Protozoal Infections - What Are They, Types, Symptoms And Treatment

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Protozoal Infections - What Are They, Types, Symptoms And Treatment
Protozoal Infections - What Are They, Types, Symptoms And Treatment

Video: Protozoal Infections - What Are They, Types, Symptoms And Treatment

Video: Protozoal Infections - What Are They, Types, Symptoms And Treatment
Video: Parasites: Protozoa (classification, structure, life cycle) 2023, December

Types of microorganisms that cause protozoal infections


  • 1 Complications after protozoal diseases
  • 2 Protozoal human diseases: varieties

    • 2.1 Amoebiasis
    • 2.2 Intestinal amebiasis
    • 2.3 Hepatic amebiasis
    • 2.4 Cutaneous amebiasis
  • 3 Diagnosis of pathology
  • 4 Treatment of the disease
  • 5 Sleeping sickness
  • 6 Diagnosis and treatment of African trypanosomiasis

    • 6.1 Malaria
    • 6.2 Toxoplasmosis
    • 6.3 Cryptosporidiosis

Medical theory defines protozoal diseases as acquired pathologies, the causative agents of which are the simplest forms of life. Single-celled parasites enter the human body through contact with soil, plants, wild and domestic animals, food. Penetrating into the systems of the body, parasitic life forms begin to divide, forming numerous colonies.

They move around the habitat with the help of flagella and cilia, further irritating the mucous membranes

Protozoa live in blood, lymph, skin tissues, cavities of internal organs (including genitals). The vital activity of the creatures described has a pathogenic effect on organs and tissues. Eating and reproducing, pathogenic protozoa poison the human body, generate painful reactions and complications.


Complications after protozoal diseases

Non-interference in the course of protozoal invasion and refusal of therapy create prerequisites for the formation of a complex of complications dangerous to health, such as:

  • Rapid weight loss;
  • Localization of inflammatory foci in the spinal cord and brain;
  • Deterioration of the functional state of bones and joints;
  • Numerous pathologies of the liver, kidneys, intestines, pancreas;
  • Colitis;
  • Iridocyclitis - inflammation of the iris of the eye;
  • Flushing out nutrients due to bouts of diarrhea.


If protozoal diseases appeared in a child at an early age, then non-interference in the progress of pathology leads to a lag in physical and intellectual development.

Protozoal human diseases: varieties

The type and nature of the disease depends on the type of parasite that has settled in the body. Infection with such types of protozoa is widespread:

  • Roots: the most famous pathogenic representative is amoeba;
  • Sporozoa: Plasmodium malaria;
  • Ciliates;
  • Flagellates.


As a result of the pathogenic effects of parasites, a person becomes a carrier of diseases such as amebiasis, malaria, toxoplasmosis, trichomoniasis, leishmaninosis, trypanosomiasis. Let's describe the common pathologies in detail.


Man is the only natural carrier of the Entamoeba histolytica parasite. The microorganism enters the host's body through the mouth through ingestion of contaminated water or food. Men 20-50 years old are more susceptible to infection. Several forms of the disease are registered:

  • Intestinal amebiasis;
  • Extraintestinal amebiasis;
  • Cutaneous amoebiasis.

Intestinal amebiasis


The most common and studied is the intestinal form of the disease. With intestinal localization, a person can be a carrier without degenerative consequences, or progressive damage to the colon can occur.

In a mild form, the disease manifests itself in alternating bouts of diarrhea and constipation. The transition to a more severe stage is characterized by general weakness, abdominal pain, blood in the stool. A diagnostic marker of intestinal amebiasis is a multiple excess of the norm in the concentration of erythrocytes with a low content of leukocytes.

The intestinal form provokes a number of complications:

  • Intestinal bleeding;
  • Purulent peritonitis;
  • Loss of hemorrhoids;
  • Perforation of the intestinal walls;
  • Appendicitis.

Hepatic amebiasis


Extraintestinal amebiasis is localized in the liver of the infected. The patient experiences pain in the right hypochondrium.

Symptoms are similar to those of acute viral hepatitis: jaundice, enlargement of the liver in size. Legs may swell, the skin becomes loose and dry, and the face turns pale. Complications of hepatic amebiasis can lead to the death of the patient.

Cutaneous amebiasis

Cutaneous amoebiasis is characterized by the formation of putrefactive ulcers in the perineum and on the buttocks. The ulcers have dark edges and a stench.

Diagnosis of pathology

To identify the disease, laboratory and instrumental methods are used: analyzes of feces, urine and blood (there is no eosinophilia when infected with amoebas); colon X-ray, computed tomography, radioisotope scanning.


Treatment of the disease

During therapy, pharmacological antiprotozoal agents are prescribed: Diloxanide, Metronidazole, Dehydroemetin, Flagil, Furamid. The course of drugs lasts from 10 to 20 days. During treatment, adherence to the diet is shown: fatty, spicy, salty and spicy foods are excluded from the diet. The reception of auxiliary agents is shown - hepatoprotectors, probiotics, immunostimulants.

Sleeping sickness

The medical name is African trypanosomiasis. Trypanosome parasites enter the body through saliva, most often through the bite of a tsetse fly. The first stage of the disease occurs one to three weeks after the bite.

