what are three ways that parasitic worms cause disease
Terminology [edit]. Although organisms such as bacteria function as parasites, the usage of the term parasitic disease is usually more restricted. The three main types of organisms causing these conditions are protozoa (causing protozoan infection), helminths (helminthiasis), and ectoparasites.ome parasites like Toxoplasma gondii and Plasmodium spp. can cause disease directly, but other organisms can cause disease by the toxins that they produce.