Showing posts with label Taenia solium. Show all posts
Showing posts with label Taenia solium. Show all posts

Thursday, July 16, 2009

Taenia solium

Cysticerci have three morphologically distinct types. The common one is the ordinary "cellulose" cysticercus which has a fluid filled bladder that is 0.5 cm to 1.5 cm in length and an invaginated scolex. The intermediate form has a scolex while the "racemose" has no evident scolex but are believed to be larger and much more dangerous. They are 20 cm in length and have 60 ml of fluid and 13% of patients might have all three types in the brain. Though humans usually serve as a definitive host, eating infected meat, fostering adult tapeworms in the intestine, and passing eggs through feces, sometimes a cysticercus (a larva sometimes called a "bladder worm") develops in the human and the human acts like an intermediate host. This happens if eggs get to the stomach, usually as a result of contaminated hands, but also of vomiting. Cysticerci often occur in the central nervous system, which can cause major neurological problems like epilepsy and even death. The condition of having cysticerci in one's body is called Cysticercosis, and is discussed in its own article.

Eggs can be diagnosed only to the family (biology) level, but if a proglottid's uterus is stained with India ink, the number of visible uterine branches can help identify the species: unlike the Taenia saginata uteri, T. solium uteri have only five to ten uterine branches on each side.

Infection with T. solium adults is treated with niclosamide, which is one of the most popular drugs for adult tapeworm infections, as well as for fluke infections. As cysticercosis is a major risk, it is important to wash one's hands before eating and to suppress vomiting if a patient may be infected with T. solium. If neurocysticercosis occurs the drug of choice is Praziquantel. This drug damages the parasites skin internally causing it to disintegrate and is then removed by the host's immune system.

Infection may be prevented with proper disposal of human feces around pigs, cooking meat thoroughly, and/or freezing the meat at -10oC for 5 days. Most cases occur because infected food handlers contaminate the food.