Ascariasis is an infection with a nematode (worm) parasite known as ascaris lumbricoides.
This round worm can reach up to 40 cm (15.7 inches) 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
Ascariasis is caused by swallowing food or water that is contaminated by feces containing eggs.
Infestations are more common in preschool age or younger children. Risk factors that increase your chances of developing ascariasis include:
- Travel to developing countries
- Living in southern states of the US
- Eating unsanitary food
- Drinking unclean water
Most people will have no symptoms. Symptoms of ascariasis may include:
- Dry cough and fever—when traveling through the lungs
- Abdominal cramps
- Poor nutrition, especially in children
- Passing a worm either by mouth, nose, or rectum
- Diseases caused by the Ascaris worm
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:
- Blood tests
- Urine tests
- Stool tests
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:
- Medications such as mebendazole, albendazole, ivermectin, and pyrantel pamoate
- Endoscopy or surgery if you have an intestinal obstruction from a large number of worms
Take these steps to reduce your chances of getting ascariasis:
- Avoid foods prepared without proper sanitation, such as unwashed hands.
- Avoid water and other drinks that may be from contaminated sources.
- Peel, cook, or wash vegetables if they may have been fertilized with human excrement.
- Wash hands when leaving the bathroom.
Center for Disease Control (CDC)
World Health Organization
Public Health Agency of Canada
Ascariasis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated April 29, 2013. Accessed July 19, 2014.
Parasites—ascariasis. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/parasites/ascariasis/. Updated January 10, 2013. Accessed July 19, 2014.
Last reviewed July 2014 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.