Parasitic diseases are a widespread and diverse group of diseases caused by helminths and protozoa that traverse the life cycle in the human body, feeding and reproducing at the expense of the "host" and causing damage to various organs and organs. systems. Considering the effect on the whole body as a whole, it is quite difficult to suspect and recognize them.
How does the infection work?
Before entering the human body, helminths and protozoa go through a cycle of development in other environments or living organisms.
- Eggs and larvae of ascaris, strongyloids, hookworms remain in the soil under certain conditions of temperature and humidity. A person becomes infected when contaminated soil enters through dirty hands, water, unwashed fruits and vegetables, directly from the ground.
- In living organisms, the following helminths undergo developmental cycles: opisthorchis (cat fluke), clonorchis, trichinella, toxocara, echinococcus, pork and bovine tapeworm. Before reaching maturity, to parasitize in a person, it is possible to change one or two intermediate hosts. They are molluscs, crustaceans, fish, insects. By eating insufficiently heat-treated fish and meat, raw water leads to infection.
Another mode of infection is direct contact with people through handshakes, common hygiene and household items, or through self-infection. We speak of contagious helminths: enterobiasis, strongyliasis, cysticercosis, giardiasis.
How to suspect a parasitic disease?
The manifestations can be varied, from mild to severe. There are rarely typical signs that give a specific pathogen. Often there are no signs, or they disguise themselves as other diseases, or disappear at the end of one parasite's development cycle and the start of another. For example, roundworm larvae 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), which does not alarm the parent.
Nevertheless, the acute and chronic phases of the course of the parasitic disease are usually distinguished.
Acute manifestations occur as a result of a general effect on the body:
- The effects of toxins - an increase in temperature up to 37 - 37. 5 degrees, weakness, headaches, decreased mood and performance, sleep disturbances;
- Allergic reactions - itching, hives, bronchospasm, shortness of breath, less often angioedema;
- Activation of the immune system - muscle and joint pain; enlarged lymph nodes, liver and spleen;
- Mechanical impact - if you look under a microscope, each helminth can see fixation devices in the body, injuring the mucous membrane: teeth, hooks, suction cups. This results in 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 absorption and digestion of food. Anemia, a lack of vitamins and minerals develop, and in young children there is stunted 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, immunity is suppressed and secondary infections join.
Thus, we have many modes of infection, mechanisms of development and manifestations of parasitic diseases. It turns out that one in two people are at risk of getting sick, right? But sometimes the helminths may not stay in the body: die and leave, or pass "on the way" without starting to parasitize (this is why the detection of a "worm" in the stool does not prove the presence of thedisease). It all depends on the stage of the helminth, its invasive properties and the human immune system. Children under 5 who are actively learning the world "on the tongue" and people with chronic illnesses and weakened immunity are more susceptible to the development of helminthiasis.
If you find any of the signs listed, have a clinical blood test with a white blood cell count. An increase in eosinophils of up to 7-10% or more will become another suspect criterion.
How to identify a parasitic disease?
- The study of feces for protozoa and helminth eggs, preferably the enrichment method - PARASEP Determines the eggs of all types of helminths and protozoa that live in the intestine
The criterion of disease activity is the detection of eggs! It means the passage of the cycle of development of the helminth in the body, its parasitism and reproduction. These are mainly intestinal helminthiasis, when a person is the final host, the "permanent home" of the parasite, and the eggs are needed for further spread and the start of the next cycle.
You should pay attention to the following points:
- Each helminth has its own cycle of development, so one study is not enough. If the result is negative, a three-step study is recommended with an interval of 3 to 7 days;
- There are such 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 can no longer develop at all. In such cases, the eggs will never appear in the stool, the disease can only be detected by determining the antibodies.
- Examination of scratching for enterobiasis - reveals only pinworm eggs in the perianal folds. Female pinworms lay eggs, leaving the intestines exclusively at night, when a person is relaxed. Therefore, the study is carried out strictly after sleep Before washing!
- The study of lamblia antigen in stool is a high precision method for the detection of lamblia. For better detection, it is recommended to adhere to a choleretic diet before testing.
- The study of antibodies directed against helminths (immunoglobulins) aims to assess the immune system against pathogens. Basically, the most persistent immunoglobulins are determined - class G (IgG), reflecting the fact of infection, but not making it possible to understand whether there is a helminth in the body now or not, because IgG is stored inthe body for a long time. the time in the "memory archive".
What should you watch out for?
- The presence of manifestations and simultaneous detection of IgG may indicate a chronic phase of helminthiasis;
- In doubtful cases, it is recommended to retest IgG after 2 weeks. An increase in the level of antibodies of 2 or more times indicates the activity of the helminth;
- With trichinosis, echinococcosis, cysticercosis, the determination of antibodies is the only possible method of laboratory diagnosis, since a person is an intermediate host for these helminths.
For your convenience, a complex "Diagnosis of parasitic diseases" has been set up, comprising a clinical blood test, total IgE (allergic component) and determination of antibodies against the most common helminths and protozoa.