Parasites in biology are considered to be those organisms that carry out their vital activity at the expense of another organism of a different biological species.
Such vital activity of the parasite does not bring any benefit to the host organism and, at best, the interaction does not lead to the development of negative effects.
At worst, the parasite causes the death of the host. In this case, either the parasite escapes into the external environment, or joint death.
Parasitic diseases of humans have been known practically since the primitive era of human existence. This fact was established in the process of observing the behavior of the immediate ancestors of man - apes. The parasites inhabiting the wool are detected by monkeys and removed from each other. This process has a very important character of social interaction.
Human intolerance to the appearance of pimples and holes in the skin also dates back to the early era of human existence. Some insect parasites in tropical zones can lay their larvae in the skin. This leads to a reflex urge to squeeze them out of the skin.
Various worms that affected the eyes, skin and gastrointestinal tract were described by ancient scientists. In the 18-19th century, with the development and introduction of microscopy into medical practice, scientists established the causes and ways of transmission of parasites that can cause specific diseases in humans.
- The beginning of the 20th century and the discovery of antiparasitic agents allowed mankind to cope with most parasitic diseases.
Thus, humanity very closely coexists with various parasites almost throughout its history. However, modern medical science makes it possible to diagnose the entire spectrum of parasites quickly and fairly accurately, which gives doctors the opportunity to treat such diseases in the shortest possible time and with minimal risks for patients.
General practitioner will help to identify parasites in the human body, symptoms and treatment. Sometimes infectious disease specialists of a narrower specialization - parasitologists - can be involved for this.
What are parasitic diseases?
Parasitic diseases are nosologies that arise after the introduction (invasion) of biological agents into the body. The latter are referred to the group of human parasites. The symptomatology of such diseases is extremely diverse and depends precisely on the agent that has penetrated and carries out its life activity in the body.
According to the way parasites affect the human body, they are usually divided into the following groups:
- Exoparasites that affect human skin and hair.
- The toxic effect of the waste products of the parasite on the body.
- Damage to the mucous membranes of the gastrointestinal tract and lungs by a parasite.
- Formation of cysts and cysts in human organs. An increase in the size of such cysts and cysts leads to specific symptoms of organ compression.
- Disruption of the normal passage of food through the gastrointestinal tract. This can lead to intussusceptions of the intestine (more often in children) or the development of intestinal obstruction.
- Parasites that live inside a person can cause sensitization and the occurrence of nonspecific allergic reactions.
- Microparasites can disrupt the functioning of blood cells, causing fever and intoxication.
- The effect of certain types of parasites on the body not only leads to severe symptoms, but can also lead to organ failure or death.
Such a variety of negative effects from parasites that arise in the body is due to different biological species that are introduced into human organs. However, such a biological diversity of parasites living in the human body allowed doctors to identify specific signs of parasitic diseases.
Parasites living in the human body
The main ways of human infection with parasites depend on the life cycle of the biological organism, which is the causative agent of the parasitic disease.
Doctors identify such ways of the parasite to penetrate a person as:
- Contact path.It is characteristic of exoparasite insects, as well as some helminths that live mainly in water, the larvae of which penetrate under the human skin. You can get infected in this way both from a sick person and through contaminated linen, bedding, personal or public hygiene items, and so on.
- Fecal-oral routeof infection. Occurs when the cysts of the pathogen enter the food after contact with infected feces, mainly from animals. Autoinvasion can also be observed - self-infection of a person if personal hygiene is not observed, and so on.
- Contamination.The pathogen enters the bloodstream when infected insects are crushed.
- Transmissive infection.The parasite enters the bloodstream when bitten by an insect that carries the disease. Most often, this route of transmission is typical for the simplest parasites, for example, malaria.
- Sexually transmitted infection.It is characteristic both for venereal diseases caused by parasites and for some helminths that can affect the urinary and genital tract of a person.
Protozoa, helminths (round and flat worms), insects, as well as some types of fungi are attributed to the causes of parasitic diseases.
The occurrence of humans with these species depends on the geographic and climatic zone. Therefore, the medicine of each country keeps its own records and a list of parasites that are specific to it.
Biological organisms that enter the human body have been studied in detail by both medical biologists and doctors, which made it possible to clearly classify all biological species that can cause parasitic diseases:
- The simplest organisms (amebiasis, balantidiasis, babeosis, Chagas disease, leishmaniasis, malaria, giardiasis, trypanosomiasis, toxoplasmosis, trichomoniasis).
- Helminths. Sometimes the term worms is used (ascariasis, dicroceliosis, diphyllobothriasis, dranculosis, clonorchiasis, opisthorchiasis, strongyloidiasis, teniasis, fascioliasis, schistosomiasis, enterobiasis, echinococcosis).
