The term "protozoan" is derived from the Greek words "protos", meaning "first", and "zoon", meaning "animal". This is the name of the kingdom of the simplest living organisms that appeared on our planet among the first. Despite the elementary nature of their structure and vital functions, a large group of these tiny creatures cause deadly protozoal infections in humans and animals. A person becomes infected with some microorganisms through his own fault, as he does not keep cleanliness. But there are also such protozoa that have learned to penetrate the victim with the help of other animals - mosquitoes, flies, ticks and others, which are not always possible to protect themselves from bites. We offer detailed information about the symptoms of infection, methods of treatment and prevention.
Morphological portrait of protozoa
In total, there are hundreds of species of protozoa on Earth. Protozoal infections cause only those that have adapted to a parasitic way of life. Protozoa live in all parts of the world, and everywhere: insoil, water, air, and other living forms. All of them consist only of a single cell, in which all the vital elements are concentrated.
Most of the protozoa can move, are predators, and reproduce not only by simple division, but also sexually. Parasitic species in the process of evolution have developed and fixed various ways of penetrating their prey. So, those of them that parasitize in the digestive tract, mainly use the alimentary route. At the same time, adults or their cysts leave their host into the environment (with feces, urine, less often saliva), where they live for a certain time, until they get into a new host by oral contact (using dirty hands and food). The protozoa, parasitizing in the blood, move from victim to victim with the help of blood-sucking insects. There are also parasites that have chosen for themselves the sexual way of penetrating a new host.
Diseases caused by protozoa
Discovered and studied to date, pathogens of protozoan infections cause the following diseases:
- amoebiasis;
- malaria;
- giardiasis;
- toxoplasmosis;
- leishmaniasis;
- sleeping sickness;
- babesiosis;
- Chagas disease;
- trichomoniasis;
- balantidiasis;
- sarcocystosis (mostly affects cattle);
- isosporosis;
- cryptosporidiosis.
Let's take a closer look at the most common of them and start with intestinal ones that have a similar etiology andpathology.
Amebiasis
This disease is also called amoebic dysentery. It is caused by certain types of amoebas that can only live in humans. Protozoal infections of this type can only be transmitted from an already infected person. Amoebic dysentery ranks second in the list of deadly diseases. Most often it is observed where there is a hot climate and complete unsanitary conditions. Cysts of parasites with feces go outside (on the ground, into the water), where they can live for several weeks. They penetrate into a new victim with food and water. Flies, cockroaches and other “companions” of a person can transfer infection to food. Once in the intestines, cysts destroy their membranes and penetrate into the tissues of the intestines, causing their ulceration and even necrosis. Sometimes with the blood, they can be carried to other organs, such as the liver. The patient has symptoms about a week after the invasion:
- abdominal pain;
- temperature;
- weakness;
- diarrhea (sometimes with blood and mucus).
Without proper treatment, the disease can become chronic, leading to perforation of the intestinal walls, peritonitis and other complications.
Diagnosis is carried out using colonoscopy, ultrasound, PCR method. For treatment, drugs "Metronidazole" or "Tinidazole" are used.
Prevention of protozoal intestinal infections, including amoebic dysentery, consists mainly in cleanliness and hygiene. Mandatory:
- before use, boil water from open reservoirs;
-observe hand and body hygiene;
- wash fruits, berries, vegetables intended for food;
- destroy insects - carriers of infection.
Also, for the purpose of prevention, all workers involved in the food industry are examined, and in the outbreak where the disease is detected, a complete disinfection is carried out.
Giardiasis
Protozoal infections, belonging to the class of intestinal infections, include this disease. Its causative agent is Giardia. Unlike amoebas, they can be transmitted to humans from dogs, cats, rodents, in which they also parasitize. The causes of infection, as in the case of amoebiasis, are the lack of sanitation and hygiene. Giardia parasitize only in the small intestine, and having moved to the large intestine, they form cysts that are excreted with feces. In the external environment, they live for more than a month. All protozoal intestinal infections have a number of common symptoms - abdominal pain, lethargy, fatigue, diarrhea.
With giardiasis, nausea, allergic dermatitis, dysfunction of the biliary tract are added to them, and diarrhea can be temporarily replaced by constipation. There is usually no blood in the stool, but mucus may be present.
Diagnosis of giardiasis is carried out by examining feces for the presence of cysts in it.
Treatment is carried out in stages:
1. Elimination of toxicosis and restoration of intestinal functions.
2. With the help of drugs "Trichopol", "Tiberal" and the like, parasites are destroyed.
3. Strengthening immunity, diet therapy, taking vitamins and prebiotics.
Prevention of giardiasis consists in maintaining cleanliness, personal hygiene, and also in examining persons, especially children, for carriage of giardia.
Cryptosporidiosis
There are not so familiar to the general public, but also very dangerous protozoan infections. One of them is cryptosporidiosis, which is caused by protozoa of the Cryptosporididae family and can lead to death. They become infected with it by oral contact, using untreated water of rivers, ponds, even water pipes, unwashed fruits or vegetables, as well as during anal sex. The course of cryptosporidiosis is mostly acute, the incubation period lasts up to one and a half weeks, rarely up to a month, and the main symptom is severe diarrhea. Patients also have:
- nausea to vomiting;
- fever;
- pain in the peritoneum;
- convulsions;
- symptoms of dehydration.
Immune people may have no symptoms, but they carry parasites.
Cryptosporidiosis leads to pancreatitis, cholecystitis, cholangitis, affects the lungs, stomach and pancreas. An ideal remedy that absolutely helps with this infection has not yet been developed.
Prevention consists in the sanitization of food, water, milk pasteurization, meticulous personal hygiene.
