Helminthic therapy

Helminthic therapy, an experimental type of immunotherapy, is the treatment of autoimmune diseases and immune disorders by means of deliberate infestation with a helminth or with the ova of a helminth. Helminths are parasitic worms such as hookworms, whipworms, and threadworms that have evolved to live within a host organism on which they rely for nutrients. These worms are members of two phyla; nematodes, which are primarily used in human helminthic therapy, and flat worms.

Helminthic therapy consists of the inoculation of the patient with specific parasitic intestinal nematodes (helminths). A number of such organisms are currently being investigated for their use as treatment including: Trichuris suis ova, commonly known as pig whipworm eggs; Necator americanus, commonly known as hookworms; Trichuris trichiura ova, commonly referred to as human whipworm eggs; Hymenolepis diminuta, commonly known as rat tapeworm cysticerci.

While the latter four species may be considered to be mutualists - providing benefit to their host without causing longterm harm - there are other helminth species that have demonstrated therapeutic effects but which also have a potential to cause less desirable or even harmful effects and therefore do not share the ideal characteristics for a therapeutic helminth. These include Ascaris lumbricoides, commonly known as human giant roundworm; Strongyloides stercoralis, commonly known as human roundworm; Enterobius vermicularis, commonly known as threadworm or seatworm; and Hymenolepis nana, also known as dwarf tapeworm.

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