[1] Parasites are organisms which derive sustenance from its host while causing it harm.

Helminths on the other hand are macroscopic, multicellular organisms that belong to the kingdom Animalia.

Helminths of class Cestoidea and Trematoda absorb nutrients, whereas nematodes obtain needed nourishment through ingestion.

Some ways in which people may acquire parasitic infections are walking barefoot, inadequate disposal of feces, lack of hygiene, close contact with someone carrying specific parasites, and eating undercooked foods, unwashed fruits and vegetables or foods from contaminated regions.

[citation needed] The use of viruses to treat infections caused by protozoa has been proposed.