Parasites in biology are considered to be organisms which perform their vital activity at the expense of another organism of a different biological species.
Such vital activity of the parasite brings no 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 early days of human existence. This fact was established during the process of observing the behavior of direct human ancestors - apes. The parasites inhabiting the wool are detected by the monkeys and separated 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 beginning of human existence. Some parasitic insects in tropical areas can deposit their larvae in the skin. This leads to a reflex urge to get them out of the skin.
Various worms that affected the eyes, skin, and gastrointestinal tract have been described by ancient scientists. In the 18-19th century, with the development and introduction of microscopy into medical practice, scientists established the causes and modes of transmission of parasites that can cause specific diseases in humans.
- The beginning of the 20th century and the discovery of antiparasitic agents enabled mankind to cope with most parasitic diseases.
Thus, humanity coexists very closely with various parasites almost throughout its history. However, modern medical science allows the entire spectrum of parasites to be diagnosed quickly and fairly accurately, giving doctors the opportunity to treat these diseases in the shortest possible time and with minimal risks to patients.
A general practitioner will help identify parasites in the human body, symptoms, and treatment. Sometimes infectious disease specialists with a narrower specialty - parasitologists - may be involved for this.
What are parasitic diseases?
Parasitic diseases are nosologies that occur after the introduction (invasion) of biological agents into the body. These refer to the group of human parasites. The symptomatology of these diseases is extremely diverse and depends precisely on the agent that has entered and performs its vital activity in the body.
Depending on how the parasites affect the human body, they are generally divided into the following groups:
- Exoparasites that affect human skin and hair.
- The toxic effect of parasite waste on the body.
- Injury 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 these 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 development of non-specific allergic reactions.
- Microparasites can interfere with the functioning of blood cells, causing fever and poisoning.
- The influence of certain types of parasites on the body not only causes severe symptoms, but can also lead to organ failure or death.
Such a variety of negative effects of parasites that occur 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 has enabled doctors to identify specific signs of parasitic diseases.
Parasites living in the human body
The main routes of human infection with parasites depend on the life cycle of the biological organism, which is the causative agent of parasitic disease.
Doctors identify the ways in which the parasite enters a person as:
- Path of the contact.It is characteristic of exoparasitic insects, as well as some helminths that live mainly in water, the larvae of which penetrate under the human skin. You can be infected in this way both from a sick person and from contaminated sheets, bedding, personal or public hygiene items, etc.
- Fecal-oral routeof infection. Occurs when cysts of the pathogen enter food after contact with infected feces, mainly animals. Self-invasion 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 of the simplest parasites, for example, malaria.
- Sexually transmitted infection.It is characteristic of both venereal disease caused by parasites and some helminths that can affect a person's urinary and genital tract.
Protozoa, helminths (round and flatworms), insects, as well as certain types of fungi are attributed to the causes of parasitic diseases.
The presence of humans with these species depends on the geographic and climatic area. Therefore, each country's drug keeps its own records and a list of parasites specific to it.
Biological organisms that enter the human body have been studied in detail by medical biologists and physicians, which has made it possible to clearly classify all biological species that can cause parasitic diseases:
- The simplest organisms (amebiasis, balantidiasis, babeose, Chagas disease, leishmaniasis, malaria, giardiasis, trypanosomiasis, toxoplasmosis, trichomoniasis).
- Helminths. Sometimes the term worms is used (ascariasis, dicrocéliosis, diphyllobothriasis, dranculosis, clonorchiasis, opisthorchiasis, strongyloidiasis, tapeworm, fascioliasis, schistosomiasis, enterobiosis, echinococcosis).
- Exoparasites (louse (pubis, head, clothes), demodicosis, fleas, insects, 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 required.
On the other hand, almost all exoinfections are diagnosed very simply - based on the clinical picture and the presence of a certain type of insect on the skin.
In general, all symptoms of parasitic diseases can be grouped into the following groups:
- Itchy skin and discomfort caused by external hairs and skin parasites (fleas, lice and others). An itchy, acne-like rash is often associated with a condition such as demodectic mange (a special type of mite).
- Pain in various parts of the body caused by the introduction of a parasite into the skin and muscles (certain types of worms that live in water).
- Pain in the eyes, blurred vision.
- Pain in the lungs, coughing up phlegm (this may be typical of the migration of ascaris larvae into the lungs, as well as echinococcal cysts from the lungs, etc. ).
- Nausea, vomiting, diarrhea are very common symptoms of most helminths which parasitize the gastrointestinal tract.
- Jaundice, liver and bile duct disorders, hepatic failure. These symptoms occur with helminths that affect the liver and bile ducts, as well as with malaria at the height of the disease.
- Stomach pain.
- Intestinal obstruction due to the closing of the intestinal lumen with a large number of roundworms or large representatives of tapeworms.
All these symptoms of the presence of parasites in the human body, in the absence of data for another pathology, should lead the doctor to the idea of a parasitic disease in humans and serve as a basis fordiagnostic and laboratory studies.
Diagnosis of parasites in humans
Depending on the type of parasite that has invaded the human body, one or the other research is conducted. 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 microscopy of insects.
General examination is usually unmistakable for diagnosis and proper treatment or disinfection of the scalp or skin. In cases of demodicosis or scabies, the diagnosis can be easily made based on the location of the rash and the presence of itching.
Scrapings performed for microscopy in this case confirm the diagnosis of intradermal parasites.
For gastrointestinal parasites, the main screening study (a diagnostic procedure that allows for a rapid and relatively informative assessment of data on the presence or absence of the disease in a large number of people)is the stool analysis.
- With a special microscopic examination of feces, the laboratory assistant assesses the presence of worm eggs, dead worms, cyst capsules, etc.
By the morphology of the helminth eggs, you can almost accurately determine the type of worm that is parasitizing in the body. Sometimes in feces segments of tapeworms are macroscopically determined. Then they are examined under a microscope to establish the appearance of a flatworm parasitizing the gastrointestinal tract.
In some cases, for example, when the diagnosis of parasites in the body is not possible by analyzing feces or is not informative, immunological studies are used. They allow you to assess the presence of antibodies against 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 true picture of the disease.
In the case of malaria, a thick drop of blood is tested for Plasmodium malaria. In addition, general blood counts, leukocyte levels, as well as all biochemical parameters of the blood, especially the liver, are evaluated.
The presence of a high level of eosinophils in the blood is a frequent sign not only of allergic diseases, but also of helminthic invasions. This is the first "bell".
Sometimes helminths in the gastrointestinal tract are a diagnostic finding on contrast x-rays, cystoscopy, FGDS, colonoscopy.
How to get rid of parasites in human body?
Treatment of parasitic infections should only be done by a doctor, subject to certain rules.
Self-medication and traditional medicine in such cases do not lead to improvement and can sometimes be fatal.
It is also important to provide preventive treatment to all family members and all contacts.
Human exoparasites, which parasitize hairy areas of the body, are destroyed with special disinfectants. Usually, a single treatment followed by hygienic washing is sufficient to kill the exoparasites.
As for the skin types of parasites (scabies, demodicosis), special ointments are used containing insecticides against these organisms.
Anthelmintics are used against round and flatworms, which act in the main lumen of the gastrointestinal tract especially on helminths. Depending on the biological type of helminths, various treatment regimens are used (from one tablet to a series of courses).
These drugs should be used strictly under the supervision of a doctor in order to recognize the negative effects and side effects of the drugs in a timely manner.
No other treatment method, no detox program, etc. can not lead to the complete death of parasites in the body and, as a result, the recovery of a person.