Analysis of feces for protozoa is a standard laboratory method for the diagnosis of protozoa and helminth infections, which is performed in adults and children. With its help, protozoa that are parasitic in the distal intestine, as well as helminths, are revealed or excluded. The protozoa that live in the human intestine consist of 20 species, of which 8 are pathogenic, and 12 are activated under favorable conditions.
WHO statistics: 9 out of 10 people on Earth are infected with different helminths. Most often they are pinworms and roundworms. An analysis of feces becomes necessary in such circumstances because parasites often do not give clinical manifestations with good immunity. But such a person becomes a source of infection for others.
In addition, parasite larvae can enter fish, animal meat and from there penetrate the human body. That is why the analysis of feces for helminth eggs and protozoa plays such an important role.
Protozoa can exist in the form of sexually mature forms (vegetative forms) and in the form of cysts - this is such a special life form of parasites, when they are as if in hibernation, do not feed and do not multiply, waiting for a favorable moment. Their danger is completely preserved.
Indications for analysis
Such analyzes are relevant for those who are at risk for infection:
- stay in a closed team (kindergartens, schools, boarding schools, barracks, places of detention, etc.);
- the inability to maintain regular hygiene due to field work;
- the presence of agricultural livestock on the farm, dog breeding.
Analysis of feces for the simplest is required with:
- placing a child in a kindergarten, school, in summer children's camps;
- hiring adults;
- obtaining permission from a doctor to visit the pool - identification of carriage;
- medical examinations of medical, trade workers, representatives of public catering, pharmaceutical products.
Such examinations are carried out every six months. It is necessary to pass an analysis of feces for helminths and protozoa to those who have some suspicious health complaints:
- causeless weight loss;
- pallor of the skin;
- weakness, fatigue after minor physical exertion;
- shortness of breath without signs of a cold and heart damage;
- irritability;
- bad sleep;
- myalgia and arthralgia;
- heaviness in the liver;
- bitterness in the mouth and morning sickness;
- dyspeptic symptoms;
- flatulence;
- tenesmus;
- teeth grinding at night;
- periodic pain around the navel;
- itching in the anus.
A history of children and adults may indicate frequent bathing in rivers and lakes with ingestion of water, constant use of well water, and a tendency to eat raw fish.
An analysis of feces is also necessary after returning from tropical countries with their exotic cuisine, with poor hygiene conditions. In young children, with their restless behavior, poor sleep, breastfeeding and constant crying and screaming, you need to immediately collect feces for analysis on worms and protozoa.
Change objectives
The frequency of the study may be different. It depends on the goal. Most often this is prevention, and feces analysis for helminth and protozoa eggs is done once a year. In this case, a referral from a doctor is not required.
Barrier measure - biomass is submitted for research to prevent the spread of worms in the family, children and work groups, etc. Such an analysis of feces on eggs of worms and protozoa is given in the direction of a doctor.
How to prepare for the study?
In general, the preparation is simple:
- for a week they stop taking medications, especially potent ones - these are antibiotics, and enzymes, and antiparasitic;
- for 2 days - laxatives;
- contraindicated preparations that give the color of feces, - with the content of iron and bismuth.
Before delivery for 2 days, mushrooms, liver, marinades, bran, soda are excluded from the diet; reduce the consumption of fruits and vegetables.
The day before the delivery of feces, you need to drink more water, take a walk at night, have a stomach massage in infants. Any examination of the intestine is done 2 weeks before the analysis or after it. With menstruation, feces are not given so that there is no blood entry.
Rules for the analysis of feces
It is necessary to purchase a special container for the delivery of feces at the pharmacy. It is convenient in that it has a special lid and spatula for collecting feces. An adhesive sticker is also attached to it, where the patient data is entered. Matchboxes and glass jars are undesirable for collecting feces.
You can use a clean and dry pot in your child’s house to collect feces. Make sure that urine does not enter the feces.
The baby is laid on a clean diaper at about the time that the baby is emptying. Mom finds out by grunting, straining.
The feces are collected in a single plastic spoon. With disposable diapers, feces are not taken from them. In extreme cases, you can make a fence from a layer not adjacent to the surface of the diaper. Such precautions are needed for purity analysis. Feces after an enema or rectal suppositories are not suitable for analysis.
How much feces do you need?
How to take an analysis of feces on the simplest? About 50 g of morning stool is taken, and with loose stool - 1-2 tsp. The test is done on 3 sides of fecal sausage:
- front (initial part of feces);
- last portion;
- from the side of the mass.
If creeping helminths are visible on the surface, they are also sent to a container with feces.
If the bowel movement was in the evening, the feces in the container are wrapped in a bag and stored separately from food in the refrigerator until morning. Ideally no more than 8 hours.
Freezing or heating feces is prohibited. In health facilities, preservatives are used for this.
The most accurate analysis is obtained during the analysis in the first hour. When passing feces to giardia or amoeba, they do not store it, but they donate it warm during the first 40 minutes.
