Types of parasites in the human body

Parasites in the human body

Parasites in the human body can appear completely unexpectedly. The reason for this is usually direct contact with the source of infection, for example, an infected person or object. There are many types of parasites that can settle in the human body: these can be giardia, pinworms, alveococci, trichinella, schistosomes, etc. In the next article you will learn in detail about the creatures that parasitize in the human body, as well as the most effective ways to fight with them.

Parasites in the human body

The human body has a very complex structure, which is susceptible to various diseases and infections, infections, viruses and parasites. Parasites that settle in the human body are microorganisms that lead a parasitic lifestyle, trying to survive by feeding on other organisms, microorganisms, cells, etc.

Parasites that find fertile ground for life and reproduction in the human body, cause very serious damage, sometimes irreparable to their health, destroy the body inside, eat and sometimes lead to human death, or interrupt the functioningof individual organs, which also worsens the quality and life of a depressing person and, in the end, shortens his life. In nature, there are millions of species of parasitic worms. Of these, there are those who parasitize only one representative of the animal world. But in nature there are also species that can exist in the body of several species of animals. Which parasites live in the human body is a question that many people ask.

A wide variety of helminth species can live in the human body. Some of them are very rare, while others are often installed internally and can lead a parasitic lifestyle for up to several decades.

Varieties of parasitism

There are the following types of parasitism: ectoparasitism - parasites that lead a superficial lifestyle in the human body. This category includes lice, insects, ticks; endoparasitism - parasites that affect a person's internal organs. They, in turn, are divided into two large groups, the simplest organisms and the helminths.

Types of parasitic protozoa: lamblia, toxoplasma, trichomonas. These types of parasitic protozoa are most commonly found in the human body.

The classification of parasites related to helminths implies their division into three major groups: nematodes, trematodes, cestodes.

Types of parasites in the human body


Pinworms are the most well-known parasites in the intestines. The disease caused by worms is called enterobiasis. Not only do people suffer from it, but so do great apes. Children are at increased risk of moth infection. According to various sources, the level of their involvement in enterobiasis at preschool age ranges from 25 to 90%. Pinworms are passed from one person to another. The infection occurs through handshake, clothes and any objects touched by a patient, provided that after contact the hands have not been washed and the moth's eggs enter the mouth (this happens mainly during meals).

Flies and cockroaches can carry the eggs of these nematode worms by sowing their food. Pinworms live in the small intestine, the cecum, the colon. They mate in the ileum, after which the female crawls out of the anus through the rectum and lays eggs in the anus. The symptoms of enterobiasis are itching in the anal area, intoxication of the body (allergic reactions, exhaustion, fatigue), anemia, increased level of eosinophils in the blood, insomnia, abdominal pain.

To get rid of enterobiasis, anthelmintic drugs are used. The dosage and course of treatment are selected by the doctor. To avoid reinfection, it is important to keep your hands clean, wash them after visiting any public place, after using the bathroom, before eating, etc.

Nails should be cut short, bedding and underwear must be thoroughly disinfected and the apartment cleaned daily.


Toxocara is a parasite in the nematode group. The disease caused by toxocaras is called "toxocariasis". This invasion in humans can be larval (ocular and visceral), as well as intestinal. The disease is widespread worldwide. Toxocara infection occurs when worm eggs enter the human digestive tract. This is most commonly seen when eating food or water contaminated with dog feces. Contact with sick animals is no less dangerous.

Natural carriers of Toxocara are cats and dogs, foxes and wolves. Once in the human body, the larva of the worm migrates through the blood vessels and can settle in any organ. The symptoms of the disease will depend on it. Most of the time, toxocariasis manifests itself in the form of allergic reactions (Quincke's edema, skin rash, bronchial asthma). During an exacerbation of the disease, an increase in body temperature of up to 38 degrees is possible, but symptoms of body poisoning are mild.

Toxocariasis can be suspected by enlarged lymph nodes: the visceral form of toxocariasis is the most common, occurs with damage to internal organs (intestines, respiratory system, heart valves).

