Types and manifestation of the simplest parasites

When it comes to parasites in the body, most people think of worms in the intestines. However, other parasites are also common, which are quite difficult to diagnose and affect other organs, not the intestines.

These are the simplest microscopic (most often parasites), which may not appear in any way for a long time. However, the simplest parasites can cause significant harm to the body.


Giardia is a microscopic flagellated parasite that has two nuclei and two sets of organelles.

the simplest parasite lamblia

Giardiasis in humans is caused by the most common type of parasite - intestinal lamblia. In addition to humans, other mammals and birds can also be infected with them. The parasite can form a cyst in the localization organ.

Giardia is present in poorly treated tap water, as well as in natural sources - springs, wells. They can be found in the meat of an infected animal or bird, in small quantities in the stool of an infected animal, sometimes they survive in the soil, therefore they are present on vegetables and berries.

Usually, infection occurs by the fecal-oral route, that is, for the development of the invasion, it is necessary to swallow a significant number of parasite cysts. Usually, children from the age of three months and adults are ill.

Most often, the disease is asymptomatic, and the patient learns about it by chance. But sometimes there is some symptomatology (constantly or intermittently). Symptoms from the gastrointestinal tract are revealed:

  • Stomach ache;
  • Bloating;
  • Nausea, sometimes vomiting;
  • Rumbling in the stomach;
  • Constipation and diarrhea alternate;
  • Dyskinesia of the biliary tract;
  • Skin allergies;
  • General weakness.

Like intracellular parasites, lamblia is treated mainly with metronidazole. However, at the first stage of therapy, it is necessary to remove intoxication and normalize the work of the bile ducts. Only after this is antiparasitic therapy prescribed. After that, therapy is carried out aimed at restoring the body's defenses and increasing immunity.


Amoebas are the simplest human parasites that cause amoebic dysentery or amoebiasis.

There are also varieties of amoebas that can affect the eyes. Cause amoebic encephalitis, but they are less common. The invasion is not the most common, only 10% of people are sick with it, according to the WHO (while for giardiasis, this figure, according to some sources, is 50%).

Amoebas are transmitted exclusively by the fecal-oral route, that is, as in the previous case, amoeba form cysts that must be swallowed in order for infection to develop.

The likelihood of becoming infected is higher in countries with hot climates and poor sanitary conditions. Cysts can retain the ability to infect for a long time while in soil, in water, on vegetables and berries grown on contaminated soil. Cockroaches and flies carry these cysts to some extent.

Like intracellular parasites, amoebae cause symptoms only 7-10 days after infection. Colitis symptoms appear: abdominal pain (in the lower part), general weakness, a slight increase in body temperature. Most often, the liver is affected, because after two to three weeks pains appear in it, the organ grows and thickens.


Toxoplasmosis is a disease that causes Toxoplasma gondi. This is the simplest organism, which is distributed mainly by representatives of the feline family that are its carriers. An infected person is also capable of spreading it.

It is transmitted by the fecal-oral route. You can get infected by eating poorly processed meat of infected animals and birds, as well as eggs. To a lesser extent, but still capable of being transmitted through the blood, in the presence of wounds (for example, when working with contaminated soil in the garden), as well as in contact with mucous membranes.

It is mostly asymptomatic and is diagnosed by chance, like many viruses, for example, during an enzyme-linked immunosorbent assay. In the acute form, cure often occurs independently. Pregnant women require treatment with pyrimethamine drugs (which are used to treat intracellular parasites).


Plasmodia are intracellular parasites that cause malaria. Five types of pathogen are capable of parasitizing in humans. Moreover, they are localized in the blood, being on the membranes of its cells.

The disease is transmitted through blood (for example, through a transfusion). It is also tolerated by some types of mosquitoes when bitten, since it is the mosquitoes that are the intermediate hosts of the plasmodium. As a result, the person becomes infected with malaria.

These mosquitoes (and, accordingly, the disease) are common in hot countries, mainly in Africa.

Malaria has severe symptoms that begin to manifest itself 5-7 days after infection. The first symptoms are joint pain, fever, severe chills. Then headache, enlargement of the spleen join.

the simplest parasite malaria plasmodium

Treatment is carried out with quinine preparations strictly under the supervision of a physician.


These are the simplest human parasites that cause trichomoniasis. Affects the human genitourinary system. It is the most common sexually transmitted disease and also the most common disease of the genitourinary system.

Transmitted exclusively through sexual contact. In women, they live in the vagina, Trichomonas in men - in the urethra, seminal vesicles, prostate gland.

In women, the symptoms are as follows: vaginal discharge, itching and flushing of the skin of the genitals, pain during urination and sexual intercourse, inflammation of the vaginal mucosa. In men: discharge from the urethra (rarely, with blood), pain when urinating, symptoms of prostatitis with damage to the prostate gland.

bubble discharge with protozoan parasites

It is necessary to treat the disease in both partners. It is treated with anti-trichomonas drugs strictly individually and under the supervision of a physician. In some cases, immune or symptomatic therapy is required.