Trichinella spiralis

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style="background:#Template:Taxobox colour;"|Whipworm
style="background:#Template:Taxobox colour;" | Scientific classification
Kingdom: Animalia
Phylum: Nematoda
Class: Adenophorea
Order: Trichurida
Family: Trichinellidae
Genus: Trichinella
Species: T. spiralis
Binomial name
Trichinella spiralis
(Owen, 1835)

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


The species Trichinella spiralis is an important parasite, occurring in rats, pigs, and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being found commonly in pork products that are undercooked.


The small adult worms mature in the intestine of an intermediate host such as a pig. Each adult female produces batches of live larvae, which bore through the intestinal wall, enter the blood (to feed on it) and lymphatic system, and are carried to striated muscle tissue. Once in the muscle, they encyst, or become enclosed in a capsule.

Life cycle

Larvae encysted in the muscles remain viable for some time. When the muscle tissue is eaten by a human, the cysts are digested in the stomach; the released larvae migrate to the intestine to begin a new life cycle. Female trichina worms live about six weeks and in that time may release larvae. The migration and encystment of larvae can cause fever, pain, and even death because of their potential to eat living tissue. One of the classic signs of Trichinella spiralis infection is a combination of splinter hemorrhages (not to be confused with those of bacterial endocarditis) and periorbital edema (eye swelling). Trichina are classified in the phylum Nematoda.


Antimicrobial Regimen

  • Trichinella spiralis[1]
  • Preferred regimen (1): Albendazole 400 mg PO bid for 8-14 days
  • Preferred regimen (2): Mebendazole 200-400 mg PO tid for 3 days THEN 400-500 mg PO tid for 10 days
  • Note (1): Both treatment schemes are suitable for adult and pediatric dosages
  • Note (1): Albendazole and Mebendazole are contraindicated during pregnancy and not recommended in children aged 2 years.
  • Alternative regimen (1): (severe symptoms) Prednisone 30 mg/day-60 mg/day for 10-15 days
  • Alternative regimen (2): Pyrantel 10-20 mg/kg single dose for 2-3 days

External links


  1. Gottstein B, Pozio E, Nöckler K (2009). "Epidemiology, diagnosis, treatment, and control of trichinellosis". Clin Microbiol Rev. 22 (1): 127–45, Table of Contents. doi:10.1128/CMR.00026-08. PMC 2620635. PMID 19136437.