A person may experience pain in the abdomen, in the right hypochondrium, dyspeptic disorders, nausea; if the respiratory system is damaged, a person has shortness of breath, a dry cough, choking attacks; if toxocars are installed in the heart valves, the patient has weakness, blue fingers and nasolabial triangle, shortness of breath; the cutaneous form is characterized by itching, a sensation of movement under the skin, inflammation of the skin and mucous membranes; in the neurological form, the parasite causes the development of inflammation of the meninges and the brain tissues themselves.

It manifests itself in headaches, nausea and vomiting, seizures and other neurological disorders. For the treatment of toxocariasis, anthelmintic drugs, pathogenic and symptomatic therapy are used.

Human Ascaris

Human Ascaris are a roundworm that parasites the small intestine. The disease that these parasites cause is called ascariasis. The owner of the roundworm and the source of infection is a sick person. Along with their feces, the worms' eggs enter the soil, where they ripen and turn into larvae. Then, this soil is transferred to food or to human hands, and in case of non-compliance with the rules of personal hygiene and poor processing of fruits, vegetables and berries - in the digestive tract.

Children and rural residents are more susceptible to infection. Ascariasis manifests itself in different stages of its development in different ways. In the phase of larvae migration through the body, an increase in body temperature occurs, a dry cough appears, wheezing in the lungs and the lymph nodes increase in size. Children suffer from ascariasis more severely than adults. Allergic skin reactions are a characteristic symptom of ascariasis. During parasitism in the intestines, the patient develops dyspeptic disorders, loose stools are replaced by constipation, frequent abdominal pain, nausea and vomiting occur. On the part of the nervous system, hysterical attacks, insomnia, mental fatigue and headaches are observed.

Hookworm and nekator

Hookworm and nekator are two types of roundworms that belong to the Ancylostomatidae family and cause a disease called hookworm. There are two ways to infect the human body with these parasites - fecal-oral (drinking contaminated water, fruits, vegetables) and percutaneous in contact with the soil (penetration occurs through the skin).

Clinical symptoms of ankylostomiasis: papulo-vesicular rash, shortness of breath and cough, loss of appetite, nausea, abdominal pain, soft stools, iron deficiency anemia. Treatment consists of taking anthelmintic drugs and eliminating anemia with iron preparations.

Wide ribbon

The broad tapeworm belongs to the tapeworms of the order Pseudophyilidea. These parasites live in the small intestine of humans and mammals that consume fish. Infection with a tapeworm causes the development of a disease such as diphyllobotriasis.

There are 12 types of tapeworms that can parasitize the human body; however, the broadest tapeworm is the most common. The infection occurs when caviar or raw and unprocessed fish with salt, which contains worm eggs, is eaten. Symptoms of the presence of the parasite in the intestines: nausea, abdominal pain, anemia.

In severe cases, intestinal obstruction occurs. To get rid of the parasite, patients receive anthelmintic drugs. Upon completion of the therapeutic course, a re-examination is mandatory for the presence of a worm in the body. Repeat anthelmintic drugs if necessary.

Bull tapeworm

The bovine tapeworm is a tapeworm that belongs to the teniid family. In the larval phase, it affects cattle and, in the tapeworm phase, it lives in the human body (in the intestines). The tapeworm causes a disease called teniarinhoz, as a rule there is a parasite in the patient's body. Human infection occurs through food after ingestion of badly treated meat (bovine).

Clinically, the disease is manifested by nausea, excessive appetite, abdominal pain, unstable stools and allergic reactions such as hives. To remove bovine tapeworm from the body, an anthelmintic medication is prescribed. In parallel, the patient must adhere to a slag-free diet, cleansing enemas, taking laxatives. After using an anthelmintic agent, the worm dies and leaves the human body naturally. Sometimes its length can be up to 12 m.