For the invasion to begin, it is enough for up to 400 trypanosomes to enter the body. An infected fly is capable of "presenting" a potential patient with half a million individuals of the parasite in one bite. Infection is inevitable.


Sleeping sickness begins with the formation of trypanides on the skin. Extremities and face, eyelids swell. Occasionally, attacks of fever occur with an increase in body temperature up to forty degrees; swollen lymph nodes; iridocyclitis develops. The patient develops chronic fatigue, the infected person is constantly sleepy. The person becomes apathetic and inhibited.

The further course of sleeping sickness is characterized by disorders of nervous activity: speech becomes indistinct; there is an uncontrolled tremor of the tongue, hands and feet; coordination of movements is disturbed.

The extreme stage of the disease is marked by regular convulsive activity of the limbs, seizures of epilepsy, paralysis. Coma and death follow later.

Diagnosis and treatment of African trypanosomiasis

To safely get rid of the disease, therapy should be started before seizure activity, coordination defects and paralysis appear.

As diagnostic measures, the Romanovsky-Giemsa test, the immunofluorescence reaction, and the enzyme immunoassay are used; puncture of the affected lymph nodes is done. To confirm the diagnosis, it is possible to inject the patient's blood into laboratory guinea pigs.


For treatment, a pharmacological course is prescribed, which includes Eflornithine, Suramin and Melarsoprol. Without treatment, a person will die with a 95% probability. It is necessary to turn to diagnostics every time you return from the areas where the tsetse fly lives, so pharmacology has not developed immunostimulating agents aimed at stopping sleeping sickness.


It is localized in the human body due to the bites of mosquitoes infected with plasmodia. Malaria is the undisputed leader in the number of deaths among infections. Malaria is deadly for people with weak immune systems.

The pathology is characterized by severe course and drug resistance. You can become a carrier of the parasite by visiting a tropical area or other areas where infectious mosquitoes live (the Caribbean, Southeast Asia, the Middle East).

Symptoms of the disease:

  • Fever;

  • Multiple allergic reactions;
  • Loss of appetite;
  • Dehydration;
  • Jaundice;
  • Vomiting and diarrhea.

Disease markers appear after 36-48 hours after the single-celled parasite enters the host's body. In severe cases, convulsive activity is additionally manifested.

For diagnosis, it is enough to take a blood sample and check it for the presence of plasmodia. The patient is shown inpatient treatment even with a low concentration of protozoan parasites in the blood sample. To eliminate pathogenic microorganisms, the patient is prescribed medications based on chloroquine. If malaria is "caught" in the regions of Southeast Asia, the infected person is assigned a complex of tetracycline and quinine.

Severe patients are additionally prescribed erythrocyte transfusion; mannitol - to restore renal function; anticonvulsants; also put droppers to normalize the water-salt balance.



The cause of infection is a unicellular organism of the species Toxoplasma gondii. It enters the human body through non-thermally processed food or through the feces of domestic animals. The described protozoal pathology is unique in that it is transmitted from a pregnant woman to a fetus.

For a child, congenital toxoplasmosis threatens developmental disabilities, difficulties in learning and communicating with others. The baby is guaranteed to be infected if the mother has acute acquired toxoplasmosis. The acquired form of the disease is characterized by enlarged lymph nodes, fever, headache and weakness.

At the initial stage, the disease can be confused with a viral infection. If there is an immunodeficiency, then complications arise such as pneumonia or encephalitis, threatening death to the carrier of the parasite.

To diagnose the disease, they use:

  • Tissue cut;
  • Seibin-Feldman test;
  • Test for the presence of IgM antibodies;
  • Injection of infected biomaterial to laboratory mice.


The most difficult is the therapy of the congenital form. The treatment course lasts more than 1 year. The child is prescribed Pyrimethamine in combination with sulfadiazine and calcium folinate. A course of glucocorticosteroids is prescribed to suppress inflammatory foci.

Acquired toxoplasmosis is treated for no longer than a month. The therapeutic course is being developed on the basis of Pyrimethamine with the additional appointment of Sulfadiazine.

In order not to get infected, you need to minimize the number of contacts with animals and subject food to thorough heat treatment.


The causative agents are intestinal protozoses, cryptosporidia, which enter the carrier's body after contact with livestock. Pathogens can also be swallowed through food or water. Once in the digestive tract, parasites disrupt the digestion process. The wearer begins bouts of vomiting and diarrhea, which wash out useful substances, upset the balance of fluid and mineral salts.

Pathogenic microbes infect not only the intestinal walls, but also the mucous membranes of the pharynx, larynx, and esophagus. The walls of the small intestine are most susceptible to destruction due to the vital activity of Cryptosporidium. On average, it takes 10 days before symptoms appear.


  • Loose stools;
  • Attacks of vomiting and diarrhea;
  • Constant weakness;
  • Rapid weight loss.


Any infection of the protozoa means a threat to life and health. Immunity is not able to cope with the pathogenic threat itself. An infected person not only experiences discomfort himself, but is himself a "walking focus" of infection, throwing out several hundred thousand pathogenic microbes into the air with each exhalation.

Especially carefully you need to approach the prevention of protozoal infections if you plan to travel to another climatic zone and a country where the local cuisine is radically different from the usual menu.