Roundworms are parasitic nematodes belonging to the Ascaris genus. The most common species affecting humans is Ascaris lumbricoides, which causes ascariasis — one of the most widespread parasitic infections worldwide. This disease is particularly common in regions with poor sanitation and hygiene conditions.
Depending on their stage of development, roundworms can grow between 15 and 35 cm in length, making them among the largest parasites capable of living in the human body. Ascariasis is especially dangerous for children, as it may impair growth, nutrition, and overall physical development.
Roundworms are transmitted orally through ingestion of their eggs. Infection may occur by:
consuming unwashed or improperly prepared food;
drinking contaminated water;
poor hand hygiene;
contact with contaminated soil.
After ingestion, the eggs hatch in the intestines, releasing larvae that enter the bloodstream and migrate through the liver and lungs. Eventually, they return to the intestines, where they mature into adult worms and may survive for more than a year.
The risk of ascariasis increases due to:
Poor hand and food hygiene — unwashed hands, fruits, and vegetables.
Inadequate sanitation — especially in areas using outdoor toilets.
Contaminated water sources — untreated or polluted drinking water.
Contact with contaminated soil — gardening or playing outdoors.
Untreated infection — allowing parasites to multiply and persist.
Ascariasis may often be asymptomatic. However, when parasite burden is high, the following symptoms may occur:
Digestive symptoms: abdominal pain, bloating, diarrhea or constipation, reduced appetite.
General symptoms: fatigue, weakness, weight loss.
Respiratory symptoms: cough, chest pain, shortness of breath, sometimes blood-tinged sputum (Löffler’s syndrome).
Skin reactions: rashes, itching, urticaria.
Severe conditions: intestinal obstruction, inflammation of the pancreas or liver.
Diagnosis is confirmed by stool examination for roundworm eggs.
Children
Children are particularly vulnerable due to frequent contact with soil and underdeveloped hygiene habits. Infection may cause abdominal pain, nutritional deficiencies, weight loss, chronic fatigue, and delayed growth. Severe infestations may result in intestinal obstruction.
Adults
Adults can also become infected, especially if their immune system is weakened. Symptoms are generally similar but often milder. Nevertheless, digestive and respiratory complications may still occur.
Untreated ascariasis may lead to:
intestinal obstruction;
intestinal wall perforation;
pneumonia or Löffler’s syndrome;
bile duct, liver, or pancreatic damage;
in rare cases — neurological symptoms such as seizures or altered consciousness.
Some complications may require surgical intervention.
Wash hands thoroughly and regularly with soap.
Wash fruits and vegetables carefully.
Drink only clean, boiled, or filtered water.
Avoid undercooked or improperly handled food.
Maintain proper sanitation and waste management.
For children, follow preventive deworming programs where recommended.
World Health Organization. Soil-transmitted helminth infections (2021).
Centers for Disease Control and Prevention. Ascariasis (2021).
Mayo Clinic. Ascariasis (2020).
National Institute of Allergy and Infectious Diseases. Ascariasis (2019).
