Trichinosis is a parasitic roundworm disease. Human cases of trichinosis have
been associated with eating undercooked homemade sausage that contains pork or
horse meat, as well as eating walrus or bear meat. Because many states have
adopted laws requiring that all garbage fed to hogs be sterilized, fewer people
get trichinosis today. Although trichinosis is very uncommon in the United
States today, it is found occasionally in rural areas.
Cause
Trichinosis is caused by the larvae (immature form) of a highly versatile
parasitic roundworm, Trichinella spiralis. This parasite can infect
virtually every meat-eating mammal. The parasite is especially common in rats
and in swine that feed on uncooked garbage.
Unlike some of the other parasitic roundworm diseases, trichinosis is not an
intestinal infection in the usual sense. It is the movement of the larvae from
the intestines and throughout the body and their encystment (becoming enclosed
in a capsule) in muscle tissue that create serious problems.
Typically, the life cycle of the parasite follows these steps:
- A person or an animal eats contaminated meat containing parasite larvae.
- Digestive juices from the stomach dissolve the capsule-like cyst and
release the larvae.
- The larvae then enter the intestine where they mature into worms and mate.
- Female worms pass larvae into the bloodstream where they make their
way through the capillaries (tiny blood vessels) into the muscle fibers.
- The larvae encyst in the muscle fibers, where they can live a long time.
Symptoms
If you are infected with the worms, you might not have or notice any
symptoms. Symptoms of larvae in your intestines include
- Diarrhea
- Abdominal cramps
- Tiredness
A week after you are infected, larvae enter your muscle tissue and can cause
these symptoms:
- Muscle aches and pains
- High fever
- Swelling in your eyes and face
- Eye infection (conjunctivitis or pink eye)
- Rashes
Being infected by a large number of parasites can cause serious problems
affecting your heart, breathing, and coordination.
Except in severe cases, symptoms usually go away within a few months. Mild
pain and fatigue, however, may last for many months.
Diagnosis
Your healthcare provider may suspect that you have trichinosis based on your
symptoms. If you have eaten raw or undercooked meat, be sure to tell your
healthcare provider. You can be diagnosed in the following ways:
- A blood test that shows an increase in the number of a type of white
blood cells called eosinophils
- Examination of muscle tissue (biopsy) under a microscope to look for larvae
Treatment
Your healthcare provider can prescribe medicine to relieve the symptoms of
trichinosis. There is no treatment for the worm infection. If your healthcare
provider diagnoses infection while you are still having digestive symptoms,
antiparasite medicines can dislodge some of the worms. Once encystment of the
parasite has begun, treatment is for any symptoms. Your chances of recovery are good.
Albendazole may help you if you start treatment very early. Steroid medicines
can relieve the inflammatory reaction when the larvae migrate. You may take
steroids along with albendazole. Steroids may, however, prolong the intestinal
phase of the infection.
Prevention
You can kill the parasites by fully cooking (allowing all parts of the meat
to reach at least 170ºF) or freezing meat.
It is important to keep in mind, however, that smoking, pickling, and other
methods of processing or preserving meats do not kill these parasites.
Source: National Institutes of Health, National
Institute of Allergy and Infectious Diseases, NIAID
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. This document was last reviewed on: 7/7/2009...#14075