Protozoal intestinal infections, rare
These include balantidiasis, the culprit of which is the infusoria Balantidium coli, and isosporosis, caused by protozoa of the genus Isospora. Ciliates Balantidiumcoli live in the gastrointestinal tract of pigs, which may be asymptomatic. They enter the human body with unprocessed meat or through the classic path for all intestinal infections. The main symptoms of the acute form of balantidiasis are diarrhea, abdominal pain, fever, signs of intoxication. With the transition of the disease into a chronic form, the manifestation of symptoms weakens or they completely disappear, but the person becomes a carrier of the pathogen.
The simplest isospores in nature are very widespread. They enter the human body through alimentary routes. The incubation period lasts for one and a half weeks, after which the disease begins acutely. The patient develops fever, vomiting, diarrhea, severe abdominal pain. In HIV-infected people, isosporiasis can cause death. Treatment is carried out with antimicrobial agents: Fansidar, Metronidazole and others.
Malaria
There are severe protozoal infections that are not always successfully treated. One such disease is malaria. Every year it affects up to 300 million people, of which about 750 thousand die. It is transmitted by malarial mosquitoes when they suck blood.
Malaria is observed all over the globe, except for regions with a very cold climate, since low temperatures are fatal for mosquitoes. Malarial plasmodia are carried with blood to the liver, where they begin to multiply with fantastic activity by simple division. One parasite can give rise to 40,000 new living organisms! Call themmerozoites. This process takes place for a patient without symptoms. After about a month and a half, young merozoites leave the liver and enter the bloodstream. Here they attach to erythrocytes and begin pathogenic activity. At the same time, the following are observed:
- fever
- unbearable headaches;
- chills;
- vomiting;
- convulsions;
- sometimes loss of consciousness;
- anemia;
- ischemia;
- release of hemoglobin into the urine.
For decades, malaria has been treated with quinine. Now new medicines have been developed, such as Artesunat, Amodiakhin, Kotrifazit, Meflokhin and others. Some of them are used not only for treatment, but also for prevention. Unfortunately, there is no vaccine against malaria.
Toxoplasmosis
This is a very dangerous protozoal infection, especially for babies. It is caused by the protozoan Toxoplasma gondii. The source of infection are many (over 180 species) domestic and wild animals. According to the WHO, half of humanity is infected with toxoplasmosis. The causes of infection are:
- eating unprocessed meat, eggs, milk;
- contact with sick pets;
- dirty hands (after working with infected animals);
- intrauterine transmission;
- blood transfusion and/or organ transplant;
- for children, parents are carriers of microorganisms.
Symptoms of the disease can be:
- temperature;
- headache;
- vomiting;
- paralysis;
- lesions of many organs andsystems.
Toxoplasmosis occurs in two forms - acute and chronic, and can be either congenital or acquired.
The prognosis for babies is extremely unfavorable, intensive therapy is being carried out to save their lives. All others do not require treatment, as the acute form of toxoplasmosis resolves on its own.
Babesiosis
This protozoan infection affects humans and animals. The carrier of the pathogen are ticks. Symptoms:
- high temperature;
- fever;
- enlarged liver and spleen.
In animals there is a sharp deterioration, diarrhea, constipation, rapid breathing, bloody urine, milk becomes bitter in cows, pregnancy is terminated in sheep. Lethality among animals from babesiosis - up to 80%.
In humans, the disease can be mild or severe. Treatment is carried out with drugs "Berenil", "Albargin", "Akaprin" and others.
Prevention of protozoan infections carried by blood-sucking insects consists mainly in their destruction, as well as in vaccination.
Exotic diseases
In addition to widespread, there are protozoan infections diagnosed only in certain regions. You can get sick with them by going there on vacation or to work. For example, in the countries of tropical Africa, the so-called sleeping sickness is common, which the tsetse fly rewards people with. After her bite, the first symptoms appear after 1-3 weeks. It can be headaches and joint pains, fever,itching. After another couple of months, a person develops numbness, confusion, loss of orientation in movements. Treatment of sleeping sickness is only medication.
There is another problem in Latin America called Chagas disease. Kissing bugs, which are carriers of the simplest microorganisms of the Trypanosoma cruzi species, bring it to people. The symptomatology of the disease is wide, since inflammatory processes occur in many organs: in the heart, liver, muscles, brain and spinal cord, and degenerative changes in organs in this case are irreversible. The disease proceeds in two stages. The first is characterized by pain in the abdomen, chest, muscles of the whole body, heart failure, fever, shortness of breath. The second for most infected people passes without symptoms, only some have symptoms of damage to the nervous, digestive and cardiovascular systems.
Prevention of protozoal and viral infections
Infection with protozoa is in many ways similar to infection with viruses. So, almost all types of fevers (dengue, yellow, West Nile, Karelian) are caused by various viruses, and mosquitoes carry them from he althy to sick. Another common carrier of protozoa and viruses is the tick, whose bites can cause encephalitis. Well, the rotavirus known to many of us gets into the body of the victim if hygiene rules are not followed.
Since the ways of infection with protozoan parasites and viruses are not much different, the prevention of protozoal and viral infections should be similar in many respects.infections. Ogulov A. T., in collaboration with Eshtokina G. M. and Abdusalamova F. M., published a book that describes many infectious, fungal, helminthic diseases. It also tells how to treat them and how to protect yourself from them. The main thing that must be observed always and by everyone is sanitation and hygiene. These postulates become a barrier for many human parasites. Preventive measures against infections carried by insects are their destruction and elimination of habitats. Well, vaccination is the best prevention of infections against which the body develops immunity.
