Parasites
Parasites are organisms that use other living beings and rely on them for nourishment and place to live. A person can get infected with parasites by consuming contaminated water or food, after an insect bite or person-to-person contact. The parasites' size varies - parasites may be tiny organisms or worms that are visible to the naked eye. Parasitic disease may also be caused by infected pets and animals and it can be lethal.