Ascariasis is an infection with a roundworm parasite.
This roundworm can grow to over 15 inches (40 centimeters) in length. Their eggs hatch in the stomach and travel to the heart and lungs. This causes a type of pneumonia. They travel to the throat where they are swallowed and enter the stomach again and develop into adult worms. Each worm lays 240,000 eggs per day. These eggs leave the body with bowel movements. The cycle begins again when contaminated food or water is eaten.
Digestive Tract and Lungs
Digestion tract and Lungs 3D
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Ascariasis is caused by swallowing food or water that is contaminated by feces containing eggs.

Risk Factors

Infestations are more common in preschool age or younger children. Other factors that may increase your chance of ascariasis include:


Most people will have no symptoms. Symptoms of ascariasis may include:
Inflammed appendix
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Your doctor will ask about your symptoms, and your travel and medical history. A physical exam will be done. You may be referred to a gastroenterologist or a specialist in tropical diseases.
Your bodily fluids and waste may be tested. This can be done with:
Images may be taken to look for evidence of the worm. This can be done with:


It is common to have more than one intestinal parasite. You may need to be treated for several. Talk with your doctor about the best treatment plan for you. Treatment options include the following:


To reduce your chance of ascariasis:


Center for Disease Control

World Health Organization


Health Canada

Public Health Agency of Canada


Ascariasis. EBSCO DynaMed website. Available at: Updated April 29, 2013. Accessed July 19, 2014.

Parasites—ascariasis. Centers for Disease Control and Prevention website. Available at: Updated January 10, 2013. Accessed July 19, 2014.

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