There are two forms of taeniasis. Taenia saginata is the cause of beef tapeworm disease, and Taenia solium of pork tapeworm disease. Humans are the definitive reservoir of these infections, with the animals acting as intermediary hosts. Two stages of each of the disease occur in the animal hosts. After the ingestion of larvae by the animals, the adult worms develop in the intestinal tract.
In addition to the intestinal tract stage there is a larval stage, in which the parasite finds its way into the general circulation and localizes in various tissues and organs, especially the muscles, where encystment of the larvae occurs. People contract the disease through eating improperly cooked meat. The ancient Greeks, Arabs, and Jews recognized these parasites diseases in animals, including the intestinal phase and the cystic stage; but it was not until the nineteenth century that the two were traced to a common source.Beef tapeworm in humans exists only in the alimentary tract; a cystic stage rarely occurs. The symptoms are mild and indistinct, and the diagnosis is established by finding the segmented worms in the feces. The disease is relatively rare in the United States because of good animal husbandry.
Taeniasis in man due to the pork tapeworm, T. solium, is more serous infection because the encystment of larvae in the tissues occurs more frequently. Localization in the brain can cause epilepsy and the manifestation of brain tumor.
Since man is the definitive host, both beef and pork tapeworm disease in animals are propagated by the dissemination of contaminated human feces in the feeding areas of cattle and swine. The incidence of the human diseases is thus related to the sanitary habits of people. Prevention of the disease involves careful disposal of human feces, proper examination of animals in abattoirs and thorough cooking of meat.
Taeniasis
