The parasitological examination of feces is carried out using a sample of feces to investigate the presence of intestinal parasites, being useful for diagnosing diseases such as hookworm, ascariasis, giardiasis or amoebiasis, for example.
Therefore, this test is recommended by the doctor when the person presents signs and symptoms of worms such as abdominal pain, loss of appetite or weight without an apparent cause, as this makes it possible to identify the cause of the change and recommend the most appropriate treatment. Know how to recognize the symptoms of worms.
Through the parasitological examination of feces, a macro and microscopic evaluation of the feces is carried out, in which the color and consistency of the feces and the presence of cysts, eggs, trophozoites or adult structures of parasites are observed. See more details about the stool test.
What is it for
The parasitological examination of feces serves to identify the presence of parasites responsible for gastrointestinal changes. Therefore, the exam can be useful to identify the following parasites:
- Entamoeba histolytica;
- Giardia lamblia;
- Ascaris lumbricoides;
- Taenia sp.;
- Trichuris trichiura;
- Enterobius vermicularis;
- Ancylostoma duodenale;
- Schistosoma mansoni.
These parasites can be identified in feces in the form of cysts, trophozoites, eggs or adult worms in feces, the latter being rarer to be identified.
When a large number of parasite eggs are identified in feces, for example, the doctor usually recommends an imaging test, such as colonoscopy or endoscopy, with the aim of identifying whether there are adult worms in the digestive system, which happens in this case. of infection by Taenia sp., Ascaris lumbricoides e Ancylostoma duodenale.
When is indicated
Stool parasitology may be indicated routinely or when the person presents symptoms of worms, such as:
- Dor abdominal;
- Loss of appetite;
- Swollen belly;
- Nausea and vomiting;
- Diarrhea.
In the presence of these symptoms, in addition to the parasitological examination of feces, the doctor may also recommend a stool culture, especially if the person has diarrheal or more pasty stools, as this may also be an indication of bacterial infection. Understand what coproculture is and what it is for.
Make an appointment with the nearest gastroenterologist to assess the need for a stool test:
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How is done
Stool parasitology is carried out by analyzing a stool sample that must be collected by the person and taken to the laboratory within 2 days after collection for the analysis to be carried out. The recommendation is that 3 samples be collected on alternate days, because some parasites have variations in their life cycle, meaning structures cannot be observed if samples are collected on consecutive days.
Furthermore, it is important that the sample collected has not had contact with the urine or the vessel and, if the presence of mucus or a whitish spot is observed in the feces, it is recommended that this area be collected for analysis. It is also recommended that you do not use laxatives, anti-diarrheal medications or antibiotics at least 1 week before the collection period, as they may interfere with the result. See more about the stool test.
In the laboratory, the appearance and color of the feces are assessed, which is important for the best diagnostic technique to be used for the examination, since, depending on the characteristics of the feces, hypotheses may arise regarding the type and degree of infection. , which allows more suitable techniques for identifying cysts, eggs, trophozoites or adult worms to be performed.
The samples then go through a preparation process so that they can be evaluated microscopically and, thus, it is possible to carry out research and identification of parasitic structures, which is indicated in the report. The report indicates the diagnostic method carried out, whether parasitic structures were observed and identified, the structure and species of the parasite, this information being important for the doctor to indicate the most appropriate treatment.
