Information

Ascariasis: Roundworm


It is a worms caused by a parasite called Ascaris lumbricoides. It is the most widespread human intestinal worms in the world.

Contamination happens when there is ingestion of infected parasite eggs, which can be found in soil, water or food contaminated by human feces.

The only reservoir is man. If eggs find a favorable medium, they can contaminate for several years.


Ascaris lumbricoides.

Ingestion of contaminated water or food (fruits and vegetables) may introduce roundworm eggs into the human digestive tract.

2- In the small intestine, each egg breaks and releases a larva.

3- Each larva enters the intestinal lining and falls into the bloodstream, reaching the liver, heart and lungs, where it undergoes some cuticle changes and increases in size.

4- Remains in the pulmonary alveoli and may cause symptoms similar to pneumonia.

5- When they leave the alveoli, they pass to the bronchi, trachea, larynx (where they cough with the movement they perform) and pharynx.

6- They are then swallowed and reach the small intestine, where they grow into adult worms.

7- After mating, the female begins to release the eggs. About 15,000 a day. This whole cycle that began with ingestion of eggs, until the formation of adults, lasts about 2 months.

8-The eggs are eliminated with the feces. Within each egg, which has a protective shell, an embryo develops that eventually gives rise to a larva.

9- Eggs contained in feces contaminate drinking water and food used by man.

What are the symptoms?

Most infections are asymptomatic. The larva releases from the egg in the small intestine, penetrates the mucosa and intravenously reaches the liver and lung from where they reach the bronchial tree. Along with the respiratory secretions they are swallowed and reach the intestines where they grow to adult size.

In many situations symptoms may arise depending on the organ affected. Ascariasis can cause abdominal pain, diarrhea, nausea, poor appetite or no symptoms. When there are large numbers of worms, there may be intestinal obstruction. The larva can contaminate the airways, causing the person to cough, bloody phlegm or asthma attack. If a larva obstructs the bile duct, there may be obstructive jaundice.

How is the diagnosis made?

The diagnosis is made by stool examination, where the parasite eggs are found.

How is it?

There are specific remedies to eradicate the larva from the human organism, all orally.

How to prevent?

Through basic sanitation measures:

It is also necessary to treat all patients with the disease. Ascariasis is more present in tropical and subtropical countries. Poor hygiene and the use of feces as fertilizer contribute to the prevalence of this worm in third world countries.