Infection by intestinal parasitic worms (geohelminths) is widespread throughout the world, affecting hundreds of millions of people. Children are particularly susceptible and typically have the largest number of worms. Three of the most common kinds of worms are roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura) and hookworm (Ancylostoma duodenale and Necator americanus). These worms live in the intestines and their numbers build up through repeated infection. It is possible to be infected with more than one kind of worm.
survives by hijacking another organism, robbing it of nutrients and
thanking it by leaving behind toxic waste. Obviously, we would be much
happier without having these pintsized freeloaders around.
Yet, there are over 100 different types of parasites
that can live in human hosts. Since the world's population is becoming
more mobile, with US tourists traveling to foreign countries where
parasites are prevalent and immigrants moving to the US from these
infections are increasing. The fact is, parasitic infections may have
reached epidemic levels in the US and most other countries.
Types of Parasites ....http://www.diagnose-me.com/symptoms-of/parasite-infection.html