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If helminthiasis is suspected or as part of a preventive medical examination, feces are analyzed for worm eggs. This laboratory diagnostic procedure has become widespread, it is prescribed for both children and adults.
What is a stool test for worm eggs?
During this manipulation, the laboratory assistant examines the feces for the presence of helminth eggs. As a result of this analysis, the eggs of almost all parasites known to medicine, and this is about 250 species, can be detected. In humans, they reproduce by laying eggs. Most varieties of helminths parasitize in the human intestine or other parts of the gastrointestinal tract. In this case, the eggs of the worms enter the digestive tract, and from there they are excreted along with the feces.
A smear containing the feces of the examined patient is examined under a microscope. Multiple magnification allows you to see the eggs and larvae of helminths in the diagnostic material.
This sign allows us to say for sure that worms of one of three groups parasitize in the body:
Nematodes (ascarids, hairy, some);
Trematodes-flukes (schistosoma, liver fluke, feline, or lanceolate);
Cestodes (tape, small and wide tapeworm).
In addition to helminth eggs, their shells, as well as dysentery amoeba, Giardia and cyclosporidia oocysts, can be found in feces.
Indications for the study of feces for eggs of worms
As a screening for a large number of adults and children, fecal analysis is carried out when issuing a health book, when entering a school, kindergarten and any team where there is a risk of helminthiasis transmission. This kind of barrier blocks the spread of parasites.
Another reason for the analysis is the suspicion of helminthiasis. Since the worms carry out their vital activity in various organs, the symptoms of parasitic invasion can be similar to manifestations of pathologies of the liver, intestines, brain, bladder, urethra, and lymph nodes. To differentiate helminthiasis from other diseases, feces are analyzed for worm eggs.
Symptoms of helminthiasis:
Itching in the anal area;
Pain in the intestines;
Alternating diarrhea and constipation, bloating;
Increased fatigue and irritability;
sleep disorders;
Vulvovaginitis in women;
Allergy symptoms due to toxic damage to the body by the waste products of helminths;
An increase in the concentration of eosinophils in the blood;
Nocturnal bruxism (grinding teeth);
Urogenital system infections.
In children, the following manifestations of helminthiasis join the listed symptoms:
Urge to defecate, ending in nothing;
Restless sleep, night crying, whims;
Irritation of the anus;
Cough of unknown etiology.
When one or more alarming symptoms appear, the therapist or pediatrician suspects helminthiasis. The analysis of feces for eggs of worms in difficult cases is supplemented with studies of sputum, bile, gastric juice, and blood. It is advisable for children attending a children’s group to conduct such a study every six months, and for adults working with young children – annually.
How to prepare for the study of feces for eggs of worms
To achieve the objectivity of the study, at least 3 stool samples must be performed. This tactic is due to the peculiarities of the life of helminths, the next generation of which may appear from eggs after receiving a negative result.
Restrictions before passing the analysis:
Do not take mineral or castor oil (for a week);
You can not use antibiotics, drugs against diarrhea and parasites, magnesium and bismuth preparations;
Irrigoscopy is not recommended;
The use of vegetables and fruits that provoke flatulence and diarrhea is limited (cabbage, pears, cucumbers, beets, oranges);
You can not drink compotes and jelly from berries of a bright color that changes the color of feces, eat them fresh (cherries, raspberries, blackberries, etc.);
Do not use drugs and alcohol.
To collect the analysis, disposable containers purchased in the pharmacy chain are used. In this case, the risk of attaching eggs or larvae from the outside to the material for research is excluded.
Collecting feces for worm eggs
The most informative is the collection of feces during the morning defecation, although the evening analysis can show objective results. The faecal sample is collected in a pharmacy container with a special device attached to it. If the collection of feces is carried out in another suitable container, use any clean sticks. It is desirable that different samples get into the container, both from the edge and from the inside of the fecal mass.
The container is sealed and sent to the laboratory, having previously signed it. It is better that the study was carried out after 40-60 minutes, a maximum of 5-7 hours after defecation. The stool sample should be stored in a cool place at a temperature not exceeding +4+8°C. If the material for analysis has been at room temperature for more than an hour, it is considered unsuitable for analysis.
The method of analysis of feces for eggs of worms
In modern helminthology, the following methods of coproovoscopy are used:
Microscopy of a native smear – examination with a significant increase in the preparation prepared from water and feces. A piece of feces soaked in distilled water is placed on a glass slide smeared with glycerin. It is mixed with glycerin, covered with a coverslip and analyzed under a microscope;
Fullenborn’s test – a study under a microscope of a film formed on the surface of a solution of feces with salt water. If there are eggs in the feces, they float up within an hour and a half;
Talman’s test – a study under a microscope of a centrifuged suspension of feces, ether and hydrochloric acid.
Worm eggs found in one of the samples give grounds to determine the result of the study as positive. The absence of traces of helminths is positioned as a negative result. The term of the study is 1-3 days, depending on the equipment and workload of the laboratory.
The results should be shown to the doctor who referred the patient for diagnosis. An analysis of feces for eggs of worms can be carried out in a bacteriological laboratory at a sanitary and epidemiological station or in a private clinic licensed to conduct such studies.