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.
Ascariasis is caused by swallowing food or water that is contaminated by feces containing eggs.
Risk factors that increase your chances of developing ascariasis include:
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.
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:
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:
Take these steps to reduce your chances of getting ascariasis:
Center for Disease Control (CDC)
The Nemours Foundation
World Health Organization
Communicable Disease Control (CDC) Unit
Manitoba Health, Public Health Branch
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
Last Updated: 11/8/2012