Parasites in biology are considered those organisms that perform their vital activity at the expense of another organism of a different biological species.
This vital parasite activity does not bring any benefit to the host organism and, at best, the interaction does not lead to the development of negative effects.
In the worst case, the parasite causes the host to die. In this case, the parasite either escapes to the external environment or dies articularly.
Human parasitic diseases have been known practically since the early era of human existence. This fact was established in the process of observing the behavior of direct human ancestors - monkeys. The parasites that inhabit 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 acne and holes in the skin also has its origins in the beginning of human existence. Some parasitic insects in tropical areas can place their larvae on the skin. This leads to a reflex impulse to squeeze them out of the skin.
Various worms affecting the eyes, skin and gastrointestinal tract have been described by ancient scientists. In the 18-19 century, with the development and introduction of microscopy in medical practice, scientists established the causes and forms of transmission of parasites that can cause specific diseases in humans.
- The beginning of the 20th century and the discovery of antiparasitic agents allowed humanity to face most parasitic diseases.
Thus, humanity coexists closely 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 these diseases in the shortest possible time and with minimal risk to patients.
The general practitioner will help to identify parasites in the human body, symptoms and treatment. Sometimes specialists in infectious diseases of a more restricted specialization - parasitologists - may be involved in this.
What are parasitic diseases?
Parasitic diseases are nosologies that arise after the introduction (invasion) of biological agents in the body. The latter are referred to the group of human parasites. The symptoms of these diseases are extremely diverse and depend precisely on the agent that took root and exerts its vital activity in the organism.
According to how parasites affect the human body, they are generally divided into the following groups:
- Exoparasites that affect human skin and hair.
- The toxic effect of the parasite's waste products 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 these cysts and cysts leads to specific symptoms of organ compression.
- Interruption of the normal passage of food through the gastrointestinal tract. This can lead to bowel intussusceptions (more often in children) or the development of intestinal obstruction.
- Parasites that live inside a person can cause sensitization and the occurrence of non-specific allergic reactions.
- Microparasites can disrupt the functioning of blood cells, causing fever and intoxication.
- The influence of certain types of parasites on the body not only leads to severe symptoms, but can also lead to organ failure or death.
This variety of negative parasitic effects that arise in the body is due to different biological species that are introduced into human organs. However, this biological diversity of parasites that live in the human body has allowed doctors to identify specific signs of parasitic diseases.
Parasites that live in the human body
The main forms of human parasitic infection depend on the life cycle of the biological organism, which is the causative agent of the parasitic disease.
Doctors identify ways the parasite can penetrate a person, such as:
- Path of contact.It is characteristic of insect exoparasites, as well as some helminths that live mainly in water, whose larvae penetrate under human skin. You can be infected this way either by a sick person or through contaminated bedding, bedding, personal or public hygiene items, and so on.
- Fecal-oral routefor infection. It occurs when cysts of the pathogen enter the food after contact with infected feces, mainly from animals. Self-invasion can also be observed - a person's self-infection 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 of the time, this transmission route is characteristic of the simplest parasites, for example, malaria.
- Sexually transmitted infection.It is characteristic of both venereal diseases caused by parasites and some helminths that can affect a person's urinary and genital tract.
Protozoans, helminths (round and flatworms), 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 geographical and climatic zone. Therefore, each country's drug maintains its own records and a list of parasites that are specific to it.
The biological organisms that enter the human body have been studied in detail by medical and medical biologists, which has made it possible to clearly classify all biological species that can cause parasitic diseases:
- The simplest organisms (amebiasis, balantidiasis, baby, Chagas disease, leishmaniasis, malaria, giardiasis, trypanosomiasis, toxoplasmosis, trichomoniasis).
- Helminths. Sometimes the term worms is used (ascariasis, dichrocelliosis, diphylobotriasis, dranculose, clonorchiasis, opistorchiasis, strongyloidiasis, teniasis, fascioliasis, schistosomiasis, enterobiasis, echinococcosis).
- Exoparasites (lice (pubic, 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 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 quite simply - based on the clinical picture and the presence of a certain type of insect on the skin.
In general terms, all symptoms of parasitic diseases can be grouped into the following groups:
- Itching and discomfort in the skin caused by external hair and skin parasites (fleas, lice and others). An itchy, acne-like 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 on the skin and muscles (some types of worms that live in water).
- Pain in the eyes, blurred vision.
- Pain in the lungs, coughing with phlegm (this situation can be typical for the migration of ascaris larvae in the lungs, as well as with echinococcal cysts in the lungs, and so on).
- Nausea, vomiting and diarrhea are very common symptoms of most helminths that parasitize the digestive tract.
- Jaundice, liver and biliary disease, liver 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 closure of the intestinal lumen with a large number of roundworms or large representatives of flat worms.
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 think about a human parasitic disease and serve as a basis for diagnostic and laboratory studies.
Diagnosis of parasites in humans
Depending on the type of parasite that invaded the human body, one or another research is carried out. If we talk about external exoparasites, which are mainly insects, the diagnosis of the disease is usually limited to a general examination, in addition to the microscopy of insects.
The general examination is usually unmistakable for proper diagnosis and treatment or cleaning 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.
The fragments removed for microscopy, in this case, confirm the diagnosis of intradermal parasites.
For gastrointestinal parasites, the main screening study (a diagnostic procedure that allows a quick and relatively informative assessment of data on the presence or absence of the disease in a large number of people) is stool analysis.
- With a special microscopic examination of the stool, the laboratory doctor assesses the presence of worm eggs, dead worms, cyst capsules and so on.
By the morphology of helminth eggs, you can almost accurately determine the type of worm that parasites in the body. Sometimes, in faeces, the tapeworm segments are determined macroscopically. They are then examined under a microscope to establish the appearance of a parasitic worm in the gastrointestinal tract.
In some cases, for example, when the diagnosis of parasites in the body is impossible by analyzing stool or is not informative, immunological studies are used. They allow you to assess the presence of antibodies to a specific 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 actual image of the disease.
In the case of malaria, a thick drop of blood is tested to detect 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".
Helminths in the gastrointestinal tract are sometimes a diagnostic finding during contrast radiography, cystoscopy, FGDS, colonoscopy.
How to get rid of parasites in the human body?
The treatment of parasitic infections should be performed only by a doctor, according to some rules.
Self-medication and traditional medicine in these cases do not lead to improvement and can sometimes be fatal.
It is also important to provide preventive treatment for all family members and contacts.
Human exoparasites, which parasite 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 parasites (scabies, demodectic mange), special ointments containing insecticides against these organisms are used.
Anthelmintics are used against roundworms and flatworms, which act on the main lumen of the gastrointestinal tract, specifically on helminths. Depending on the biological type of helminths, various treatment regimens are used (from one pill to a series of cycles).
These drugs should be used strictly under the supervision of a doctor to timely recognize the negative and side effects of the drugs.
No other treatment method, detox programs and so on can lead to the complete death of parasites in the body and, as a result, the healing of a person.