Ascariasis
(Roundworm)
Pronounced: ASS-car-EYE-uh-sis
Definition
Ascariasis is an intestinal worm infestation present worldwide, though mostly in tropical climates.
Ascaris lumbricoides is a nematode (round worm) parasite that can reach up to 40 cm in length. As with most parasites, Ascaris have a complex life cycle that begins with ingesting their eggs. After hatching in the gut, immature forms of the parasite travel to the heart and lungs, causing a type of pneumonia. They then migrate into the throat where they are swallowed, enter the gut again, and develop into adult worms. The eggs they lay (240,000 per worm per day) pass out with feces, to begin their cycle again when contaminated food or water is ingested.
Digestive Tract and Lungs
Risk Factors
The following factors increase your chances of developing ascariasis:
- Preschool age or younger
- Travel to developing countries
- Living in southern states of the US
- Eating unsanitary food
- Drinking unclean water
Symptoms
If you experience any of these symptoms do not assume it is due to ascariasis. These symptoms may be caused by other health conditions. If you experience any one of them, and have been exposed to risks, see your physician.
- Pneumonia (dry cough and fever)
- Wheezing
- Abdominal cramps
- Vomiting
- Malnutrition, especially in children
- Passing a worm either by mouth, nose, or rectum
-
Diseases caused by Ascaris
- Gallbladder disease
- Liver abscess
- Pancreatitis
- Appendicitis
- Peritonitis
Appendicitis
Diagnosis
Your doctor will ask about your symptoms, travel and medical history, and perform a physical exam. You may be referred to a gastroenterologist or a specialist in tropical diseases. Tests may include the following:
- Blood and urine tests
- Stool specimens to search for worm eggs
- Intestinal x-rays or ultrasound imaging
Treatment
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:
- Drugs—Mebendazole, albendazole, and pyrantel pamoate are all effective medications that kill Ascariasis.
- Endoscopy or surgery—Intestinal obstruction from a large number of worms may require further intervention.
Prevention
To help reduce your chances of getting ascariasis, take the following steps:
- Avoid foods prepared without proper sanitary precautions, such as unwashed hands.
- Avoid water and other drinks possibly from contaminated sources.
- Peel, cook, or wash vegetables in an appropriate cleaning solution if possibly fertilized with human excrement.
- Wash hands when leaving the bathroom.
RESOURCES:
Center for Disease Control (CDC)
http://www.cdc.gov
The Nemours Foundation
http://kidshealth.org
World Health Organization
http://www.who.int
CANADIAN RESOURCES:
Communicable Disease Control (CDC) Unit
Manitoba Health, Public Health Branch
http://www.gov.mb.ca/health/publichealth/cdc/index.html
Health Canada
http://www.hc-sc.gc.ca/index_e.html
References:
Ascariasis. DynaMed website. Available at: http://www.dynamicmedical.com/dynamed.nsf?opendatabase . Accessed October 4, 2005.
Beers MH, Berkow R. The Merck Manual . 17th ed. West Point, PA: Merck & Co;1999.
Weller PF, Nutman TB. Intestinal nematodes. In: Kasper DL et al., eds. Harrison's Principles of Internal Medicine . 16th ed. New York: McGraw-Hill; 2005:1256-1257.
Last reviewed November 2008 by David L. Horn, MD, FACP
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.
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