The simplest parasite is an organism that is adapted to invade and live in the cells and tissues of other organisms. The simplest parasites cannot live alone in an open environment like other protozoa, but must invade the body of another organism to receive protection and nourishment.
The simplest parasites and their varieties
The simplest organisms are eukaryotic systems that exist as structurally and functionally independent individual cells (including those species that are herd or form colonies). Protozoa develop relatively complex subcellular features (membranes and organelles) that allow them to survive in harsh environmental conditions. Most protozoa are microscopic organisms, and only a few grow large enough to be visible to the naked eye. Like unicellular eukaryotes, they move to survive, feed, and reproduce.
There are some of the simplest parasites that cause problems. They are present in our food, soil and water and can make us very ill if they ever enter us.
Each different protozoan parasite can cause different diseases in our body. Some of them can cause serious diseases of the respiratory tract (passage of air from the nose to the lungs) and the central nervous system (brain, cranial nerves and spinal cord), while others live in the intestines, causing symptoms such as diarrhea and are not fatal.
There are four types of protozoan parasites that are classified according to the way they move:
- sarcoids are a group of amoebae that move with the help of pseudopods and contractions that change the shape of their cells;
- mastigophores move with the help of flagella;
- siliophores use lashes;
- sporozoites are immobile when mature.
Life cycle of parasites from protozoa
Most protozoa have enormous reproductive potential because they have a short generation time, undergo rapid successive development, and produce large numbers of offspring asexually or sexually. These characteristics are responsible for many of the simplest infections, causing acute symptoms of the disease quickly.
The stages of development of protozoan parasites that occur in the host usually consist of feeding on trophozoites and can be found intracellularly (in host cells) or extracellularly (in hollow organs, body fluids, or internodes between cells). Although trophozoites are ideal for their parasitic way of life, they are not very resistant to external environmental conditions and do not survive long outside their hosts. To move from host to host, protozoan parasites use one of four main modes of transmission: direct, fecal-oral, transmissible, and predator-to-prey.
Ways of transmitting protozoan parasites to humans
- Direct transmission of parasites through intimate contact with the body - sexually (for example, Trichomonas is a fungus that causes trichomoniasis in humans).
- Faecal-oral transmission of ecologically stable stages of cysts - parasites pass into the faeces of one host and are transmitted by food or water to another (eg Entamoeba histolytica, Giardia duodenalis and Balantidium coli are all forms of fecal cysts that lead to amoebic dysentery, giardiasis and balantidiosis).
- Transmission occurs when parasites are ingested by blood-sucking arthropods (insects or arachnids) and transmitted to new hosts by biting (e. g. , Trypanosoma brucei, transmitted by tsetse flies and causing sleeping sickness, and Plasmodium spp. , Haemosporidia). ).
- Transmission from a predator to prey occurs when the simplest parasite gets stuck in the victim's tissues (eg cow, goat, pig) and is eaten by a predator (in our case a human).
The simplest human parasites and the diseases they cause
Acanthamoeba. This parasite infects a person's eyes or brain and causes exogenous amebiasis. He can live in any region of the world. People can get it when they clean contact lenses with tap water.
Babesia. It infects red blood cells and causes a condition called babesiosis. Different types of parasites live in different parts of the world. It is transmitted by ticks when bitten.
Balantidium (Balantidium coli). Lives in the intestinal mucosa, causes blinking dysentery, also called balantidiosis.
Blastocystis. This parasite infects the intestines of the host. It enters humans through ingested food contaminated with human or animal feces. The disease caused by this parasite is called blastocytosis.
Cryptosporidium. It lives in the human intestine. Distributed throughout the world. It enters the human body through ingested food contaminated with human or animal feces.
Amoeba from dysentery (Entamoeba histolytica). This simplest parasite causes intestinal amoebiasis. They are most common in areas with high population density, poor sanitation and tropical regions. It is transmitted by faecal-oral route.
Giardia lamblia. Lives in the lumen of the small intestine. If people consume food or water contaminated with feces, sleeping Giardia cysts can infect the body, causing intestinal giardiasis. It is especially dangerous for children and requires mandatory adherence to the treatment regimen.
Isospora (Isospora belli). Affects the epithelial cells of the small intestine. Distributed throughout the world. It is transmitted by faecal-oral route and is the cause of isosporia.
Leishmania. It parasitizes a person's skin and internal organs. It exists all over the world in various forms. It is transmitted by some species of mosquitoes when bitten.
Naegleria fowleri. It causes primary amoebic meningoencephalitis because it lives in the human brain. Infection occurs through contaminated soil, pools and contaminated water.
Plasmodium (Plasmodium falciparum, P. vivax, P. ovale, P. malariae). The parasites enter the red blood cells and cause malaria. They exist in the tropics, where anopheles, also known as mosquitoes anopheles, are transmitted.
Rhinosporidium seeberi. It multiplies in the nose and nasopharynx, growing there in the form of spores. It exists in India and Sri Lanka. People who swim in public waters can become infected with the parasite when the nasal mucosa is in contact with contaminated material.
Toxoplasma gondii. It affects the liver, heart, eyes and brain. Widespread parasite worldwide. People can become infected after eating raw or undercooked pork, lamb, goat or milk. It can also exist in contaminated food or soil due to cat feces. The disease caused by this parasite is called toxoplasmosis or parasitic pneumonia.
Trichomonas vaginalis. Infects the female urogenital tract. Symptoms differ between men and women. It causes trichomoniasis, a sexually transmitted infection.
Trypanosomes (Trypanosoma brucei, Trypanosoma cruzi). The first type of parasite affects the central nervous system, blood and lymph. It is transmitted by the tsetse fly and causes the so-called. Sleeping sickness. The second parasite causes Chagas disease, affecting the blood, muscles, nerves, heart, esophagus and intestines. It is also transmitted through insect bites.
How to treat infections caused by protozoan parasites in humans?
The treatment plan for protozoan parasite infection will depend on the specific diagnosis. Your doctor will usually prescribe medicines, such as trichomoniasis, giardiasis or cryptosporidiosis. Medicines are not usually prescribed for toxoplasmosis unless there are conditions to do so in the form of pregnancy, some other illness, or a severe and prolonged infection.
Your doctor may recommend other treatments to relieve your symptoms. For example, many parasitic infections can cause diarrhea, which often leads to dehydration. Therefore, when treating an infection caused by protozoan parasites, it is usually recommended to drink plenty of fluids to make up for the loss in the body.
How can protozoan parasites be prevented?
There are several steps you can take to reduce your risk of contracting a parasitic infection:
- practice safe sex with a condom;
- wash your hands regularly, especially after handling raw food or feces;
- Cook food to the recommended core temperature.
- drink clean water, including bottled water when traveling;
- avoid ingesting water from lakes, streams or ponds;
- Avoid cat litter and feces during pregnancy.
If you suspect you have a parasitic infection, make an appointment with your doctor. They can help diagnose the cause of your symptoms and recommend a treatment plan. The earlier you start treatment, the sooner you can help stop the spread of the infection among others.