Human parasites are represented by different groups, one of which is the protozoan. They can cause diseases of varying severity and diagnosing these microorganisms is not as easy as groups with more complex organization. For convenience, in the article they are presented in the table with the main features.
Characteristic
The simplest includes organisms of primitive organization, united in a tile of protozoa. 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 be seen only under a microscope, and it is impossible to see them with the naked eye.
Many of the simplest parasites have an extremely primitive structure. Once in the host's body, they begin to multiply. Sometimes this happens by dividing it into two parts, sometimes by multiple divisions. In the latter case the disease progresses rapidly, the symptoms appear rapidly, sometimes it can eventually even lead to the death of the person.
Peculiarities of biology
The organism of protozoan human parasites consists of two main parts: the nucleus and the cytoplasm, in which all other organs are located. The core can be one or more.
Protozoa have the ability to form cysts if environmental conditions become unfavorable. Because of this, they can remain viable for a long time, remain immobile, and act without nutrients. As soon as the conditions return to normal, the cyst membrane is destroyed and the microorganism continues to function normally. Incest also allows parasites to successfully spread from organism to organism.
All protozoa are divided into several categories according to anatomy, mode of movement and other characteristics:
- ფლაგელა;
- Sarkod
- Sporozoites
- Celitis.
In each group there are species whose intermediate or final host is human.
Basic types
Protozoan-type parasites cause many diseases and parasitize various organs. For convenience, they are given in the table.
| Name | Infected parts of the body | Method of infection | Symptoms |
|---|---|---|---|
| Balantidia | Lower intestines | Eat boiled pork or water cysts | Balantidiasis is often accompanied by diarrhea. White mucus and bloody discharge appear in the stool. The mucous membrane of the large intestine becomes inflamed and in such cases the bleeding may increase. With the progression of the disease occurs human fatigue, in rare cases can lead to death. |
| Ameba mouth | Mouth cavity, gum pockets, dental plaque | A person becomes infected by carrier kissing, using dirty dishes, and eating contaminated food. | It rarely occurs in people who do not have abnormal lesions in the oral cavity. During inflammation, the oral cavity is nourished by epithelium, microbes, leukocytes, and erythrocyte cells. Can cause periodontal disease. |
| Dysenteric Ameba | Through the blood vessels it reaches the lungs, liver, heart, genitals, kidneys. Terminates in the intestinal lumen | Take with food or water | In some cases, the disease is asymptomatic. If dysentery Ameba attacks the intestinal wall, then the pathogenic stage begins. Characterized by colitis, tissue necrosis, liver damage, abscesses may appear. Very severe consequences cause metastases to the brain and other organs. Possible fatal outcome. Sometimes the disease takes a course of relapse. Self-healing rarely occurs |
| Intestinal giardiasis | Duodenum and bile ducts. | Oral route | Giardia attaches to the mucous epithelium and impairs the absorption of nutrients. Inflammation of the mucous membrane and persistent diarrhea develop. If the infection covers the bile ducts, jaundice of the skin occurs. Some people develop immunity to intestinal obstruction, especially in countries with tropical climates. |
| Trichomonas vaginal | In women - on the vaginal mucosa, in men - in the prostate epidermis and urethra. | During sexual intercourse, as well as during childbirth from mother to child | Trichomoniasis is manifested by foamy discharge, itching and burning of the genital mucosa, pain during sex, the appearance of bloody discharge from the urethra, and so on. Sh. Complications of trichomoniasis include inflammation of the vulva with protozoan activity, cystitis, prostatitis, and infertility |
| Trypanosoma Bruce | Cerebrospinal fluid and brain | After biting a tsetse fly, which is an intermediate host | It starts with fever and swollen lymph nodes, continues with apathy, insatiable desire for sleep, muscle paralysis and fatigue. If left untreated, coma and death occur. |
| Skin leishmaniasis | Contact with a sick person or animal | On the skin, most often on the face or hands | The incubation period lasts from 2 months to 5 years, after which a brown dense nodule appears at the site of the insect bite. Grows, and then a purulent ulcer opens in its place. The disease lasts for several years and then becomes the final scar of the wounds. Complications can be disorders of the heart, kidneys, and adrenal glands. |
| Toxoplasma | Infected pets, mostly cats, sometimes become infected while eating protozoa | Liver, heart, eyes, brain | In congenital form - multiple pathologies of fetal development, death in infants, mental retardation, multiple infections. Acquired toxoplasmosis causes high fever, enlarged liver, headache, vomiting, convulsions. Often takes a chronic course with increased fatigue and eye damage. Rarely found in latent form |
| Isospora | From an infected person with fecal-oral transmission | Small intestinal epithelium | The incubation period lasts about 10 days. Then the body temperature rises, vomiting and diarrhea occur. The disease is acute for a week or two, then recovery occurs |
| Crypto sporadia | Oral route | Intestinal epithelial tissues | Incubation lasts about a week, then diarrhea begins, possibly involving spots. Stomach may ache, fever may appear, signs of dehydration are possible. With a patient with an insufficient immune status, the infection can affect other organs: lungs, pancreas, stomach, etc. Sh. |
Worms are the simplest
Sometimes you may hear the phrase that a patient is infected with the simplest worms. It must be understood that protozoa are exclusively cellular microorganisms, in extreme cases, organizing colonies. But 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 much more complicated: they have differentiated organs that perform special physiological functions. Therefore, classifying worms as protozoa is fundamentally incorrect.
Helminths are sometimes called the simplest parasites compared to insects: flies, lizards, etc. Sh. , Since the latter stands much higher than the evolutionary ladder. In this interpretation, the name worms is allowed as a protozoan.