Our world is beautiful and fantastically diverse. Thousands of life forms are admired for their beauty, strength, ability to survive and other unique features. But, unfortunately, there are creatures in the world that absolutely do not attract and differ only in that they live at the expense of other creatures. These are parasites. Medical parasitology deals with those that are dangerous to human he alth and life.
It's hard to even imagine how many of them exist on Earth. These are viruses, and bacteria, and fungi, and helminths, and insects, and protozoa - only a few million species, and most of them are capable of causing harm to one degree or another. To determine exactly what kind of parasites have settled in a person and cause him trouble, there are special medical research institutions, for example, in Moscow this is the Marcinovsky Institute of Parasitology and Tropical Medicine. Here they conduct research to identify pests and prescribeeffective treatment.
Such institutions exist in many large cities of all developed countries of the world, because parasites attack people of all ages, races, nationalities and genders, and at any time of the year. How to recognize that you have become a victim of a small pest and killer? What to do and where to run for help? Let's figure it out.
What is parasitology?
First of all, let's get acquainted with some terms. The most common of these is parasitology. This is a whole science that studies all biological parasites, their morphological features, vital activity, principles of parasitism, etiology, pathogenesis, as well as the development of methods to combat them and the discovery of new drugs for the treatment of diseases they cause. One of the major areas of this science, specializing in human pests, is medical parasitology. It can be defined as follows - this is a section in medicine that studies all forms of pathogenic activity of pests - how they infect a person, what diseases it causes, how they proceed, what are dangerous, how to treat them and how to protect yourself from them.
There is also veterinary parasitology, which, in principle, is the same as medical, only for animals. In nature, there is a group of organisms that can infect both humans and animals. But in most cases, microorganisms have adapted through evolution for parasitic activity in any one kind of host, for example, only in birds or only in humans, or only in warm-blooded animals. That's whyThere are two branches of parasitology, one of which deals with microorganisms that cause diseases in humans, the other in animals.
Sections of medical parasitology
The army of parasites is not only numerous, but also many-sided. Each of their species has its own characteristics of life activity peculiar only to it and causes completely different pathologies. To facilitate the task of scientists and somehow differentiate the research they are engaged in, several sections have been identified in medical parasitology that are interested only in certain types of living forms:
- protozoology;
- arachnoentomology;
- helminthology.
Important: the symptoms of invasion caused by representatives of any of these sections are very often similar to the symptoms of diseases not associated with infection by parasites, therefore, without appropriate tests, medications that do not lead to a positive result can be prescribed. To exclude the possibility of invasion, you need to contact the medical center of parasitology (if there is one in the village) or another medical institution that diagnoses parasitic diseases.
Medical Protozoology
The compound word "protozoology" is composed of three simple ones, which in Greek mean the following: "proto" - the first, "zoo" - animal and "logia" - in free translation, this is a speech about something, a doctrine. That is, the section of medical parasitology, protozoology, deals with the study of parasitic life forms that arose among the first on Earth. All of themunicellular protozoa - amoeba, ciliates known from school and others. Most of them live in the environment without causing us trouble, but some members of the group have adapted to life in other organisms. Once in a person, they cause parasitic or, in other words, invasive diseases in him. These dangerous microorganisms include:
1. Amoeba. Their dimensions are 0.5 mm or less, and the body is constantly changing shape, protruding some processes and drawing in others. These tiny creatures, once in the human intestines, cause a formidable disease amoebiasis, which occupies the “honorable” second place in the world in terms of mortality from invasive pathologies. Several species of amoebas parasitize humans. Dysentery (Entamoeba histolytica) is the culprit of dysentery, the protozoan of the genus Acanthamoeba provokes amoebic keratitis, and a number of amoebae cause amoebic encephalitis. You can become infected by drinking water or products containing amoebic cysts, as well as by close contact with their carrier. Once in the intestine and embedded in its walls, amoeba with blood spread throughout the human body, settle in other organs, more often in the liver and form additional foci of amoebiasis.
2. Flagellates. As the name implies, these protozoa move with the help of cilia, flagella and other similar formations. Medical parasitology and parasitic diseases are closely related, no matter what kind of organisms are considered. In particular, flagellar vaginal Trichomonas cause urogenital trichomoniasis, fraught with infertility, and in cases where theypregnant women get sick, trichomoniasis can cause miscarriage. Trichomonas, unlike many other parasites, live only in humans and are transmitted through close contact (sexual). Other prominent representatives of the flagellates are members of the genus Leishmania, the Gambian trypanosoma that causes the deadly African trypanosomiasis. Trypanosomes are carried by tsetse flies. Once in a person, the parasites move to the brain. Their activity disrupts the work of almost all body systems. There are also sporozoans, the most dangerous of which is considered to be Taxoplasma gandi, which causes toxoplasmosis.
3. ciliates. Among them there are not only shoes, but also Balantidium coli, the entry of which into the intestine leads to a serious illness balantidiasis. Intestinal balantidium can be contracted from domestic animals by eating their undercooked meat, as well as by drinking water and foods with parasite cysts.
Medical arachnoentomology
Arachnis is Greek for spider. Accordingly, arachnoentomology is a medical parasitology dealing with arachnids and, in general, arthropods that parasitize humans. In total, more than one and a half million such parasites have been discovered. They can be temporary (attacked, drank blood and left the victim) and permanent (live on the victim from birth to death). This group of parasites poses a great danger for the reason that they carry severe, and often even fatal, parasitic diseases. So, ticks reward us with encephalitis, relapsing fever, borreliosis,scabies, fleas bring us plague, typhus, bedbugs - Chagas disease, mosquitoes - malaria, anthrax, yellow fever. There are other dangerous parasitic insects - midges, tsetse flies, horseflies, wood lice. In addition, there is a huge detachment of insects that are not inherently parasites, but also carry the most dangerous diseases. These are flies, cockroaches, various bugs.
