Parasitic diseases are a widespread and diverse group of diseases caused by worms and protozoa that go through a life cycle in the human body, feeding and reproducing at the expense of the "host" and causing damage to various organs and systems. Given its effects on the whole body as a whole, it is quite difficult to suspect and recognize it.
How does the infection occur?
Before entering the human body, helminths and protozoa go through a cycle of development in other environments or living organisms.
- Eggs and larvae of roundworms, qualitative, tapeworms remain in the soil under certain temperature and humidity conditions. A person becomes infected when contaminated soil enters through dirty hands, water, unwashed fruits and vegetables, directly from the soil.
- In living organisms, the following helminths undergo a developmental cycle: opisthorchis (cat fluke), clonorchis, trichinella, toxocara, echinococcus, pigs and bovine tapeworms. Before reaching maturity, to commit parasites on a person, it is possible to change one or two intermediate hosts. These are mollusks, crustaceans, fish, insects. Eating fish and meat that is not thermally processed, raw water leads to infection.
Other modes of infection are through direct contact of people through handshakes, regular hygiene and household items, or by self-infection. We are talking about infectious helminths: enterobiasis, strongyloidosis, cysticercosis, giardiasis.
How can parasitic diseases be suspected?
Manifestations can vary, from mild to severe. Rarely are there special signs that emit a particular pathogen. Often there are no symptoms, or they masquerade as another disease, or disappear when 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 intestine. The child may be bothered by a short cough (similar to the flu), which does not worry the parent.
Even so, the acute and chronic phases of parasitic diseases are usually distinguished.
Acute manifestations occur due to general effects on the body:
- Effects of toxins - an increase in temperature to 37 - 37. 5 degrees, weakness, headache, decreased mood and performance, sleep disturbances;
- Allergic reactions - itching, urticaria, bronchospasm, shortness of breath, less frequent 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, each helminth can see tools to correct the body, injuring the mucous membranes: 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. Often, the intestine suffers, prolonged mechanical action causes its inflammation, disorders of absorption and digestion of food. Anemia, lack of vitamins and minerals develop, 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. In the long run, immunity is suppressed and secondary infections merge.
Thus, we have many modes 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 live in the body: die and go, or pass "late" without starting to do parasites (which is why the detection of "worms" in the feces does not prove the presence of the disease). Much depends on the level of the helminth, its invasive nature and the human immune system. More prone to the development of helminthiasis are children under the age of 5 years, actively studying the world "on the tongue" and people with chronic diseases and weakened immunity.
If there are any of the listed symptoms, perform a clinical blood test with the number of leukocytes. An increase in eosinophils to 7-10% or more would be another suspicious criterion.
How to identify parasitic diseases?
- Fecal study for protozoa and helminth eggs, better enrichment method - PARASEP Determining the eggs of all types of helminths and protozoa living in the intestine
The criterion for disease activity is egg detection! This means the course of the helminth development cycle in the body, its parasitism and reproduction. These are especially intestinal helminthiases, when a person is the last host, the "permanent residence" of the parasite, and eggs are needed for further spread and the beginning of the next cycle.
You should note the following:
- Each helminth has its own development cycle, so one study is not enough. If the result is negative, a three-time study is recommended with an interval of 3-7 days;
- There is such a form of helminthiasis, when a person is an intermediate host (carrier of helminth larvae) or a "biological deadlock", when the larvae have confused the host and cannot grow any further at all. In such cases, the eggs will not appear in the stool, the disease can only be detected by determining antibodies.
- Examination scrapes enterobiasis - only reveals pinworm eggs in the perianal fold. Female cream worms lay eggs, leaving the intestines exclusively at night, when one is relaxing. Therefore, the study is done strictly after bedtime Before washing!
- Study of lamblia antigens in feces is a high -precision method for detecting lamblia. For better detection, it is recommended to adhere to a choleretic diet before performing the test.
- Antibody studies against helminths (immunoglobulins) aim to assess the immune system against pathogens. Basically, the most persistent immunoglobulin is determined - class G (IgG), which reflects the fact of infection, but it is not possible to understand whether there are helminths in the body now or not, because IgG is stored in the body for a long time in the memory archives".
What should you pay attention to?
- The presence of simultaneous manifestations and detection of IgG may indicate a chronic phase of helminthiasis;
- If in doubt, it is recommended to retest IgG after 2 weeks. An increase in antibody levels of 2 times or more indicates helminth activity;
- With trichinosis, echinococcosis, cysticercosis, antibody determination is the only possible laboratory diagnostic method, because a person is an intermediate host for these helminths.
For your convenience, has been formed a complex "Diagnostics of parasitic diseases", including clinical blood tests, the amount of IgE (allergy component) and the determination of antibodies against the most common helminths and protozoa.