Intestinal parasites in adults and children: symptoms, signs, methods of prevention and control

Intestinal parasites are worms that live in the human intestine, feeding on the contents or sucking blood from the intestinal wall.

In humans, they can cause serious, life-threatening illnesses. They are mainly found in children living in tropical and subtropical regions of rural Africa, the Middle East, South Asia, Indonesia, and Central and South America.

In people from the Mediterranean regions of Europe and southern North America, they are relatively rare.

The adult size can reach from 1 mm to several meters. They penetrate the human intestinal wall and begin to suck blood from them or live there freely, using nutrients.

Intestinal parasites

The result of such an important activity of parasites is inflammation of the small or large intestine, ulcers, anemia, vitamin deficiency (mainly A, C, B12). In more severe cases, intestinal obstruction may occur and then a surgeon should be contacted for help.

Larvae can migrate to other organs (liver, spleen, bladder, muscles, lungs, brain), where they form cysts and cause allergic inflammation.

Invasion is the infection of a person, animal or plant with any parasite (including worms).

Symptoms of infection

Intestinal parasites can live in a person's intestines for years without causing any symptoms.

General symptoms and signs may appear weeks or months after invasion and manifest as pallor, weakness, frequent fatigue (due to anemia caused by blood loss from the worms), sleep disturbances, and sleep disturbances. weight loss.

Abdominal symptoms can last from weeks to months and include:

  • Blistering.
  • Halitosis.
  • Eat well.
  • Vomiting.
  • Itching in the anal area.
  • Diarrhea.
  • Blood in stool.
  • Presence of worms or their particles in feces.
  • Itching and rash on the skin.
  • Swelling around the eyes.

Source of infection

Eggs of intestinal parasites enter the external environment along with the feces of an infected person or animal. Outside of the human body, eggs take days or weeks to develop into cysts or immature worms (larvae), which can enter the human body through dirty hands or when you eat unwashed raw vegetables.

Another source of infection is eating undercooked meat from domestic pigs, fish or wild animals (wild boars, deer, etc. ).

It can also be infected by fleas carried by pets.

Some intestinal parasites can enter through the skin when swimming or walking barefoot; Once they reach the small or large intestine, they begin to develop into adults.

Parasites can enter the human body through dirty hands

Types of intestinal parasites

Roundworm (roundworm)

Human roundwormfound all over the world. It reaches a length of 16 cm and is as thick as a pencil.

Nematodes are mainly found in tropical areas. After entering the intestines, they begin to suck blood from the intestinal wall.

Roundworm size

Pinworm. . . White worm, the length reaches no more than half a centimeter. At night, they can emerge to the surface of the anus and lay eggs in its area, resulting in intense itching.


Trichinella.They cause trichiasis, which you can get if you eat thoroughly cooked contaminated meat.

They can travel from the intestines to muscles and other organs, where they form cysts, encapsulations that are difficult to remove. The main symptoms are abdominal pain, muscle, joint pain, eye swelling and skin rash.


Leaf fluke disease

Flukes in bloodcause intestinal schistosomiasis. They are found mainly in Africa, the Middle East, the Caribbean and South America. They are no more than 25 mm long and about 1 mm thick. Eggs can be found in the blood in feces and urine.

Flukes in blood


Wide ribbonenters the human body through the consumption of contaminated fish. In length, the parasite can reach 10 m. Distribution in Europe and the United States.

Wide ribbon

Beef and pig tapeworms.You can get this disease by eating undercooked beef or pork.

The parasite is widespread around the world, and people living in rural areas are especially vulnerable. Adult worms can be more than 20 m long.

Pork tapeworm

Cucumber tapeworm.Common in domestic dogs and cats. Humans are rarely infected with this intestinal parasite because fleas are the main source of distribution of cucumber tapeworm eggs.

Cucumber tapeworm

Diagnosis and prevention

If you experience bloating, diarrhea, weakness, or unexplained weight loss, your healthcare provider should first suspect intestinal parasites as a possible cause. To confirm this, it is necessary to donate blood and stool for analysis.

As a precaution, simply follow these recommendations:

  • Wash hands frequently after using the toilet, in contact with soil, and after handling pets.
  • Do not walk barefoot or swim in stagnant shallow water.
  • Handle meat products thoroughly.
  • Regular medical check-ups.