What tests must be taken to identify worms?
Worm examinations must be carried out regularly in order to identify the disease in a timely manner. The most famous of them is the analysis of feces, which is performed before you get a job or a trip to a sanatorium, but this is not the only and not the most reliable way to identify parasites. A combination of tests provides the most accurate answer.
What tests for worms are available
The list of tests that need to be done to identify parasites is quite long.
The most important are:
- Stool analysis, also known as worm eggs, is the most common method. Advantages - massive use, no need for complex equipment. Minus - lack of accuracy;
- ELISA, also called blood test for worms. Advantages - high accuracy. Disadvantages - only reveals certain phases of parasite development, at other times the result will be questionable;
- Analyzes of other biological media (urine, sputum, duodenal contents, epidermis). Benefits - they allow you to identify parasites in the locations that are inaccessible to other assays. Disadvantages - associated with significant inconvenience to the patient.
Typically, a patient is prescribed a combination of several tests to identify the parasite. The criterion for recovery is considered as a negative ELISA result and several negative results of the study of the biological environment in which the worms were detected.
Analysis of worm egg feces
Most worms live in the intestines, so the most common test for worms is stool testing. He is prescribed for routine medical examinations for adults and children before being sent to a sanatorium or a children's camp as part of a health book during hospitalization. This analysis is also given by people who have been in contact with infected patients who have eaten untested foods who have noticed characteristic symptoms of worms.
There is no need to prepare specifically for the analysis, you can collect stool at any time of the day, but the most indicative is morning stool. Immediately before giving birth, wash the perineum to avoid urinary impurities and genital discharge.
Feces for analysis of worms are collected in a special container. It is sealed and a special spoon is attached to collect the material. To collect the most informative part of the material, take a sample from the center of a part stool. The container should be about a third full. You must deliver it to the laboratory the same day.
In the laboratory, a specialist examines feces under a microscope and identifies worm eggs in it. Most of them have a characteristic shape that allows you to accurately determine the type of worm. Based on the results of the analysis, a conclusion is issued about the absence of eggs or about their presence and type, after which treatment is prescribed.
This is the most common but least accurate worm test. The reason is that there may not be eggs in the part that has come in the container, despite the fact that there are worms. Therefore, if the patient complains of characteristic symptoms or has come in contact with the source of infection, it is necessary to undergo 5-6 tests with an interval of 2-3 days. In this case, the probability of detecting parasites increases significantly. Along with the examination of stool, other diagnostic procedures are prescribed.
Skin Scraping
This analysis usually supplements stool. The most accurate result is obtained by diagnosing pinworms that lay eggs on the skin surface near the anus. Indications for such an analysis are routine examination of children and adults, registration of a child in a kindergarten, school, camp or sanatorium, hospitalization of children and adults, suspicion of pinworm infection (itching in the anus, digestive disorders, contact with sick people). Most often, children suffer from this disease, which explains the name of the worm (children's pinworm).
There is no need to prepare for the analysis of worms, you should not wash the perineum - so it is possible to wash eggs from parasites, you should refrain from bathing or showering the night before. The analysis is performed in the morning. A special film is used that collects material from the skin of the gluteal fold. The examination is also performed under a microscope. It does not detect other helminthiases except pinworms.
Urinalysis
This study is the least prescribed as parasites almost never live in the urine. Situations are possible when pinworms are found in the urine test, but this indicates a violation of the rules of transmission of the test - parasites and their eggs enter the container from the skin of the perineum. Most often this situation occurs in girls, less often in boys.
But there are still indications for testing. Some tropical parasites live in the kidneys and urinary tract, which a person is "rewarded" by a trip to Asian and African resorts. With the increasing availability of exotic recreational areas, the prevalence of parasites that are not characteristic of our country is also growing. For this reason, it is recommended to take a urine and blood sample for worms after a trip to resorts.
Types of worms found in the urine:
- Trichomonas;
- Distomum hematobium;
- Filaria sanguinis hominis;
- Taqnia echinococcus.
Also in the urine there may be eggs from liver parasites - echinococcus and flukes.
Sputum analysis
There are a number of parasites that spend all or part of their lives in the lungs. The symptomatology of their appearance is not characteristic - catarrhal phenomena develop in the bronchi (inflammation, cough, wheezing). Hemoptysis, pneumonia of unknown origin and other phenomena of the lungs may be noted.
Parasites detected by sputum worm test:
- Ascaris - in the larval stage they need oxygen;
- Echinococci and alveococci - tissue parasites that live in parenchymal organs, including the lungs;
- Dwarf fly - lives mainly in the lungs;
- Strongyloidosis, noncatorosis - parasites characterized by intestinal localization, the location in the lungs is found to be atypical.
To collect sputum does not require special preparation, but it is advisable to brush teeth and take the material in the morning. Before that, it is useful to drink plenty of fluids - this improves the lining of sputum. The collection container should be clean but not necessarily sterile - bacteria do not play a role in the diagnosis. In this case, both the parasites and their eggs are detected. If the patient is unable to cough up sputum, it is removed from the trachea using a suction cup.
It is possible to use drugs that improve the discharge of sputum, stimulate its formation to obtain more accurate results of the analysis of worms. In combination with a blood test for worms, it gives very accurate results. Unlike stool tests, eggs are more likely to be present.
Blood test
ELISA or blood test for worms - the most accurate method for determining this. Helminths cause a strong reaction from the immune system - the content of eosinophilic leukocytes increases, the production of immunoglobulins increases, and specific antibodies against parasites appear. It is on their discovery that the ELISA method is built.
Antibodies to parasites are extremely specific - they can be unambiguously diagnosed while present only in the blood in the presence of parasites and within 3 weeks of their disappearance.
Blood from a vein is required for analysis. No special training required. The result can be achieved within two days. The accuracy is close to 100%, the specificity of antibodies does not allow an erroneous result. The criterion for cure is a negative result one month after treatment.
Analysis of duodenal contents
The ducts of the bile ducts and pancreas open into the duodenum. These organs are often affected by echinococcosis and opisthorchiasis. The parasites lay eggs that pass through the ducts into the intestines. The technique of analyzing the contents of the duodenum for worms makes it possible to detect these diseases much more accurately than to analyze feces.
The material is taken with a duodenal probe on an empty stomach. If the patient has a pronounced gag reflex, pain relief is used. The procedure is quite unpleasant, therefore it is used only in cases where the results of other tests are questionable.
When to test for worms
Worm examinations should be performed in the following situations:
- The patient experiences symptoms of a helminth infection;
- The patient has been in contact with sources of invasion (sick people, untested products, areas with an unfavorable hygienic environment);
- Confirmation is required that the patient is not a source of infection (employment, medical records, out-of-town recreation, hospitalization).
How to test for worms
To be tested for worms, you need a referral from your doctor. Most examinations do not require preparation and if there are nuances, the doctor will explain them when prescribing an examination. Indications are required for a physician to prescribe.
In commercial clinics you can take an analysis regardless of the indication. The price varies considerably. The time to achieve the results of defecation and scraping is about a week, the analysis of urine, sputum, blood is about. 2 days depending on laboratory workload.
Which helminths can be detected using tests
The analysis for worms detects most types of parasites - intestinal and extraintestinal forms. The most accurate is a blood test for worms, which allows you to identify the parasite.