Pork tapeworm

The swine tapeworm is a parasitic tapeworm that infects mammals. Intermediate carriers may be pigs, dogs, rabbits, camels, but the final owner is always a man. If an adult parasite is found in a person's body, they speak of a disease like teniasis. When the parasite is in the patient's body in the larval stage, the disease is called "cysticercosis".

The tapeworm infection of pork occurs when eating raw pork. Sometimes the sources of cysticercin are by sowing hands or water. A patient with teniosis poses an epidemiological danger to himself (infection with larvae of the brain, skin, eyes or skeletal muscles) and to others.

Symptoms of teniasis: abdominal pain, loss of appetite, irritated stools, headaches, frequent dizziness, fainting (teniasis of the brain and eyes is extremely dangerous). For the treatment of teniasis, the patient is admitted to a hospital. Under the supervision of doctors, anthelmintic drugs are prescribed, after which, after 2 hours, the patient starts to take a saline laxative, which allows to get rid of the worm segments and eggs. Surgery is necessary to treat cysticercosis of the eyes and brain.


Echinococcus is a tapeworm in the order Cyclophyllidae. Adults parasitize the intestines of dogs and cats and are found in jackals and wolves. For humans, parasite larvae are dangerous and can cause a serious disease - echinococcosis. Larvae can infect human internal organs, forming echinococcal cysts in them. For echinococci, humans act as intermediate hosts.

The infection is carried out by contact (in the process of cutting carcasses, when interacting with a sick animal), or food (when using contaminated food or water). At risk are people who are dedicated to raising animals or who have constant contact with animals. Symptoms may not appear for many years. When the asymptomatic stage ends, there is pain, itching of the skin at the place where the larva is introduced and hives are possible. In addition, the functioning of the organ within which the parasitic echinococcus larva is impaired. An increase in body temperature and fever are observed during suppuration of the cyst.

Complete healing of echinococcosis is only possible by surgery. The cyst is peeled, being careful not to damage its membrane. If the bladder is too large, it is punctured and the contents sucked. Before and after the operation, antiparasitic drugs are prescribed to the patient. In the case of radical cyst removal, the prognosis for recovery is favorable.


Alveococcus is a helminth of the cestoid group. The worm has a fatal disease of alveococcosis, characterized by the formation of a primary focus in the liver with the subsequent spread of metastases to other organs. Infection occurs when the parasite's oncospheres enter the mouth.

This can occur during hunting, in the process of cutting wild carcasses, in contact with domestic animals or when eating unprocessed wild fruits and forest herbs. Symptoms of alveococcosis are reduced to pain in the right hypochondrium, belching, nausea. Often, there is itchy, allergic reactions. Suppuration of a tumor with a parasite and its penetration into the abdominal or pleural cavity is not excluded.

Alveococcal metastases can be found in the brain and lungs. The treatment of the disease is immediate, but must be supplemented with antiparasitic drugs.


Giardia (another name for Giardia) is a flagellated parasite belonging to the order Diplomonadida. Giardia causes a disease called "giardiasis" and parasites the small intestine of humans, as well as many other mammals and even birds.

Lamblia infection occurs via the fecal-oral route: food, water and household contact methods. Of greatest importance in terms of transmission of infection is the use of raw water, contaminated food, the use of public items sown with lamblia cysts. The main symptoms of giardiasis are nausea, abdominal pain, stool disorders and excessive gas.

In addition, patients suffer from allergic reactions, intoxication and neurotic disorders. Giardiasis therapy is performed with the help of antiprotozoa, as well as with the inclusion of enzymes, choleretic and enterosorbent agents in the treatment regimen.

Histological amoeba

Histological amoeba is a protozoan parasite that causes a disease called amoebiasis. The disease is manifested by the formation of ulcers in the large intestine, followed by lesions in other internal organs. Amoeba infection occurs via the fecal-oral route, after mature water or food cysts enter the human gastrointestinal tract. Possible transmission of parasites by contact through dirty hands. Flies can transmit amoebas.

