The simplest living things that live in the Earth’s body of water, soil and air number up to 15, 000 species. Some of them are the oldest inhabitants of our planet. In the millions of years since the first living organism appeared, most protozoa have hardly changed. But they have learned to adapt well to the new living conditions and find a way to survive. One of the most obvious ways of existence for these living things has become parasitism, including the human body.
Parasitism
It is a kind of complex relationship between two beings when one parasite uses another organism as a habitat or food source.
The organism in which the parasite lives is called the host. It can be constant if it experiences the entire cycle of development of the parasite in it, and is intermediate when the pathogenic organism spends only a certain part of its life cycle in it.
Parasites are types of interactions between protozoa that involve not only living and parasitizing at the expense of the other, but also endangering the life of the host, as many types of parasites cause severe forms of disease in humans, animals, and crops.
The simplest human parasites have chosen almost every organ and system in the human body, develop quite actively, and sometimes live in it for years. This symbiosis leads to the chronicity of the disease and a decrease in the effectiveness of the treatment process.
Ways to get into the body:
- through the hands and mouth;
- through the skin;
- contact;
- from mother to fetus;
- by biting insects and animals;
A comprehensive science that studies the phenomenon of parasitism, the biology and distribution of parasites, diagnostics, methods of treatment and prevention of parasitic diseases.
The simplest pathogenic parasites that cause various forms of disease are found almost everywhere. These are fresh and salt water, soil, various household items and household items, public places. Protozoal infections are called protozoal or protozoan infections.
What are the simplest human parasites
The human body, like any more or less large body, is a very attractive object for parasitic life patterns. In addition to protozoa, multicellular parasites (helminths) can also inhabit the human body.
According to habitat, the simplest species can be endogenous (living in the human body) or exogenous (after the skin has been chosen as a habitat). Occasionally, during their development, parasites pass through the body, selecting the most suitable habitat for a given stage of development.
The microscopic size and primitive structure allow the simplest parasites to successfully survive and multiply under the most difficult conditions. Each member of this species is characterized by a structure consisting of a single cell, filled with cytoplasm, intracellular fluid, in which all metabolic processes take place with the participation of organelles (structures that perform different functions to maintain vital activity)
The functions of the movement can be performed by dedicated flags, cilia and pseudopods. The main process (food) is performed in several ways:
- ingestion through the mouth of the cell;
- flows with pseudopodia (jaws);
- absorption at the membrane surface.
Adverse conditions can become an indication for the formation of cysts that are resistant to the external environment of the membranes. They are necessary for the simplest human parasites to move from one host to another and can hold a prisoner in the parasite for up to several years.
The reproductive cyst is characterized by the formation of a thin temporary shell, which is necessary for a protozoon to divide for a short time.
Important!The simplest human parasites are the pathogens of protozoal infections: giardiasis, trichomoniasis, sleeping sickness, amoebic dysentery, malaria.
Types of protozoan parasites
According to the nature of reproduction and movement, nutrition, we distinguish 4 main classes of the simplest human parasites:
Ostoroz
For example, lamblia, leishmania, trichomonas, trypanosomes. They have a long oval or pear-shaped body. Thin cytoplasmic outgrowths may have 1 to 8 flags composed of the finest fibers. They move forward with a flagellum, as if twisted into the space in front of them. They feed both on the absorption of the finished nutrients and across the membrane. Reproduction in most cases is done simply by dividing it into two daughter cells. Flags can live in colonies of up to 10, 000 individuals.
Sporozoa
For example, the plasmodia of malaria is Gondia Toxoplasma. Representatives of this protozoan species are characterized by a very complex developmental pathway: from the carrier to human blood and then to the liver, where the parasite multiplies and affects the red blood cells. Reproductive toxins cause disease in the human host. For the next developmental cycle, the pathogens must re-enter the host, where the maturation of male and female cells and the formation of spores occur. After ripening, the spores are killed and the parasite re-enters the host. The cycle repeats itself.
Ciliates
For example, balantidia. The cilia are characterized by movement with the help of the cilia. There are two cells in the cell of the body: the big nucleus controls all the vital processes, and the small one is assigned the main role on the sexual side of the protozoa’s existence. Reproduction is done by dividing the cell in half, for most species it is done daily, some for several times a day. The food is driven by the movement of the cilia into a special cavity (cell mouth), processed inside the cell by the digestive vacuole, and undigested residues are not removed.
Sarcode
For example, the amoeba is a dysentery. It doesn’t have a permanent shape, it forms a lot of jaws that you use to move and grab food. It multiplies by simple division. It can exist in several forms: tissue, luminal, precision. The tissue form lives in the intestines of only one sick person. The other forms can also be found in the host.
