Pork Parasites

Pork parasites are expected because, given the pig’s lifestyle and omnivorous diet (eating anything and everything), the swine is the animal whose meat contains the most parasites. In this article, presented are the three most prevalent pork parasites that have significant repercussions for human health, but these are by no means unique.

Trichinella spiralis

undercooked pork
Pork parasites: Trichinella Spiralis

This parasite belongs to the zoological order Nematodes (roundworms), which affect swine and wild boar primarily and the horse. One gram of infested pork may contribute as many as 3000 trichinae larval cysts.

Consumption of infected pork products leads to an infestation of trichinosis worms, which appears typically about 17 days after the intake of contaminated meat. The following are a characterization of trichinosis symptoms:

  • Edema and swelling of the face or eyelids;
  • Myalgia (muscle pain), fever, and headache;
  • Blood analysis shows an increase in eosinophilic leukocytes.
The Trichina Cycle
1. Swine contract the trichina parasite eating infested rats.
2. Humans take in the trichina larvae by eating infested pork or wild boar.
3. Stomach acid dissolves the larval cysts, thus releasing the trichina larvae.
4. The larvae mature in the intestine, transforming into adults measuring three to four mm in length. Each female lays approximately 1500 eggs about the size of a red blood cell, which then passes into the bloodstream.
5. The trichina eggs are distributed in the bloodstream throughout the body’s muscles, forming new larvae-containing cysts.
Trichina Parasites: How to Detect and Destroy Them
Pork infested with trichina larvae presents a normal appearance. An infestation can only be detected by a microscopic examination of a meat sample by a veterinarian. Curing the hams of swine or wild boar does not affect trichina larvae. Destroying trichina parasites in pork requires: Cooking the meat until it is done to the point that it has lost its rosy color. The drawback to this, however, is the formation of carcinogenic substances. Freeze the meat for 20 days at -15ᵒC (5ᵒF)

The foods that most often transmit pork parasites are:

Wild boar looking fierce with blurred trees in the background
Pork parasites: Wild boar
  • Wild boar and the products made from it, particularly sausages.
  • Pork that has not been properly cooked or roasted, above all when it has been home-slaughtered.
  • Uncooked pork sausages.

Although one might think that trichinosis is a disease of the past, there are continuous outbreaks around the world. In the United States, there are some 57 cases annually according to the Centers for Disease Control in Atlanta, even though it Is thought that many more cases go undiagnosed. In Spain, in the Statutory Community of Navarra alone, there were 71 reported cases.

Toxoplasma gondii

undercooked pork
Pork parasites: Toxoplasma gondii

This pork parasite is a protozoan (microscopic unicellular animal) that promotes swelling of the lymph nodes, fever, and asthenia. When pregnant women are infected, it can produce miscarriage or fetal brain damage and blindness. You can contract toxoplasma in two ways:

  1. Contact with infected animals, particularly cats;
  2. Consumption of infected raw or undercooked pork. Raw pork, as it is eaten in some Asian countries, is a frequent cause of toxoplasmosis.

An investigation carried out at the Federico II School of Medicine in Naples (Italy) concluded that the consumption of cured pork (ham, sausage) or any raw meat, even once a month, triples the risk of toxoplasmosis.

trichinosis bear
Pork parasites: Tenia solium

Tenia solium

Tenia solium or pork tapeworm is a flatworm from two to five meters in length that lives parasitically in the intestine. Its eggs pass to the blood and form cysts in the brain and other organs, causing cysticercosis disease. Contamination is caused by one of the following mechanisms:

  • Eating pork not adequately cooked, which may contain live larvae. Up to 25% of swine in rural areas of some developing countries are infested.
  • Eating vegetables containing tenia eggs because of being irrigated with contaminated human sewage.
From Rat to Pig to Human
From ancient times it has been known that eating the meat of rats, swine, and even horses can produce a variety of disorders, which, in some cases, may prove fatal. Two thousand seven hundred years ago in ancient Israel, the prophet Isaiah wrote, “…those eat the flesh of pigs and rats and other abominable things—they will meet their end together.”   However, it was not until 1835 when the British anatomist and zoologist Sir Richard Owen discovered the parasite that causes trichinosis in humans in the flesh of swine. Today it is well known that the primary vector for the trichina parasite that affects swine and humans is the rat.

REFERENCES

George D. Pamplona-Roger, M.D. “Encyclopedia of Foods and Their Healing Power.” George D. Pamplona-Roger, M.D. Encyclopedia of Foods and Their Healing Power. Trans. Annette Melgosa. Vol. 1. Chai Wan: Editorial Safeliz, 2005. 322, 323. Print. [pork parasites]

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