Parasites are organisms that live by stealing the nutrients of their guests, and almost always become popular as something more evil thanks to horror movies and science fiction (ahem, Alien).
But the reality is that parasitic infections are more common in humans than you imagine. For example, malaria is caused by a parasite, and this disease kills 600,000 people each year, according to the World Health Organization.
However, of the parasites we discuss here, you surely already know them. They are called helminths and protozoa and cause gastrointestinal symptoms.
Definitely, you have heard about infections by helmitos like intestinal . . .