Human parasites are represented by different groups, one of which is protozoa. They are capable of causing diseases of varying severity, and diagnosing these microorganisms is not as easy as groups with more complex organizations. For this, in the article they are presented in a table with main characteristics.
Speciality
The simplest include organisms with a primitive organization, which are combined in the Protozoa phylum. It has more than 15 thousand species, and some of them lead a parasitic lifestyle in the human body. All of them are characterized by small size, they can only be seen with a microscope, and it is impossible to notice them with the naked eye.
Many simple parasites have an extremely primitive structure. Once in the host's body, they begin to multiply. Sometimes it splits into two, and sometimes splits into severalIn the latter case, the disease develops rapidly, symptoms appear quickly, sometimes eventually being able to cause the death of a person.
features of biology
The organism of protozoan human parasites consists of two main parts: the nucleus and the cytoplasm, in which all other organelles are located. The core may be one or more.
Protozoa have the ability to form cysts when environmental conditions are unfavourable. Because of this, they are able to remain viable for long periods of time, remain immobile and function without nutrients. As soon as conditions return to normal, The cyst shell is destroyed, and the microorganism continues its normal function. Enssistion also allows parasites to spread successfully from organism to organism.
All protozoa are divided into several categories based on anatomy, mode of movement and other characteristics:
- flagellum;
- Sarcode
- sporozoans
- ciliates
Within each group, there are species for which humans are the intermediate or definitive hosts.
main types
Protozoan types of parasites cause many diseases and are parasitized in different organs. For convenience, they are presented in the table.
| Name | infected body parts | mode of transmission | Symptom |
|---|---|---|---|
| balantidia | lower intestine | eating uncooked pork or cysts | Balantidiasis is often accompanied by diarrhea. White mucus and bloody discharge appear in the stool. The colonic mucosa ulcerates, and in such cases bleeding may increase. With the progression of the disease, the person experiences exhaustion, in rare cases thismay cause death. |
| mouth amoeba | oral cavity, gingival pocket, dental plaque | A person becomes infected by kissing a carrier, using dirty utensils, and eating contaminated food. | It rarely affects people who do not have pathological lesions in the oral cavity. In inflammation, the oral amoeba feeds on epithelium, microbes, leukocytes and erythrocyte cells. May cause periodontal disease. |
| dysentery amoeba | Through the bloodstream it enters the lungs, liver, heart, genitals, kidneys. settles in the intestinal lumen | ingestion with food or water | In some cases, the disease is asymptomatic. If dysenteric amoeba invades the intestinal walls, the pathogenic stage begins. It is characterized by colitis, tissue necrosis, liver damage, abscesses. Very serious consequences are metastases to the brain and other organs. Potentially fatal outcome. Sometimes the disease takes a recurrent course. Rarely there is self-healing |
| Intestinal Giardia | Duodenum and bile ducts. | oral route | Giardia sticks 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, a yellowing of the skin appears. Some people develop intestinal giardia. develop immunity, especially in countries with tropical climates. |
| trichomonas vaginalis | in women - on the vaginal mucosa, in men - in the epidermis of the prostate and in the urethra | during sexual intercourse, as well as during childbirth from mother to child | Trichomoniasis is manifested by foamy discharge, itching and burning on the mucous membranes of the genital organs, pain during sex, the appearance of bloody discharge from the urethra, etc. A complication of trichomoniasis is inflammation of the vulva due to protozoan activity, leading to cystitis, prostatitis and infertility. |
| Trypanosoma brucei | cerebrospinal fluid and brain | After being bitten by a disturbed fly, which is an intermediate host | Begins with fever and swelling of lymph nodes, continues with somnolence, an insatiable urge to sleep, muscle paralysis and exhaustion. If left untreated, coma and death result. |
| cutaneous leishmania | contact with a sick person or animal | on the skin, often on the face or hands | The incubation period lasts from 2 months to 5 years, after which a brown dense lump appears at the site of the insect bite. It enlarges, and then a purulent ulcer opens in its place. Disease for several yearsLasts, and then the final scarring of lesions. Complications can be disorders of the heart, kidneys and adrenal glands. |
| toxoplasma | Infected domestic animals, mainly cats, sometimes become infected by feeding on protozoa | liver, heart, eyes, brain | In congenital form - multiple pathologies of fetal development, death in infancy, mental retardation, multiple infections. Acquired toxoplasmosis provokes high fever, enlarged liver, headache, vomiting, convulsions. Often a chronic course with fatigue and eye damageTakes. Rarely Occurs in a Covert Form |
| isospora | from an infected person with fecal-oral transmission | small intestine epithelium | The incubation period lasts about 10 days. Then the body temperature rises, vomiting and diarrhea appear. The disease is acute for a week or two, then recovery occurs |
| crypto sporidia | oral route | epithelial tissue of the intestine | Incubation lasts about a week, then diarrhea begins, possibly with the inclusion of spotting. There may be abdominal pain, fever, signs of dehydration. With an insufficient immune status of the patient, The infection can affect other organs: lungs, pancreas, stomach, etc. |
what insects are the simplest
Sometimes you can hear the phrase that the patient is infected with the simplest worms. It should be understood that protozoa are exclusively unicellular microorganisms, in extreme cases, organize colonies. But they are never multicellular like worms and wormsThere are.
In protozoa, all processes take place within the cytoplasm and cell nucleus, whereas in worms, the physiological organization is much more complex: they have differentiated organelles that perform specialized physiological functions. Hence, classifying worms as protozoais fundamentally wrong.
Sometimes helminths are called the simplest parasites in comparison with insects: bedbugs, lice, etc. , because the latter are very high on the evolutionary ladder. In this interpretation, the name of worms is accepted as protozoa.