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Ascariasis – Symptoms And Treatment Of Roundworms In Humans: The parasite Ascaris lumbricoides can cause pictures of diarrhea, cramps and weight loss. Ascariasis is an intestinal parasitic disease caused by the helminth Ascaris lumbricoides, a roundworm in humans that can grow up to 40 cm in length.
Estimates suggest that more than 1 billion people worldwide are infected with Ascaris lumbricoides, but most are unaware of this, as they do not have relevant symptoms.
In this article we will address the following points:
- What is Ascariasis?
- How to get Ascaris?
- How is the life cycle of Ascaris lumbricoides?
- What are the symptoms of ascariasis?
- How is the diagnosis of ascariasis made?
- How is the treatment of Ascaris lumbricoides infection?
What Is Ascariasis?
The Ascaris lumbricoides, popularly known as a Small intestinal roundworms, is a nematode roundworms in humans which is light red in color, cylindrical body and thinner ends, which usually has between 15 and 30 cm long.
Infection with Ascaris lumbricoides occurs throughout the world, but it is more prevalent in countries with a hot climate and poor sanitation conditions. Ascariasis can occur at any age but is more common in children between 2 and 10 years.
Most people infected with Ascaris do not have symptoms unless their intestines are infested with hundreds of worms.
How we get ascariasis
A person infected by the ascaris worms daily wipes out thousands of Ascaris eggs through the feces. In places without proper sanitation, these feces contaminate soils and water. Ascaris transmission occurs when a healthy person accidentally ingests these eggs present in the environment.
Children often become infected by playing on contaminated soils. Dirty hands can carry eggs directly into their mouths or contaminate toys or objects that will later come into contact with the mouths of other children. Adults, on the other hand, usually become infected from drinking water or contaminated food.
Once in the environment, the eggs of Ascaris are very resistant and can remain viable for several years, if they find suitable conditions of humidity and temperature. Water filtration, food cooking and proper washing of raw fruits and vegetables are sufficient to eliminate eggs and prevent contamination of new individuals.
A previous infection by Ascaris does not guarantee immunity, it is perfectly possible for one person to develop the parasite several times throughout life.
Life Cycle Of Ascaris Lumbricoides
Eggs eliminated in the feces contain Ascaris embryos in their interior. After a few days in a suitable environment, still inside the egg, the embryo becomes a larva, which, after passing through 2 seedlings, becomes able to infect those who ingest it.
Therefore, the Ascaris egg is only capable of infecting humans if it contains mature larvae inside them, called L3 larvae, a process that takes 2 to 4 weeks to occur. If the larvae inside the egg are still in the L1 or L2 phase, the worm is not able to survive in the digestive tract, being unlikely to contaminate whoever ingested it.
Infected eggs ingested release L3 larvae into the duodenum, the first part of the small intestine. After they become free, L3 larvae cross the wall of the small intestine and reach the bloodstream where, within 4 to 5 days, they will migrate to the liver, heart, and finally lungs.
In the lungs, L3 larvae undergo 2 more seedlings over 10 days and become L5 larvae. After being mature, the larvae migrate to the upper respiratory system, close to the oral cavity, and can be expelled through the mouth through a cough or swallowed, returning to the digestive system. Again in the small intestine, the L5 larva undergoes its last molt, becoming an adult worm.
An adult worm usually lives for 1 to 2 years within the gastrointestinal tract. The Ascaris adults do not multiply within the intestines. Females eggs need to be disposed of in the environment to develop viable larvae. Hence, the number of worms in a person only increases if they ingest new eggs throughout their life. If there is no new contamination, after 2 years, all worms die and the patient is no longer contaminated.
Symptoms of roundworms in humans
In most cases, Ascaris lumbricoides infection is asymptomatic. However, patients with a high number of worms in their gastrointestinal tract may show symptoms during the migration phase of the larva or during the adult phase of the worm.
The most common clinical manifestations of ascariasis are:
An inflammatory picture of the lungs (pneumonitis) during the brief passage of the larvae through the respiratory system is quite common. Manifestations such as a dry cough, bronchitis, fever, and chest pain are called Loeffler’s syndrome. In the blood count, the increase in the number of eosinophils is typical of this syndrome.
During episodes of a cough, it is possible that the patient expels one or more larvae of Ascaris through the mouth.
The ascariasis symptoms related to the gastrointestinal system are abdominal pain, nausea, vomiting, diarrhea, abdominal distension and weight loss. Contaminated children may present malnutrition and growth retardation due to reduced absorption of important nutrients from the intestine. Elimination of adult worms in feces may also occur.
In cases of large infestation of worms, a “cake” of Ascaris can cause intestinal obstruction, requiring surgical or endoscopic intervention to remove worms.
Diagnosis of ascariasis roundworm
The diagnosis of roundworms in humans is usually made through the identification of eggs of Ascaris lumbricoides in feces. The problem with parasitic stool examination is that the first eggs only appear in the stool about 40 days after the patient has become infected. Therefore, in the early stages, such as during lung infection, stool examination is usually negative.
In cases of elimination of the worm by mouth or feces, it should be collected and taken for medical examination.
Treatement Of Ascaris Lumbricoides
Several drugs can be used to treat ascariasis, the most common of which are:
- Albendazole 400 mg single dose.
- Mebendazole 100 mg twice daily for 3 consecutive days.
- Levamisole 150 mg in a single dose.
- In the case of intestinal obstruction by Ascaris, the indicated drugs are Piperazine, 50 to 100 mg/kg/day + mineral oil, 40 to 60 ml/day for 2 days.
The drugs mentioned above are more effective against adult worms than against larvae. Therefore, after 3 months, the patient should be tested again for ascariasis. If it is positive, a new treatment should be indicated.
It is also important to test people living in the same residence since the contamination of family members is very common.