Important!The primitive structure, the formation of cysts, the simplest mode of reproduction, the microscopic size, all these factors allow the simplest parasites to penetrate the most protected tissues of the human body and, in the absence of adverse effects, many serious and sometimes difficult to diagnose pathological conditions.
What diseases are caused by protozoan parasites
In addition to the above factors, the parasitic lifestyle of the simplest microorganisms is also aided by anaerobic respiration, although many can use dissolved oxygen.
Diseases caused by protozoan parasites include:
Malaria
The main symptoms are fever attacks, joint pain, vomiting, anemia, convulsions. Enlargement of the spleen may occur. Malaria is characterized by a recurrent course of the disease, with periods of rest and exacerbation. Depending on the type of pathogen, the forms are distinguished: three-day, four-day, and tropical. The disease is common in Africa and South Asia. For many centuries, as today, the main drug of treatment is quinine, a drug made from the bark of the cinchona tree. Despite the development of synthetic analogues, deaths from infection occur in areas that do not have access to modern medical care.
Amoebiasis (dysentery amebiasis)
This is caused by the simplest parasite amoeba in the dysentery class of sarcodes. The infection can be intestinal and extraintestinal (development in the liver). 7-10 days after infection, the first symptoms appear: abdominal pain, weakness, low-grade fever (up to + 37, 5 ° C). About 10% of them may develop severe diarrhea with traces of blood and mucus. Every third person is infected with a fever. It is characterized by an enlarged liver and in some cases a liver abscess. If treatment is not started on time, prolonged diarrhea will cause dehydration, weakness, and exhaustion of the patient's body. Outbreaks occur in countries with hot climates.
Giardiasis
The disease is the simplest cause of the class of flagellate lamblia. These parasites have 4 pairs of flags and a suction cup with which they are attached to the inside of the small intestine. When infected, symptoms include pain and bloating in the upper abdomen, murmur and nausea, disturbance of the normal functioning of the gut, skin changes (atopic dermatitis), abnormalities in the function of the gallbladder, general weakness and loss of strength, loss of appetite and sleep. Giardiasis is widespread in hot climate regions in Asia, Africa and Latin America.
Leishmaniasis
The disease is caused by the parasite leishmania belonging to the flag class. The main symptoms of leishmaniasis of the skin and mucous membranes are skin lesions in the form of ulcers. Edema and deformity may occur in mucosal form. If the respiratory system is affected, it can be fatal in rare cases. The visceral form is characterized by enlargement of the liver and spleen, fever and anemia. The disease is common in 88 countries, mainly in tropical and subtropical climates.
Trichomoniasis
The disease is caused by a Trichomonas parasite belonging to the flagellate class. The urinary system is affected. The main symptoms in women are itching and burning, hyperaemia of the external genitalia, the presence of unpleasant-smelling secretions, and sometimes unpleasant sensations during sexual intercourse and urination. In men, in most cases, the disease is asymptomatic, sometimes there is pain during urination and discharge, and symptoms of prostatitis may occur.
Balantidiasis
The pathogen is a parasite belonging to the class ciliates balantidia. Typical symptoms are abdominal pain, diarrhea and tongue lining. In acute cases of the disease, a rise in temperature and signs of general intoxication are possible. The infection can also be chronic, with intermittent periods of remission and worsening. In complex cases, intestinal perforation and peritonitis are possible.
Toxoplasmosis
The disease is caused by the parasite Gondia Toxoplasma, a sporozoa parasite. Typical symptoms of the disease are damage to the eyes, nervous system, heart muscle, lymph nodes, liver and spleen. It occurs mainly in chronic form. Often, the primary infection is very simple, under the guise of a common ARVI. Thereafter, immunity appears forever and further infection is impossible. The greatest danger to the fetus during pregnancy: if the child survives, with severe damage to the nervous system and eyes.
Dream disease
The disease is caused by the simplest parasite of the flagellate class, the gambia or Rhodes trypanosome. Typical signs of the first stage are fever, headache, and joint pain. After 7-20 days, the second stage of the disease begins: disturbances in the perception of the surrounding world begin, disturbances in movement coordination, numbness, and sleep disturbances. Outbreaks of the disease are localized in some regions of tropical Africa, in the habitat of the main vector of tsetse fly infection;
Chagas disease
The pathogen is a parasite from the cruzi class of flagellate trypanosoma. The primary symptoms are fever, swollen lymph nodes, headache and swelling at the site of the bite. In the initial stage, signs of the disease may be absent, and after 8-12 weeks, secondary symptoms may develop in 30-40%: enlargement of the ventricles, dilation of the esophagus, colon. The second stage of the disease can last for 10 to 30 years after infection. The infection was most prevalent in Latin America.
