Giardiasis is an infectious disease caused by the flagellated microorganisms Giardia lamblia, affecting the duodenum and jejunum. Giardiasis is detected in 10% of the adult population and in 65% of children, which is associated with non-compliance with sanitary and epidemiological rules.
When entering the human body Giardia begin to actively multiply and affect the duodenum and small intestine, leading to a violation of their function - peristalsis, absorption and wall digestion. Diarrhea develops. Further, the biliary tract and gallbladder, as well as the pancreas, may be involved in the process with the development of inflammation of these organs.
The "gold standard" of diagnosis is the detection of giardia by microscopy in feces and bile obtained by duodenal probing (bile sampling with a special instrument through the mouth opening, bypassing the esophagus and stomach). However, the parasite is not always excreted with feces, which makes it necessary to multiple repeat the test. In addition, it can only be detected in "fresh", warm feces.
In recent years, more convenient and less painful method of diagnosing giardiasis has been successfully used by detecting specific antibodies to giardiasis. The test "determination of IdA for Giardia lamblia" refers to the serological diagnosis of infectious diseases. The test material is blood, in which antibodies to the pathogen are detected. Antibodies are components of the body's immune system that are produced to destroy a particular foreign protein-antigen. In this case, the antigen is giardia. There are several types of antibodies: IgA, IgD, IgE, IgG and IgM. However, the immune system cannot always cope with giardiasis, even with very high concentrations of antibodies. Each of these antibodies has its own function and its own period of occurrence. Class IdA antibodies are detected within 10-14 days after infection, then after 2 weeks their level decreases significantly. Consequently, IgА antibodies help to identify the acute stage of giardiasis, which can be very difficult to diagnose using other methods.