Parasitic diseases are a diverse and widespread group of diseases caused by helminths and protozoa that go through the life cycle of the human body, feed and reproduce at the expense of the "host" and cause damage to various organs and systems. Given the effect on the whole body as a whole, it is quite difficult to suspect and recognize them.
How infection occurs?
Before entering the human body, helminths and protozoa go through a developmental cycle in other environments or living organisms.
- The 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 enters through dirty hands, water, unwashed fruits and vegetables, directly from the ground.
- In living organisms, the following helminths undergo developmental cycles: opisthorchis (cat trematode), clonorchis, trichinella, toxocara, echinococcus, porcine and bovine tapeworms. Before reaching maturity, to parasitize on a person, it is possible to change one or two intermediate hosts. These are mollusks, crustaceans, fish, insects. Eating insufficiently thermally processed fish and meat, raw water leads to infection.
Another form of contagion is through direct contact with people through handshakes, common hygiene and household items or by self-infection. We are talking about contagious helminths: enterobiasis, strongyloidosis, cysticercosis, giardiasis.
How can a parasitic disease be suspected?
Manifestations can vary, from mild to severe. There are rarely typical signs that carry a specific pathogen. Often there are no signs, or they disguise themselves as other diseases, or disappear when one cycle of parasite development ends and another begins. For example, roundworm larvae first enter the human lungs, where they mature and migrate to the intestines. The child may be bothered by a brief cough (similar to a cold), which does not alarm the parents.
However, the acute and chronic phases of the parasitic disease course are generally distinguished.
Acute manifestations occur as a result of a general effect on the body:
- The effects of toxins: a rise in temperature of up to 37-37. 5 degrees, weakness, headaches, decreased mood and performance, sleep disturbances;
- Allergic reactions: itching, hives, bronchospasm, shortness of breath, less often Quincke's edema;
- 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 devices for fixing on the body, damaging 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 impaired inflammation, absorption and digestion of food. Anemia, lack of vitamins and minerals develops, and in young children there is a delay in growth and weight gain. The gallbladder and biliary tract (giardiasis) can 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.
So, we have many forms of infection, mechanisms of development and manifestations of parasitic diseases. It turns out that one in two people is at risk of getting sick, right? But sometimes helminths may not stay in the body: they die and leave, or pass "in passing" without beginning to parasite (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. Most susceptible to the development of helminthiasis are children under 5 years of age, who actively learn the world "in the language" and people with chronic diseases and weakened immunity.
If you find any of the listed signs, do a clinical blood test with a white blood cell count. An increase in eosinophils of up to 7-10% or more will become another suspicious 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 for disease activity is the detection of eggs! This means the passage of the development cycle of helminths in the body, their parasitism and reproduction. It is mainly intestinal helminthiasis, when a person is the final host, the "permanent residence" of the parasite, and the eggs are necessary 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 a single study is not enough. If the result is negative, a three-time study with an interval of 3-7 days is recommended;
- Such forms of helminthiasis exist, 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 further. In such cases, the eggs will never appear in the feces, the disease can only be detected by the determination of antibodies.
- Examination of the scraping for enterobiasis: only reveals pinworm eggs in the perianal folds. Female pinworms lay eggs, leaving the intestines exclusively at night, when the person is relaxed. Therefore, the study is carried out strictly after sleeping before washing!
- The stool lamblia antigen test is a highly accurate method for the detection of lamblia. For better detection, it is recommended to follow a choleretic diet before the test.
- The study of antibodies against helminths (immunoglobulins) aims to evaluate the immune system against pathogens. Basically, the most persistent immunoglobulins are determined - class G (IgG), which reflects the fact of infection, but does not make it possible to understand whether there is a helminth in the body now or not, since IgG is stored in the body for a long time weather. time in the "memory file".
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 retest for IgG after 2 weeks. An increase in the level of antibodies by 2 times or more 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 developed, which includes a clinical blood test, total IgE (allergic component) and the determination of antibodies against the most common helminths and protozoa.