courtesy of

Ascariasis is a disease caused by Ascaris Lumbricoides, an intestinal roundworm known as a nematode.  A. lumbricoides is among the largest and most common human infections worldwide.  Infecting children, more than adults, A. lumbricoides can be found in 1 in 4 humans internationally.  In areas with particularly poor sanitation, that number can approach 100% due to the means of infection of Ascaris, something to be addressed in the Life Cycle section of the website. The worms can range from 20-35 cm long for a female worm, with males often no longer than 30 cm, and sometimes as short as 15cm.  The female worms are thicker, while the males are thin and can be identified by its tail, which curves inward.



This website has been created for a class at Stanford University. All information contained here has been compiled from various medical sources by Michael Lazar ('07). He can be contacted at:

Michael Lazar, Class of 2007

Stanford University

Parasites & Pestilence: Infectious Public Health Challenges

Professor Scott Smith,