Parasitic diseases are a widespread, diverse group of diseases caused by helminths and protozoa that pass through the life cycle in the human body, feeding and multiplying at the expense of the "host" and causing damage to various organs and systems. in general, it is quite difficult to suspect and recognize them.
How does the infection go?
Before entering the human body, helminths and protozoa go through a cycle of development in another environment or living organisms.
- Eggs and larvae of roundworms, strongyloids, hookworms remain in the soil under certain conditions of temperature and humidity. A person becomes infected when contaminated soil gets through dirty hands, water, unwashed fruits and vegetables, directly from the ground.
- In living organisms, the following helminths go through developmental cycles: opisthorchiasis (feline fluke), clonorchis, trichinae, toxocara, echinococcus, swine and bovine tapeworm. Before reaching maturity to parasitize a person, it is possible to change one or two intermediate hosts. These are mollusks, crustaceans, fish, insects. Eating undercooked fish and meat, raw water leads to infection.
Another way of infection is through direct contact of people through handshakes, general hygiene and household items or through self-infection. We are talking about infectious helminths: enterobiosis, strongyloidiasis, cysticercosis, giardiasis.
How can a parasitic disease be suspected?
The manifestations can be varied, from mild to severe. Rarely, there are typical signs that give a specific pathogen. Often there are no signs or they disguise themselves as other diseases or disappear when one cycle of the parasite's development ends and another begins. For example, the larvae of the ascaris first enter the human lungs, where they mature and migrate to the intestines. The child may be bothered by a short cough (similar to a cold) that does not alert the parent.
Nevertheless, a distinction is usually made between the acute and chronic phases of the parasitic disease.
Acute manifestations occur as a result of a general impact on the body:
- The effects of toxins - fever up to 37 - 37, 5 degrees, weakness, headache, decreased mood and performance, sleep disorders;
- Allergic reactions - itching, urticaria, bronchospasm, shortness of breath, rarely Quincke's edema;
- Activation of the immune system - pain in muscles and joints; enlarged lymph nodes, liver and spleen;
- Mechanical impact - if you look under a microscope, any helminth can see fixing devices in the body, injuring the mucous membrane: teeth, hooks, suction cups. The result is abdominal pain, frequent bowel movements and dyspepsia.
The chronic phase is characterized by damage to certain organs and systems. Most often the intestine suffers, prolonged mechanical action leads to its inflammation, impaired digestion and digestion of food. Anemia develops, lack of vitamins and minerals, and in young children there is a delay in growth and weight gain. The gallbladder and bile ducts (giardiasis) may be affected; cardiovascular system, lungs, nervous system (usually trichinosis); lungs and liver (echinococcosis) and so on. With a long course of immunity is suppressed and secondary infections join.
So, we have many ways of infection, mechanisms of development and manifestations of parasitic diseases. It turns out that every second person is at risk of getting sick, right? But sometimes helminths may not stay in the body: die and go away or pass "in passing" without starting to parasitize (so the detection of a "worm" in the stool does not prove the presence of the disease). Much depends on the stage of the helminth, its invasive properties and the human immune system. More susceptible to the development of helminthiasis are children under 5 years of age, actively learning the world "in language" and people with chronic diseases and weakened immunity.
If you find any of these signs, take a clinical blood test with a white blood cell count. An increase in eosinophils to 7-10% or more will become another suspicious criterion.
How to recognize a parasitic disease?
- Stool testing for protozoa and helminth eggs, preferably the enrichment method - PARASEP Identifies the eggs of all types of helminths and protozoa that live in the gut
The criterion for disease activity is the detection of eggs! This means passing the development cycle of the helminth in the body, its parasitism and reproduction. These are mainly intestinal helminthiasis, when a person is the final host, the "permanent residence" of the parasite, and the eggs are needed for further spread and the beginning of the next cycle.
You should pay attention to the following points:
- Each helminth has its own development cycle, so one study is not enough. If the result is negative, a triple study with an interval of 3-7 days is recommended;
- There are forms of helminthiasis when a person is an intermediate host (carrier of helminth larvae) or a "biological dead end" when the larvae have confused the host and cannot develop at all. In such cases, the eggs will never appear. in faeces, the disease can only be detected by antibody testing.
- Scraping test for enterobiosis - reveals only eggs of pinworms in the perianal folds. Female squirrels lay eggs, leaving the intestines exclusively at night when a man is relaxed. Therefore, the examination is performed strictly after sleep Before washing!
- Examination of giardia antigen in faeces is a highly accurate method for detecting giardia. For better detection, it is recommended that you adhere to a choleretic diet before testing.
- The study of antibodies against helminths (immunoglobulins) is aimed at assessing the immune system against pathogens. In principle, the most resistant immunoglobulins are determined - class G (IgG), which reflects the fact of infection, but does not allow to understand whether there is a helminth in the body at the moment or not, because IgG is stored in the body for a long time in the "archive". of memory ".
What should you pay attention to?
- The presence of manifestations and the simultaneous detection of IgG may indicate a chronic phase of helminthiasis;
- In doubtful cases, it is recommended to test the IgG again after 2 weeks. Increasing the level of antibodies by 2 times or more indicates the activity of the helminth;
- In trichinosis, echinococcosis, cysticercosis, the determination of antibodies is the only possible method for laboratory diagnosis, as man is an intermediate host for these helminths.
For your convenience, a complex "Diagnosis of parasitic diseases" has been formed, including a clinical blood test, total IgE (allergic component) and determination of antibodies to the most common helminths and protozoa.