Human intestinal worms are affecting millions of people all over the world, but they are to be found more often in tropical and sub-tropical areas, especially during rainy seasons.
Children are more often infected by intestinal worms, and sometimes even with more than one type of worm at a time.
There are three common worms that infect humans:
This is one of the most common worms, with an estimate of over one quarter of world's population!
More details (and pictures) about roundworms
More details (and pictures) about Whipworms
More details (and pictures) about Hookworms