What is "helminths"

n. (plural of helminth English)

Helminths , also commonly known as parasitic worms, are large multicellular organisms, which when mature can generally be seen with the naked eye. They are often referred to as intestinal worms even though not all helminths reside in the intestines; for example schistosomes are not intestinal worms, but rather reside in blood vessels.

There is no clear consensus on the taxonomy of helminths; it is more of a commonly used term to describe certain worms with superficial similarities. These are flatworms (platyhelminthes), namely cestodes (tapeworms) and trematodes (flukes), and roundworms or nemathelminths ( nematodes) – both of these are parasitic worm types – and the annelida, which are not parasitic or at the most ectoparasites like the leeches.

Many, but not all, of the worms referred to as helminths belong to the group of intestinal parasites. An infection by a helminth is known as helminthiasis, soil-transmitted helminthiasis, helminth infection or intestinal worm infection. The same naming convention applies to all helminths whereby the ending "-asis" (or in veterinary science the ending "-osis") at the end of the name of the worm is added to signify the infection with that particular worm, for example Ascaris is the name of a particular helminth, and ascariasis is the name of the infectious disease caused by this helminth.

Helminths are worm-like organisms living in and feeding on living hosts, receiving nourishment and protection while disrupting their hosts' nutrient absorption, causing weakness and disease. Those that live inside the digestive tract are called intestinal parasites. They can live inside humans and other animals. In their adult form, helminths cannot multiply in humans. Helminths are able to survive in their mammalian hosts for many years due to their ability to manipulate the immune response by secreting immunomodulatory products. Helminth ova (or eggs) have a strong shell that protects the eggs against a range of environmental conditions.

Helminthology is the study of parasitic worms and their effects on their hosts. The word helminth comes from Greek hélmins, a kind of worm.