Parasitic diseases. Suspicion and diagnosis

Parasitic diseases are a widespread group of various diseases caused by helminths and protozoa that live in the human body, multiply by feeding on "hosts" and damage various organs and systems. Given the effects on the whole body as a whole, it is very difficult to doubt and recognize them.

the presence of parasites in the body

How does the infection occur?

Before entering the human body, helminths and protozoa undergo a period of development in other environments or living organisms.

  • Roundworms, eggs, earthworms and larvae remain in the soil at certain temperatures and humidity. People become infected when contaminated soil enters directly from the ground from dirty hands, water, unwashed fruits and vegetables.
  • In living organisms, the following helminths go through developmental stages: opisthorchis (cat fluke), clonorchis, trichinella, toxocara, echinococcus, pork and bovine tapeworm. It is possible to change one or two midwives to parasitize a person before reaching the age of puberty. These are mollusks, crustaceans, fish, insects. Eating enough thermally processed fish and meat, raw water causes infection.

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

How to suspect a parasitic disease?

Manifestations can range from mild to severe. In rare cases, there are typical symptoms that give a certain pathogen. Often there are no symptoms or they hide like other diseases or disappear after the end of one period of development of the parasite as the beginning of another. For example, ascaris larvae first enter the human liver, where they mature and migrate to the intestines. A short cough (similar to a cold) that does not bother the parents can bother the child.

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

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

  • Effects of toxic substances - fever up to 37 - 37, 5 degrees, weakness, headache, decreased mood and performance, sleep disorders;
  • Allergic reactions - itching, urticaria, bronchospasm, shortness of breath, less Quincke's edema;
  • Activation of the immune system - muscle and joint pain; enlarged lymph nodes, liver and spleen;
  • Mechanical effects - if you look under a microscope, you can see devices that attach to each helminth in the body, injuring the mucous membrane: teeth, hooks, suction cups. The result is abdominal pain, frequent bowel movements and dyspepsia.

The chronic stage is characterized by damage to certain organs and systems. The intestine often suffers, and long-term mechanical action causes inflammation, assimilation and digestion of food. Anemia, vitamin and mineral deficiencies develop, and growth and weight gain are delayed in young children. The gallbladder and bile ducts (giardiasis) may be affected; cardiovascular system, lungs, nervous system (usually trichinosis); lungs and liver (echinococcosis), etc. With a long course, immunity is suppressed and secondary infections are combined.

Thus, there are 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, isn't it? However, sometimes helminths may not remain in the body: die and leave, or "pass" before they begin to parasitize (therefore, the presence of a "worm" 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. The most susceptible to the development of helminthiasis are children under 5 years of age, those who are actively learning the world in "language" and people with chronic diseases and weakened immunity.

If you find any of the symptoms listed, take a clinical blood test with your leukocyte count. An increase of 7-10% or more in eosinophils will become another questionable criterion.

How to diagnose a parasitic disease?

  1. Fecal examination for protozoa and helminth eggs, preferably enrichment method - PARASEP Identifies all types of helminth and protozoa eggs living in the gut

    The criterion of disease activity is the detection of eggs! This means the period of helminth development in the body, its parasitism and reproduction. These are mainly intestinal helminthiasis, when a person is the last host, the parasite's "permanent habitat" and the eggs are needed for further spread and the beginning of the next period.

    You should pay attention to the following points:

    • Each helminth has its own developmental cycle, so a single study is not enough. If the result is negative, a study three times in 3-7 days is recommended;
    • These forms of helminthiasis are present when a person has an intermediate host (a carrier of helminth larvae) or a "biological impasse" when the larvae mix with the host and cannot develop further. In such cases, the egg will never appear in the stool, the disease can be detected only by the appointment of antibodies.
  2. Shearing examination for enterobiosis - only pinworm eggs are found in perianal wrinkles. Female pinworms lay eggs, the intestines leave only at night, when a person is comfortable. Therefore, the study is carried out strictly after sleep before washing!
  3. The study of lamblia antigen in feces is a high-precision method for the detection of lamblia. It is recommended to follow a choleretic diet before the test for better detection.
  4. The study of antibodies against helminths (immunoglobulins) is aimed at assessing the immune system against pathogens. Basically, the most resistant immunoglobulins are prescribed - class G (IgG), which reflects the fact of infection, but because IgG is stored in the body for a long time, it is not possible to determine whether there is a helminth in the body. time "in the memory archive".

What should you pay attention to?

  • The presence of manifestations and the simultaneous detection of IgG may indicate a stage of chronic helminthiasis;
  • In case of doubt, it is recommended that IgG be retested after 2 weeks. A 2-fold or greater increase in antibody levels indicates helminth activity;
  • Determination of antibodies to trichinosis, echinococcosis, cysticercosis is the only possible method of laboratory diagnosis, because a person is an intermediate host for these helminths.

For your convenience, a complex "Diagnosis of Parasitic Diseases" has been developed, including a clinical blood test, total IgE (allergic component) and determination of antibodies against the most common helminths and protozoa.