Trichinella spiralis
What is Trichinosis?
Trichinosis is a
disease caused by the roundworm, Trichinella spiralis.
T. spiralis is a parasitic nematode that lives in the
skeletal muscle of meat-eating animals, such as swine.
Once the female roundworm releases its larvae within the
intestinal lining, the larvae travel through the
circulatory system to the heart. They then get
passed along through the bloodstream until they arrive in
the striated skeletal muscle. When T. spiralis
arrive in the skeletal muscle, they grow to a length of about
one millimeter, coil and encyst within the muscle.
The encysted nematodes can live for up to ten years in this
form.
How do these organisms infect humans?
To answer this
question, it is important to remember that these organisms
reside in the very muscles that humans enjoy eating so much;
that is, pork chops, ham, and ribs. When enjoying a delicious meal
of this sort, it is important to make sure that these pieces of infected meat
are fully cooked. If they are not, the cysts will
remain and could be ingested. If these cysts are ingested,
they will travel to
the stomach to be digested. The stomach contains pepsin and
hydrochloric acid to help break down the food. Pepsin and
HCL(hydrochloric acid) also break down the cysts freeing
these roundworms. They will then travel into the host’s
intestines and release their larvae. The larvae continue traveling
through the bloodsteam to the person's muscles and encyst
there, just as they would in pigs or other meat-eaters.
Human hosts that have eaten infected meat experience a wide range of symptoms. Some of the symptoms of relatively small infections include fever, diarrhea, pain, and sometimes vomiting. These symptoms begin to show about two to three days after eating the contaminated food. Some symptoms are so mild that the individual may not even need to go to the clinic. In more severe cases this roundworm can cause inflammation of the heart (myocarditis), lungs (pneumonitis), or brain (encephalitis). These symptoms can sometimes be fatal.
Treatment of trichinosis primarily consists of decreasing
the symptoms that are present in the infected individual. Most
times this is done by prescribing aspirin and nonsteroidal
anti-inflammatory drugs. When infected, it is also suggested
that you get a lot of rest to help give your body time to
recover.
Prevention of
trichinosis is very simple. There are a few ways to help
prevent the prevalence of this disease. One way is to feed
swine only grain or cooked garbage and meats because
uncooked food could contain these encysted T. spiralis
species. The other way to help prevent trichinosis is to
make sure meat is fully cook until it is no longer pink. It
is especially important not to undercook meat when the
meat being eaten is from animals that are prone to
infection.
To learn how this organism requires its nutrients from its host click here