Human parasites are represented by different groups, one of which is the protozoa. They can cause diseases of varying severity, and it is not easy to diagnose them as groups with a more complex organization of these microorganisms. For convenience, in the article they are presented in a table with the main features.
Characteristic
The simplest include organisms with a primitive organization that combine in the Protozoa phylum. There are more than 15, 000 species, some of which live a parasitic lifestyle in the human body. All of them are characterized by small size, they can be seen only with a microscope and can not be seen with the naked eye.
Many of the simplest parasites have an extremely primitive structure. They begin to multiply after entering the body of the host. Sometimes this happens by splitting it in half, and sometimes by splitting it in half. In the latter case, the disease progresses rapidly, the symptoms appear quickly, and sometimes can even lead to the death of a person.
Features of biology
The body of protozoa human parasites consists of two main parts: the nucleus and the cytoplasm, where all other organelles are located. The key can be one or more.
Protozoa have the ability to form cysts when environmental conditions are unfavorable. Therefore, they can survive for a long time, remain motionless and live without nutrients. As soon as the condition returns to normal, the cyst crust is destroyed and the microorganism continues to function normally. Ensisting also allows parasites to spread successfully from body to body.
All protozoa are divided into several categories according to anatomy, mode of movement and other features:
- flagella;
- sarkod
- sporozoles
- eyelashes.
In each group, there are species in which people are intermediate or definitive hosts.
The main types
Protozoa-type parasites cause many diseases and parasitize various organs. For convenience, they are presented in the table.
| ad | Infected body parts | Method of infection | Symptoms |
|---|---|---|---|
| Balantidiya | lower intestines | Eat uncooked pork or water with cysts | Balantidiasis is often accompanied by diarrhea. White mucus and bloody discharge are seen in the stool. Ulcers form in the mucous membrane of the large intestine, and in such cases, bleeding may increase. With the development of the disease, a person becomes depleted, and in rare cases can result in death. |
| mouth amoeba | Oral cavity, gingival pockets, dental plaque | A person is infected by kissing a carrier, using dirty dishes, and eating contaminated food. | Rarely affects people without pathological lesions in the oral cavity. During inflammation, oral amoebae feed on epithelium, microbes, leukocytes, and erythrocytes. May cause periodontal disease. |
| dysenteric amoeba | It penetrates the bloodstream into the lungs, liver, heart, genitals and kidneys. Located in the lumen of the intestine | Setting with food or water | In some cases, the disease is asymptomatic. If the dysenteric amoeba attacks the intestinal walls, the pathogenic stage begins. Colitis is characterized by tissue necrosis, liver damage, abscesses may appear. Very serious consequences cause metastases to the brain and other organs. Possible fatal outcome. Sometimes the disease takes a recurrent course. Rarely, self-healing occurs |
| Intestinal Giardia | Duodenum and bile ducts. | oral route | Giardia adheres to the mucous epithelium and impairs the absorption of nutrients. Inflammation of the mucosa and persistent diarrhea develop. If the infection covers the bile ducts, jaundice appears. Some people develop immunity to intestinal giardiasis, especially in countries with tropical climates. |
| Trichomonas vaginalis | In women - in the vaginal mucosa, in men - in the epidermis of the prostate and urethra. | During sexual intercourse, as well as during childbirth | Trichomoniasis manifests itself as foamy discharge, itching and burning in the mucous membranes of the genitals, pain during sexual intercourse, the appearance of bloody discharge from the urinary tract, etc. is expressed by. cystitis, prostatitis and infertility |
| Trypanosoma brussei | Cerebrospinal fluid and brain | After being bitten by an intermediate host Chechen fly | It begins with fever and swelling of the lymph nodes, followed by apathy, irresistible desire to sleep, muscle paralysis and exhaustion. If left untreated, coma and death can occur. |
| Skin leishmaniasis | Contact a sick person or animal | On the skin, mostly on the face or hands | The incubation period lasts from 2 months to 5 years, after which a dense brown nodule appears at the site of the insect bite. It grows, then a purulent ulcer opens in its place. The disease lasts for several years, and then the final scarring of the wounds occurs. Complications can be disorders of the heart, kidneys and adrenal glands. |
| Toxoplasmosis | Infection occurs when infected pets, especially cats, eat protozoa | Liver, heart, eyes, brain | In the congenital form - numerous pathologies of fetal development, infant mortality, mental retardation, numerous infections. Acquired toxoplasmosis causes high fever, enlarged liver, headache, vomiting, and convulsions. Often takes a chronic course with increased fatigue and eye injury. Rarely occurs in secret |
| Isospore | From a person infected with fecal-oral transmission | epithelium of the small intestine | The incubation period lasts about 10 days. Then the body temperature rises, vomiting and diarrhea appear. The disease worsens within a week or two, and then recovery occurs |
| Crypto sporidia | oral route | Intestinal epithelial tissues | The incubation lasts about a week, after which diarrhea probably begins with the entry of spots. Stomach pain, fever may appear, signs of dehydration are possible. With an insufficient immune status of the patient, the infection can affect other organs: the lungs, pancreas, stomach, etc. |
Worms are the simplest
Sometimes you can hear the patient say that he is infected with the simplest worms. It should be noted that protozoa are only single-celled microorganisms that, in extreme cases, form colonies. However, they are never as multicellular as worms and helminths.
In protozoa, all processes take place in the cell cytoplasm and cell nuclei, while in worms the anatomical organization is more complex: they have differential organs that perform special physiological functions. Therefore, it is fundamentally wrong to classify worms as protozoa.
Helminths are sometimes called the simplest parasites compared to insects: bedbugs, lice, etc. , because the latter are higher on the evolution ladder. In this interpretation, the name of the worms is allowed as protozoa.