The element is a clause if there is a subject and a verb, and it is a phrase if both of these parts of speech are not present. What comes after the introductory element is always an independent clause, or complete sentence, on its own, and the introductory element gives meaning to it.
A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.
Common helminthes include: roundworms or ascariasis, tapeworms, pinworms, hookworms and strongyloidiasis. Roundworms or ascariasis are the most common type of intestinal parasite in the world. This worm not only affects humans, but it can also affect animals like pigs. It is not communicable; it can only be acquired through eating of the worm's eggs (present in infected foods).