- Exoparasites (louse (pubic, head, clothes), demodicosis, fleas, bugs, scabies).
Signs of parasites in the human body
Unfortunately, there are no exact signs of parasites in the human body and no symptoms that would indicate this or that type of parasitic infection. This leads to the fact that for an accurate diagnosis, for example, helminthiasis, specific tests are needed.
On the other hand, almost all exo-infections are diagnosed quite simply - based on the clinical picture and the presence of a certain type of insect on the skin.
In general terms, all the symptoms of parasitic diseases can be grouped into the following groups:
- Skin itching and discomfort caused by external hair and skin parasites (fleas, lice, and others). An acne-like and itchy skin rash is often associated with a condition such as demodicosis (a special type of tick).
- Pain in various parts of the body caused by the introduction of a parasite into the skin and muscles (some types of worms that live in the water).
- Pain in the eyes, blurred vision.
- Pain in the lungs, coughing up phlegm (this situation can be typical for the migration of ascaris larvae in the lungs, as well as with echinococcal cysts of the lungs, and so on).
- Nausea, vomiting, diarrhea are very common symptoms of most helminths that parasitize the gastrointestinal tract.
- Jaundice, disorders of the liver and biliary tract, liver failure. These symptoms occur with helminths that affect the liver and biliary tract, as well as with malaria at the height of the disease.
- Stomach pain.
- Intestinal obstruction due to closure of the intestinal lumen with a large number of roundworms or large representatives of flatworms.
All these symptoms of the presence of parasites in the human body, in the absence of data for another pathology, should prompt the doctor to think about a parasitic human disease and serve as a basis for diagnostic and laboratory studies.
Diagnostics of parasites in humans
Depending on the type of parasite that has invaded the human body, one or another research is carried out. If we are talking about external exoparasites, which are mainly insects, then the diagnosis of the disease is usually limited to a general examination, as well as insect microscopy.
General examination usually provides accurate diagnosis and appropriate treatment or sanitization of the scalp or skin. In the case of demodicosis or scabies, the diagnosis can be easily established based on the location of the rash and the presence of itching.
Scrapings taken for microscopy in this case confirm the diagnosis of intradermal parasites.
For gastrointestinal parasites, the main screening study (a diagnostic procedure that allows you to quickly and relatively informatively assess data on the presence or absence of the disease in a large number of people) is the analysis of feces.
- With a special microscopic examination of feces, the laboratory assistant evaluates the presence of eggs of worms, dead worms, cyst capsules and so on.
By the morphology of helminth eggs, you can almost accurately determine the type of worm that parasitize in the body. Sometimes in the feces, the segments of the tapeworms are macroscopically determined. Then they are examined under a microscope to establish the appearance of a flatworm parasitizing in the gastrointestinal tract.
In some cases, for example, when the diagnosis of parasites in the body is impossible by analyzing feces or it is not informative, immunological studies are used. They allow you to assess the presence of antibodies to a particular type of helminth. Unfortunately, due to the special immunological relationship between the human immune system and the parasite, the level of antibodies in some cases may not reflect the real picture of the disease.
In the case of malaria, a thick drop of blood is tested to detect Plasmodium malaria. Also, general blood counts, leukocyte levels, as well as all biochemical parameters of blood, especially liver, are assessed.
The presence of an increased level of blood eosinophils is a frequent sign of not only allergic diseases, but also helminthic invasions. This is the first "bell".
Sometimes helminths in the gastrointestinal tract are a diagnostic finding during contrast radiographs, cystoscopy, FGDS, colonoscopy.
How to get rid of parasites in the human body?
Treatment of parasitic infections should be carried out only by a doctor, subject to certain rules.
Self-medication and traditional medicine in such cases does not lead to improvement, and sometimes can be fatal.
It is also important to provide preventive treatment for all family members and contacts.
Human exoparasites, which parasitize on hairy areas of the body, are destroyed with special disinfectants. Usually, a single treatment followed by a hygienic wash is sufficient to kill exoparasites.
When it comes to skin types of parasites (scabies, demodectic mange), special ointments containing insecticides against such organisms are used.
Antihelminthics are used against round and flatworms, which act in the main lumen of the gastrointestinal tract specifically on helminths. Depending on the biological type of helminth, various treatment regimens are used (from one tablet to a series of courses).
Such drugs should be used strictly under the supervision of a physician in order to timely recognize the negative effects and side effects of drugs.
No other methods of treatment, detox programs, and so on can lead to the complete death of parasites in the body and, as a result, to the cure of a person.