Smaller Larger

Ascariasis by Ricker Polsdorfer, MD

Definition

Ascariasis is an infection with an intestinal worm. It occurs around the world. It happens more often in tropical climates.

Ascaris lumbricoides is a nematode (round worm) parasite. It can reach up to 40 cm 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. They enter the stomach again and develop into adult worms. The eggs they lay (240,000 per worm per day) pass out with bowel movements. The cycle begins again when contaminated food or water is eaten.

Digestive Tract and Lungs

Causes

Ascariasis is caused by swallowing food or water that is contaminated by feces containing eggs.

Risk Factors

Risk factors that increase your chances of developing ascariasis include:

Preschool age or younger
Travel to developing countries
Living in southern states of the US
Eating unsanitary food
Drinking unclean water

Symptoms

If you have any of these symptoms do not assume it is from ascariasis. These symptoms may be caused by other health conditions. If you experience any one of them, see your doctor.

Dry cough and fever
Wheezing
Abdominal cramps
Vomiting
Poor nutrition, especially in children
Passing a worm either by mouth, nose, or rectum
Diseases caused by the Ascaris worm
- Gallbladder disease
- Liver abscess
- Pancreatitis
- Appendicitis
- Peritonitis

Appendicitis

Diagnosis

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. 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.
Endoscopy or surgery—You may need a procedure if you have intestinal obstruction from a large number of worms.

Prevention

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.

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

References:

Ascariasis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed . Updated October 25, 2012. Accessed November 8, 2012.
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 2012 by Daus Mahnke, MD

All EBSCO Publishing proprietary, consumer health and medical information found on this site is accredited by URAC. URAC's Health Web Site Accreditation Program requires compliance with 53 rigorous standards of quality and accountability, verified by independent audits. To send comments or feedback to our Editorial Team regarding the content please email us at HLEditorialTeam@ebscohost.com.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.