Teniasis is a disease caused by the adult form of tapeworms, Taenia solium (from the pig) and Taenia saginata (from the ox). Often the patient does not even know that they live with the parasite in their small intestines.
Tapeworms are also called "lonely", because in most cases the carrier brings only one adult worm.
They are highly competitive for the habitat and, being hermaphrodites with physiological structures for self-fertilization, do not require partners for copulation and egg laying.
The man with the worms presents the tapeworm in the adult state of his intestines and is therefore the definitive host. The last rings or proglottids are hermaphroditic and suitable for fertilization. Generally, sperm from one ring fertilize eggs from another segment in the same animal.
The amount of eggs produced is very large (30 to 80 thousand in each proglot), being a guarantee for the perpetuation and propagation of the species. The pregnant rings detach periodically and fall with the stool.
O intermediate host is the pig, animal that, because it is coprophagous (which feeds on feces), eats pregnant proglottids or eggs that have been released in the middle. Within the animal's intestines, the embryos leave the protection of the eggs and through six hooks pierce the intestinal mucosa. Through the bloodstream, they reach the muscles and liver of the pig, becoming larvae called cysticercos, which present the invaginated scolex in a gallbladder.
When man feeds on raw or undercooked pork meat containing these cysticerci, the vesicles are digested, releasing the evergreen sclex that attaches to the intestinal walls through the hooks and suction cups.
The man with such characteristics develops the teniasis, that is, has the helminth in the adult state and is its definitive host.
The cysticerci are similar to whitish pearls of varying diameter, usually the size of a pea. In popular language they are called "popcorn" or "canjiquinhas".
- By eating raw or undercooked meat, man can ingest cysticerci (tapeworm lasvas).
- In the gut, the larva breaks free, fixes the sclex, grows and gives rise to adult tapeworm.
- Mature proglots, containing testicles and ovaries, reproduce with each other and give rise to pregnant, egg-filled proglottids. Pregnant proglottids fall together in groups of 2 to 6 and are released during or after bowel movements.
- In the soil, they break and release eggs. Each egg is spherical, about 30 mm in diameter, has 6 small hooks and is known as the oncosphere. They spread in the medium and can be ingested by the intermediate host.
- In the animal's intestines, eggs penetrate the intestinal lining and fall into the blood. They mainly affect the sublingual muscles, diaphragm, nervous system and heart.
- Each egg turns into a larva, a miniature tapeworm called cysticercus, the size of which resembles that of a small grain of hominy. This larva contains a scolex and a short neck, all surrounded by a protective vesicle.
- By self-infestation, eggs pass into the bloodstream, develop into cysticerci (larvae) in human tissues, causing a disease, cysticercosis, which can be fatal.
Often teniasis is asymptomatic. However, dyspeptic disorders such as appetite disorders (severe hunger or loss of appetite), nausea, frequent diarrhea, nervous disorders, irritation, fatigue and insomnia may arise.
Prophylaxis and Treatment
Prophylaxis consists of health education, cooking meat well and supervising meat and meat products (sausage, salami, chorizo, etc.).
Regarding treatment, this consists in the application of single dose (2g) of niclosamide. Other alternative drugs such as dichlorophene, mebendazole etc. may be used. Pumpkin seed tea is widely used and recommended to this day by many doctors, especially for children and pregnant women.