other disease of the gastrointestinal tract. Therefore, doctors advise people who are at risk should make a study of giardiasis. Who needs to be examined:
- For children attending gardens, junior school.
- For children attending 24-hour general education institutions.
- Children of younger age group and adolescents wishing to enter any educational and medical institutions( dispensaries, children's homes, boarding schools).
- Personnel serving all of the above facilities.
- Sludge disposal.
- Persons who have close contact with infected patients.
Methods for diagnosis of Giardiasis
There are several methods for diagnosing giardiasis. Some of them have a direct purpose. The others are indirect.
Direct research on lamblia includes analysis of feces for cysts, fenestration of duodenal contents. An example of indirect diagnosis - options that allow to detect antibodies( Ig immunoglobulins).Why does an enzyme immunoassay refer to an indirect diagnosis? Because it helps to detect the presence of a parasite, to determine at what stage infection occurs, but who exactly settled in the intestine of an infected person for antibodies is quite problematic.
Each of the above methods has its positive and negative sides. To understand why all three studies are used during the diagnosis of giardiasis, knowledge of the shortcomings of each one helps.
How is the lamblias study carried out?
Fibrogastroduodenoscopy is used to extract duodenal contents. Using a special probe from the duodenum, 35 ml of contents are taken. The material is immediately sent to the laboratory for examination under a microscope. In the presence of carrier, it is possible to detect primarily vegetative forms of lamblia in duodenal contents. But cysts are also present. The disadvantage of this diagnostic option is one - it is very laborious. Requires the use of special endoscopic equipment and the presence of qualified medical personnel. In this case, sometimes the analysis turns out to be of little informative.
The most effective is the analysis of feces for cysts. There are several ways to conduct it:
- An infected person can have a native smear. Such a survey can detect both vegetative forms and cysts.
- Smear with coloring done with Lugol's solution.
- The most commonly used methods are enrichment. They can be produced mechanically or with the use of formalin-ether enrichment. Subsequent microscopy is considered mandatory.
The technique of putting in feces for such diagnostic tests is extremely simple: the feces are collected, placed in a sealed jar and surrendered to the laboratory. Between the collection of feces and the analysis of stool should not take more than twelve hours. The first analysis of feces can give a negative result, but this does not end with diagnostic studies. Two or three days later, the patient will again be asked to submit the described analysis. If suspected of Giardiasis, the feces of an infected person are examined for five weeks at intervals of one week.
Laboratory diagnosis of Giardiasis
To identify the stage of infection, serological or enzyme immunoassay is often used. The material is taken from the vein, blood is given on an empty stomach. To diagnose giardiasis, only serum is used. Throughout the course of the disease in the blood formed immunoglobulins( antibodies) of different classes( M, G or A).Antibodies of class M, for example, appear in the blood at the stage of the incubation period of giardiasis. Immunoglobulins of class G are formed when giardiasis passes into a chronic stage. Since class G immunoglobulins persist in the blood for a long time, it is impossible to use an enzyme immunoassay to diagnose the curability of the infection.
Physicians today are inclined to consider the described diagnostic technique as a little informative. All because the level of immunoglobulins( antibodies) largely depends on indirect factors: the state of protective functions of the organism of an infected person, the intensity of the lambliasis. With high immunity, antibodies to lamblia in the blood of the infected patient are not detected at all. In addition, antibodies in the blood can be detected by parasitizing other protozoan microorganisms, with parasites in the intestine of the patient may not be. That is why the described survey is considered of little informative.
How to diagnose giardiasis?
Ignorance of the process of diagnosing giardiasis by ordinary people gives an excuse for unscrupulous institutions that provide services in the formulation of the described diagnosis and dictate favorable conditions for the examination. Today, many clinics and hospitals offer only an enzyme-linked immunosorbent assay or ultrasound. But, as already mentioned above, this analysis is not always effective. In addition, such a study is more expensive than other alternatives.
Study of feces for lamblia cysts is a method of mass diagnostics. It is very common, it has high effectiveness. But because of the presence of "blind gaps( cysts are not produced every day, but undulating, with flashes that occur about once every seventeen days), certain difficulties in diagnosing are formed. That's why to identify the real picture, sometimes you have to produce several material charges. For busy and impatient people, this becomes not very convenient. Recently, a new diagnostic study of feces for lamblia antigen has been used more and more often. It makes it possible to detect the presence of protozoan microorganisms even in those "blind" periods, when cysts are not excreted. The disadvantage of this option is one - it can be made only by specialized institutions located in large cities with good technical equipment.
Duodenal contents are not collected in babies because of the high risks of complications. Complications can occur in adult patients. They can be expressed in the form of perforation, the appearance of bleeding. In adolescents, neurotic disorders often appeared after the diagnostic study described.
So how do you diagnose giardiasis? The most informative scheme is as follows: first, analysis of feces. In the presence of characteristic clinical manifestations and the absence of the presence of cysts in the feces, the analysis of blood for antibodies becomes justified. In addition, an ultrasound is always prescribed for a sick child. It helps to see the presence or absence of biliary dyskinesia and enlargement of the liver - the characteristic symptoms of chronic giardiasis.