Medical Helminthology
Among human parasites there are not only microscopic, but also quite large, perfectly visible to the naked eye, and sometimes even huge individuals. These are worms and worms, and scientifically helminths. Every year every second inhabitant of our planet becomes infected with them, and in Russia, according to research, 99% of the inhabitants suffer from helminthiasis. Therefore, it is difficult to overestimate the importance of the work that medical parasitology is engaged in, saving our citizens from this infection. Not only those who do not observe hand hygiene or eat unwashed fruits and vegetables can catch helminths, but also those who eat undercooked dishes from meat of domestic animals, poultry, fish, and drink unpurified water.
You can get infected even by accident, for example, by swallowing an ant carrying helminthic larvae or cysts with food. There is a group of worms (they are called contact worms) that enter the body of the victim through intact skin. Medical parasitology, in particular helminthology, deals not only with the differentiation of types of worms, but also with the study of their development cycles, since for one group a person is the final owner, and for another -intermediate.
It is also important to study how and at what stage of its development a parasite can infiltrate a person, which animal becomes an intermediate host, and how human life is connected with this. This is especially true for flatworms. For example, for a bovine tapeworm growing in the human body up to 10 meters long, it is cattle, for a pork tapeworm - pigs, for a wide tapeworm - fish.
Nematodes
This is the name of roundworms, of which 24 thousand species have been discovered and described in nature. Fortunately, not all of them parasitize in humans, but those that have chosen people for themselves in the process of evolution cause quite unpleasant diseases in us - nematodes. The most famous roundworms to a wide range of the population are pinworms, which are the most common helminths in children throughout the world and cause the disease enterobiasis. Pinworms live only in humans (in the intestines), infection occurs through dirty hands, unwashed fruits and vegetables, linen and household items used by the patient.
A parasitologist easily determines pinworm invasion by the only characteristic symptom - severe itching in the anus, since helminths lay their eggs there. To cause itching, they secrete a special acid. The patient begins to comb these places, and during this process the eggs fall on the hands, and then into the mouth, on clothes, toys - anywhere. In the external environment, they live a long time, so the next victim, if she does not wash her hands, can easily settle pinworms in herbody. Another well-known representative of nematodes are roundworms, which cause ascariasis. They also live only in man, but at various stages of their development they settle in the lungs or in the intestines. The source of infection in this case is also only a sick person, and the cause of infection lies in insufficient personal hygiene.
Diagnosis
As can be seen from the above, there are hundreds of human parasites, and each has its own characteristics. To establish an accurate diagnosis, the parasitologist must collect an anamnesis:
- finds out the conditions under which infection could occur (the patient's life, his work or being on vacation, for example, in the forest or in countries where epidemics of parasitic diseases are frequent);
- the presence or absence of the patient's contacts with animals of various groups, and so on);
- symptoms of the disease (is it itching, rash, signs of intoxication, weakness, anemia).
Laboratory tests play a decisive role in making a diagnosis. They are direct and indirect. Direct ones consist in the detection of eggs, larvae or other living forms of parasites in human secretions (feces, sputum, urine). This work is carried out by the laboratory of parasitology, where the patient must submit only fresh materials for research. So, some types of helminths can be found in feces no later than 20 minutes after defecation.
If it is difficult or even impossible to collect fresh material (for example, if the parasites are in the liver, in the brain),perform indirect analyses. They consist in the detection in the patient's blood of special antibodies produced by the body to protect against invasion.
Treatment
Parasitology medical preparations for the destruction of parasites in the human body offers a wide variety. There is no single remedy that saves from all forms and types of invasion. Therefore, only doctors should prescribe treatment, and only after an accurate diagnosis. To date, drugs have been developed that include mebendazole, diethylcarbamazine, levamisole, piperazine adipate and other substances. Each of them is capable of destroying only a certain type of parasites. In some cases, for example, when infected with a bovine tapeworm, treatment is carried out surgically.
Veterinary parasitology
This section is important not only for people who have pets, but for each of us, since even those who have absolutely no contact with animals anywhere and in any way can become infected by eating meat, fish, or can become a victim of insect bites. Veterinary parasitology solves a very wide range of problems:
- examines pets for the presence of all currently known parasites in them;
- produces healing;
- makes sure that contaminated meat, milk, other livestock products, as well as fish and seafood do not get on store shelves, examines live and fallen animals, and in case of detection of invasion en masse establishes quarantine zones.
Prevention
In order not to suffer from many types of parasites, excellent vaccines have been developed to date. It is necessary to apply them when traveling on vacation or work to the countries of Latin America, Africa, and other regions where specific insects live (kissing bug, tsetse fly, and others) that can cause dangerous diseases. For vaccination, you must contact the Institute of Parasitology or a medical institution in your locality that is engaged in this activity. For residents of regions where outbreaks of diseases caused by parasitic insects are frequent (for example, for tick-borne encephalitis, this is the Urals, Siberia, the Far East), and for those who have gathered in these regions for permanent or temporary residence, vaccination is also mandatory.
An important point in the prevention of invasive diseases is to eat only products tested by the sanitary and epidemiological service. In addition, do not use water from reservoirs without first boiling.
But the main means of preventing invasions, accessible to all segments of the population, is hygiene, that is, washing hands, fruits, vegetables, as well as sufficient cooking of meat, fish, milk.
