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<unk> ng these conditions are protozoa <unk> ng protozoan infection), helminths (helminthiasis), and ectoparasites. Protozoa and helminths are usually endoparasites (usually living inside the body of the host), while ectoparasites usually live on the surface of the host. Protozoa are single-celled, microscopic organisms that belong to the kingdom Protista. Helminths on the other hand are macroscopic, multicellular organisms that belong to the kingdom Animalia. Protozoans obtain their required nutrients through pinocytosis and phagocytosis. Helminths of class Cestoidea and Trematoda absorb nutrients, whereas nematodes obtain needed nourishment through ingestion. Occasionally the definition of "parasitic disease" is restricted to diseases due to endoparasites.
medical cause of Infection
causes of Infection
symptom of Abscess
medical cause of Abscess
picture of Opportunistic infection
types of Head injury
symptom of Hepatitis
symptom of Sepsis