Trichinella

Trichinella

 

Trichinosis is a zoonotic disease that is transmitted by uncooked pork products.

Epidemiology

  • Incidence – very low in U.S.
  • Transmission – raw or undercooked infected meat
    • Domestic pigs
    • Wild boar
    • Walrus
    • Black bear
    • Dog
    • Horse

Organism

  • Trichinella spiralis (pork worm) is among the smallest of parasitic nematodes
  • Only member of the family Trichinellicae
    • Found coiled in cysts in muscles of bear, rat, pig and man
    • Transmission occurs when infected meat is eaten without proper cooking
      • Cyst dissolves, parasite matures and deposits larvae in deep mucosa  
      • Larvae enter lymphatics and are carried to all parts of body and again encyst

Clinical Presentation

  • Symptoms from larval migration appear the second week after infection
    • Periorbital and facial edema
    • Hemorrhages in retina, nail beds, subconjunctival
    • Inflammatory muscle changes
    • Myocarditis, encephalitis and pneumonia account for most deaths

Diagnosis

  • Laboratory testing
    • Trichinella antibody testing

Treatment

  • Treatment unsuccessful in most patients
  • Glucocorticoids are used for severe myositis and myocarditis
  • Infected patients usually recover with bedrest

Prevention

  • Fully cooking pork or freezing at -15°C for 3 weeks