Parasitic diseases. How to suspect and diagnose

Parasitic diseases are a widespread, diverse group of diseases caused by helminths and protozoa that go through the life cycle in the human body, feed and reproduce to the detriment 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 doubt them and recognize them.

the presence of parasites in the body

How did the infection unfold?

Before entering the human body, helminths and protozoa go through a developmental cycle in other environments or living organisms.

  • Eggs and larvae of roundworms, strongyloids, ankylomia remain in the soil under certain conditions of temperature and humidity. Man becomes infected when contaminated soil enters through dirty hands, water, unwashed fruits and vegetables, directly from the ground.
  • In living organisms, the following helminths go through developmental cycles: opisthorchis (feline fluke), clonorchis, trichinella, toxocara, echinococcus, swine and bovine tapeworm. Before reaching maturity, in order to parasitize a person, it is possible to change one or two middle hosts. These are mollusks, crabs, fish, insects. By eating insufficiently heat-treated fish and meat, raw water leads to infection.

Another way of infection is direct contact of people with handling, usual hygiene and household items or self-infection. We are talking about infectious helminths: enterobiasis, strongyloidosis, cysticercosis, giardiasis.

How can a parasitic disease be suspected?

Manifestations can vary from mild to severe. Rarely are there typical signs that betray a particular pathogen. Often there are no signs or they disguise themselves in other diseases or disappear as one cycle of parasite development ends and another begins. For example, ascaris 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 bother the parent.

However, the acute and chronic stages of the parasitic disease usually differ.

Acute manifestations occur as a result of the general impact on the body:

  • 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 the fixing devices in the body, injuring the mucous membranes: teeth, hooks, rubber cups. The result is abdominal pain, frequent bowel movements and dyspepsia.

The chronic phase is characterized by damage to certain organs and systems. The intestine most often suffers, prolonged mechanical action leads to its inflammation, impaired absorption and digestion of food. Anemia develops, a lack of vitamins and minerals, and in young children there is a delay in growth and weight gain. The gallbladder and bile duct (giardiasis) may be affected; cardiovascular system, lungs, nervous system (usually trichinosis); lungs and liver (echinococcosis) and so on. Immunity is suppressed for a long time and secondary infections join.

So, we have many ways of infection, mechanisms of development and manifestations of parasitic diseases. It turns out that every other person is at risk of getting sick, right? But sometimes helminths may not stay in the body: die and go or pass "in passing" without starting to parasitize (which is why the detection of "worms" in the feces does not prove the presence of the disease). Much depends on the stage of the helminth, its invasive properties and the human immune system. Children younger than 5 years are more susceptible to the development of helminthiasis, they actively learn the world "in language" and people with chronic diseases and weakened immunity.

If you find any of these signs, do a clinical blood test with a white blood cell count. An increase in eosinophils to 7-10% or more will become another questionable criterion.

How to recognize a parasitic disease?

  1. Fecal testing for protozoa and helminth eggs, preferably enrichment method - PARASEP Determines eggs of all types of helminths and protozoa living in the intestines

    The criterion for disease activity is the detection of eggs! This means the passage of the development cycle of helminths in the body, its parasitization and reproduction. These are mainly intestinal helminthiases, when the 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 items:

    • Each helminth has its own development cycle, so one study is not enough. If the result is negative, a triple test with an interval of 3-7 days is recommended;
    • There are such forms of helminthiasis, when a person is a temporary host (carrier of helminth larvae) or "biological dead end", when the larvae have confused the host and cannot develop further at all. In such cases, the eggs will never appear in the feces, the disease can only be detected by antibody determination.
  2. Scraping examination for enterobiasis - reveals only pinworm eggs in perianal folds. Pinworm females lay eggs, leaving the intestines exclusively at night, when the person is relaxed. Therefore, the study is conducted strictly after bedtime Before washing!
  3. The study of lamblia antigen in feces is a highly accurate method for detecting lamblia. For better detection, it is recommended to adhere to a choleretic diet before testing.
  4. The helminth antibody study (immunoglobulins) aims to assess the immune system against pathogens. Basically, 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 or not, since IgG is stored in the body for a long time in the "memory archive".

What should you pay attention to?

  • The presence of manifestations and simultaneous detection of IgG may indicate a chronic phase of helminthiasis;
  • In suspicious cases, it is recommended to re-test IgG after 2 weeks. An increase in antibody levels of 2-fold or more indicates helminth activity;
  • In trichinosis, echinococcosis, cysticercosis, antibody determination is the only possible method of laboratory diagnosis, since the person is an intermediate host for these helminths.

For your convenience, a complex "Diagnosis of parasitic diseases" has been formed, which includes a clinical blood test, total IgE (allergic component) and determination of antibodies to the most common helminths and protozoa.