by Ricker Polsdorfer, MD
Ascariasis is an infection that causes problems in the lungs or bowels.
A roundworm parasite causes ascariasis. The roundworm can grow to over 15 inches (40 centimeters) in length. Their eggs hatch in the stomach and the larvae travel to the liver and lungs. This causes a type of pneumonia. They get into the throat during coughing or working their way up. Once swallowed, they grow into adult worms in the stomach. Their eggs leave the body in the stool.
The cycle starts again when a person takes in food or drinks contaminated with stool that has eggs.
Risk Factors TOP
Roundworms are most common in places with poor sanitation or sewage control. The risk of getting sick is highest in Asia and the western Pacific.
Risk is also higher if exposed to tainted soil or water. This can happen with:
Most people not have symptoms. In those that have them, infection may cause:
The worms can cause problems in the gallbladder, liver, pancreas, and appendix.
The doctor will ask about your symptoms. You will be asked about your health and travel history. A physical exam may point to roundworms. If needed, you may also have:
Medicines treat the roundworm parasites. Surgery can treat bowel obstruction.
Always wash your hands after using the bathroom.
When you travel to places where ascariasis is common:
Centers for Disease Control and Prevention
World Health Organization
Public Health Agency of Canada
Travel and Tourism—Government of Canada
Ascariasis. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116444/Ascariasis . Updated January 16, 2017. Accessed May 25, 2018.
Ascariasis. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/infectious-diseases/nematodes-roundworms/ascariasis. Updated February 2017. Accessed May 25, 2018.
Parasites—ascariasis. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/parasites/ascariasis/. Updated February 15, 2018. Accessed May 25, 2018.
Last reviewed May 2018 by David L. Horn, MD, FACP
Last Updated: 5/25/2018
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