Another way to spread amoebiasis is through sex (anal intercourse). Symptoms of amebiasis: feces with abundant mucus, abdominal pain, blood in the stools, weight loss, anemia. In addition, extraintestinal amebiasis is characterized by the formation of abscesses in the organs affected by parasites (lungs, brain, liver, etc. ). For the treatment of intestinal amebiasis, antiparasitic drugs are prescribed.

The duration of therapy is determined by the severity of the course of the amoebiasis.


A disease called gnatostomosis is caused by mature larvae and nematodes Gnathostoma spinigerum. The infection occurs by eating unprocessed fish, frog or bird meat, as well as by drinking unboiled and uninfected water. The symptoms of the disease are manifested by coughing and pain at the place where the larva penetrates under the skin, local inflammation and increased body temperature.

Intense edema and itching are typical. As a rule, after a week of symptom manifestation, they disappear, but reappear over many years. Dangerous damage to the eyeball and brain often ends in death. Treatment involves the use of anthelmintic drugs and surgery. During the operation, the parasites are removed from the skin.


Trichinae are round parasitic worms that, in the larval phase, live in the muscles (oculomotor, masticatory muscles, diaphragm) and in adulthood - in the lumen of the small intestine. The disease caused by Trichinella is called "Trichinosis". It's deadly.

Human infection occurs through the consumption of raw or poorly processed meat from wild and domestic animals. Symptoms include loss of appetite, vomiting, diarrhea and abdominal pain. In the future, muscle pain, swelling of the eyelids and rashes appear. The treatment of parasitic infestation is carried out with the help of anthelmintic drugs. Antihistamines are prescribed at the same time and corticosteroids are prescribed as needed.


Schistosomes are worms of the trematode genus. They cause a disease called schistosomiasis. Human infection occurs during bathing, in the process of washing clothes or watering the soil with schistosomiasis larvae. They are able to penetrate the human body even through intact skin and mucous membranes. Symptoms in the acute phase of the disease are manifested by an increase in temperature to high levels, itchy skin and the appearance of papules throughout the body.

After the disease becomes chronic, the infected person may show signs of colitis, prostatitis, colitis, ascites, hydronephrosis, etc. Anthelmintic drugs are used to treat the disease. Surgical intervention is necessary for complications of genitourinary schistosomiasis.

There are many parasites that can harm the human body. Most of them enter their owner's body through the gastrointestinal tract if safe cooking technology is not followed and basic hygiene procedures are not followed.

Adaptive properties of parasites

  • long life expectancy (helminths live in the human body for years, and sometimes while the parasite's host lives);
  • the ability to suppress or modify the immune response of the host organism (an immunodeficiency state arises, conditions are created for the penetration of pathogens from outside, as well as for the "disinhibition" of internal foci of infection);
  • many types of helminths, entering the digestive tract, release anti-enzymes, which save them from death; the digestion process is interrupted, toxic allergic reactions of various severities appear: urticaria, bronchial asthma, atopic dermatitis;
  • stages of development (egg, larva, change of hosts);
  • ability of eggs to survive for years in the external environment;
  • sexual reproduction, in which genetic information is exchanged, and this is already the highest stage of development, leading to an increase in the heterogeneous population, that is, the parasites are less vulnerable;
  • lack of immunoprophylaxis methods, as the immune response is weak and unstable;
  • disseminated helminths, many habitats (water, soil, air, plants and animals).

Preventing parasites in the body

Preventive measures to prevent parasite infestation must be comprehensive. First of all, it is necessary to follow the basic rules of personal hygiene, eat only washed fruits and vegetables, as well as heat-treated fish and meats, and drink only clean water. Most experts advocate the prevention of helminthiasis with pharmaceutical antiparasitic drugs - a parasitologist will help you choose the necessary medicine and correctly calculate your dosage.

You can complement this therapy with folk remedies that have anthelmintic effect - for example, eat more onions, garlic, various spices, regularly eat pumpkin seeds.