Important!Most of the simplest parasites enter the human body if the rules of hygiene and personal hygiene are not followed.
Routes of infection
Any microorganism can penetrate the human body through the skin or through natural openings. For most protozoan parasites in the environment, methods of human infection are limited to the four most common:
- Contact and household. This route of infection becomes available to the simplest organisms in violation of hygiene and personal hygiene rules. After all, most microorganisms, when they pass from the body of one host to the body of another, can form cysts and remain in this state until they enter a favorable environment, in other words, inside a person. Infection can occur at any time: when shaking hands, using other household items (towels, bedding, dishes), with dirty water (in a pond);
- Stool-oral (giardiasis). In this case, the infection occurs when the parasite leaves the intestines with feces or vomiting. If hygiene rules are not followed, the parasite enters the water, food, or hands of the new host and enters the body. Poorly washed vegetables and herbs can also become sources of infection, and in children, dirty hands after playing in the sandbox or playing with pets;
- Through contaminated food (toxoplasmosis). The meat of most animals, especially wild animals, can contain cysts of protozoan parasites that enter the human body with insufficient heat treatment. Infection is also possible with dairy products that have not undergone health checks and raw fish without adequate heat treatment;
- Infectious (malaria, sleeping sickness). Infection occurs by the transmission of the pathogen through the saliva of the carrier. The disease is transmitted directly by the infected insects to a susceptible organism.
In addition to the main methods of infection, the infection can occur in a number of ways, which are much less common:
- Transplacental by penetration of protozoan parasites from the infected mother through the placenta to the fetus;
- Hemocontact, when blood infected with parasites enters the patient's body (during medical procedures, drug injections, sexual intercourse);
- Sexual infection occurs only through sexual contact.
Prevention
Prevention of infection with protozoan parasites involves, above all, adherence to hygiene and hygiene rules. Exclusion of the possibility of infection with parasites can be achieved by reasonably following a number of suggestions:
- Heat treatment of meat, dairy and fish products is sufficient (according to the temperature rules according to the technology). Particular attention will be paid to products that have not passed the health inspection;
- Thoroughly wash fruits, vegetables, berries and herbs, preferably with boiling water. If heat treatment is impossible, especially when feeding children, it is better to remove the skin;
- Regular medical examinations, especially if infection with protozoan parasites is suspected;
- Adherence to a sexual partner and refusal to use drugs;
- In order to prevent infection by insect bites, special measures can be taken: use of medicines, destruction of mosquitoes, mosquito nets and repellents, destruction of transgenic (malaria-resistant) mosquitoes, development of a vaccine.
Important!The body's resilience is of great importance in the prevention of any infection, including the simplest human parasites. After all, if a cyst finds itself in unfavorable conditions where it lacks nutrition, or if immune cells are constantly attacking a foreign object, the parasite will either die or leave the host.
There are many foods that are natural immunostimulants (garlic, ginger, broccoli, carrots, green tea) whose balanced consumption can provide invaluable help to the body in boosting immunity.
In addition, some products have a negative effect on the growth and reproduction of protozoa, especially those that have settled in the digestive tract: rice and pearl barley porridge, dried fruits, fried apples, vegetable oil, steamed vegetables. When treating parasites, products that trigger fermentation processes should be restricted or completely excluded: bakery products and sugar.
Currently, the pharmaceutical industry offers a number of expensive antiparasitic drugs. However, their effective use can only be achieved through preventive measures and adherence to a certain diet, the composition of which can be consulted by a qualified professional.
Let's not forget the folk remedies, time tested and many generations. With all methods and combinations of methods, parasites will have very little chance under medical supervision.
Conclusion
At the beginning of the 21st century, it can be stated that humanity has achieved much in the development of parasitology. The message of a new discovery of a particular drug is always happily received by people who need help and treatment today.
The simplest human parasites continue to be a serious problem in many countries, where the development of medicine and society as a whole leaves much to be desired. There are many more places on our planet where diseases like malaria, sleeping sickness, leishmaniasis and many more are spreading. And people are waiting and hoping that everyone will have a chance to live without disease.
In our time, parasitic diseases are relevant, requiring social interaction in all areas of human life, aimed at improving the medical care of the population, adherence to personal and public hygiene rules and standards, preventive measures, and health and education work, hygiene natural foci of pathogens.
Various scientific studies in the field of parasitology are currently underway in many countries around the world:
- developing scientific bases and methods for monitoring infectious and parasitic infections;
- study of the biological characteristics and variability of pathogens of major diseases caused by protozoan parasites;
- quality control and environmental safety of meat and fish products;
- conducting basic research to study the development, genetic diversity and ecology of the pathogens of parasitic diseases.