The volume of collected feces should be 1/3 of the sterile container. The result, as a rule, is ready on the same day in the evening or the next morning.
Where to do fecal analysis?
Analysis of feces for ovum and protozoa is carried out in any clinic that has a laboratory. A referral for analysis is taken from the district nurse. The analysis is valid from the date of issue within 10 days.
Analysis urgency
In practice, the analysis of feces for protozoa and worms does not happen cito. Except in urgent cases, when urgent hospitalization is necessary with the results on hand.
Stool Histology
Histological examination of feces is considered the most accurate. It can not only detect the presence of infection, larvae and cysts, but also try new antiparasitic agents on them with a further assessment of the result.
Macroscopy
Her armament has a magnifying glass or a stereoscope, with which you can detect mature worms or their fragments. All suspicious parts are taken from the feces with tweezers and laid out on a Petri dish, where they are examined with a magnifying glass. Or under a microscope on a glass slide.
Microscopy
Analysis of feces for protozoa is, first of all, microscopy of a stained smear of feces in order to detect parasites. It allows you to find worm eggs (coprooscopy) or larvae (lavroscopy) in feces, scrapings, sputum and bile. Under the microscope, eggs of ascaris, broad tape, schistosomes, and hepatic trematode are detected. It includes several methods.
Thick smear method
Analysis of feces for protozoal cysts and their vegetative forms. A pea sample the size of a pea is applied and rubbed onto a glass slide, after which the glass is covered with a special hygroscopic cellophane strip soaked with special substances and dyes (green malachite, phenol, etc.).
In this state, the mixture is aged 30 minutes. Viewing in this case is accelerated by 30 times. It should be noted that the analysis for cysts is not entirely informative, because cysts of parasites are in many respects similar.
Sedimentation method
The material is centrifuged to obtain a precipitate. The essence of the method is the difference in the specific gravity of the reagent and helminth eggs. The eggs are concentrated in the sediment, which is examined under a microscope. The method is used for eggs with a high specific gravity.
Flotation method
This is a microscopic analysis of feces for the simplest method of enrichment or flotation. Here the same basis, but the eggs of the worms emerge and concentrate in the film on the surface. Further, the film falls under the microscope.
The resulting feces are pre-treated in a flotation solution. Sometimes these methods are combined.
A single study is 50% informative, it only reveals the presence of invasion. But a single study is not enough to make a diagnosis and choose a treatment. A 3-fold study with a weekly break is required. Normally, no helminths or parasites in the feces should be.
Enterobiosis scraping
No preparation is needed here. Scraping or perianal prints are taken immediately after waking up in the morning, before all hygiene procedures and the act of defecation. This approach is needed for the reliability of the analysis.
Contraindication can be a skin injury in the anus. Since the material should be examined within the first 2 hours, it is better to take the fence in a hospital or a specialized laboratory. By scraping, they also detect tapeworms.
Scraping
There are three methods of scraping:
- stick in a sterile container;
- spatula on the glass;
- on glass with adhesive tape.
In the latter case, it is important not to touch either the tape or the glass. For a few seconds, you need to attach the tape to the folds of the anus, then transfer the tape to the glass.
Stick back so that no bubbles form. Glass is immersed in a sterile container.
If adult pinworms are found during the collection of the analysis (they look like small white worms), then they are dipped in 75% alcohol and also sent for analysis. Material requirements: scraping should be investigated within 2 hours, otherwise the performance decreases.
Analysis of feces for helminths and protozoa is used not only to identify them, but also to monitor the treatment after it is over. For an accurate diagnosis, just one analysis of feces is not enough - the most indicative serological analysis with the determination of antibodies in the blood.
Disadvantages of the method
With a small number of parasites in the collected feces, the result can be false negative. The same picture arises if it was not possible to catch the moment of isolation of eggs or protozoa themselves in accordance with their life cycle. Therefore, in the presence of clinical symptoms and a negative analysis, feces are given again after a week.
What is a coprogram?
It differs from conventional stool analysis in its detailed, thorough investigation.
A coprogram is not just an analysis to identify the parasite's eggs, but also a method for assessing the functioning of the digestive tract. This includes the definition of:
- evacuation functions of the intestines and stomach;
- enzymatic activity or inactivity of the digestive tract;
- the state of the microflora of the small intestine;
- the presence of any inflammation in different parts of the digestive tract;
- the presence of latent gastrointestinal bleeding;
- parasites and their eggs in the feces.
Such an analysis is carried out only with warm feces.
Research results
During the analysis, the laboratory assistant fills in the form, which puts a mark “-” or “+” - the presence or absence of parasites. The type of detected helminth is indicated below. For the reliability of the result, feces are given 3 times with a break of 10 days.
For amoeba and lamblia, feces are generally given up 5 times. In children, feces for worms are given three times with an interval of 2-3 days.
Only with all 3 analyzes is a negative result true. Otherwise, treatment is necessary. Bottom line: fecal analysis is necessary to confirm the clinic or suggestions. In another case, the diagnosis is not made.