Human parasites are represented by different groups, one of which is protozoa. They are capable of causing disease of varying severity, and these microbes are not as easily diagnosed as populations with more complex tissues. For convenience, in this paper, they are presented in tabular form with the main characteristics.
feature
The simplest includes organisms with primitive tissues, which are grouped into phyla protozoa. It has more than 15, 000 species, some of which live parasitic lifestyles inside the human body. They are all characterized by their small size, which can only be seen with a microscope, and is impossible to notice with the naked eye.
Many of the simplest parasites have extremely primitive structures. Once inside the host, they begin to reproduce. Sometimes this happens by splitting in half, sometimes it happens by multiple splitting. In the latter case, the disease progresses rapidly, symptoms appear quickly, and sometimes eventually lead to death.
characteristics of biology
The organism of a protozoan human parasite consists of two main parts: the nucleus and the cytoplasm, in which all other organelles are located. Cores can be one or more.
Protozoa have the ability to form cysts if environmental conditions become unfavorable. Because of this, they are able to stay alive for long periods of time, motionless and without nourishment. Once conditions return to normal, the cystic shell is destroyed and the microbe continues its normal function. Encapsulation also allows parasites to successfully transmit from one organism to another.
All protozoa are divided into several groups based on anatomy, locomotion, and other characteristics:
- flagellum;
- code
- Sporozoites
- Ciliates.
Within each group, there are species in which humans are the intermediate or final host.
main type
Parasites of the protozoan type cause many diseases and inhabit different organs. For convenience, they are listed in a table.
| name | Infected body part | Infection mode | symptom |
|---|---|---|---|
| Barantidia | lower intestine | eating raw pork or water with cysts | Balanitis is usually accompanied by diarrhea. White mucus and bloody discharge appear in the stool. Ulceration of the colonic mucosa, in which case bleeding may increase. As the disease progresses, a person develops exhaustion, which in rare cases can lead to death. |
| Mouth Amoeba | Mouth, gingival pockets, plaque | A person becomes infected by kissing a carrier, using dirty dishes, and eating contaminated food. | It rarely affects people without pathological lesions in the mouth. In inflammation, oral amoeba feeds on the epithelium, microbes, white blood cells, and red blood cells. May cause periodontal disease. |
| dysentery amoeba | Through the blood, it penetrates to the lungs, liver, heart, genitals, kidneys. settle in the intestinal lumen | Take with food or water | In some cases, the disease is asymptomatic. The pathogenic phase begins if the dysentery amoeba attacks the intestinal wall. It is characterized by colitis, tissue necrosis, liver damage, and may develop abscesses. Very serious consequences can lead to metastases in the brain and other organs. Possibly fatal outcome. Sometimes the disease recurs. Self-healing rarely occurs |
| Giardia intestinalis | Duodenum and bile ducts. | Oral route | Giardia sticks to the mucous epithelium, disrupting nutrient absorption. Mucosal inflammation and persistent diarrhea develop. If the infection covers the bile ducts, yellowing of the skin occurs. Some people develop immunity to intestinal Giardia, especially in countries with tropical climates. |
| Trichomonas vaginalis | Women - vaginal mucosa, men - prostate epidermis and urethra | During sexual intercourse, and during childbirth from mother to child | Trichomoniasis manifests as foamy discharge, itching and burning of the mucous membranes of the genital organs, pain during intercourse, and bloody discharge from the urethra. Complications of trichomoniasis are inflammation of the vulva, cystitis, prostatitis and infertility due to protozoan activity |
| Trypanosoma brucei | Cerebrospinal fluid and brain | After being bitten by the intermediate host tsetse fly | It starts with fever and swollen lymph nodes, then apathy, an irresistible urge to sleep, muscle paralysis and exhaustion. If left untreated, coma and death can occur. |
| Cutaneous Leishmania | contact with sick people or animals | On the skin, most commonly on the face or hands | The incubation period is 2 months to 5 years, after which brown dense nodules appear at the site of the insect bite. It increases, followed by a purulent ulcer in its place. The disease persists for several years, and then the wound develops the final scarring. Complications may be diseases of the heart, kidneys, and adrenal glands. |
| Toxoplasma gondii | Infected domestic animals, mainly cats, sometimes become infected when eating food with protozoa | liver, heart, eyes, brain | Congenital - multiple pathologies of fetal development, death in infancy, mental retardation, multiple infections. Acquired toxoplasmosis causes high fever, hepatomegaly, headache, vomiting, and convulsions. A chronic course of increased fatigue and eye damage often occurs. rarely in latent form |
| Isosporium | Infected from fecal-oral transmission | Small intestinal epithelium | The incubation period lasts about 10 days. Then the body temperature rises, and vomiting and diarrhea occur. Acute onset of illness for one to two weeks, then recovery |
| Cryptosporidium | Oral route | intestinal epithelium | Incubation lasts for about a week before diarrhea begins, possibly with spots. The stomach may be injured, a fever may appear, and signs of dehydration are possible. Since the immune status of the patient is insufficient, the infection can affect other organs: lungs, pancreas, stomach, etc. |
Worms are the easiest
Sometimes you can hear phrases that patients are infected with the simplest of worms. It must be understood that protozoa are entirely unicellular microorganisms that, in extreme cases, organize colonies. But they are by no means as multicellular as worms and worms.
In protozoa, all processes take place in the cytoplasm and nucleus, while in worms, the anatomical tissues are much more complex: they have differentiated organs that perform specialized physiological functions. Therefore, classifying worms as protozoa is fundamentally wrong.
Compared to insects, worms are sometimes called the simplest parasites: bed bugs, lice, etc. , because the latter are much higher up the evolutionary ladder. In this interpretation, the name worm is allowed as a protozoan.